Purpose of review: Evidence suggests that short-chain fatty acids (SCFAs) derived from microbial metabolism in the gut play a central role in host homeostasis. The present review describes the current understanding and physiological implications of SCFAs derived from microbial metabolism of nondigestible carbohydrates.
Recent findings: Recent studies indicate a role for SCFAs, in particular propionate and butyrate, in metabolic and inflammatory disorders such as obesity, diabetes and inflammatory bowel diseases, through the activation of specific G-protein-coupled receptors and modification of transcription factors. Established prebiotics, such as fructooligosaccharides and galactooligosaccharides, which support the growth of Bifidobacteria, mainly mediate acetate production. Thus, recent identification of prebiotics which are able to stimulate the production of propionate and butyrate by benign saccharolytic populations in the colon is of interest.
Summary: Manipulation of saccharolytic fermentation by prebiotic substrates is beginning to provide information on structure–function relationships relating to the production of SCFAs, which have multiple roles in host homeostasis.