Elucidating the Host Metabolic Response to Consumption of Kombucha-associated Microorganisms

项目总结

PROJECT SUMMARY Kombucha is a popular fermented tea that contains probiotics. This beverage has seen a surge in popularity in the United States since the turn of the century and is purported to have many health benefits. Some of these health claims have been cursorily examined, however, none have been rigorously tested and the mechanistic interactions between the microbial components of Kombucha and the host remains unexplored. I will elucidate the host metabolic response to consumption of Kombucha-associated microbes (K. microbes), thereby informing its use in complementary health approaches. The impact of individual probiotic microbes on human health is difficult to deconvolute as humans consume a complex diet, have trillions of gut microbes (including many unidentified species), and measuring host-microbe interactions is not feasible in human subjects. Therefore, animal model systems are essential to investigate the effects of consuming probiotics, including those in Kombucha, on host physiological processes. Caenorhabditis elegans is an excellent model system to explore how K. microbes modulate the host pathways that govern lipid homeostasis, because their microbiomes are easily manipulated through the food source provided and they are a well-established system to study metabolism and the aging process in vivo. I have established a standardized method to maintain C. elegans on a diet exclusively consisting of K. microbes that is consistent with the community found in the fermenting culture (confirmed through 16S rRNA sequencing). In preliminary investigations, I observed that populations of C. elegans exclusively consuming K. microbes, as compared to a control diet (E. coli, the standard laboratory food source), have altered expression of core lipid metabolism genes (e.g., beta-oxidation, fatty acid desaturation), decreased fat levels, and an increased median lifespan. Critically, the molecular mechanisms by which K. microbes alter host physiology is completely unknown. Therefore, I plan to use molecular and genetic approaches in C. elegans to systematically identify the molecular mechanisms that govern the host response to K. microbe consumption and elucidate the components of Kombucha that are necessary and sufficient to confer the observed metabolic and lifespan phenotypes. The proposed experiments will provide unprecedented insight into the mechanism by which K. microbe consumption reconfigures host metabolism.