Development of a bio-functional fermented soy beverage supplemented with microbial exopolysaccharides and its effect on the human gut microbiome .

The gut microbiome plays a key role in modulating human health and well-being. Exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) are emerging as novel polymers that could exert a prebiotic effect modification of this microbiome. Thus, incorporation of EPS to enhance food functionality is of interest. This study investigates the impact of a fermented soy beverage, supplemented with EPS produced by DSA_O or DSA_F, on the faecal microbiota as assessed using an model of the human distal colon. The soy beverage (SM) was prepared by fermentation with GB3 followed by supplementation with EPS_O (SMO) or EPS_F (SMF). Faecal samples from healthy donors were inoculated into a faecal fermentation medium with SM, SMO and SMF and incubated anaerobically at 37 °C for 24 h. After incubation, samples were subjected to shotgun metagenomic and short-chain fatty acid (SCFA) analysis. SMO and SMF were more effective than SM at enhancing the alpha diversity of the faecal microbiota after 24 h incubation. In addition, SMO promoted the growth of the health-associated species and , the latter of which is considered a next-generation probiotic. Butyrate and propionate levels were higher in faecal samples fermented with SMO and SMF than in SM. Taken together, these preliminary results indicate a potential role of EPS produced by to be used as a functional food ingredient, modulating the gut microbiome as well as increasing the levels of SCFAs.