Researchers are beginning to uncover how the gut microbiome influences other parts of the body, including the brain, writes Clio Korn, a graduate student at the University of Oxford, at the Conversation.
The microbiome, he notes, has an early developed link with the immune system, and when a member of the microbiome that's usually there in low numbers becomes more abundant, that can set off an immune response with a range of effects. Elevated immune-related molecules, Korn says, have been linked to conditions like depression.
Additionally, other research has found that germ-free mice are less anxious than normal mice. But the timing of exposure was also important: germ-free mice exposed at three weeks of age to microbiome bacteria later acted like normal mice, while germ-free mice exposed to microbiome bacteria at 10 weeks were less anxious.
"Like the data on microbiome-immune interactions, these findings highlight the critical role gut bacteria play early in life," Korn says.