Gut feeling about better health

The emerging science about the bugs in our digestive systems could translate into new ways of improving health

You could say that Fergus Shanahan had a good week. Last Monday we heard the Alimentary Pharmabiotic Centre, which Shanahan directs, is to get funding for the next six years as part of a Science Foundation Ireland "hub" to look at research on food and the bugs that live in our gut.

A few days later he was on the other side of the Atlantic picking up a major award bestowed by the Canadian Association of Gastroenterology, for his work on gut bacteria.

Prof Shanahan, a consultant gastroenterologist and professor of medicine at University College Cork, is fascinated by those trillions of bacterial cells that call us home.

"Well over 90 per cent of the cells in the body are microbial and there are up to 100 times more microbial genes in the body than human genes," he says.

Why does it matter what is living in and on us? Because the emerging science about our "microbiota" holds the potential to translate into new ways of improving health, explains Shanahan, and he believes Ireland is well placed to catch that wave.

Molecular methods

Studies are now tumbling out that link the microbiota, and particularly the bugs that live in the gut, with a range of conditions, including cardiovascular disease, bowel inflammation and even some types of cancer, he explains.

"The bacteria don't necessarily cause disease, but they are involved in the process. So some of us have bugs that are protecting us and others may have bacteria that are contributing to our risk."

In recent years researchers have been able to get a better handle on what bacteria are in the gut by using molecular methods to characterise them. The increased speed and falling costs of the analysis are major drivers of the progress, explains Shanahan. "We can now do in minutes what used to take months."

And what the research turns up is sometimes surprising: Shanahan describes how research by Prof John Cryan at UCC suggests a link between bugs in the gut and levels of chemical messengers in the brain - in mice at least.

"There is emerging evidence that diet, through influencing the microbiota, does influence mood and behaviour," says Shanahan. "We see it in animals but it is tougher to study in humans."

Altering the gut bugs in animals can also affect the quality of the fat they store, he adds, referring to work carried out by Dr Catherine Stanton in Teagasc, Moorepark.