There is extensive evidence from laboratory animal studies and human clinical trials that dietary flavonoids derived from fruits and vegetables protect against inflammation in the intestinal tract and also induce health benefits in distal organs. The genesis of the health-promoting effects of individual flavonoids and their mixtures has been linked not only to their direct effects but also to their metabolism by intestinal microbes. The aryl hydrocarbon receptor (AhR) and its ligands also play a protective anti-inflammatory role in the intestine. We hypothesized in the parent R01 that the anti-inflammatory activities of flavonoids are due, in part, to their structure-dependent activity as AhR ligands and their interactions with the microbiome. We proposed in the parent R01 to characterize the structure-dependent effects of flavonoids on AhR signaling, identify novel microbial metabolites of flavonoids and associate specific flavonoid metabolites with their source microorganisms, and examine the AhR-mediated effects of flavonoids and their metabolites in organoid 3D cultures. Based on exciting preliminary data showing that the murine fecal microbial community varies with gender as well as the expression of the AhR, we propose in this supplement application to investigate the effects of gender- and AhR-dependent variation in the microbiota composition on the production of flavonoid-derived metabolites. While the original study proposed using both male and female metabolomic and DNA sequencing analyses to identify AhR-active flavonoid-derived metabolites, the study design was not adequately powered to elucidate gender effects. Thus, the supplement application addresses the ?Increase Sample Size? research approach listed the RFA. Supplement Aim 1 will characterize gender and genotype-dependent variations in the ability of the murine intestinal microbiota to produce novel flavonoid derivatives. In Supplement Aim 2, we will investigate using 3D organoid in vitro models the role of the AhR in mediating the gender-dependent effects of flavonoid derivatives on intestinal resilience.
The proposed experiments will identify novel dietary flavonoid-derived microbial metabolites that are produced in a gender-specific manner in mice and elucidate their effects on Arylhydrocarbon (AhR) receptor mediated signaling and resilience in the gastrointestinal tract. !