Comparative Study of the Impact of Selenomethionine Content in Selenium-Enriched Yeast on Gut Microbiota

• 1、Biotechnology School, Jiangnan University

Abstract：This study utilized Saccharomyces cerevisiae (brewer\'s yeast) as the research subject, employing an in vitro Biomimetic Gastrointestinal Reactor (BGR) to simulate digestion and assess the impact of selenium-enriched yeast with varying concentrations of selenomethionine on the gut microbiota of healthy individuals. The experimental design included a control group (OR) with regular yeast (selenium-free) as a negative control, selenium-enriched yeast (SE) with approximately 30% of total selenium as selenomethionine, a mutated high-selenomethionine selenium-enriched yeast (MU) with about 60% of total selenium as selenomethionine, and a commercially produced selenium-enriched yeast tablet (MA) with approximately 3% selenomethionine content. The total selenium addition in all samples was controlled at 250 μg based on the recommended selenium intake. After 48 hours of fermentation, the concentrations of acetic acid, propionic acid, and SCFAs in MU were 16.37±0.174 mmol/L, 13.02±0.215 mmol/L, and 35.0±0.385 mmol/L, respectively, showing significant differences (P<0.05) compared to OR and MA. Compared to OR, the increases were 30.16%, 36.94%, and 22.62% respectively; compared to MA, the increases were 99.63%, 56.12%, and 89.84%, respectively. Additionally, 16s rRNA sequencing results indicated that MU significantly increased the proportion of Bacteroidetes, suggesting that high-selenomethionine yeast is most effective in benefiting gut microbiota. These results support the theory that high-selenomethionine selenium-enriched yeast is more beneficial to human health than conventional selenium-enriched yeast, offering new insights for the development of selenium-enriched yeast products.

Keywords： Selenomethionine Selenium-enriched yeast Short-chain fatty acids Branched-chain fatty acids