Reference Number: 209
The human gut microbiota ferments dietary nondigestible carbohydrates into short-chain fatty acids (SCFA). These microbial products are utilized by the host and propionate and butyrate in particular exert a range of health-promoting functions. Here an overview of the metabolic pathways utilized by gut microbes to produce these two SCFA from dietary carbohydrates and from amino acids resulting from protein breakdown is provided. This overview
emphasizes the important role played by crossfeeding of intermediary metabolites (in particular lactate, succinate and 1,2-propanediol) between different gut bacteria. The ecophysiology, including growth requirements and responses to environmental factors, of major propionate and butyrate producing bacteria are discussed in relation to dietary modulation of these metabolites. A detailed understanding of SCFA metabolism by the gut microbiota is necessary to underpin effective strategies to optimize SCFA supply to the host.
SIGNIFICANCE OF THIS STUDY
Butyrate and propionate are short-chain fatty acids produced by the gut microbiota. They are especially important in human health, having been linked to protection against colorectal cancer, promoting satiety and reducing cholesterol. This study suggests it may be possible to manipulate the level of production of butyrate and propionate in the body through dietary intervention.