The combination of yeast cell wall and Heyndrickxia coagulans SANK70258 maximized butyrate production in an in vitro gut model

Abstract In recent years, increasing attention has been paid to synbiotic formulations comprising prebiotics and probiotics. Yeast cell walls (YCW) constitute a well-known industrial material with partial prebiotic effects. Its potential as a synbiotic agent that can add value to functional food has not been evaluated. In this exploratory research, we aimed to test if the probiotic bacterium Heyndrickxia coagulans SANK70258 (COA), when combined with YCW, could modulate the gut microbial community and increase the concentration of short-chain fatty acids (SCFAs), particularly butyric acid. To this purpose, we performed an in vitro fermentation assay using fecal samples from healthy participants. Non-supplemented control samples and YCW, COA, and SYN (COA + YCW) treatments were included. SCFAs production and microbial composition were analyzed at 48 h. Butyrate concentration was highest in the SYN treatment, possibly in association with the availability of fermentable YCW-derived carbon sources. YCW-derived substrates might support the proliferation of Bacteroides , which may in turn be associated with COA-mediated promotion of butyrate-producing bacteria such as Faecalibacterium . COA might additionally suppress some Bacteroides -competitive taxa, further facilitating Bacteroides proliferation. Thus, combining YCW with COA in a SYN formulation could improve butyrate production and promote a healthier gut environment.