Over the past 20 years he has worked to understand how the body's defense system responds to disease with the ultimate goal of developing therapies that help stimulate these systems to work more efficiently and with less reliance on vaccines and antibiotics. Over the past decade Dr. Koci's laboratory has focused on understanding how changes in the microbial diversity of the chicken gut influences gut function and overall health. His research has demonstrated that changes in gut bacterial populations are associated with changes in immune activation. His current research is focused on identifying the chemical signals allowing the gut bacteria to communicate with the immune system in the hopes of using these signals to increase immune responses during times of disease and decrease immune activity when it's not allowing that energy to be used for growth.