The overall goal of this project is to determine the underlying mechanism by which subtherapeutic antibiotics promote animal growth, specifically the role that commensal GUT microbiota play in the…

Purdue University received a $449,020 Project Grant from the U.S. Department of Agriculture's National Institute of Food and Agriculture (NIFA) under the Laying Hen and Turkey Research Program (CFDA 10.245), effective September 15, 2025, through September 14, 2028. The project aims to determine the underlying mechanism by which subtherapeutic antibiotics promote animal growth, specifically investigating the role of commensal gut microbiota in this growth-promoting effect. The research will employ cecal microbiota transplantation (CMT), harvesting digesta from the cecum of turkeys and transplanting the bacteria to other young turkeys to systematically control microbiome composition. By isolating the effect of commensal microbiota in the absence of other confounding factors, this methodology will enable researchers to confirm or refute the importance of microbiota to animal growth phenotypes.

This research directly supports NIFA's priority focus on gut health and microbiome research within poultry production systems. The CMT methodology, adapted from human microbiome research practices, provides a controlled and reproducible experimental approach to isolate the microbiota's specific contribution to growth outcomes. The project's findings are expected to establish evidence-based understanding of microbial mechanisms affecting turkey production efficiency and sustainability, with potential applications to the broader laying hen and turkey industry in developing non-antibiotic growth promotion strategies.

The overall goal of this project is to determine the underlying mechanism by which subtherapeutic antibiotics promote animal growth, specifically the role that commensal GUT microbiota play in the growth-promoting effect of subtherapeutic antibiotics. We will usececal microbiota transplantation (CMT) to systematically control the composition of the microbiome. To do this we will harvest the digesta from the cecum (a portion of the intestinal tract between the large and small intestines) and give the bacteria from the digesta to other young turkeys. We will keep birds that recieve the transplant from control birds separate from bird receiving bacteria from birds FED antibiotics. Human microbiome research relies heavily on this same method. They observie contrasting phenotypes in human populations, transplanting human feces from each population to germ-free mice, and then determining if the same phenotype is observed in the mice as their fecal donors. If the expected phenotype is observed, the hypothesis is confirmed and that the microbiota plays a role in establishing the phenotype. Without this method, incorrect assumptions might be made that the microbiota plays an important role in a phenotype. This method also removes confounding factors that are common in antibiotic feeding trials. The commensal intestinal microbiota are surely not the sole cause of the animal growth phenotype, but a contributing factor among many that lead to the growth phenotypes. The key is that we will isolate the effect of the commensal microbiota via CMT to turkey poults to determine the role of the corresponding microbiota in the absence of the other factors. This project is relevant to the laying HEN and turkey research program because IT will establish a controlled and reproducible method to experimentally isolate the microbiota to either confirm or refute the initial assumption of the importance of the microbiota to animal growth phenotypes.