Past research has shown that the microbes living in your gut can dictate how body fat is stored, hormone response and glucose levels in the blood, which can ultimate set the stage for obesity and diabetes. Now new research suggests that the colonies of bacteria in our intestine play an important role in your body's response to the flu vaccine.
In the study, Emory University immunologist Bali Pulendran, PhD, and colleagues followed up on a unexpected finding in a 2011 paper: the gene that codes for a protein called toll-like receptor 5 (TLR5) was associated with strong vaccine response. Science News reports that in the latest experiment:
[Researchers] gave the flu vaccine to three different groups: mice genetically engineered to lack the gene for TLR5, germ-free mice with no microorganisms in their bodies, and mice that had spent 4 weeks drinking water laced with antibiotics to obliterate most of their microbiome.
Seven days after vaccination, all three groups showed significantly reduced concentrations of vaccine-specific antibodies in their blood—up to an eightfold reduction compared with vaccinated control mice, the group reports online ... in Immunity. The reduction was less marked by day 28, as blood antibody levels appeared to rebound. But when the researchers observed the mice lacking Tlr5 on the 85th day after vaccination, their antibodies seemed to have dipped again, suggesting that without this bacterial signaling, the effects of the flu vaccine wane more quickly.
Previously: The earlier the better: Study makes vaccination recommendations for next flu pandemic, Working to create a universal flu vaccine and Tiny hitchhikers, big health impact: Studying the microbiome to learn about disease
Photo by Queen's University