The study published in the scientific journal Gastroenterology, investigated Irritable bowel syndrome (IBS) using living bacteria. The researchers at Linkoping University in Sweden led the study; they showed that the intestinal barrier of patients with IBS allows bacteria to pass more freely than in healthy people.

In IBS, the bowel function is disturbed and leads to repeated episodes of abdominal pain and usually gives rise to diarrhea or constipation. About 10% of people in Sweden suffer from IBS, among which women are affected twice than men.

Asa Keita and Susanna Walter, from Department of Clinical and Experimental Medicine (IKE), led the study. The people affected by IBS were regarded as a diffuse group. They found that the colon (or large intestine) in people with IBS and healthy individuals react to bacteria in a significantly different way.

Although the aroused conditions were unclear, it was found that the changes in ways the brain interacts with the bacterial flora in the gut are involved. The large intestine comprises a layer of mucous, epithelial cells (enterocytes) and immune cells. In the current study, the layer of epithelial cells was examined for its permeability to bacteria.

In the study, small tissue samples from the large intestine of 37 women with IBS were investigated and compared with samples with no intestinal symptoms. The membranes were studied with the aid of an instrument, Ussing chamber. The transport of substances and bacteria through living tissue was measured.

As infection with Salmonella typhimurium is known to increase the risk for developing IBS, the interaction of Salmonella strain with the intestinal membrane was studied. Besides, a strain of Escherichia coli HS (E. coli) was considered. Both pathogenic bacteria passed through the intestinal mucosa of patients with IBS, with twice the intensity of healthy individuals.

Asa Keita said that “Patients with IBS in our study had a higher passage of bacteria in the model system.” However, these findings cannot be directly used in clinical practice and require further research. There is something that makes one layer of the intestinal mucosa of patients with IBS more subtle to bacteria than in healthy subjects, he added.

The mast cells were also studied; these are a type of immune cell involved in immune defense, protects against micro-organisms. These cells play a significant role in regulating the passage of bacteria across the intestinal membrane in both people with IBS and healthy individuals; however, the mechanism was more active in patients with IBS.

The study has shown that people with IBS are clearly different from healthy people in the way in which the colon reacts to bacteria. The intestinal barrier of patients with the gastrointestinal disease IBS allows bacteria to pass more freely than in healthy people