Summary: One of the most important functions of the human gut microbiota is the production of short-chain fatty acids (SCFAs) such as acetate, propionate and butyrate, which are end products of fermentation mostly from dietary fibres. SCFAs have been shown to benefit gastrointestinal barrier integrity, protect against pathogen invasion and reduce inflammation. On average, American adults only consume up to 40% of the recommended daily intake of fibre, however a diet lacking in fibre is implicated in the etiology of a long list of diseases. To address a low intake of dietary fibre, supplements known as prebiotics which are microbially fermentable have been used. Prebiotics are a promising approach for promoting gastrointestinal health as they are able to increase SCFA production. This study is a randomised crossover trial where individuals were treated with different prebiotics in order to assess the contribution of different types of prebiotics and their SCFA production. A secondary aim included determining what microbiological factors influenced SCFA production. The authors found that prebiotics varied in their impact on SCFA production, for e.g inulin increased butyrate production but wheat dextrin decreased it. Their analysis also showed that individual identity such as baseline microbiological factors exerted a much larger effect on prebiotic response to SCFA production compared with dietary fibre for instance.The authors therefore confirmed the involvement of the microbiota in the relationship between prebiotics and SCFA production, indicating that personalised prebiotic recommendations that focus on the particular microbiota of the individual may be beneficial.
Background: Short-chain fatty acids (SCFAs) derived from gut bacteria are associated with protective roles in diseases ranging from obesity to colorectal cancers. Intake of microbially accessible dietary fibers (prebiotics) lead to varying effects on SCFA production in human studies, and gut microbial responses to nutritional interventions vary by individual. It is therefore possible that prebiotic therapies will require customizing to individuals.
Results: Here, we explored prebiotic personalization by conducting a three-way crossover study of three prebiotic treatments in healthy adults. We found that within individuals, metabolic responses were correlated across the three prebiotics. Individual identity, rather than prebiotic choice, was also the major determinant of SCFA response. Across individuals, prebiotic response was inversely related to basal fecal SCFA concentration, which, in turn, was associated with habitual fiber intake. Experimental measures of gut microbial SCFA production for each participant also negatively correlated with fiber consumption, supporting a model in which individuals’ gut microbiota are limited in their overall capacity to produce fecal SCFAs from fiber.
Conclusions: Our findings support developing personalized prebiotic regimens that focus on selecting individuals who stand to benefit, and that such individuals are likely to be deficient in fiber intake.
Article Publication Date: 29.07.22