Protocols for the Use of Gut Models to Study the Potential Contribution of the Gut Microbiota to Human Nutrition Through the Production of Short-Chain Fatty Acids

The colonic microbiota influences human energy status through the metabolic activity of the taxonomically diverse prokaryotic residents that number up to 1012 cells per gram. The principal means by which this happens is probably via short-chain fatty acids (SCFAs) (mainly acetate, propionate and butyrate), which are continually produced by fermentation of dietary fibre, absorbed through the colonic epithelium, transported via the hepatic portal vein to the liver and then converted to glucose and other lipids. SCFAs may also regulate appetite via G protein-coupled receptor (GPR43) activation and signalling. Since the colonic microbiota is inaccessible for routine investigation, microbiologists have used human faeces as a surrogate for intestinal contents, animal models and various in vitro systems. These range in complexity from batch cultures of isolated gut bacteria through defined consortia grown in batch and continuous culture to multistage continuous culture models that reproduce features of the proximal and distal colons. Such systems have been used to investigate the metabolism of gut bacteria for several decades and can be adopted for studies specifically focussing on SCFA production in the context of nutrition/obesity. SCFAs generated by bacterial fermentation can be analysed using gas chromatography, or more inclusive data can be obtained via metabonomics/metabolomics. Whilst culture and FISH provide a useful means of bacteriological analysis, next-generation sequenc...
Source: Springer protocols feed by Microbiology - Category: Microbiology Source Type: news