Fecal microbiota transplantation reduces IBS symptoms

Last Updated: 2020-08-07

By Will Bogga MD

NEW YORK (Reuters Health) - Fecal microbiota transplantation (FMT) reduces symptoms of irritable bowel syndrome (IBS) in some patients, but the benefits wane over time, according to findings from a placebo-controlled randomized trial.

"Although several studies confirm the beneficial effects of FMT in IBS patients, currently knowledge does not allow for FMT to be implemented in routine practice for IBS patients," said Dr. Danny De Looze of Ghent University Hospital and Ghent University, in Belgium.

"Further research is needed to better understand which patient groups are best suited for this line of treatment," he told Reuters Health by email. "Our research suggests that the key lies in the microbiota composition and compatibility of both donor and patient."

The microbiome appears to be altered in patients with IBS, but no consistent microbial IBS signature has been established. Several studies have investigated the use of FMT in IBS patients, but two recent placebo-controlled trials yielded conflicting results in mixed IBS populations.

Dr. De Looze and colleagues investigated the potential for FMT to treat IBS patients with severe bloating and to evaluate the associated microbiota changes in 62 patients with refractory diarrhea-predominant or mixed-type IBS who had symptoms of severe bloating.

Significantly more patients in the FMT group (24/43, 56%) than in the placebo group (5/19, 26%) obtained adequate relief of general IBS symptoms and abdominal bloating at 12 weeks following FMT (determined by responses to two key questions), the researchers report in Gastroenterology.

Response rates were significantly better among female patients than among male patients in the FMT group (69% vs. 29%, respectively) but not in the placebo group.

FMT was also associated with significant reductions in secondary outcomes, including abdominal discomfort, number of stools, urgency, abdominal pain and flatulence, but no such improvements were seen in the placebo group.

IBS patients who responded to FMT treatment had higher microbial diversity at baseline, compared with patients who failed active FMT treatment. But there were no taxa, specific donor enterotype, or donor-recipient enterotype matching that could be linked to FMT success.

At one year following transplantation, most initial responders (19/24, 79%) had lost the benefits of FMT, with a median time to loss of response of four months (range, 3.5-12 months).

Among the 12 placebo-group participants who crossed over to actual FMT, 58% obtained adequate relief of symptoms.

A quarter of the patients who failed to respond to the initial FMT experienced an improvement of abdominal symptoms after retransplantation with a different donor, whereas retransplantation of patients who initially responded to FMT but whose symptoms recurred was beneficial in 67%.

"Irritable bowel syndrome is a very heterogeneous patient population in which one therapy does not fit all," Dr. De Looze said. "Even within the subpopulation of IBS patients with predominant abdominal bloating, not all patients respond to therapy in a similar way. This should be taken into account when treating these patients."

"Fecal microbiota transplantation may become a major player in the therapeutic arsenal of IBS, but at this point our knowledge of the exact mechanisms is too limited to allow for its use as a mainstream treatment," he concluded.

SOURCE: https://bit.ly/2OTEJb7 Gastroenterology, online July 15, 2020.