Study Finds That Foodborne Fungus May Interrupt Gut Healing In Crohn’s Disease


As described by the Crohn’s & Colitis Foundation, Crohn’s Disease is explained as “an inflammatory bowel disease that causes chronic inflammation of the gastrointestinal tract.” This basically means that there is constant inflammation of the gut, occuring mostly in the small intestine. Because it is a chronic illness, it means that it has no cure, and even the causes of Crohn’s disease are not yet completely understood.

According to the National Institute of Diabetes and Digestive and Kidney Diseases, they estimate that “more than half a million people in the United States have Crohn’s disease.” But what’s stressing is that, although experts don’t know why, this illness has also become more common in the United States than in any other part of the world.

For patients suffering from Crohn’s Disease, even minor injuries within the gut do not heal properly, which end up causing abdominal pain, diarrhea, bleeding and other bothersome symptoms.

Researchers have recently found that a common yet normally harmless foodborne fungus has settled in the intestinal wounds of a mouse model of the disease, as well as in humans.

Harmless fungus is often found in common foods such as sausages, wine, beer, cheese and an array of other fermented foods. But a new study has found that this normally nontoxic fungus could actually prevent the healing of intestinal ulcers in patient’s suffering from Crohn’s Disease.

But researchers also share that the evidence is still quite new, which means that they cannot recommend any dietary changes for patients just yet. Meanwhile, antibiotic treatments used on patients may also disturb the good and friendly gut bacteria, hence allowing the fungi to survive within the gut.

Scientists continue to study and develop medications like oral antifungals, in order to improve the intestinal wound healing in the gut, which will aid in reducing symptoms as a result.

This research study, which has been published in the journal Science, was led by scientists from Washington University School of Medicine in St. Louis, MO, alongside the Cleveland Clinic in OH.


How It Exploits Weakness in Patients with Crohn’s Disease

The fungus is actually a kind of yeast otherwise known as Debaryomyces hansenii (D. hansenii) found more often in foods such as beer, wine, sausages and other processed meats, cheeses and fermented foods.

While this type of fungus is usually harmless to people that are considered to be healthy, it can take advantage of the weakness in the intestinal lining of individuals that have been diagnosed with Crohn’s disease by penetrating the tissue.

First author and instructor in Pathology and Immunology at the School of Medicine, Dr. Umang Jain, shares, “If you look at stool samples from healthy people, this fungus is highly abundant. It goes into your body and comes out again. But people with Crohn’s disease have a defect in the intestinal barrier that enables the fungus to get into the tissue and survive there. And then it makes itself a home in ulcers and sites of inflammation and prevents those areas from healing.”

But because the study is still so new, Dr. Jain points out that patients don’t need to refrain from consuming processed meats or cheese.

In order to investigate further, Dr. Jain plans to carry out a bigger study to find out if one’s diet truly determines just how much fungus remains within the intestines.

He adds, “If so, it is possible dietary modulation could lower levels of the fungus and thereby reduce symptoms of Crohn’s disease.”


The Sites of Injury

Dr. Jain and his team studied mice models with injured intestines in order to figure out what hinders any wound healing in the gut of those suffering from Crohn’s disease.

The research team found that when they sequenced microbial DNA in the animals’ gut, it showed that there was an abundance of D. hansenii in the areas where there was injury.

In order to find out whether this was the same for humans, the team also compared biopsies from the intestines of 10 people that were considered healthy with the intestines of seven other patients diagnosed with Crohn’s disease. The gut tissue of those seven people with Crohn’s all had fungus, yet the ten healthy ones only harbored it.

After which, the study team compared tissue samples from inflamed and uninflamed areas within the guts of ten patients with Crohn’s disease. What this revealed was that the fungus only remained at the sites of injury and inflammation, rather than throughout the entire gut.

Again, these results prove to be strong evidence that the fungus remains in the inflamed areas, but it is still not sure whether it is actually responsible for hindering any wound healing either.

In order to find out whether there actually is a causal link, the research group decided to grow D. hansenii cultures from the guts of injured mice, as well as individuals in the lab. Researchers then introduced the fungi ‘into the injured intestines of antibiotic-treated, microbe-free mice, the fungi colonized their wounds and slowed down healing.’

By treating the mice with amphotericin B, which is an antifungal drug that eliminates fungus, it also quickened the process of healing.


An Unintended Consequence

Meanwhile, in a comment article also published in the Science journal, Tyson Chiaro and Dr. June L. Round from the University of Utah School of Medicine in Salt Lake City also share that friendly or “good” bacteria is actually known to help promote the healing of gut lining in patients with Crohn’s. But since doctors normally treat the disease with antibiotics, it can actually slow down or lessen the benefits of this bacterial species.

The authors also share that “this may have the unintended consequence of exacerbating inflammation by allowing fungi to colonize parts of the gut lining formerly dominated by bacteria.”

Although the new study has discovered that the antifungal amphotericin B can help heal ulcers in patients suffering from Crohn’s disease, it isn’t normally used in humans since it has to be injected in the bloodstream and not just ingested. But Dr. Jain and his colleagues are working with chemists to create an oral antifungal for people to use.

In the meantime, they are hoping that a new treatment and maybe dietary changes could actually improve the symptoms of Crohn’s disease by working to speed up any wound healing. Notably, it’s still not a cure since inflammation is still going to be present.

Dr. Jain reiterates, “But in people with Crohn’s [disease], impaired wound healing causes a lot of suffering. If we can show that depleting this fungus in people’s bodies – either by dietary changes or with antifungal medications – could improve wound healing, then it may affect the quality of life in ways that we have not been able to do with more traditional approaches.”