THE LINK BETWEEN BACTERIA AND THE BRAIN: Does your gut hold the key to your mind?

• Author: Crane, Misti
• Position: MEDICINE & HEALTH

MICHELLE Roley-Roberts and her husband Ryan know a lot more about what is living inside their guts than most. The couple recently agreed to let researchers inspect the bacteria in their intestines in hopes of better understanding the increasingly clear connection between the human mind and intestinal tract. Researchers at Ohio State University and Nationwide Children's Hospital want to answer questions about what biological differences could contribute to changes in the gut and in cellular-level communication between the gut and the brain.

"This is a really hot area in terms of behavior research, and right now we know relatively little. There's so much to learn about how the gut and the immune system and the brain interact," says Jan Kiecolt-Glaser, director of OSU's Institute for Behavioral Medicine Research at the Wexner Medical Center.

Scientists around the world are exploring the gut/brain axis in the quest for knowledge about mood disorders, such as depression; neurodegenerative diseases, including Alzheimer's; and chronic conditions, such as Crohn's disease. The work is based on communications between the enteric nervous system--a network of neurons that runs the gastrointestinal tract and sometimes is called "the second brain"--and the central nervous system. The idea is to understand better the influence of bacteria and other gut microbes on those cellular-level conversations.

Kiecolt-Glaser has built an international reputation on understanding how stress--and stress reduction--shapes human health. In recent years, as she heard more and more from her colleagues about the potential importance of the microbiome, she became fascinated with its role in this relationship.

In the current study, married couples present an opportunity to unearth important information, she notes. "We have a really nice paradigm where there's likely overlap on a variety of influences, including diet, exercise, pets, smoking, and alcohol use."

However, it is the differences between one partner and the other that might hold the most interest. "When we look at couples and compare stress levels, we might see important differences--and, when we evaluate all of the couples, it's possible we'll be able to identify some patterns."

The researchers are working with a private company to analyze fecal samples provided by couples in the study. They aim to analyze 175 couples in all. "Overall, the greater the diversity of bacteria in your gut, the better your health. We...