Through an endoscopic study of a cohort of more than 1,000 patients, Austrian researchers have discovered that bacterial biofilms were present in the gut in most cases of irritable bowel syndrome. This could be the cause of the disease.
Irritable bowel syndrome (IBS), which affects an average of 5% of the adult population, is a benign disorder of the functioning of the intestine and colon, but can cause significant discomfort, such as abdominal pain, diarrhea or constipation. The diagnosis is usually made between the ages of 30 and 40, although the syndrome can also occur earlier, in children or adolescents. Among patients, women tend to be more affected than men, with a ratio of three to one in the adult population.
For IBS patients, coping with the disease is further complicated by the fact that they are often victims of misdiagnosis. Even with currently available techniques, IBS can only be diagnosed by a process of elimination. Most IBS patients do not consult a doctor until they have severe symptoms. And, again, doctors may not take them seriously simply because the cause of the disease has not been clearly established.
But that may be changing. In a study published in the journal Gastroenterology, researchers from the University of Vienna show that irritable bowel syndrome is in most cases associated with bacterial biofilms in the gut, which can be observed on endoscopic examination.
Alteration of the intestinal microbiota by drugs
“For the first time, we have succeeded in identifying a cause of irritable bowel syndrome while demonstrating how this disease can be more accurately diagnosed, classified and assessed,” says Christoph Gasche, head of the Laboratory of Molecular Gastroenterology at the Medical University of Vienna and leader of the study.
According to the researchers, the people who most often suffer from irritable bowel syndrome are those who have taken many medications throughout their lives, which have altered the balance of their gut microbiota, including the formation of bacterial biofilms. Patients who have previously undergone organ transplants are at particular risk.
“Some drugs, such as proton pump inhibitors, can disrupt the balance of the bacterial ecosystem. The bacteria then go into survival mode. To have a better chance of surviving this stress, they clump together for safety and form biofilms, a kind of protective space that makes them resistant to antibiotics and other environmental toxins,” explains Dr. Gasche.
Toward a possible treatment for irritable bowel syndrome
In total, more than 1,000 colonoscopies were performed in a multicenter study, and it was found that two-thirds of those with IBS symptoms also had biofilms in the small or large intestine. However, these mucosal biofilms were also present in one-third of patients with ulcerative colitis.
“Until now, studies have always assumed that this sticky film was formed by residues of impurities in the gut that were difficult to remove. However, we have now been able to show that this is where the bacterial matrix adheres,” explains Dr. Gasche.
This discovery could lead to a possible treatment for irritable bowel syndrome that relieves symptoms. Indeed, in many cases it is possible to flush out these biofilms in from the colon. However, the options to remove biofilms from the small intestine, where they are also common remain limited. But this discovery is encouraging. “Biofilms, reflecting an imbalance in the intestinal flora, might well explain the symptoms of patients suffering from irritable bowel syndrome and, consequently, lead to new therapeutic approaches,” the authors conclude.