Comparative Analysis of Fucosyllactose-Induced Changes in Adult Gut Microbiota and Short-Chain Fatty Acid Production Using the Simulator of Human Intestinal Microbial Ecosystem Model.

As the third most abundant solid component of human milk, human milk oligosaccharides (HMOs) exert well-known effects on the infant gastrointestinal tract, including promoting Bifidobacterium growth and preventing pathogen infection. However, the effects of HMOs on the adult gut microbiome remain unknown. In this study, we examined the effects of 2'-fucosyllactose (2'-FL) and 3-fucosyllactose (3-FL), the most abundant HMOs, on the adult gut microbiome using the Simulator of Human Intestinal Microbial Ecosystem (SHIME^Ⓡ), which can simulate human gastrointestinal conditions. Healthy adult feces were subjected to SHIME^Ⓡ and incubated with either 2'-FL or 3-FL. The changes in the short-chain fatty acid concentration in feces and the gut microbiota composition were investigated using high-performance liquid chromatography and 16S rRNA gene sequencing, respectively. The addition of 2'-FL or 3-FL altered the microbial composition and increased acetate, propionate, and butyrate concentrations in the adult SHIME^Ⓡ culture. Remarkably, a difference was observed in the timing of butyrate production because of the addition of 2'-FL and 3-FL. The present findings can help clarify how FLs affect the gut microbiome of Japanese adults and support the development of targeted products.