A study on the influence of fermented vegetable yeast on the microbiome of the human gut flora shows that the intake of vegetable yeast resulted, among other effects, in a visible change in the bacterial composition of the gut in the women tested (1) and the homeostasis of the intestinal microbiome was supported (3). 26 women with a BMI of 30 to 35 took liquid herbal yeast daily for three weeks. At the beginning and end of the study, they were examined by physicians and their blood and stool samples were also analysed (sequencing of 68 species of bacteria). In summary, the following results were observed: Herbal yeast affects the composition of the gut microbiome, appears to influence a microbial shift toward homeostasis, has a positive effect on the ratio of firmicutes to bacteroidetes (F/B ratio), appears to promote the growth of butyrate-producing bacteria in young obese women and seems to lower blood pressure in both metabolically unhealthy (MUO) and metabolically healthy
individuals (MHO) (2).

(1) P. Joller, Sophie Cabaset, Susanne Maurer., “Influence of a food supplement on the gut microbiome in healthy overweight women”, Functional Food in Health and Disease, 28.10.2020: 10(10):428-438. (2) Helen I. Joller-Jemelka, Peter Joller, Sophie Cabaset, Nahrungsergänzung bei übergewichtigen Frauen und Auswirkungen auf das Mikrobiom, Schweizer Zeitschrift für Ernährungsmedizin 1|2021. (3) Peter Joller, Sophie Cabaset., Towards homeostasis: Correlations in the Gut Microbiome of Young Overweight Females following a Yeast Nutritional Supplement, Archives of Clinical and Biomedical Research, Okt. 2021.