Beyond Celiac: Study Sheds New Light on Obesogenic Effects of Gluten - Are PPARs & Bacteria Both Involved?

Cornflakes peanut butter cookies - guaranteed not gluten free ;-)

With Christmas Eve being over, and grandma's cookies, Christmas stollen, and all sorts of other stuff from the bakery in front of you (literally), Christmas Day may actually prove to be a way more "dangerous" than Christmas Eve - not just because of the total amount of calories, but also because of the low satiety effect of these sweet treats.

A recent paper by scientists from the Universidade Federal de Minas Gerais in Belo Horizonte in Brazil does now point to another reason you better give those bakery products a wide berth - not just, but especially with the energy overshoot on Christmas day: Gluten!

Study confirms for the first time what scientists and laymen alike have been speculating about

In what the scientists claim is the first well-controlled study of the effects of gluten intake on metabolic health in a non-celiac, but Western-style diet scenario, Fabíola Lacerda Pires Soares and her colleagues put two groups of C57BL/6 mice on identical, iso-caloric high fat (hypercaloric) diets that differed only in terms of the amount of gluten that was added to the chow (0% gluten vs. 4.5% gluten).

Interestingly, the gluten diet did not influence any of the usual suspects, like food intake, total fat-free mass, fecal lipids excretion, blood lipid profile, blood total protein and ectopic (liver and muscle) lipid concentration (if you look closely you will realize that the gluten-free group actually had higher TRIGs, although the difference did not reach statistical significance).

Figure 1: Usual suspects and closer look at the effects 8 weeks gluten supplemented vs. gluten-free diets had on serum markers of metabolic syndrome and visceral fat parameters (Soares. 2013)

The data in figure 1 (right) does yet also show that the gluten content of the diet did nevertheless have a significant impact on the total body mass, visceral fat mass, lipid content and most importantly the adipocyte size.

Figure 2: Absolute adipokine levels (left) and fasting glucose and insulin levels, as well as Homa-IR (Soares. 2013)

Add to that the blunted expression of the anti-inflammatory and anti-diabetic fat hormone adiponectin and the increased the >5x higher expression of leptin (figure 2). And mix that with the reduced expression of PPAR-alpha and gamma of which Soares et al. argue that they may well be the key factor in the detrimental modulatory effect the addition of gluten had on the visceral fat structure and the lowered expression of the fat liberating enzymes LPL and and HSL, as well as reduced levels of the fat burning proteins ACC and CPT-1 (figure 3).

Figure 3: PPAR-alpha, -gamma, LPL, HSL, ACC and CPT-1 expression compared to rodents on regular chow (left); crown like structures in stained slices from visceral fat, inflammatory markers TNF-alpha and IL-6 (Soares. 2013)

So, even if the initially mentioned blood markers (aka the usual suspects) would suggest that both the gluten-consuming and gluten-free rodents were similarly bad off, the profound difference in inflammatory markers within the adipose tissue and the presence of comparatively many necrotic and inflammatory adipocytes in the crown like structures stand in line with increases in HOMA-IR, fasting glucose and insulin and an already compromised glucose clearance which are well-known harbingers of the metabolic syndrome.

These observations do not simply shed a whole new light on a hitherto largely ignored contributer to the etiology of the metabolic syndrome, they do also show that one of the reasons it has not been identified before is an over-reliance on BMI, total fat mass and serum lipids in the early stages of diabesity.

Reardless of whether the gut microbiome is part of the mechanism by which gluten predisposes the development of metabolic syndrome. Eating more inulin- and beta-glucan rich foods like Jerusalem artichokes, agave, bananas, onion, steel cut oats, wild yams, yacon, etc. certainly won't hurt your efforts to get lean, stay lean and leave the role of the obese diabetic to the other (read more)

Bottom line: The study at hand provides a good reason to limit your intake of "healthy whole grains" and other gluten containing foods, regardless of whether you suffer from celiac or not. Whether the established detrimental effects of gluten on the integrity of the intestinal wall and the increased leakage of bacterially produced endotoxins from the highly unfavorably changes in the gut microbiome in response to the high fat diets (Hildebrandt. 2009) are part of, or even the primary cause of these observations still has to be elucidated. The same goes for strategies to counter the translocation of the endotoxins across the gut lining (cf. "Shedding some light on the leaky gut") and the dose response relationship between the total amount of gluten in your diet and its effects on your metabolism. With 7% of pure gluten, it goes without saying that you would basically have to live of wheat in order to get to anywhere similar amounts of gluten in the diet... that said: Is it possible that the effects occur only in the presence of the high fat diet? After all, this alone has been shown to favor a pro-inflammatory gut microbiome.

You see there are enough questions to be answered in 2013 and the SuppVersity is going to be the place you will read the respective answers first ;-)

References:

• Hildebrandt MA, Hoffmann C, Sherrill-Mix SA, Keilbaugh SA, Hamady M, Chen YY, Knight R, Ahima RS, Bushman F, Wu GD. High-fat diet determines the composition of the murine gut microbiome independently of obesity. Gastroenterology. 2009 Nov;137(5):1716-24.e1-2.
• Soares FL, de Oliveira Matoso R, Teixeira LG, Menezes Z, Pereira SS, Alves AC, Batista NV, de Faria AM, Cara DC, Ferreira AV, Alvarez-Leite JI. Gluten-free diet reduces adiposity, inflammation and insulin resistance associated with the induction of PPAR-alpha and PPAR-gamma expression. J Nutr Biochem. 2013 Dec 17.

Probiotics for Athletes: The Supplemental 10 Billion CFS Leaky Gut Solution for the Fermented Food Refusinek?

Yogurt is probably the best known probiotic food, but there are way more traditional fermented foods that have been part of the human diet for centuries. No wonder that the combination of being "ancestral" and being supported by the latest research renders them so appalling to the "paleo community". I do yet suspect that the average gymbro will be more inclined to buy a pill or powder than Kefir, Kimchi and Kraut... and why not? It's convenient and as long it works... it does, doesn't it?

The gut microbiome and its effect on metabolic and overall health are all the rave these days. As I already pointed out in previous posts on this matter, we are yet only beginning to grasp the complex interactions between the nasty and not so nasty intestine and the way we look, feel or perform. That this does not hinder hundreds of companies to make all sorts of partly warranted, partly unwarranted claims about the myriad benefits the ingestion of their product would have on your health, I actually don't mind too much that the 2x2g servings of probiotics (Bifidobacterium bifidum W23, Bifidobacterium lactis W51, Enterococcus faecium W54, Lactobacillus acidophilus W22, Lactobacillus brevis W63, and Lacto-coccus lactis W58) the 23 healthy male triathletes, runners and,cyclists (age 30–45 years) who participated in one of the latest studies from the Centre for Physiological Medicine at the Medical University of Graz, consumed for 14 weeks in addition to their regular diets were, just like the study itself, sponsored by Winclove, a European producer of "high potency" probiotics (Lamprecht. 2013).

A sponsored study is better than no study and all the more outrageous claims, right?

The  5×10^9 colony forming units (CFU) of bacteria each serving of the powdered supplement provided had to be dissolved in 100-125ml of plain water an were to be ingested one hour prior to meals twice daily. Other than that, the subjects who had been randomly assigned to a supplement and a placebo group were simply instructed not to make any significant changes to their dietary or training regimen.

Before the first (week 0) and second (week 14) exercise test that consisted of three incremental cycle ergometer exercise tests, in the course of which the workload was increased every by 20 W every minute until voluntary ex-haustion (this usually took 15-18min) that were followed by 2x15 minutes of cycling at 60W (80rpm; 1st and 2nd) three minute cool down at the same light intensity, the participants received identical breakfasts containing

Cycling eergometer tests now (left) and then (right) - the colors are not the only thing that differs ;-)

• Coffee w/ milk (low fat) or Tea w/ lemon & honey (10g)  
• 3 slices wheat or rye bread 
• Butter 20 g 
• Marmalade/jam 30 g 
• One slice low fat ham 
• One piece of cheese 
• 250 mL fruit juice 
• 250 mL water

The three days before the tests the participants had to abstain from any type of strenuous exercise. Activity and dietary intake were controlled by training and food logs, respectively.

So how actually do you measure "leaky gut" or a beginning leaky gut? Zonolin & cytokines

It stands to reason that  Lamprecht et al. did not simply gut the tummies of their subjects open in order to take tissue samples and analyze the integrity of the gut wall. Moreover, even if the had done so, they may not even have been able to see the subtle changes and differences in the permeability of the intestinal wall that occur after only 14 weeks in trained athletes whose bodies and thus digestive tracts were already well-accustomed to their habitual training load. Therefore the researchers picked several well known markers of oxidation and inflammation, namely

• protein carbonyl (CO) groups, as they have also been observed in other inflammatory disease, including Alzheimer’s disease (AD), rheumatoid arthritis, diabetes, sepsis, chronic renal failure, and respiratory distress syndrome etc. (Dalle. Donne. 2003),
• TNF-alpha, which modulates the acute phase of inflammation and has long been identified as a potential mediator of the transition from Crohn's Disease to "leaky gut" (Hollander. 2002), and
• IL-6, the chronic overexpression of which is and - despite its recently reevaluated importance as an important signalling in the energy sensing pathway of the musculature (cf. Pedersen. 2013)- will remain problematic

as well as the gut specific haptoglobolin zonolin to elucidate the status of the gut lining and the impact of the supplementation regimen. Contrary to the TNF-alpha and IL-6 even of which these days everybody appears to have gotten wind they are in one way or another involved in the "bad inflammation we all have to avoid", only the friends of Rob Wolf's podcast will probably have an idea of what zonolin is and what it dies in the human body. Produced in the liver and intestinal epithelial cells, zonolin  is thought to be the main physiological modulator of intercellular tight junctions (Fasano. 2011). Actually it's pretty straight forward: 

The more zonolin your body produced the "leakier" your gut will become. 

Unfortunately those "leaks" in-between the cells are about as indiscriminate as the open back door of your house, in terms of whom they let pass through. This can come handy, when you want certain molecules, such as medications (e.g. Salama. 2006), to pass into the blood stream, it's exercise, or I should say stress induced over-expression, however, opens the doors to whomever or rather whatever is hanging around in your digestive tract,  including pathogens and their toxic byproducts, such as lipopolysaccharides (Groschowitz. 2009). These large molecules(LPS) consisting of a lipid and a polysaccharide joined by a covalent bond which are (among others) produced by the same gram-negative bacteria which have been shown to over-populate the intestines of obese people  act as endotoxins and elicit strong immune responses in animals and human being. Next to their involvement in the etiology of the metabolic syndrome, LPS have also been implicated in chronic fatigue syndrome , and similar pathologies (Maes. 2008), which are brought and maintained by the constant endotoxin influx from the stomach.

Tighter gut, lower oxidation and correspondingly lower "inflammation"

After this somewhat lengthy dissertation about the zonolin <> LPS <> all sorts of pathologies connection it should be clear that the most important change the 11 participants in the probiotics group experienced during the 14-week treatment period was the ~30% reduction in zonolin expression in the stool (cf. figure 1):

Figure 1: Zonolin in stool and markers of protein oxidation (carbonyl proteins) and inflammation (TNF-alpha and IL-6); all values expressed relative to average of both groups at baseline, i.e. week 0 (data calculated based on Lamprecht. .2013)

It is certainly difficult to quantify the downstream effects of this changes in zonolin in the stools of the participants on "gut integrity", but since the analyses of all other markers was carried out in the blood, the changes in protein carbonyl levels, TNF-alpha and IL-6 expression are indicative of ..

*Note: in view of the role IL-6 plays as a regulator of exercise induced changes in energy metabolism (Pederson. 2013), it is actually a good thing that the IL-6 levels post exercise did not differ between groups, while the baseline levels (=chronic = "bad inflammation") did.

• reduced oxidation (which is actual damage) to the proteins and a (10% lower carbonyl protein before, 48% lower protein carbonyls after the exercise test in week 14), as well as a
• correspondingly reduced baseline response of the immune system (32% and 28% lower  TNF-alpha and IL-6 before and 31% and identical* TNF-alpha IL-6 response after the exercise test in week 14)

which are in turn most likely brought about by reduces LPS exposure due to a "tighter gut" and / or a reduction of the gram-negative bacteria and other LPS producing intruders in response to the probiotic supplement.

Bottom line: As I've already pointed out in the introduction and as the "and / or" statement in the last sentence of the previous paragraph suggests, we are still far away from a true understanding of the diverse effects the good and the bad subtenants in our digestive tract exert on our metabolic and overall health.

For those who have already forgotten about this - glutamine can also help keeping your gut intact during phases of intense training + it keeps the nasty subtenants in your gut from eating away the amino acids in your food and supplements.

It is therefore too early to say that "every hard training athlete will benefit from the long term or even better chronic usage of a probiotic supplement!". If we do however take into account how much money way too many trainees spent on absolutely useless supplements, the 105€ you would currently have to pay for the exact same (pretty expensive) probiotic that was used in the study, are probably well-invested.

I would however expect that consuming larger quantities of fermented will not just have similar effects on the integrity of your intestines; and what's more, in view of the fact that they are also replacing other (for most people less healthy) foods in your diet, they are way more likely to have beneficial "side effects" on your body composition and performance than 2x2g of powdered probiotics ;-)

References:

• Dalle-Donne I, Rossi R, Giustarini D, Milzani A, Colombo R. Protein carbonyl groups as biomarkers of oxidative stress. Clin Chim Acta. 2003 Mar;329(1-2):23-38.
• Fasano A: Zonulin and its regulation of intestinal barrier function: the biological door to inflammation, autoimmunity, and cancer. Physiol Rev 2011, 91:151–175.
• Groschowitz KR, Hogan SP: Intestinal barrier function: molecular regulation and disease pathogenesis. J Allergy Clin Immunol 2009, 124:3–20
• Hollander D. Crohn's disease, TNF-alpha, and the leaky gut. The chicken or the egg? Am J Gastroenterol. 2002 Aug;97(8):1867-8.
• Maes M, Leunis JC. Normalization of leaky gut in chronic fatigue syndrome (CFS) is accompanied by a clinical improvement: effects of age, duration of illness and the translocation of LPS from gram-negative bacteria. Neuro Endocrinol Lett. 2008 Dec;29(6):902-10.
• Lamprecht M, Bogner S, Schippinger G, Steinbauer K, Fankhauser F, Hallstroem S, Schuetz B, Greilberger JF. Probiotic supplementation affects markers of intestinal barrier, oxidation, and inflammation in trained men; a randomized, double-blinded, placebo-controlled trial. J Int Soc Sports Nutr. 2013 Sep 20;9(1):45.
• Pedersen BK. Muscular interleukin-6 and its role as an energy sensor. Med Sci Sports Exerc. 2013 Mar;44(3):392-6.
• Salama NN, Eddington ND, Fasano A. Tight junction modulation and its relationship to drug delivery. Adv Drug Deliv Rev. 2006 Apr 20;58(1):15-28. Epub 2006 Mar 6.

Inulin & Beta Glucan Reduce Body Fat Gain By -50% & -33%! Both Have Similar Effects on the Gut Microbiome, But Only Inulin Appears to Be More Than An Appetite Suppressant

What do these Jerusalem artichokes, agave, bananas, burdock, camas, chicory, coneflower, costus, dandelion, elecampane, garlic,jicama, Leopard's-bane, mugwort, onion, wild yams, yacon and a whole host of other foods have in common? Right! They contain inulin. Whether you will be able to get a whopping amount of 10% inulin in your diet w/out the use of supplements or "enriched" foods, is yet as questionable as how beneficial this actually is for friends of physical culture.

The gut microbiome is not just one of the hottest topics in the (health-)blogosphere, it is also a subject of ongoing research. Research, however, that is, if we are honest, still very much in its infancy. As impressive as the results from the latest studies into the metabolic downstream effects of the administration of fermentable fiber to rodents may be and as obvious as their relation to certain changes in the gut microbiome of the animals may appear - in the end, our understanding of the underlying mechanisms does not allow any reliable prognoses like "double the amount of lactobacilli and you will eventually be able to lose that pouch of body fat you've been carrying around for years now". And yet, if the results from the latest rodent experiments at the Imperial College in London, could be reproduced in humans, I can already foresee that both, the consumption and use of the foods I listed in the caption of the image to the right, as well as related products, extracts and supplements, which contain more or less significant amounts of the naturally occurring polysaccharides, we usually refer to as inulin, will increase in the months and years to come.

Fermentable fiber and the gut-brain-axes: The key to lifelong leanness?

If this is not your first visit to the SuppVersity, you will certainly be aware that the idea of a magic pill (or fiber) that will allow you to eat whatever, whenever and in whichever amounts without having to cope with the metabolic consequences is illusive. When the addition of 10% inulin (or beta glucan) to the diets of 36 male C57BL/6 mice had an "anti-obesogenic" effect, this does not mean that the poor critters who were kept on a hypercaloric high fat (41.8%) diet for 8 weeks did not get obese. What it does mean, though, is that the addition of 10% fermentable (=being food for certain gut bacteria) fiber in the form of

*the producers of these products did not fund or support the study (at least the scientists don't mention that in the respective disclosure ;-)

• inulin from Synergy(TM)*, a fructan based preparation containing both long and short chain
  fructooligosaccharides, or
• beta-glucan from Glucagel(TM)* a highly rich (,80%) barley derived b-glucan preparation

to their otherwise iso-caloric diet (the HFD control contained cellulose) was not without helped to mitigate the negative effects of this diet - a fact the majority of you, of whom I would expect that they are not on a fast-food diet should keep in mind, before they head over to their favorite online supplement vendor and type "Synergy inulin" into the search box.

Figure 1: Effect of addition of 10% fermentable fiber as inulin or beta glucan to the high fat diet of male mice on cumulative weight gain (left), body composition and fatness (middle) and food intake (right) over the course of 8 weeks (data adapted from Arora. 2013)

In spite of that, the results are simply too impressive not to think about their implications in otherwise healthy and even more so previously obese individuals. This is particularly true, because the same microbial changes about which the authors write in a previously published paper from May 2013 that the ...

"[...] increases in both Bifidobacteria and Lactobacillius and a significant increase in short chain fatty acids (SCFA) [went hand in hand with] increase in neuronal activation within the arcuate nucleus (ARC) of animals that received In [inulin] supplementation" (Anastasovska. 2013)

do not (and this is a result of the researchers very latest experiments) simply blunt the rodents appetite. If that was the case, the rodents that received the beta glucan supplemented chow and consumed 12% less energy should have had the most favorable body composition. A cursory glance at figure 1 will yet tell you that this was not the case, though.

Inulin beats beta glucan when it comes to body fat reduction / repression

If we take a closer look a the differential effects of inulin and beta glucan, there yet only one figure that really sticks out and that's the accumulation of fat within the musculature of the animals. The "beautiful marbling" people are looking for in their steaks, however, usually is a harbinger of impeding or even existing skeletal muscle insulin resistance. A muscle fat content above the high fat control (it's certainly a weakness that we don't have a "real" control group on standard rodent chow, here) as Arora et al. observed it in the tissue samples of the beta glucan group, does thus tell you something about its potential usefulness, or rather uselessness of this specific type of fermentable fiber.

Figure 2: Effects of the different types of fermentable fiber on cecal microflora groups (figures are in scientific notation, this means "1E+6" equals 1mio, "1E+9" would be 1 billion etc.; data based on Arora. 2013)

In conjunction with the information about the corresponding changes in the gut microbiome (see figure 2), which appear virtually identical in both groups (specifically the extreme increasesin in both Bifidobacteria (BIF) and Lactobacillius (LAB) really stick out), this does however suggest that the modulatory effect on the composition of the gut flora, or at least the part of it the scientists evaluated in the study at hand, cannot be the only driving force behind the beneficial metabolic effects of inulin.

Inulin or beta glucan? This is not a question... 

While the latter, i.e. inulin, which has by the way been found to directly suppress lipogenesis in a 2011 study by Belgian scientists in a similar HFD rodent model (Dewulf. 2011), appears to be promising for everyone, regardless of whether he or she is poisoning him- or herself with the standard American diet (which is, with its high fat and high carbohydrate content de facto an identical twin of the so-called "high fat diet" in rodent studies), the ingestion of larger amounts of the former, i.e. beta glucan, does at least appear questionable.

If you want to use inulin to your metabolic advantage, you better make sure you get your self a more comfortable place to answer the call of nature - it could call thrice as often! Moreover, large amounts of inulin and other fermentable fiber can induce gastrointestinal distress-

The question is therefore not so much whether it's worth supplementing (it's certainly worth to incorporate some of the initially mentioned foods into your diet, as most of them contain a whole list of other advantageous micronutrients) with inulin or beta glucan - the answer would obviously be inulin - but rather whether it's worth adding larger amounts of inulin to an already healthy diet. And while we cannot answer this question based on the results of the previously cited rodent studies, we could argue that Marwa Zenhom and her colleagues from the Christian Albrecht University in Kiel have already supplied relevant evidence that this would be the case (Zenhom. 2011). After all, the German researchers have been able to show that the PPAR-gamma related anti-inflammatory effects (significant reductions IL-12 secretion in Caco-2 cells and gene expression of IL-12p35, IL-8, and TNFa as well as NF-kB) of oligosaccharides are not (exclusively) brought about by their effects on the gut microbiome, because bacteria simply were not present in their in-vitro study with human Caco-2 cells (cells from the gut lining). Bassaganya-Riera et al. even argue that this effect could be beneficial for IBS patients (Bassaganya-Riera. 2011).

Whether having 10% of your diet in form of inulin, or to make this more conceivable, having 1 tablespoon of plain inulin for every 9 tablespoons of whatever else you eat is either feasible or reasonable, is a whole different story (to put that into perspective: The average inulin intake of Westerners is 1-10g per day (van Loo. 1995). Even 10g would yet only be enough if you ate only 100g of food within 24h!)... and I must forewarn you, if you go by the fecal volume of the mice in the Arora study, it is possible that you will spend >3x more time on the toilette than usual ;-)

References:

• Arora T, Loo RL, Anastasovska J, Gibson GR, Tuohy KM, Sharma RK, Swann JR, Deaville ER, Sleeth ML, Thomas EL, Holmes E, Bell JD, Frost G. Differential effects of two fermentable carbohydrates on central appetite regulation and body composition. PLoS One. 2013;7(8):e43263.
• Anastasovska J, Arora T, Sanchez Canon GJ, Parkinson JR, Touhy K, Gibson GR, Nadkarni NA, So PW, Goldstone AP, Thomas EL, Hankir MK, Van Loo J, Modi N, Bell JD, Frost G. Fermentable carbohydrate alters hypothalamic neuronal activity and protects against the obesogenic environment. Obesity (Silver Spring). 2013 May;20(5):1016-23.
• Astegiano M, Pellicano R, Terzi E, Simondi D, Rizzetto M. Treatment of irritable bowel syndrome. A case control experience. Minerva Gastroenterol Dietol. 2006 Dec;52(4):359-63.
• Bassaganya-Riera J, DiGuardo M, Viladomiu M, de Horna A, Sanchez S, Einerhand AW, Sanders L, Hontecillas R. Soluble fibers and resistant starch ameliorate disease activity in interleukin-10-deficient mice with inflammatory bowel disease. J Nutr. 2011 Jul;141(7):1318-25.
• Dewulf EM, Cani PD, Neyrinck AM, Possemiers S, Van Holle A, Muccioli GG, Deldicque L, Bindels LB, Pachikian BD, Sohet FM, Mignolet E, Francaux M, Larondelle Y, Delzenne NM. Inulin-type fructans with prebiotic properties counteract GPR43 overexpression and PPARγ-related adipogenesis in the white adipose tissue of high-fat diet-fed mice. J Nutr Biochem. 2011 Aug;22(8):712-22.  
• van Loo J, Coussement P, de Leenheer L, Hoebregs H, Smits G. On the presence of inulin and oligofructose as natural ingredients in the western diet. Crit Rev Food Sci Nutr. 1995 Nov;35(6):525-52.
• Zenhom M, Hyder A, de Vrese M, Heller KJ, Roeder T, Schrezenmeir J. Prebiotic oligosaccharides reduce proinflammatory cytokines in intestinal Caco-2 cells via activation of PPARγ and peptidoglycan recognition protein 3. J Nutr. 2011 May;141(5):971-7.

Stevia - More Than Super Sweet: More Scientific Evidence, More Potential Implications for Weight Loss & -Maintenance, Anti-Diabetic & -Autoimmune and Even Pro-Anabolic Effects

Image 1: Stevia is sweeter than sugar, healthier than sugar and could even help reverse some of the damage sugar may already have done to your pancreas.

I know that a few of you were almost furious, when I had the audacity to mention the case-report on the pro-cortisol effects of stevia in the On Short Notice post on Saturday, August 18, 2013; and though I did emphasize that this was most likely something like an allergic reaction and/or an issue with solvents, heavy metals (click here for data on heavy metals in stevia leaves; based on Das. 2013), or whatever else may have been in the specific stevia product the lady used; I suspect that you will like today's blogpost which is basically an update on the beneficial effects stevia could have on your overall and metabolic health, much better.

So what's the latest about stevia, then?

Previous studies have already hinted at the fact that the benefits of the use of stevia go well beyond a mere reduction in energy intake and the overall glucose load the average sweet tooth is exposing her- / himself to. Against that background, the results of a recent publication from the School of Pharmacy in Madhya  Pradesh in India are actually not really surprising.

Figure 1: Blood glucose response (mg/ml) to oral glucose load (left) and superoxide dismutase (SOD) levels in mice treated with 250mg/kg (HED: 20mg/kg; ~1.4-2.0g) stevia extract/day (right; data based on Sharma. 2013)

With most previous studies being conducted on isolated pancreatic islet cells in the petri dish, this is however one of the few studies, which in which the scientists were able to observe a robust in-vivo effect from the administration of no more than 250mg/kg of stevia extract (Herbocal) to alloxan-diabetic (this is a model of type II diabetes that is induced by the injection of the drug Alloxan aka 2,4,5,6-pyrimidinetetrone, an oxygenated pyrimidine derivative) and healthy rodents for 28days - with benefits for both, the sick (normalization of blood glucose and restoration of endogenous antioxidants) and the healthy animals (no drop of blood glucose to hypoglycemic levels and increases in SOD above baseline!)

Could stevia not just ameliorate, but actually "heal" diabetes?

Figure 2: It takes it's time but stevia appears to (fully?) restore pancreatic function!

What's also intriguing are the time-course and general trend of the beneficial effects on blood glucose levels in the diabetic group. If you take a closer look at the data in figure 2 you could even speculate that another four weeks later the blood glucose levels would have totally normalized! And if that were the case, this would mean that the steviosides and rebaudiosides, the active molecules in stevia extracts, could actually have the ability to restore or repair the pancreatic beta cells that have been destroyed by either years of high blood glucose (normal type II diabetics) or the assault of the toxic sugar equivalent alloxan (in the study at hand). and protect healthy individuals against future damage by increasing the endogenous antioxidant system (as can be seen by the allegedly non-significant, but probably still physiologically relevant increase in SOD in figure 1, right)

"But this won't work in humans, will it?"

The above is certainly a good question, but in view of the fact that the short term benefits (e.g. +40% increase in insulin response in type II diabetic with -18% reduced postprandial glucose AUV with 1g of stevia in Gregersen et al. 2004), of which the Hermansen group at the Aarhus University Hospital in Aarhus, Denmark, argues that they are based on the interaction of rebaudioside A (cf. table 1) with the ATP-sensitive K-channels of the pancreatic cells in healthy and its glucagon (and thus gluconeogenesis) inihibiting effects in diabetic individual (Abdula 2004 & 2008; Jeppesen. 2007), have already been reproduced in human trials, I would say that it is more than likely that we will see similar effects in humans, as well, once the correct dosing has been established

Note: especially if you use those combination products of stevia + sugar alcohol you are very unlikely to get sufficient amounts of stevia to elicit those restorative effects; this does not mean that this is a better alternative than aspartame or cyclamate, but in those tiny amounts stevia is a sweetener, not a substance with almost drug-like effects.

Table 1: What's in stevia leaves?
(based on Yadav. 2013)

The latter is by the way all the more likely in view of the fact that Maryam Mohammadi-Sichani and her colleagues from the Falavarjan Branch-Islamic Azad University and the Esfahan University of Medical Sciences in Iran found that stevia extracts will also kill S. mutans, a common bacteria in your mouth that has its share in the development of dental caries and shows, irrespective of generally lower caries rates in type I diabetics, a hitherto not fully explained correlation with (poorly controlled) type I diabetes (Siudikiene. 2006).

Your gut starts in your mouth: The stevia - bacteria connection

These observations stand in line with previous results, of a whole host of peer-reviewed studies Yadav & Guleria summarize in a 2013 review that's about to be published in the November edition of Critical Revision of Food Science, as follows :

Image 2 (20th Century Fox): You better feed your gut bacteria right, otherwise they will disbehave just like the Alien in Ellen Ripley in Alien 3  - read more about the "Gut Type Diet" and how what you eat influences the bacterial composition of your gut on the SuppVersity

"[...] Different extracts showed differential inhibitory activity against various microbes. This experimentation confirmed the antibacterial as well as antifungal potential of Stevia leaf extract and documented that Stevia might be a source of new non-antibiotic antibacterial and antifungal agent. Its antifungal activity was estimated to be higher than the standard fungicide usually used against plant pathogens. Such extraordinary antimicrobial activity of Stevia has presented it as a potent non-antibiotic pharmaceutical and an efficient food preservative. Stevioside alone has been observed to significantly reduce the amount of inflammation mediators and activate cytotoxic cells of the host. These activities suggested that stevioside might play a synergistic role with the innate immunity of the host. Thus stevioside is antibacterial, antifungal, anti-inflammatory, anti-tumorous, and safe for use. While at the same time rebaudioside A has been reported to be clinically insignificant." (Yadav. 2013; my emphases)

In other words, stevia could exert part of it's beneficial effects via the immune-modulatory effects it exerts due to it's impact on the human gut microbiome, the contribution of which to the etiology of both diet-induced type II, but also auto-immune type I diabetes is getting more and more attention among researchers, as of late:

"[...] the autoimmune microbiome for T1D may be distinctly different from that found in healthy children. These data also suggest bacterial markers for the early diagnosis of T1D. In addition, bacteria that negatively correlated with the autoimmune state may prove to be useful in the prevention of autoimmunity development in high-risk children." (Giongo. 2011; my emphases)

And even if the whole "bacteria theory" of autoimmune disease and inflammation turns out to be yet another sidetrack - you will always have the

• beneficial effects on skeletal muscle insulin sensitivity and glucose uptake that has been established by Lailerd et al. in insulin sensitive and resistant mice and the 
• hopefully physiologically relevant increase in satellite cell activity, Bunprajun et al. observed earlier this year in response to lower NF kappa-beta activity (=modulation of inflammation) in an in-vitro model (Lailerd. 2004; Bunprajun. 2013) 

as additional* arguments to satisfy your sweet tooth with stevia instead of sugar or artificial alternatives (*in addition to being able to avoid the "alternatives").

And as long as you keep an eye on the overall amount of food you consume, instead of simply stuffing yourself until you feel like there was no tomorrow, the previously discussed effects any sweetener - natural, artificial, or whatever else the future may hold - could have on your ability to sense the energy density of your foods should not be all too much of a problem problem (cf. "Sweeter Than Your Tongue Allows").

References:

• Abudula R, Jeppesen PB, Rolfsen SE, Xiao J, Hermansen K. Rebaudioside A potently stimulates insulin secretion from isolated mouse islets: studies on the dose-, glucose-, and calcium-dependency. Metabolism. 2004 Oct;53(10):1378-81.
• Abudula R, Matchkov VV, Jeppesen PB, Nilsson H, Aalkjaer C, Hermansen K. Rebaudioside A directly stimulates insulin secretion from pancreatic beta cells: a glucose-dependent action via inhibition of ATP-sensitive K-channels. Diabetes Obes Metab. 2008 Nov;10(11):1074-85. Epub 2008 Apr 22.
• Das, K., R. Dang, L. Hegde and A.S. Tripathi. Assessment of heavy metals in dried stevia leaves by Atomic Absorption Spectrophotometer grown under various soil conditions. Middle–East J. Sci. Res. 2011; 8: 107-113.
• Giongo A, Gano KA, Crabb DB, Mukherjee N, Novelo LL, Casella G, Drew JC, Ilonen J, Knip M, Hyöty H, Veijola R, Simell T, Simell O, Neu J, Wasserfall CH, Schatz D, Atkinson MA, Triplett EW. Toward defining the autoimmune microbiome for type 1 diabetes. ISME J. 2011 Jan;5(1):82-91.
• Gregersen S, Jeppesen PB, Holst JJ, Hermansen K. Antihyperglycemic effects of stevioside in type 2 diabetic subjects. Metabolism. 2004 Jan;53(1):73-6.
• Jeppesen PB, Dyrskog SE, Agger A, Gregersen S, Colombo M, Xiao J, Hermansen K. Can stevioside in combination with a soy-based dietary supplement be a new useful treatment of type 2 diabetes? An in vivo study in the diabetic goto-kakizaki rat. Rev Diabet Stud. 2006 Winter;3(4):189-99. Epub 2007 Feb 10.
• Sharma R, Yadav R, Manivannan E. Study of effect of Stevia rebaudiana bertoni on oxidative stress in type-2 diabetic rat models Biomedicine & Aging Pathology. 2013 August 28.
• Siudikiene J, Machiulskiene V, Nyvad B, Tenovuo J, Nedzelskiene I. Dental caries and salivary status in children with type 1 diabetes mellitus, related to the metabolic control of the disease. Eur J Oral Sci. 2006 Feb;114(1):8-14.
• Yadav SK, Guleria P. Steviol Glycosides from Stevia: Biosynthesis Pathway Review and their Application in Foods and Medicine. Crit Rev Food Sci Nutr. 2013 Nov;52(11):988-98. 

Saturated Fat Kills Gut Bacteria & Modifies Genes in the Distal Small Intestine - Another Reason Why We Get Fat? Plus: Bacteria, Fiber, SCFA, GLP-1 & PYY Revisited

Image 1: Bacteria, there are >100 trillion of them right inside of your digestive track, you can hardly know them all and scientists do neither - the only thing we are beginning to understand, though, is that it may be a good idea to get them to know at least somewhat better ;-)

I guess some of you have already noticed that I was (and probably am now, again) somewhat behind, as far as answering your questions, comments an wise remarks are concerned. Actually it is still more of a coincidence that today's SuppVersity news, which, as you see is not an Adelfo Cerame post (don't forget to keep the fingers crossed for him! This is his weekend!), could actually be interpreted as my somewhat lengthy response to a comment from Vincente on the effects of GLP-1 on chocolate preference in rats and an interesting hypothesis of his, on how this could all relate to my previous post on the fat burning effects of GLP-1 ("Eat More, Burn More and Lose Fat Like on Crack with GLP-1!?"). What, that was Vincente's reasoning, what, if those obese individuals had just messed up their gut bacteria an would lack those beneficial bacteria, which convert the fiber and resistant starch that makes it through your small intestine, right down into your long one to short chain fatty acids?

Does obesity come from within?

I guess by now some of you may already be asking themselves, where all that relates to GLP-1 and eating more, burning more and losing fat like on crack. Well, the missing link if you will is actually not a link, but rather a receptor - the free fatty acid receptor, FFR, which "sniffs" the presence of the short chain fatty acids and triggers the release of GLP-1 and PYY. Those two incretin hormones, of which researchers have found within the past 10 years or so that they are way more than mere "satiety signals. Several research studies in rodents have shown that the anti-obesogenic effects of GLP-1 and PYY are if at all, only partly mediated by reductions in food intake, yet mostly via complex downstream effects on total energy expenditure, glucose and fatty acid oxidation.

Contrary to exogenously administered GLP-1, which is actually being used in the treatment of diabetes an the metabolic syndrome, the in-vivo data from rodent studies, which suggests that high fiber diets protects those little critters from diet induced obesity (Aziz. 2008; Shen. 2008; Zhou. 2008) have, as Robertson et al. pointed out only recently, not yet been confirmed in humans trials (Robertson. 2013). Moreover, the latest results from the Merck Reserach Lab show, contrary to previous evidence from the Cambridge Institute for Medical Research (Tolhorst. 2013), that even our current assumption with respect to the underlying mechanism, could at least be incomplete (Lin. 2013). This does not mean that the short chain fatty acids would not produce the desired increase in GLP-1 nad PYY, but rather that their effects are not solely mediated by  the aforementioned free fatty acid receptor in the gut.

Let's make things even more complicated and bring some long chain fatty acids to the table!

What is yet self-evident though is that the way GLP-1 and PYY modulate energy utilization punches yet another huge hole in the prostrated "calories in vs. calories out hypothesis", one that has little to nothing to o with insulin and one that acquires yet another shade of gray, when we look at the long-chain counterpart of the "bacterial excrements" the dreaded or beloved (depending on the standpoint of the individual) saturated fatty acids (SFA) and a recently published study by scientists from the Wageningen University in the Netherlands (De Wit. 2013), who investigated the long-term effects (8 week, study conducted on mice) of high fat diets with fats from different fat sources

• palm oil - representing the saturated fatty acids,
• olive oil - representing the mono-unsaturated fatty acids, and
• safflower oil - representing the polyunsaturated fatty acids

on body weight gain, liver triglycerides and the whole other standard parameters and their relation changes in the gut microbiome and the amount of fat that "left" the animals undigested.

Figure 1: Fecal fat and energy loss, total energy intake and relative (to control on normal chow) liver triglycerides, oral glucose tolerance and weight gain over the 8 week study period (de Wit. 2013)

A casual look at the data in figure 1 should suffice to see that there is a profound mismatch between almost all classic features of the metabolic syndrome of which we would usually expect that they would be closely associated:

• the rodents in the palm oil group ate the least amount of energy, excreted the greatest amount of fat and total energy in their feces and still gained the greatest amount of body weight and had the highest amount of liver triglycerides (beginning non-alcoholic fatty liver disease)
• the rodents in the olive oil group did not consume significantly more amount of energy or excrete significantly more amount of fat / energy in their feces and still gained ~40% less body weight and did not exhibit similarly high triglyceride storage in the liver as the rodents on the saturate fat (palm oil)
• the rodents in the safflower oil group were comparably ravenous (+20% energy intake), but although they did not excrete more energy and fat than their peers, their bosy weight gain was profoundly reduced and their liver triglycerides were better than in the "non high fat control group" and yet their glucose tolerance was not the best, but the worst of all the three groups

All that does only make sense, when a second parameter, or I should say another 100 trillion bacterial parameters come into play and the SFA induced reduction in microbial diversity and
composition (increased the firmicutes/bacteroidetes ratio) are accounted for, as well. those, this is at least what de Wit et al. believe are namely responsible for the complex changes in genes that regulate the fatty acid metabolism and expression of inflammatory markers, the scientists observed

Chicken or egg, cause of correlation? Or just gut optimization?

Even tde Wit et al. do yet point out that their observations do not provide significant evidence to establish a causal relationship between the bacterial changes, which are a direct result of an overflow of (selectively) antimicrobial saturated fats into the distal part of the intestine, the subsequent disturbances in the bacterial balance and (human!) gene expression in the gut and the  particularly pronounced obesogenic effects of saturated fatty acids.

You could, at least in my humble opinion, even argue that these are simply adaptive effects that ensure that the "host", in this case the rodents, "gets the most" out of his diet - after all, this is exactly what we are seeing here: A modulation of genes related to the conservation and storage of energy, such as the downregulation of the Bcmo 1 gene that predisposes to the development of obesity and non-alcoholic fatty liver disease (Hessel. 2008),  which allows for maximal energy efficiency despite greater fecal energy loss.

Conclusion? Drink safflower oil?

That these results should not be taken as an incentive to guzzle safflower oil (or drop your coconut oil for the latter) should be obvious. Just as obvious, by the way, as the realization that despite all the hoopla and my own excitement about the newly discovered importance of the gut microbiome as one of the possible contributers to the global obesity epidemic. We are understanding way too little about its interactions with its host, i.e. us, to exclude that we are not - yet again - confusing cause and effect, causation and correlation and take our gut microbiome, which is eventually nothing else than a mirror of our healthy or unhealthy lifestyle for the real deal, and try to modulate and fix the mirror image with anti-, pro- or prebiotics without working on what stands right before the mirror: The sedentary, convenience food consumer, who works to jobs and rather watches TV till late at night instead of getting his 7-8h of sleep....

References:

1. Aziz AA, Kenney LS, Goulet B, Abdel-Aal el-S. Dietary starch type affects body weight and glycemic control in freely fed but not energy-restricted obese rats. J Nutr. 2009 Oct;139(10):1881-9. Epub 2009 Aug 19. 
2. Hessel S, Eichinger A, Isken A, Amengual J, Hunzelmann S, Hoeller U, Elste V,  Hunziker W, Goralczyk R, Oberhauser V, von Lintig J, Wyss A. CMO1 deficiency abolishes vitamin A production from beta-carotene and alters lipid metabolism in mice. J Biol Chem. 2007 Nov 16;282(46):33553-61.
3. Lin HV, Frassetto A, Kowalik EJ Jr, Nawrocki AR, Lu MM, Kosinski JR, Hubert JA, Szeto D, Yao X, Forrest G, Marsh DJ. Butyrate and propionate protect against  diet-induced obesity and regulate gut hormones via free fatty acid receptor 3-independent mechanisms. PLoS One. 2013;7(4):e35240.
4. Robertson MD. Dietary-resistant starch and glucose metabolism. Curr Opin Clin Nutr Metab Care. 2013 Jul;15(4):362-7. 
5. Shen L, Keenan MJ, Martin RJ, Tulley RT, Raggio AM, McCutcheon KL, Zhou J. Dietary resistant starch increases hypothalamic POMC expression in rats. Obesity  (Silver Spring). 2009 Jan;17(1):40-5. Epub 2008 Oct 23.
6. Tolhurst G, Heffron H, Lam YS, Parker HE, Habib AM, Diakogiannaki E, Cameron J, Grosse J, Reimann F, Gribble FM. Short-chain fatty acids stimulate glucagon-like peptide-1 secretion via the G-protein-coupled receptor FFAR2. Diabetes. 2013 Feb;61(2):364-71.
7. Zhou J, Martin RJ, Tulley RT, Raggio AM, McCutcheon KL, Shen L, Danna SC, Tripathy S, Hegsted M, Keenan MJ. Dietary resistant starch upregulates total GLP-1 and PYY in a sustained day-long manner through fermentation in rodents. Am J Physiol Endocrinol Metab. 2008 Nov;295(5):E1160-6.
8. de Wit NJ, Derrien M, Bosch-Vermeulen H, Oosterink E, Keshtkar S, Duval C, de Vogel-van den Bosch J, Kleerebezem M, Müller M, van der Meer R. Saturated fat stimulates obesity and hepatic steatosis and affects gut microbiota composition by an enhanced overflow of dietary fat to the distal intestine. Am J Physiol Gastrointest Liver Physiol. 2013 Jun 14.
9. Zhou J, Martin RJ, Tulley RT, Raggio AM, McCutcheon KL, Shen L, Danna SC, Tripathy S, Hegsted M, Keenan MJ. Dietary resistant starch upregulates total GLP-1 and PYY in a sustained day-long manner through fermentation in rodents. Am J Physiol Endocrinol Metab. 2008 Nov;295(5):E1160-6. 

Gut Bacteria Modulation: Ramp Up Your Short-Chain Fatty Acid Production With Fermentable Starches Within 6 Days. Longterm Fat Loss, Gut Health & Cancer Protection Possible

You cannot handpick several billion lodgers in your intestine, but you can attract the right one by providing them with the foods they like. Contrary to the current probiotic hype, the key to gut and metabolic health lies in the prebiotics you are stuffing down your piehole.

It's quite funny, only 5 years ago, everyone was still smiling at people who spent extra bucks on yogurts and other dairy products that were enriched with certain bacteria strains - strains, which were and obviously still are supposed to have health-promoting effects. The fact that probiotic yogurts and similar stuff have meanwhile made it into the store brand line-up of the large discount-markets (at least here in Germany) is however clear cut evidence that the previously laughed at idea that gut bugs are something you want to foster and promote has meanwhile turned into another of those partly highly questionable, but widely accepted pieces of "nutritional wisdom". The question that remains is, will they join the ranks of other scientific hypothesis that have made it n allegedly oversimplified from the bench to the store-boards before their time was ripe? Hypotheses such as the "cholesterol is bad for your heart", the "pasta and rice will keep you lean" and the "fat makes fat" hypotheses?

Don't worry, I am neither going to rant, nor am I suggesting that the whole idea about the importance of the gut microbiome is similarly flawed as the "eat fat and get fat"-hypothesis. The thing I do yet want to point out, before I tell you more about the latest scientific findings, is that our knowledge about the good and the bad guys in our intestines, about the ways they interact and about the short- and longterm effects of these interactions are so limited that my gut tells me (all puns intended) that everything that goes beyond the classics, i.e. the consumption of a diet rich in various types of fibers and a reasonable amount of fermented foods could well turn against us in a not very distant future.

Feeding the good guys: Does it work? And how does it work?

Based on the currently available evidence, it does however in fact look like the shift towards short-chain fatty acid producing bacteria, the scientists from the University of Minnesota and the scientist from the Fred Hutchinson Cancer Research Center initiated in their 20 study participants (ten men and ten women) who had been recruited via flyers around the University campus (that alone goes to tell you how "mainstream" the notion of beneficial gut bacteria has become). The subjects were health and aged between 18 and 60 years, they were non-smokers and were not taking any prescription meds and contrary to the average American (cf. "How Fat We Have Become") their BMIs were in the normal range.

Table 1: Macronutrient composition of the test meal on day 1 and the supplemental cereal bars and beverages the subjects consumed in the course of the 6-day study period on four occasions every day (Klosterbuer. 2013)

"Participants consumed five treatments in a double-blind, cross-over design with treatment periods of 7 d followed by a 21 d washout period. On day 1 of the study, following a 12 h fast, participants arrived at the GCRC and consumed either a low-fibre control breakfast or one of four fibre-containing breakfasts. Meals consisted of a muffin, hot cereal, and fruit-flavoured beverage. For the next 6 d, participants consumed the study products at home. Treatments were provided as cereal bars and a beverage mix, which was pre-measured into 500 ml water bottles. Participants were instructed to consume four cereal bars and one beverage over the course of each day." (Klosterbuer. 2013)

Obviously the test breakfast, as well as the bars and beverages the dietary composition of which you can see in table 1 contained additional "functional" additives. As indicated by the titles above the respective columns in table 1, these were

• 

  Figure 1: Short-chain fatty acid content of the stools (top), number of stools and consistency (1=hard, 4=diarrhea, middle), gastrointestinal symptoms (bottom, Klosterbuer. 2013)

  for the breakfast, 25 g SCF or RS alone or in combination with 5 g pullulan (SCF+P and RS+P),
• for the beverages and bars in the treatment groups, 20g SCF or RS alone or in combination with 5 g pullulan (SCF+P and RS+P) for the beverages and bars and
• for the beverages and bars in the control group, fully digestible maltodextrin

• the short chain fatty acids (SCF) were produced via hydrolysis of maize starch, followed by
  cooling to form a branched structure, 
• the resistant starch (RS) was a type 3 (RS3) retrograded starch roduced from heat moisture-treated, high-amylose maize starch, and 
• pullulan is a linear glucose homopolysaccharide that's formed during the fermentation of dextrin by the yeast Aureobasidium pullulans.

All test products were provided by Tate and Lyle, Inc. and - as you can likewise see in table 1 matched for macronutrient and energy content. All bars and beverages were meant to be consumed along with participants regular diets.

Astrology was yesterday, feceology (=poopology ;-) is the future!

Aside from the obligatory protocols on the state of their digestive health the subjects also had to collect stool samples, which were then analyzed by the researchers who were looking at the RNA and DNA content of the samples to identify any changes in the makeup of the gut microbiom, without exact quantification of individual strains. What they found was that ...

"[a]mong the treatments, the control was significantly different from the SCF (P<0.001) and SCFþP(P<0.0002) treatments. The SCF treatment was significantly different from the RS treatment (P<0.007), and the SCF+P treatment was significantly different from the RS+P treatment (P<0.002). The GMC [gut microbial community] following the consumption of the SCF and SCF+P treatments was not significantly different." (Klosterbuer. 2013)

Now this certainly does not sound very informative, right? It in fact isn't but let's be honest, what's the additional value of me telling you that the scientists were able to associate a certain peak in the bacterial make up with either Anaero-coccus vaginalis or Parabacteroides goldsteinii and another one with either Parabacteroides distasonis or Parabacteroides merdaeusing anisilico?  Not much, right.

"I know that we know nothing" An adequate description of the "state of the art"

My casual observation that knowing the funky names of the individual bacteria that felt specifically cosy in the acidified short-chain fatty acid loaden milieu that formed in response to the dietary intervention is about as useful to you as knowing all the names of the tiny insects in the Amazon Delta. In view of the fact that this is not much different for the scientists who were not even able to tell exactly which bugs they were looking at here. In fact, we have not even come so far to say "little do we know" - the current state of our "understanding" of the complexity of the gut microbiom is simply far from allowing any reliable prognosis statements on which bacteria we want in which ratios.

Figure 2 (first published in "Waxy Maize Reloaded"): Changes in postprandial energy expenditure (left) and fatty acid oxidation (right) after the ingestion of regular and WM-HPD pancakes (data adapted from Shimotoyodome. 2011)

That being said the net increase in SCFA production that was achieved by all treatments in the study at hand is an endpoint that may provide at least some orientation. After all, you will probably all remember the impressive results of theh Shimotoyodome study from 2011 (see figure 2) I discussed in conjunction with the post on WM-HDP, back in the day. While this is likewise still speculative, it's still highly likely that the increase in fatty acid oxidation the researchers observed in their human subjects after the consumption of pancakes that had been enriched with resistant starch (RS4) is a direct consequence of the increased short chain fatty acid production in the colon.

There is yet an important "on the other hand" we must not forget

GLP-1 is also partly responsible for the profound weight loss after bariatric surgery. In this case it is yet not the rise in short chain fatty acids, but as the scientists speculate the mechanical stretch and the influx of dietary fat that would otherwise have been absorbed earlier during the digestive process that triggers the release of the "satiety hormone" glucacgon-like peptide 1 (GLP-1, read more)

In fact, the aformentioned beneficial effects on the fatty acid metabolism and the concomitant reductions in insulin, which were brought about by an increase in GLP-1 (learn more about the potent fat burning effect of GLP-1) and decreases in GIP, respectively, have recently been traced back directly to the influence of SCFA in the long intestine. In a cleverly designed study, Lin et al. were able to show that the expression of these quasi-hormonal peptides, appears to be mediated by a direct interaction of bacteria-generated (or simply ingested) short-chain fatty acids in the gut with a speficic free free fatty acid receptor 3 (FFAR-3) in the gut lining (Lin. 2013).

As far as this part of the equation goes, we do therefore actually "know" something, what we do not know, but there are obviously a couple of my beloved "on the other hands" we still have to take into account. The most significant of these is unquestionably that impressive results as those that were observed in the very short run in the Shimotoyodome study will only arise in scenarios, in which the regular sugars and starches 90% of the Western population literally lives on are replaced with fermentable alternatives.

As long as you keep on the twinkies and dingdongs diet, the composition of your gut microbiome won't save you - no matter how good the critters are in turning fermentable starches into short chain fatty acids.

Figure 3: Different resistant starch content of various foods (% dry matter; based on Goni. 1996)

After all none of the simple sugars and easily digestible starches will even make it to the colon before they are either directly or after being disassembled by the enzymes in your gut taken up into the blood stream - the couple of  SFCA you either ingest as a supplement or your gut bacteria may be producing from additional pre-biotics (the term used in a very broad sense here and in the following paragraphs) you may be taking won't save you from the "fat" consequences.

Remember: If A → B & A → C, this does not imply B → C

Epidemiological studies such as Layden et al.'s 2013 analysis of the body composition of young, obese women in which the researchers found a negative correlation between body fatness (esp. visceral obesity) and the SCFA production in the colon do therefore not necessarily tell us that having a certain gut microbiome protects you from obesity (Layden. 2013). Observational studies like these, but also all experiments in which the human or rodent "participants" had the chance to compensate for the intake of fermentable starches or other supplements by skipping on foods they'd otherwise consume, simply tell us that eating fermentable starches is better than eating sugary junk - not more, but also not less.

Can saturated fat cause endotexemia? Learn the answer here!

If the ladies with the lower visceral fat in the Layden study consumed a diet that was devoid of fermentable starches, they would not produce any short chain fatty acids no matter how the composition of their gut microbiome may look like (in fact it would soon look like a "ghetto" full of unwanted bacterial tenants not paying their rent in form of healthy SCFA ;-). It should be obvious that the same goes for the anti-cancer effects of the SCFAs butyrate, propionate and acetate (Matthews. 2013), as well as all the other beneficial health effects which have been linked back to the bacterially manufacture two- to six-carbon chain FAs.

All the aforementioned benefits require the reguar ingestion of more than just trace amounts of fermentable starches. These pre-biotics will automatically have the "beneficial" bacteria in your gut get the better of the "bad guys" and it is a necessary prerequisite that any probiotics you are consuming either in pill form or from enriched foodstuff can take full effect. In other words:

Pre-biotics don't support probiotics, it's the other way around. Probiotics can support and accelerate the desired permanent change the regular consumption of prebiotics will bring about.

I know the product descriptions on the shiny websites of the snake oil industry will conceal that, but without a consequent and permanent change in your dietary habits, you can as well flush your super-potent 100 billion bacteria per serving probiotic directly down your toilette.

---

Even the nicest subtenants can become a real problem, when they come over without being asked day by day. Unfortunately, all sorts of gut bacteria (even the "good" ones) have as imilarly nasty habit of translocating through a leaky gut wall into parts of your body, where you certainly don't wont them... read about the nasty consequences, here

Long story short: All the current hoopla about probiotics, the tons of "enriched" products on the shelves of the supermarket, the capped super-*place your favorite strain here* with bazillions of "life-bacteria" in them and for which you would have to spend half your monthly salary, if you wanted to consume enough of them to override the baseline effect your diet, all of them are about as useful as a stimulant based fat burner on a hypercaloric diet.

You are what you eat, not what your supplement! The same goes for the composition of the bugs in your gut and if you want them to produce short chain fatty acids for you you better make sure they get the raw materials on a consistent basis. That this works like a charm within no more than 6 days is evidenced by the study publication of which triggered this lengthy discussion.

Whether all the purported health benefits will become visible in the short, long or very long term will yet still have to be elucidated... and that this is probably not going to happen, when you try to get your fermentable starches from bread only (0.25g per slice vs. navy beans 10g per 1/2 cup and even bananas 5g per banana)

References:

• Goñi I, García-Diz L, Mañas E, Saura-Calixto F. Analysis of resistant starch: a method for foods and food products  Food Chemistry. 1996; 56(4):445–449.
• Layden BT, Yalamanchi SK, Wolever TM, Dunaif A, Lowe WL Jr. Negative association of acetate with visceral adipose tissue and insulin levels. Diabetes Metab Syndr Obes. 2013;5:49-55. 
• Klosterbuer AS, Hullar AJH, Li F, Traylor E, Lampe JW, Thomas W, Slavin JL. Gastrointestinal effects of resistant starch, soluble maize fibre and pullulan in healthy adults. British Journal of Nutrition. 2013 [Epub ahead of print].
• Lin HV, Frassetto A, Kowalik EJ Jr, Nawrocki AR, Lu MM, Kosinski JR, Hubert JA, Szeto D, Yao X, Forrest G, Marsh DJ. Butyrate and propionate protect against diet-induced obesity and regulate gut hormones via free fatty acid receptor 3-independent mechanisms. PLoS One. 2013;7(4):e35240.
• Shimotoyodome A, Suzuki J, Kameo Y, Hase T. Dietary supplementation with hydroxypropyl-distarch phosphate from waxy maize starch increases resting energy expenditure by lowering the postprandial glucose-dependent insulinotropic polypeptide response in human subjects. Br J Nutr. 2011 Jul;106(1):96-104.
• Wroblewska M, Brzuzan L, Jaroslawska J, Zdunczyk Z. Effect of buckwheat sprouts and groats on the antioxidant potential of blood and caecal parameters in rats. Int J Vitam Nutr Res. 2011 Sep;81(5):286-94.

Saturated Fat & Postprandial Endotoxemia. Caffeine & Max. vs. Submaximal Exercise. Lactoferrin & the Battle Against Visceral Obesity. High Intensity Strength Training, Free Testosterone & the Use of Perceived Recovery Scales

Gram negative bacteria, as these E. coli bacteria which have been photographed with a low-temperature electron micrograph (magn. x10,000) tend to produce endotoxins in your gut, while gram positive bacteria tend to produce exotoxins on your food - nasty, ha?

It has been estimated that a single cell of Escherichia coli contains approximately 106 Lipid A or endotoxin molecules with a mass of about 100,000 Da (the exact mass varies according to the LPS type). The typical human intestinal tract can harbor approximately one gram of endotoxin, which is ~2-4x more than what scientists used in previous rodent studies as a "lethal dose" (Kawai. 1991). Aside from the information about the lethal dose of endotoxins in rodents, these figures, which are at the same time the SuppVersity figures of the week are part of the study by Mani et al. with which we are going to kick off this week's installment of On Short Notice. I guess these figures give you an idea of the toxic potential within your gut and why all the hoopla about leaky guts, the human microbiome, pro- and prebiotics, endotoxemia and co. is probably not all hype, but a hitherto largely neglected aspect of human health (and disease)

Saturated fat < > gut interaction sheds a dark shadow on the "benign fat of our ancestors"

(Mani. 2013) -- According to a study from the University of Iowa, the endotoxemia response to a meal, i.e. the amount of inflammatory innately produced toxins from your gut that enter circulation in the postprandial phase, is increased in response to a meal that's high in saturated fat.

Figure 1: Endotoxin permeablity and changes in serum endotoxin levels in the hours subsequent to the ingestion of a test meal containing either 50ml  coconut (CO), vegetable (VO) and fish oil (FO) in otherwise healthy pigs (Mani. 2013).

The scientists also found that omega-3 fatty acids from fish and cod liver oil reduced the amount of endotoxins hitting the blood stream and that olive, as well as vegetable oils exhibited a neutral effect. As the data in figure 1 (left) goes to show you, the underlying mechanism behind the saturated fat induced influx of toxins was a whopping +60% increase in the endotoxin permeability (Papp) of the guts of the 24 pigs on which the experiments have been conducted.

Click here to read more about a previous study that shed some light on the effects of certain nutrients on the gut microbiome.

Now you can certainly argue that the ground corn-soybean meal dough that was at the base of the test-meal was "the devil" here, but let's be honest, for the average Jane and Joe, there are similar "devils" in any standard meal, they consume, so that the finding that the addition of 50 ml fish oil (FO), vegetable oil (VO) or coconut oil (CO) made such a difference in terms of the influx of pro-inflammatory endotoxins is nothing you can simply ignore. The same goes for the fact these effects occurred in response to the ingestion of organic coconut oil (according to the researchers purchased from Spectrum Naturals Inc.), is actually somewhat unsettling and certainly not in line with some of the previously established benefits of coconut oil consumption, such as it's waist reducing effects in overweight subjects (click here to learn more).

What's also interesting is that previous rodent studies yielded different results. Laugerette et al., for example, found a similar increase as Mani et al. in mice, but in response to canola and sunflower oil (Laugerette. 2013). This raises the question in how far the effects may be mediated by the baseline diet and the corresponding bacterial composition of the small and large intestine (or species specific effects?). After all, the gram negative bacteria of which scientists believe that they increase in response to high fat diets have the highest endotoxin content. They populate the distal ileum and the colon and are supposedly the main sources for circulating endotoxin (Berg. 1999) - if you had less of them to begin with, you are not as likely to suffer from an acute influx of endotoxins in response to the ingestion of SFAs. Moreover, what it the endotoxins were released in response to the antimicrobial effects of coconut oil?

Update: Wyatt Brown left an interesting comment on this issue on the SuppVersity facebook wall, I do not want to deny anyone, so I thought I'd just update the post with it:

I'm glad people are talking about the endotoxemia thing, that's what we do at SuppVersity, have the discussions nobody else does! I think it's important to recognize that, especially for the paleo/ancestral types who accuse grains of inducing intestinal permeability and then go and eat diets that cause intestinal permeability...and because endotoxemia is bad...

But I don't think that all is lost, the evolutionary argument may just need to be modified a little. The current paradigm involves looking at individual foods, or worse yet (though that was supposed to be an improvement) broad classes of macronutrients, and our adaptation to them. Well, it looks like those might have been wrong in some ways, maybe we aren't fully adapted to some foods, but then again maybe we are adapted to a particular kind of diet that makes those foods all right.

Some of the antioxidants in orange juice prevent intestinal permeability from dietary fats it seems the bile acids secreted during digestion are to blame, and it's an oxidative mechanism, so the orange juice prevents this (Ghanim. 2010). It also works with grape polyphenols (Ghanim. 2011).

Moreover, it seems that feeding mice a diet rich in fermentable fibers prevents endotoxemia - maybe due to butyrate production and its protective effects on intestinal cells (Cani. 2007). And acutely, fiber with a high fat meal also prevents the effect (Ghanim. 2013). It's probably due its ability to sequester excess bile acids (Vahouny. 1980)

So it would appear that we are adapted to a diet containing those fats but also containing fruit and fiber.

As you see, Wyatt makes a pretty valid point, when he hints at other contributing factors of which I know that they got forgotten way too often in the paradigmatic and downright stupid and unproductive high fat vs. low fat and the SFA vs. PUFA skirmishes on the Internet.

I guess, there is still much to learn here and I hope you are aware that the SuppVersity is the place you can do just that: Learn something new everyday!

Caffeine's effect on muscular fatigability during maximal vs. supramaximal stimulation

There is no question that caffeine can have beneficial effects on exercise performance - whether every athlete benefits to a similar degree is yet as questionable as the "ideal" dosage to elicit optimal fat loss effects without the negative side effects that are associated with the chronic overconsumption of any type of stimulant (click here to learn more about the narrow margin between "just enough" and "already too much")

(Tallis. 2013) -- In a very straight forward in vitro experiment, researchers from the Coventry University in the UK found that the ergogenic effects of caffeine depend on the intensity of the muscular contractions. When the scientists exposed isolated soleus muscles to up to 70µM of caffeine (that's still within what you would consider a "physiological dosis"), Tallis et al. observed that the muscular endurance increased only, when the muscles were challenged at submaximal intensities (+19.2%), while it decreased by 17.6% upon maximal challenge.

Whether or not this is important for the average strength trainee remains questionable. After all the "endurance" part of your regimen is usually conducted at submaximal intensities and weheter you can do one interval more or less probably doesn't matter as well. For a professional cyclist participating in a time trial, those 17.6% may well make the difference between victory and defeat. On the other hand, there is more to "endurance" than local muscular fatique, so that caffeines effects on the central nervous system will at least ameliorate, if not totally counter these potential downsides.

Lactoferrin, an overlooked visceral fat annihilator?

I don't even know if all of you are familiar with the globular glycoprotein lactoferrin that is widely represented in various secretory fluids, saliva, tears, nasal secretions and - above all - colostrum. It has a very important role in the immune defenses of your body and according to a recent review by Japanese scientists, it does also exert direct lipolytic (breakdown and release of fat from) and anti-adipogenic effects in vitro and in vivo.

All of you who read the "Ask Dr. Andro" installment on Milk & Colostrum should at least have heard of lactoferrin before. It's one of the anti-microbial, anti-fungal and immune modulating molecules in the white elixir of mammalian life that's also suppose to exert antagonist effects on the opioid receptors (read more).

A hitherto still unsolved problem is the delivery of the lactoferrin to the target tissue, but with the advent of specifically enteric coated lactoferrin which circumvents the breakdown of the 80kDa protein in the acidic milieu of the stomach and allows its passage via the lymphatic system into the mesenteric (visceral) fat pad, where it accumulates, interacts with the lactoferrin receptor LRP1 which is directly located on the adipocytes of the visceral adipocytes and suppresses the expression of PPARγ reduces the expression of perilipin and thus shuts down lipogenesis and increases lipolysis in existing adipocytes. Accordingly, respective supplements could in fact become "a highly safe and a promising dietary supplement" that has in addition to its already well-known beneficial effects on the immune system the ability the potential to "be used to promote human health globally" (Ono. 2013). But let's be honest, haven't we heard claims like that before?

Perceived recovery 48h after a workout correlates with free testosterone levels

(Sikorski. 2013) -- Yeah, I know the whole free testosterone after a workout discussion is pathetic, but what about free testosterone levels 48h hours after the workout, i.e. amidst the hot recovery phase? According to a soon to be published study in the Journal of Strength and Conditioning Research a standardized test to elicit the perceived recovery (PRS) appears to be surprisingly accurate to predict the drop in free testosterone after a session of high volume resistance training designed to elicit a large amount of fatigue and muscle damage. 

"All subjects participated in a high volume resistance training session consisting of 3 sets of 10-12 repetition maximum loads for each of the following exercises: full squats, bench press, deadlifts, pullups, bent over rows, dips, shoulder press, barbell curls and triceps extensions. Rest periods were 1 minute between sets, and 2 minutes between exercises." (Sikorski. 2013)

The scientists from the University of Tampa recruited 35 highly resistance-trained subjects (aged 21.3 ± 1.9 years) with an average squat, bench press, and deadlift of 1.7± 0.2, 1.38 ± 1.9 and 2.07 ± 2.7 times their bodyweight for their study. The subjects had a minimum experience of 3 years of resistance training and were thus probably way more capable to access their own recovery status than the average Jane or Joe after with a dozen of irregular workouts under her / his belt. Blood analyses, soreness and PRS tests were conducted at before, immediately after and 48h after the workout (total weight lifted in the training session was 16,353 ± 3,691.8 kg) and revealed ...

Read more about the hormonal effects of different workout styles in this previous SuppVersity post

• a significant increases in leg, chest and arm soreness from pre to post exercise,
• a significant increases in creatine kinase (CK; measure of muscle damage) from 189.4 ± 100.2 to 512 ± 222.7 U/L (p < 0.05),
• no changes in cortisol, testosterone, and free testosterone from pre to immediately post workout,
• a significant moderate, and inverse relationship between leg soreness and PRS scores and  low, inverse relationships between chest and arm soreness and PRS scores, 
• a significant, moderate inverse relationship between CK and PRS 

yet only when the CK values peaked 48h after the workout, however, the aforementioned "low, direct relationship with PRS" (Sikorski. 2013) was observed. As the researchers point out this result could be

"[...] important for those individuals that have neither the resources (time, monetary or otherwise) nor the expertise to draw blood and perform chemical assays to determine recovery status and or muscle damage. [...] This, in the bigger picture, may help appropriately design periodization plans designed aimed at functional overreaching and ensure proper overload. Moreover, and perhaps more importantly, the ability to indicate level of recovery following heavy resistance training expeditiously and accurately may be a critically important step in prevention of overtraining." (Sikorski. 2013)

The scientists do yet also emphasize that "future work is needed addressing other variable influencing recovery and long-term studies investigating the usefulness of the PRS in training" before a more general recommendation can be issued.

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That's it for today folks. As usual there are a couple of interesting facebook posts for you to check out and discuss

• Upping your vitamin D levels does nothing to reduce knee pain or cartilage loss in patients with symptomatic knee ostearthritis (read more)
• "The one-two punch", retinoic acid suppresses obesity by both promoting energy expenditure and by inhibiting adipogenesis (read more)
• More evidence of intrauterine dietary priming: Low protein in the womb + high caloric diet afterwards => insulin resistance (read more)

and obviously, you are invited to post your thoughts or questions on any of today's items in the comment area of this post.Aside from that, I wish all of you an exciting weekend ;-)

References:

• Berg RD. Bacterial translocation from the gastrointestinal tract. Adv Exp Med Biol 1999, 473:11–30. 
• Cani PD, Neyrinck AM, Fava F, Knauf C, Burcelin RG, Tuohy KM, Gibson GR, Delzenne NM. Selective increases of bifidobacteria in gut microflora improve high-fat-diet-induced diabetes in mice through a mechanism associated with endotoxaemia. Diabetologia. 2007 Nov;50(11):2374-83.
• Ghanim H, Sia CL, Upadhyay M, Korzeniewski K, Viswanathan P, Abuaysheh S, Mohanty P, Dandona P. Orange juice neutralizes the proinflammatory effect of a high-fat, high-carbohydrate meal and prevents endotoxin increase and Toll-like receptor expression. Am J Clin Nutr. 2010 Apr;91(4):940-9.
• Ghanim H, Sia CL, Korzeniewski K, Lohano T, Abuaysheh S, Marumganti A, Chaudhuri A, Dandona P. A resveratrol and polyphenol preparation suppresses oxidative and inflammatory stress response to a high-fat, high-carbohydrate meal. J Clin Endocrinol Metab. 2011 May;96(5):1409-14.
• Ghanim et al. The Intake of Fiber Suppresses the High-Fat High-Carbohydrate Meal-Induced Endotoxemia, Oxidative Stress and Inflammation. Endocr Rev, Vol. 33 (03_MeetingAbstracts): OR03-1
• Kawai Y, Kaneda K, Morisawa Y, Akagawa K. Protection of mice from lethal endotoxemia by use of an ornithine-containing lipid or a serine-containing lipid. Infect Immun. 1991 Aug;59(8):2560-6. Erratum in: Infect Immun 1992 Jan;60(1):320.
• Laugerette F, Furet JP, Debard C, Daira P, Loizon E, Geloen A, Soulage CO, Simonet C, Lefils-Lacourtablaise J, Bernoud-Hubac N. Oil composition of high-fat diet affects metabolic inflammation differently in connection with endotoxin receptors in mice. Am J Physiol Endocrinol Metab. 2013;302:E374–386.
• Mani V, Hollis JH, Gabler NK. Dietary oil composition differentially modulates intestinal endotoxin transport and postprandial endotoxemia. Nutrition & Metabolism. 2013;10(6).
• Ono T, Morishita S, Murakoshi M. Novel  function of bovine lactoferin in lipid metabolism: Visceral fat reduction by enteric-coated lactoferrin. Pharma Nutrition. 2013 [accepted manuscript] 
• Sikorski EM, Wilson JM, Lowery RP, Joy JM, Laurant CM, M-C Wilson S, Hesson D,
  Naimo MA, Averbuch B, Gilchrist P. Changes in Perceived Recovery Status Scale
  Following High Volume, Muscle Damaging Resistance Exercise. J Strength Cond Res.
  2013 Jan 2. [Epub ahead of print]
• Tallis J, James RS, Cox VM, Duncan MJ. The effect of a physiological concentration of caffeine on the endurance of maximally and submaximally stimulated mouse soleus muscle. J Physiol Sci. 2013 Jan 6.
• Vahouny GV, Tombes R, Cassidy MM, Kritchevsky D, Gallo LL. Dietary fibers: V. Binding of bile salts, phospholipids and cholesterol from mixed micelles by bile acid sequestrants and dietary fibers. Lipids. 1980 Dec;15(12):1012-8.