A study by the University of Utah demonstrates that an imbalance in the gut bacteria is caused if a protein component, called MyD88, is missing from the immune system. The study used mice models to test their immune system hypothesis and the results revealed that it is the immune system that encourages growth of a healthy community of beneficial bacteria vital for optimal digestive health.
“Our work highlights that the immune system shapes the composition of bacterial communities in the intestine,” said senior author June Round, Ph.D., assistant professor of pathology at the University of Utah School of Medicine. “This interaction is important because it’s becoming more and more clear that resident microbes are very important for our health.”
The MyD88-controlled pathway is involved in inflammatory bowel disease (IBD), and Chrohn’s disease characterized by an imbalance among the thousands of species of “good” bacteria that inhabit the gut.
Loss of MyD88 disturbs the microbial community because it disrupts production of IgA.IgA is an antibody that regulates which types of bacteria, and how many, are allowed to inhabit the gut and which gut bacteria can bind to IgA. Without MyD88, IgA cannot bind to beneficial bacteria.
A balanced microbial community does not only promote digestive health, but that it also shapes the host’s immune system.
“There is a conversation between our immune system and our resident bacteria,” said Round. “The microbes can send signals that tell our immune system how to develop and in turn our immune system can shape what types of microbes live on our body.”
MyD88 Signaling in T Cells Directs IgA-Mediated Control of the Microbiota to Promote Health. Jason L. Kubinak, Charisse Petersen, W. Zac Stephens, Ray Soto, Erin Bake, Ryan M. O’Connell and June L. Round. Cell Host and Microbe, Jan. 22, 2015