EAGER: Integrating host-associated microbes into trait-based community ecology frameworks

Northwestern University, Evanston IL

Investigators

Abstract

Knowledge of how communities of animals respond to environmental change is important for understanding patterns of biodiversity. Identifying the traits that allow a species to occupy a given environment also allows us to predict if that species will be able to persist in the face of environmental perturbation. Research over the past two decades has shown that microbes living in the gastrointestinal tracts of mammals, known as the gut microbiome, can shape host metabolism, immune function, and behavior. The composition and function of the gut microbiome also varies with host environmental factors, such as diet. Because of these interactions, the gut microbiome could be considered a host trait that responds to environmental shifts and helps determine whether host populations can persist. Nevertheless, the gut microbiome has generally not been integrated into models of host ecology. This project aims to determine the extent to which gut microbiomes influence host population dynamics and can therefore be considered a host trait that contributes to the improvement of models of host ecology. The study focuses on two populations of wild, black and gold howler monkeys (Alouatta caraya) in Argentina. Here, the climate is subtropical, with marked seasonal changes in temperature and plant community structure, which puts A. caraya at high risk for nutritional stress. Additionally, one of the two study populations experiences stronger seasonal climate shifts than the other. The research team will collect data describing climate and plant community structure as well as A. caraya diet for five groups of A. caraya in each population during three seasons. Fecal samples for describing the microbiome and its function, and urine for describing A. caraya energy balance and inflammation status, will also be collected along with demographic data. These data will be integrated to determine how the gut microbiome shifts in response to environmental variation, to identify physiological consequences for A. caraya, and to link these processes to A. caraya population dynamics. The results will be a critical first step toward integrating the gut microbiome into trait-based host ecological frameworks. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.