Preventive and therapeutic responses to digestive diseases are well-informed by a detailed understanding of how healthy states are maintained, and thus efforts to understand how gut microbes contribute to normal gut development is of significant interest to gut gastric health. While rodent-based, germ-free animal models are most commonly used, they are expensive (>$200/individual) to maintain and use, severely constraining research into finding causative links between gut bacteria and healthy or diseased host states to a few, well-funded research groups. The proposed work establishes the American cockroach (Periplaneta americana) as low-cost (<$1/individual) germ-free model system for conducting hypothesis-driven investigations into microbial community-host interactions at the gut interface. Germ-free P. americana is a useful complementary experimental platform because it shares many of the same gut bacteria found in mammals, many of whom are cultivable, and exhibits many of the same digestive and developmental abnormalities observed in germ-free rodents. The proposed work will reintroduce endemic gut bacteria via fecal transplants and artificial assemblages of cultivated bacteria to identify species that elicit normal development and growth. Future work will exploit P. americana's inherent omnivory to examine how human diets impact gut bacterial dynamics and subsequent host gastric health and development. Furthermore, high-achieving undergraduates from Howard University will be partnered with Ohio State University postdocs and graduate students to participate in proposed activities as summer research assistants and the PI will give contributed talks at historically black universities and Hispanic serving institutions to actively promote academic research careers and recruit high-achieving undergraduates for the Ohio State University summer research opportunities program.
The gut epithelium is among the few sites in which host, microbes and the environment converge with significant evolutionary and ecological consequences. Prevention and therapeutic responses to digestive diseases are well-informed by a detailed understanding of how normal or healthy states emerge and are maintained, and thus efforts to understand how gut microbes contribute to normal gut development is also of significant interest. The contributions of bacterial species to gut health can be challenging because gut communities are comprised of many species with overlapping functional abilities. Germ-free rodent models are often used because they can be inoculated with desired bacteria and then host conditions can be assessed. Unfortunately, germ-free rodents are expensive to maintain and use (>$200/individual) and this limits research into finding causative links between gut bacteria and healthy or diseased host states. The proposed work seeks to establish the utility of the American cockroach (Periplaneta americana) as an experimental platform for detailing microbial community-host interactions at the gut interface and to provide low-cost (<$1/roach), alternative tools for hypothesis-testing and robust preliminary data collection. Germ-free P. americana (GF-PA) can be reared without antibiotics and substantial preliminary data indicates that many of the gut structural and cellular abnormalities associated with germ-free rodents are observed. The proposed work will build on and use this new experimental microbiome research tool kit to 1) identify gut symbionts critical for gut structural and digestive development and 2) detect host gene products differentially expressed in gut tissues in the presence of gut symbionts.