Metabolism intestinal microflora

Finally, the fact that anthocyanins can reach the brain represents a beginning of an explanation of the purported neuroprotection effects of anthocyanins. Anthocyanins may be eliminated via urinary and biliary excretion routes. " The extent of elimination of anthocyanins via urine is usually very low (< 0.2% intake) in rats and in humans, indicating either a more pronounced elimination via the bile route or extensive metabolism. As mentioned earlier, in the colon, non-absorbed or biliary excreted anthocyanins can be metabolized by the intestinal microflora into simpler break-down compounds such as phenolic acids that may be (re)absorbed and conjugated with glycine, glucuronic acid, or sulfate and also exhibit some biological... 

Z. Djouzi and C. Andrieux, Compared effects of three oligosaccharides on metabolism of intestinal microflora in rats inoculated with a human faecal flora, Br. J. Nutr., 78 (1997) 313-324. 

Flavonoids in general are extensively metabolized by enterocyte and hepatic cell enzymes and by intestinal microflora. Therefore, it is necessary to explore the biological activity of flavonoids and their metabolites in specific tissues, because the metabolites found in the blood flow or any specific organ may differ among themselves and from... 

Intestinal Metabolism Intestinal drug metabolism can occur by microflora present in the gut lumen, as well as by enzymes present in luminal fluids and in the intestinal mucosa [166], Metabolism of xenobiotics by gut microflora is low in comparison to metabolism by the gut mucosa and liver [62], However, the intestinal microflora (e.g., Bacteroides and Bifidobacteria) may play an important role in the first-pass metabolism of compounds that are poorly or incompletely absorbed by the gut mucosa, especially in the lower parts of the intestine. This bacterial metabolism is largely degradative,... 

Bolton GC, Griffiths LA. 1978. Metabolism of hydrazines and hydrazides by the intestinal microflora. Experientia (Switzerland) 34 1484-1486. 

In this chapter we survey recent findings that describe the metabolic fate of the xenobiotic moieties of mercapturic acid pathway (MAP) metabolites that are excreted from the liver with the bile. We show that the products of the MAP undergo an enterohepatic circulation that is mediated by intestinal enzymes and/or intestinal microflora. 

Scheline, R.R., The metabolism of (-l-)-catechin to hydroxyphenylvaleric acids by the intestinal microflora, Biochim. Biophys. Acta, 222, 228, 1970. 

Okubo, T., Ishihara, N., Oura, A., Serit, M., Kim, M., Yamamoto, T., and Mitsuoka, T., In vivo effect of tea polyphenol intake on human intestinal microflora and metabolism, BioscL Biotechnol Biochem., 56, 588, 1992. 

The metabolic transformation of many drugs is catalysed by various enzyme of the intestinal microflora. The anaerobic microflora and colon are rich in reductases which may be responsible for a significant proportion of the azoreductase and nitroreductase activity. The enzymes and other factors that may produce change in the nature of intestinal microflora might also produce changes in the metabolism pattern of the drugs. 

Intestinal microflora plays a key role in the metabolism and bioavailibility of isoflavones [86]. After ingestion, soybean isoflavones are hydrolyzed by intestinal glucosidases, which release the aglycones, daidzein and genistein, Fig. (16). 

Metabolism may be mediated by intestinal microflora, epithelial enzymes, or liver enzymes preceding entry into the systemic circulation. Chloramphenicol is well absorbed when administered orally to calves less than 1 week old, but it is inactivated by microflora when administered to ruminants. Similar observations have been made after oral administration of amoxicillin, ampicillin, and cephalexin therapy in young calves (11). On the other hand, trimethoprim, which is extensively metabolized in the liver and may undergo some metabolism in the rumen, shows higher systemic availability in the newborn calf and kid, due probably to the lower metabolic activity in the neonatal animal. 

The bacterial composition of the intestinal microflora is relatively stable however, the metabolic activity of the organisms can be easily altered (54). Any metabolic alteration caused by perturbation of the intestinal microflora may affect the metabolism of endogenous compounds and also compromise the effectiveness... 

Scheline RR. 1968. Metabolism of phenolic acids by the rat intestinal microflora. Acta Pharmacol Toxicol (Copenh) 26 189-205. 

Yuan JP, Wang JH, Liu X. 2007. Metabolism of dietary soy isoflavones to equol by human intestinal microflora—implications for health. Mol Nutr Food Res 51 765-781. 

By far the most predominant metabolic pathway for water-soluble azo dyes is cleavage of the azo linkage by azoreductase of the liver and extrahepatic tissue or by intestinal microflora in the body [25,26], Oxidative metabolism occurs for lipid-soluble dyes, e.g., solvent dyes. Three oxidation pathways are known for such dyes (1) C-(ring-)hydroxylation, (2) A-hydroxylation at a primary or secondary amino group or (3) by stepwise oxidation of the methyl groups of dimethylamino compounds (demethylation). All three oxidative degradation ways leave the azo bond intact. For further details of the mechanisms, see [27,28],... 

Variation in the fermentable fiber content of diets used in toxicity studies and in human diets may influence the toxicity of xenobiotics metabolized by the intestinal microflora. These results emphasize the importance of characterizing the fiber in diets when investigating the influence of dietary fiber on disease processes and chemical toxicity. 

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