Enhancement of carbohydrate metabolism by probiotic and prebiotic intake promotes short-chain fatty acid production in the gut microbiome: a randomized, double-blind, placebo-controlled crossover trial

Short-chain fatty acids (SCFAs) are thought to be a key factor in the health benefits of prebiotics and probiotics. This study investigated the effect of Bifidobacterium animalis subsp. lactis GCL2505 and inulin (BL + IN) on fecal SCFAs and gut microbial composition and function. A placebo-controlled, randomized, double-blind, crossover study was conducted with 120 participants. Two weeks of BL + IN intake significantly increased acetate, propionate, and butyrate concentrations and Bifidobacterium abundance compared to placebo. Functional analysis of the gut metagenome showed enrichment of genes associated with carbohydrate and amino acid metabolism, suggesting an enhanced capacity for SCFA production. A responder was defined as a participant with increased fecal SCFAs after BL + IN consumption. Responder metagenomes exhibited greater enrichment of genes involved in SCFA production and carbohydrate metabolism. In conclusion, short-term BL + IN ingestion may benefit healthy adults by increasing fecal SCFAs through influencing the composition and functional activation of SCFA-associated pathways in the gut microbiome.