New Study Indicates Role of Fungi in Crohn’s Disease
Crohn’s disease belongs to a group of conditions known as Inflammatory Bowel Diseases (IBD). Crohn’s disease is a chronic inflammatory condition of the gastrointestinal tract. Crohn’s disease can affect any part of the GI tract. While symptoms vary from patient to patient, the common symptoms of Crohn’s disease include persistent diarrhea, rectal bleeding, urgent need to move bowels, abdominal cramps and pain, constipation and bowel obstruction.
An international team from the Case Western Reserve University School of Medicine has now identified a fungus as a key factor in the development of Crohn’s disease, as well as linked a new bacterium to the previous bacteria associated with the illness. Recently published in mBio, the findings provide promising hope for new treatments and hopefully, an ultimate cure. According to Mahmoud A Ghannoum, PhD, professor and director of the Center for Medical Mycology at Case Western Reserve and University Hospitals Cleveland Medical Center, researchers have already determined that bacteria are one of the major factors in the development of Crohn’s disease.
Noting that patients with Crohn’s exhibit abnormal immune responses to these bacteria – which are resident in the intestines of all people – Ghannoum points out that most research is focused in that area. However, fungi are also present in everyone’s intestines. Fungi are eukaryotes: organism whose cells contain a nucleus; they are closer to humans than bacteria, which are prokaryotes: single-celled forms of life with no nucleus. The fungal community in the human body is known as the mycobiome, while the bacteria are called the bacteriome.
The researchers studied the mycobiome and bacteriome of patients with Crohn’s disease and their Crohn’s-free first degree relatives in nine families in northern France and Belgium, and in Crohn’s-free individuals from four families living in the same geographic area. They discovered strong fungal-bacterial interactions in those with Crohn’s disease. Two bacteria and one fungus were found in higher concentrations in sick patients in relation to their healthy family members, suggesting that the bacteria and fungus interact in the intestines. The microorganisms work together to produce a biofilm — a thin, slimy layer that adheres to, among other sites, a portion of the intestines — which can prompt inflammation that results in the symptoms of Crohn’s disease. Additionally, the researchers found that the presence of beneficial bacteria was significantly lower in the Crohn’s patients, corroborating previous research findings.
Although fungi have been linked to the disease in mice, this is the first time the relationship has been observed in humans.
Final comments from Ghannoum temper enthusiasm, however. “Among hundreds of bacterial and fungal species inhabiting the intestines, it is telling that the three we identified were so highly correlated in Crohn’s patients,” said Ghannoum. “Furthermore, we found strong similarities in what may be called the ‘gut profiles’ of the Crohn’s-affected families, which were strikingly different from the Crohn’s-free families. We have to be careful, though, and not solely attribute Crohn’s disease to the bacterial and fungal makeups of our intestines. For example, we know that family members also share diet and environment to significant degrees. Further research is needed to be even more specific in identifying precipitators and contributors of Crohn’s.”
If you are a Crohn’s or ulcerative colitis healthcare professional, search the listings on our website for career opportunities across the United States.