Regular Consumption of Kombucha Alleviates Depression Symptoms and Modulates the Gut Microbiome in Mice

Objectives: Fermented food is consumed widely for its health benefits. Recent studies have shown the benefits of consuming fermented food on mental wellbeing but the underlying mechanisms remain to be explored. Methods: In this study, we investigate the impact of regular consumption of kombucha (a fermented tea beverage) on gut microbiome and behavior in a 2x2 mouse model, in which mice were fed a high fat and high sugar diet (TWD) or a regular chow diet (CTRL) with or without kombucha supplementation through drinking water for seven weeks. At the end of feeding, we assessed behavior through forced swimming, and marble burying tests, and also harvested cecum, colon and ileum digesta for bacteriome (16s rRNA) and mycobiome (ITS2) sequencing and metabolomics analysis. Results: Our results showed that the mice fed kombucha exhibited less immobility time in the forced swimming test under either CTRL or TWD diet and less marbles buried when fed kombucha under TWD diet (P< 0.05). Consumption of kombucha also modulated the gut microbiome, resulting in lower alpha diversity and significant clustering across cecum, ileum and colon in both gut bacterial and fungal communities (P< 0.05). Kombucha supplementation with the TWD was associated with high abundances of Akkermancia muciniphila, Clostridiaceae and Saccharomyces cerevisiae, while Aspergillus flavus was higher in mice fed CTRL. Kombucha also caused the changes in the gut metabolome. Conclusions: Overall, kombucha consumption modulated gut microbiome and metabolome and decreased depressive behaviors in mice under TWD and CTRL diet. These results warrant further investigation on the influences of Kombucha on the gut brain axis and its value as a potential therapeutic approach to address neurological disorders. Funding Sources: This study was funded by the Minnesota Agricultural Station and Agricultural Research Education, Extension and Technology Transfer Program at the University of Minnesota.