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.

"By manipulating the bugs in the gut, she can change the composition of the fat, the kinds of fatty acids that are under the skin and in the liver and brain," he says. "That has implications for the food industry."

Variety linked with health

For older humans, having a diverse community of bugs in the gut could be associated with better health, according to a study carried out by Paul O'Toole, Shanahan and other colleagues at the APC.

"We showed that the diversity of food was correlated with the diversity of microbiota, and that in turn correlated with health, frailty, independence and inflammation," he says.

"So for elderly people it's not enough to guarantee that they get enough calories and vitamins, you have to have diversity too."

That opens up the opportunity for functional foods, he notes. "These foods could be about getting the diversity of nutrients into the person in a palatable way and ultimately feeding the gut microbes in a way that translates into improved health and less inflammation."

Shanahan believes that emerging food-based treatments now offer an opportunity for Ireland.

"The pharmaceutical industry has made great advances but there is a change - there is a decline in the blockbuster and we are not seeing the pipeline in the pharma industry any more," he says.

"One reason is that a number of the conditions that ail us may not be suitable to a drug. Foods may have a increasing role, particularly the whole area of functional foods that provide a benefit beyond their nutritional capacity.

Economic gains

"That means the food sector in Ireland has loads of opportunities to be not just an old reliable but to really help us - we are in an ideal position to exploit all the opportunities that food can bring us."

The new SFI-funded APC-Ireland centre will include UCC, Teagasc, Mercy and Cork University Hospitals and Cork Institute of Technology as well as around 13 industry partners.

"The new funding from SFI is an affirmation of what APC scientists achieved during the past decade," says Shanahan.

"But more importantly, it enables us to bring the research to a new level and to translate advances into economic gains for Ireland in terms of jobs, intellectual property and assistance to our indigenous food industry."