The vast majority of animals are populated by diverse communities of symbiotic microbes. Indeed, most of the cells and unique genes associated with animals’ bodies are of microbial origin and animals have potential access to the products of their microbes’ genes. Certainly some symbiotic microbes are pathogenic, but many are beneficial to their hosts. For example, symbiotic microbes are critical contributors to animal nutrition and immune health, and they can serve as important catalysts for the effective development and functioning of animal tissues. As a consequence of these realizations, many biologists are beginning to view animals and their symbiotic microbes as emergent individuals, that is, as holobionts rather than as autonomous entities. The Theis Lab takes a hologenomic approach to investigating pathogenic and beneficial host-microbe interactions within the realms of medicine and behavior.
Identifying and managing microbial etiologies of pregnancy complications
Preterm birth is the leading cause of neonatal morbidity and mortality. Worldwide, 15 million premature neonates are born annually, and urban environments in the United States, including Detroit, Cleveland, St. Louis, Baltimore, New Orleans, and Atlanta, have among the highest premature birth rates. Intra-amniotic infection is the only etiology of preterm birth for which definitive causation has been established. Nevertheless, many of these infections are subclinical and we lack efficacious predictive microbial biomarkers of preterm birth risk. A principal focus of the Theis Lab is studying the microbial ecology of human reproduction to identify and ultimately manage polymicrobial causes of preterm birth.
Elucidating how the microbiome shapes animal behavior, and vice versa
Behavior is a primary means animals have for mediating their circumstances within the dynamic physical and social environments they inhabit. Therefore, behavior can be a primary target of natural and sexual selection. It is becoming increasingly clear that symbiotic microbes can substantially contribute to animals’ behavioral phenotypes. For example, they can protect their hosts from predators, increase their foraging efficiencies and reproductive outputs, and serve as the integrated machinery behind their chemical communication systems. The Theis Lab uses a comparative, multi-omics approach to elucidate and evaluate the functional and developmental ramifications of animals’ relationships with odor-producing symbiotic microbes. The Lab also investigates how animal social behavior, at individual and landscape levels, influences the structure and function of microbiomes. This research can provide natural animal model systems for addressing critical inquiries in human disease ecology.