Colon tissue more permeable to bacteria in IBS
Bacteria permeates colonic epithelial tissue more easily in patients with irritable bowel syndrome, passing more freely through the intestinal barrier, according to new research.
Further, investigators found evidence to suggest that vasoactive intestinal polypeptide (VIP) and mast cells may contribute to the increased permeability of the colonic epithelial tissue.
“People affected by IBS have been regarded as a rather diffuse group,” Åsa Keita, PhD, a researcher in the department of clinical and experimental medicine at Linköping University in Sweden, said in a press release. “Our study has shown that people with IBS are clearly different from healthy people in the way in which the ... colon ... reacts to bacteria.”
Keita and colleagues evaluated colon biopsies collected from 32 women with IBS and 15 healthy women matched by age, and using an Ussing chamber, they measured translocation of Escherichia coli HS and Salmonella typhimurium through the mucosal tissue.
They found that larger numbers of both bacteria passed through the epithelium in colon biopsies from IBS patients compared with controls (P < .0005), and both bacteria passed through the mucosa about twice as fast in the samples from IBS patients compared with controls.
“Patients with IBS in our study had a higher passage of bacteria in the model system,” Keita said in the press release. “But we cannot transfer this result directly to clinical practice, and further research is needed. What we can say, however, is that there is something that makes one layer of the intestinal mucosa of patients with IBS more sensitive to bacteria than in healthy subjects.”
Further study of some of the biopsy samples also revealed that mast cells appeared to play a role in regulating bacteria translocation in both IBS patients and controls, but this appeared to be more active in patients with IBS. Additionally, plasma samples from IBS patients showed higher VIP levels than controls.
Both mast cells “and VIP appear to be important factors in the regulation of this bacterial translocation through the mucosa, and these mechanisms seem to be up-regulated in IBS,” Keita and colleagues wrote. “Future studies are required to elucidate the relationship between these epithelial abnormalities, mucosal immune activation, and symptom generation in IBS subjects.” – by Adam Leitenberger
Disclosures: The researchers report no relevant financial disclosures.