A lot of chatter goes on inside each one of us and not all of it happens between our
ears.

Researchers at McMaster University have discovered that the “cross-talk” between
bacteria in our guts and our brains plays an important role in the development of
psychiatric illness, intestinal diseases and probably other health problems including
obesity.

“The wave of the future is full of opportunity as we think about how microbiota or
bacteria influence the brain and how the bi-directional communication of the body and
the brain influence metabolic disorders, such as obesity and diabetes,” says Jane
Foster, associate professor in the Department of Psychiatry and Behavioural
Neurosciences of the Michael G. DeGroote School of Medicine.

Foster's research shows gut bacteria influences how the brain is wired for learning
and
memory. The research paper has been published in the March issue of the science
journal Neurogastroenterology and Motility.

The study's results show that genes linked to learning and memory are altered in
germ-free mice and, in particular, they are altered in one of the key brain regions for
learning and memory – the hippocampus.

“The take-home message is that gut bacteria influences anxiety-like behavior
through
alterations in the way the brain is wired,” said Foster.

Foster's laboratory is located in the Brain-Body Institute, a joint research initiative
of
McMaster University and St. Joseph's Healthcare in Hamilton. The institute was created
to advance understanding of the relationship between the brain, nervous system and
bodily disorders.

“We have a hypothesis in my lab that the state of your immune system and your
gut
bacteria – which are in constant communication – influences your personality,” Foster
said.

She said psychiatrists, in particular, are interested in her research because of the
problems of side effects with current drug therapy.

“The idea behind this research is to see if it's possible to develop new therapies
which
could target the body, free of complications related to getting into the brain,” Foster
said. “We need novel targets that take a different approach than what is currently on
the market for psychiatric illness. Those targets could be the immune system, your
gut function…we could even use the body to screen patients to say what drugs might
work better in their brain.”