Focus starts to shift to fungal critters in your gut

THE connections among different parts of the human body are full of surprises, but here’s one you might not have considered: could a thing that causes dandruff on your head also be contributing to your digestive problems?

That’s one mystery scientists are trying to unravel with research into the fungi that live in your gut.

While bacteria have been a scientific focus for more than a decade, the fungal critters there are starting to get more attention.

Already, these studies have uncovered striking connections between fungi and several chronic illnesses, including Crohn’s disease and ulcerative colitis.

“It’s a very exciting area of science to be involved in,” said

David Underhill, research chair for inflammatory bowel diseases at Cedars-Sinai Medical Center in Los Angeles. His team is investigating the links between fungi in the gut and inflammatory bowel diseases.

Earlier work, Underhill said, focused on bacteria, because there are far more of them in our bodies, compared with any other type of organism. Fungi number in the hundreds of thousands, with just a handful of different species. For years, fungi were given scientific short shrift.

Now researchers have turned their attention to fungi, what some call the “mycobiome”. It has quickly become evident that these organisms play a distinct role in our health.

One fungus at the centre of Underhill’s research is Malassezia.

Although its name may be unfamiliar, you’re coated in it. The fungus colonises the skin shortly after birth. For some people,

Malassezia on the scalp creates irritation that causes dandruff.

It also turns up inside our bodies, along the digestive tract.

Underhill and his colleagues published a study in the journal Cell Host & Microbe that suggested a link between Malassezia in the gut and Crohn’s disease. Individuals with Crohn’s had high concentrations of Malassezia on their intestine walls, while healthy patients had almost none. The researchers then demonstrated that adding this type of fungi to the gut – at least, in mice – was enough to exacerbate the inflammation seen in Crohn’s.

This work built on a growing body of evidence linking fungi to inflammatory bowel diseases. As early as 2010, researchers reported that antifungal medications helped patients with bowel disease go into remission. By 2012, Malassezia in particular was found to be associated with these kinds of disease.

The link between Crohn’s and

Malassezia raises the possibility – not yet proven – that something as simple as a generic antifungal drug could provide relief: wipe out the fungus, wipe out the inflammation.

Underhill and his colleagues are just one of many teams eager to test the idea in clinical trials.

Although we’re far from declaring antifungals a panacea for gut ailments, scientists are optimistic that further research into the mycobiome will help solve the mysteries surrounding these inflammatory diseases, and offer new treatments. |

THE potential to improve the lives of hundreds of thousands of patients – and to uncover complex processes we never realised were at the root of these diseases – has made the fungal field tantalising to medical researchers.