What causes IBS is still not known, but experts think the overgrowth of harmful bacteria in the gut could be the reason. The theory is that probiotics help balance the bacteria in the gut so that the body’s digestive system functions properly. Probiotics have become so popular over the years that you can easily find them in foods like yogurt, chocolate and granola bars, or in supplements and powders. In a clinical trial conducted in Bavaria, Germany, researchers used a dead bacterial strain of Bidfidobacterium bifidum, the live form of which is commonly used to treat IBS, to see if it would be just as effective at improving IBS symptoms. They randomly assigned 443 people with IBS to receive either two capsules of heat-inactivated Bifidobacterium bifidum or two placebo capsules, twice daily, for eight weeks. They then measured whether stomach pain improved by at least 30 percent over the duration of the trial period and whether all IBS symptoms were relieved at least half the time while the capsules were being taken. Out of 221 participants who received the probiotic, 34 percent reported feeling relief from stomach pain and from overall IBS symptoms, compared with 19 percent of the 222 participants who received the placebo. Also observed was a strong placebo effect, which is common in IBS studies, but the probiotic treatment was still better than placebo. “Our results show for the first time that dead or alive, it’s possible to preserve the beneficial effects of some probiotic bacteria,” says a coauthor of the study, Viola Andresen, MD, of the University of Hamburg teaching hospital in Germany, in a press release. “They could be just as effective as live probiotics, as well as even safer, with the added commercial benefit of a longer shelf life.” The research was published in April 2020 in the journal Lancet Gastroenterology & Hepatology. “The probiotic bacteria worked in a third of IBS patients in this study,” says Madhusudan Grover, MBBS, an assistant professor of medicine in physiology and a consultant in the division of gastroenterology at the Mayo Clinic, who was not involved with the study. “Although this was better than the response seen with placebo, more needs to be done to understand the subset of IBS patients who might benefit from this product and what the mechanisms are by which this probiotic acts in the gut.” Although the study authors don’t know exactly how this potential treatment works, they think the dead bacterial cells are able to stick to cells lining the stomach in the same way that live probiotics do. This may help to strengthen the gut’s barrier against harmful bacteria and toxins, which otherwise may contribute to the symptoms of IBS. RELATED: IBS Treatment Options and Prevention Strategies

The Benefit of Taking Dead Probiotics

Live probiotics aren’t for everyone. Different strains of probiotics cause varying effects in different people. In fact, some strains might overgrow and cause infections. According to an article published in May 2015 in the journal Clinical Infectious Diseases, bacterial overgrowth is more of a risk if you have an immune system disorder (such as cancer and autoimmune diseases), are a premature infant, or have a chronic illness like heart disease. “Using this type of inactivated bacteria could be helpful for patients who can’t tolerate live cultures,” says Dr. Grover. “Especially in patients who have immunocompromised conditions.” Still, he stresses the need for more research to determine which patients might benefit. “It would be important to know its effects on bowel symptoms like bowel frequency, consistency, and ease of passage, because that’s an important part of IBS,” he says.