Research Question Three: How do gut microbiota alter host metabolism and the aging process?

We are interested in understanding how the gut microbiome impacts host metabolism and aging. Using C. elegans as our primary model system, we use an interdisciplinary approach to investigate how microbially derived metabolites impact host nutrient sensing, metabolic, and homeostatic pathways. Our current studies are focused on understanding how probiotic microbes module host metabolism.

Kombucha Tea (KT), a fermented tea with roots in traditional Chinese medicine, has surged in worldwide popularity. KT contains a symbiotic culture of yeast and bacterial species, many of which are considered human probiotics. Its popularity is in part due to the many purported health benefits surrounding KT including improved digestive health, weight loss and increased longevity, however none of these health benefits have been rigorously studied in a laboratory setting and the molecular basis of KT-associated health benefits have yet to be thoroughly explored in any animal model. We have established a standardized method to maintain C. elegans on a diet exclusively consisting of Kombucha-associated microbes (KTM) that is consistent with the microbial community found in the fermenting culture. Remarkably, animals consuming a KTM exclusive diet display strikingly reduced lipid level and have an established gut microbiome yet develop and reproduce similarly to E. coli-fed animals.

In addition to these physiological phenotypes, we found that KTM consumption triggers widespread transcriptional changes within core metabolic pathways including those that govern lipid storage and lipolysis. Based on our findings, we propose that KTM-fed animals are exhibiting a fasting-like metabolic state, even in the presence of sufficient nutrient availability, possibly through induction of nutrient sensing pathways that regulate the expression of core genetic pathways associated with lipid metabolism. As a part of this project, we have had the opportunity to work with several core facilities at UNC and employ various physiological, cell biological, biochemical, and genomic techniques. Elucidating the host metabolic response to KT consumption will provide unprecedented insight into how this popular fermented beverage may impact human health and inform its use in complementary healthcare plans.