155 Personalized nutrition from pets to humans.

Abstract Introduction: Gut microbiota have far-reaching influence on animal physiology and health, but high inter-individual variation in microbial composition presents challenges in harnessing their full metabolic potential to improve health outcomes. Understanding how the gut microbiota responds to dietary modifications across species offers valuable insight into host-microbiota interactions and microbial community dynamics, ultimately guiding strategies to optimize microbial synthesis of health-promoting and health-deteriorating metabolites. This talk explores comparative microbial structural and functional changes of dogs vs cats to various dietary fiber sources, identifies shared and unique microbial taxa involved in health-related metabolite production, and discusses the potential for applying insights from the field of human personalized nutrition to tailored companion animal diets. Methods: In a series of crossover trials, dogs and cats were fed species-appropriate diets formulated with ten distinct fiber sources, each for a two-week period. Fecal microbiome composition via 16S rRNA gene amplicon sequencing and metabolite profiles via gas chromatography were analyzed at the conclusion of each dietary intervention. Microbiome data processing and analyses were conducted with the QIIME2 software platform. Results: Marked differences were observed in microbiome composition between species. Interestingly, diversity metrics and microbial metabolic responses, such as short-chain fatty acid concentrations, were divergent across fiber sources within and between species. Differential abundance modeling identified shared and unique microbial taxa related to fecal metabolite concentrations, offering potential targets for interventions aimed at modulating gut microbiota for companion animal health. Conclusions: These results emphasize the importance of considering species-specific gut microbiome responses to dietary fibers when formulating companion animal diets. The identification of key microbial taxa associated with health-promoting metabolites offers exciting opportunities to develop more tailored, individualized dietary strategies for improving companion animal health. Future studies will test probiotic, prebiotic, and synbiotic interventions targeting the microbes and metabolic pathways identified in these studies utilizing a personalized nutrition approach.