Probiotics — even inactive ones — may relieve IBS symptoms

Irritable bowel syndrome (IBS) is a chronic gut-brain disorder that can cause a variety of uncomfortable gastrointestinal symptoms including abdominal pain and diarrhea, constipation, or a mix of the two. IBS can reduce quality of life, often results in missed school or work, and can have a substantial economic impact.

Physicians diagnose IBS by identifying symptoms laid out in the Rome Criteria, a set of diagnostic measures developed by a group of more than 100 international experts. Limited diagnostic testing is also done, to help exclude other conditions that could present with similar symptoms.

Although the precise cause of IBS remains unknown, recent research suggests that an imbalance in intestinal microbiota (the microorganisms living in your digestive tract) and a dysfunctional intestinal barrier (which, when working properly, helps keep potentially harmful contents in the intestine while allowing nutrients to be absorbed into the bloodstream) may be involved in the development of IBS in some people. Because of this, methods to restore the microbiota have been explored as treatment for this condition.

Balance of bacteria is important for gut health

Many digestive processes rely on a balance of various bacteria, which are found naturally in the gastrointestinal tract. If these bacteria fall out of balance, gastrointestinal disorders may occur, possibly including IBS.

Probiotics, which are bacteria or yeast that are associated with health benefits, may help restore this balance. Most probiotics used in IBS treatment fall under two main groups: Lactobacillus and Bifidobacterium. These probiotics are thought to assist the digestive system. Among other functions, they may strengthen the intestinal barrier, assist the immune system in removing harmful bacteria, and break down nutrients.

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The American College of Gastroenterology conducted a meta-analysis of more than 30 studies, which found that probiotics may improve overall symptoms, as well as bloating and flatulence, in people with IBS. However, the overall quality of evidence of studies included in the meta-analysis was low, and specific recommendations regarding use of probiotics for IBS remained unclear.

The probiotic strain Bifidobacterium bifidum MIMBb75 has been reported to adhere particularly well to intestinal cells, and therefore may have an advantage in altering the intestinal microbiota and increasing the intestinal barrier.

In a clinical trial published in Alimentary Pharmacology & Therapeutics, once-daily Bifidobacterium bifidum MIMBb75 significantly improved overall IBS symptoms, as well as individual IBS symptoms including abdominal pain, bloating, and fecal urgency.

Recent study finds inactive probiotics relieve IBS symptoms

Advantages of inactive probiotics

Previously, general consensus held that only active, living bacteria may have beneficial effects. But these results suggest that heat-inactivated Bifidobacterium can play a significant role in relieving symptoms of IBS, a syndrome with typically limited options for relief.

This is important because inactive probiotics have several potential advantages over active probiotics. For example, they are more likely to be stable, particularly if exposed to excessive heat. Inactive probiotics are also easier to standardize than active probiotics. Active probiotics also raise concerns for patients who may be susceptible to infection; inactive probiotics should relieve these concerns. Whether other strains of heat-inactivated probiotics will also improve IBS symptoms remains unknown.

Anthony Lembo, MD, is Director of the GI Motility and Functional Bowel Disorders Program at Beth Israel Deaconess Medical Center and Professor of Medicine at Harvard Medical School in Boston, MA.

This article is republished from Harvard Health Publishing under a Creative Commons license. Read the original article.