Yeast β-glucan reduces obesity-associated Bilophila abundance and modulates bile acid metabolism in healthy and high-fat diet mouse models

Abstract

Emerging evidence links dietary fiber with altered gut microbiota composition and bile acid signaling in maintaining metabolic health. Yeast β-glucan (Y-BG) is a dietary supplement known for its immunomodulatory effect, yet its impact on the gut microbiota and bile acid composition remains unclear. This study investigated whether dietary forms of Y-BG modulate these gut-derived signals. We performed 4-week dietary supplementation in healthy mice to evaluate effects of different fiber composition (soluble vs particulate Y-BG) and dose (0.1 vs. 2%). We found that 2% particulate Y-BG induced robust gut microbiota community shifts with elevated liver Cyp7a1 mRNA abundance and bile acid synthesis. These diet-induced responses were notably different when compared to the prebiotic inulin, and included a marked reduction in fecal Bilophila abundance which we demonstrated as translatable to obesity in population-scale American Gut and TwinsUK clinical cohorts. This prompted us to test whether 2% Y-BG maintained metabolic health in mice fed 60% HFD over 13 weeks. Y-BG consistently altered the gut microbiota composition and reduced Bilophila abundance, with trends observed in improvement of metabolic phenotype. Notably, Y-BG improved insulin sensitization and this was associated with enhanced ileal Glpr1r mRNA accumulation and reduced Bilophila abundance. Collectively, our results demonstrate that Y-BG modulates gut microbiota community composition and bile acid signaling, but the dietary regime needs to be optimized to facilitate clinical improvement in metabolic phenotype in an aggressive high-fat diet animal model.

Eugenol, A Major Component of Clove Oil, Attenuates Adiposity, and Modulates Gut Microbiota in High‐Fat Diet‐Fed Mice

“…Bilophila, belongs to phylum Desulfobacterota, is a kind of bile-tolerant microorganisms, which is associated with the development of obesity. [48,49] Nativida et al [50] found that HFD is beneficial to the growth of the Bilophila wadsworthia, and the synergy of the HFD and B. wadsworthia promoted inflammation, bile acid metabolism disorders, and intestinal barrier dysfunction, resulting in the glucose metabolism disorder and liver steatosis. Our study pointed out that EU supplementation reduced the relative abundance of Bilophila in mice fed with HFD.…”

Dynamic Changes in the Gut Microbial Community and Function during Broiler Growth

“…Bilophila was associated with obesity in mice induced by a high-fat diet ( 41 ), but it was also found to be significantly negatively correlated with broiler weight ( 42 ). As a potential beneficial bacterium, Akkermansia was more abundant in the better-fed efficacy group hens ( 43 ).…”

An important polysaccharide from fermentum

“…Among them, gallbladder bacteria are closely related to the formation of obesity, and Fermentum β-polysaccharide could significantly reduce the abundance of gallbladder bacteria. In addition to reducing obesity-related gallbladder bacteria, Fermentum β-polysaccharide also increased the abundance of liver Cyp7a1 mRNA and bile acid synthesis, effectively alleviating obesity-related diseases in obese mice ( So et al, 2021 ). According to another study, Fermentum β-polysaccharide significantly inhibited the high expression of SGLT-1, a major glucose transporter protein in the small intestinal mucosa.…”