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Abstract

Some colonic luminal molecules resulting from bacterial metabolism of alimentary or endogenous compounds are believed to exert various effects on the colonic epithelial cell physiology. We isolated surface epithelial cells and intact colonic crypts in order to test bacterial metabolites in the pig model, which is often considered relevant for extrapolation to the physiopathology of the human gastrointestinal tract. Using colonocytes isolated with EDTA, we found that the initial cell viability, estimated by the membrane integrity and oxidative capacity measurement, fell rapidly despite several experimental attempts to preserve it such as the use of a medium designed to increase the adherence of epithelial cells and of a coated extracellular matrix, the presence in the culture medium of the oxidative substrate butyrate, and the use of an inhibitor of the caspases involved in cell apoptosis. In contrast, using dispase and collagenase as proteolytic agents, we were able to obtain pig colonic crypts that maintain an excellent membrane integrity after 4 h. Using this preparation, we were able to test the presumably cytotoxic luminal compounds hydrogen sulfide, ammonia, and deoxycholic acid on colonic crypt viability. Of these, only deoxycholic acid was found to significantly alter the cellular membrane integrity. It is concluded that pig colonic crypts can be useful for the in vitro appraisal of the cytotoxic properties of luminal compounds.

Study of in vitro digestion of Tenebrio molitor flour for evaluation of its impact on the human gut microbiota

“…Fecal ammonia concentration in humans varies between 12 mM to 30 mM and increase with high intakes of protein (Scott et al, 2013). Higher levels can be considered negative for colonocytes, however, ammonia concentration levels obtained in this study seem to be within "safe levels" (up to 70 mM) (Leschelle et al, 2002;Tsujii et al 1992).…”

Cooking Has Variable Effects on the Fermentability in the Large Intestine of the Fraction of Meats, Grain Legumes, and Insects That Is Resistant to Digestion in the Small Intestine in an in Vitro Model of the Pig’s Gastrointestinal Tract

“…Heat treatment also induces an increase in the propionate molar ratio. Limiting H 2 S production is beneficial because this component is reputed as toxic to the intestinal mucosal barrier via DNA damage, alteration of the cellular respiration, and inhibition of the butyrate oxidation in colonocytes . As H 2 S originates from the fermentation of sulfur-containing AA and of dietary and mucinous inorganic sulfur by sulfate-reducing bacteria, the increase in H 2 S could be explained by an alteration of methionine and cysteine at temperatures around 120 °C, making them more resistant to enzymatic hydrolysis in the small intestine and thus more available as fermentation substrate in the large intestine. , Whereas oven-cooking insects at 150 °C for 30 min and at 200 °C for 10 min had similar impacts on digestibility and intestinal fermentation, autoclaving insects seemed the most detrimental thermal treatment (reduced IVDMD and higher H 2 S production).…”

Use of Physiologically Based Kinetic Modeling to Predict Deoxynivalenol Metabolism and Its Role in Intestinal Inflammation and Bile Acid Kinetics in Humans

“…13 Thus, it could be speculated that the DON-induced bile acid malabsorption resulting in elevated bile acid levels in the colon may contribute to the DON induced diarrhea and associated body weight loss. Moreover, high amounts of bile acids reduce intestinal integrity and increase intestinal permeability in the colonic crypts of pig 48 and in the small intestine of rabbit. 49 Reduced intestinal integrity is related to pro-inflammatory cytokine production and inflammatory bowel disease in human intestine.…”