It is well established that changes in the composition of animal gut microbiota are correlated with health and fitness. In many animals, microbial partners contribute to host health by producing nutrients that are in short supply in the host diet. Very commonly, net nutrient production by the microbes is dictated by metabolic competition and cooperation among multiple bacterial taxa and strongly influenced by the metabolites derived from the animal host, but the mechanistic details of the multi-way metabolic interactions are poorly understood. 

To investigate the processes shaping animal-microbe metabolic interactions and to derive estimates of the composition and amount of nutrients exchanged between animal and microbe, the Ankrah Lab reconstructed genome-scale metabolic models of the bacterial community in the Drosophila gut. They hypothesized that the composition of gut microbiota influences host health by modifying the nutritional inputs available to the host through the synthesis and consumption of host- and microbial-derived nutrients. Their simulations reveal that, among gut microbes, competitive interactions dominate and the quality and quantity of nutrients available to the host is influenced by the composition of gut microbiota, which synthesize and consume host and microbe derived nutrients. 

Their studies elucidate the metabolic basis of animal-microbe interactions and provide the methodology to select the optimal microbial consortia for personalized microbial therapies in treating diseases associated with microbial dysbiosis.