Probiotics in Irritable Bowel Syndrome

Irritable bowel syndrome or spastic colon is a common digestive problem that occurs in about 5-20% of the population. It occurs more in young women. The pathogenesis is unknown.

   Diagnostic studies are usually normal and are done usually to exclude any other cause mimicking IBS. Treatment usually involves high fiber and fluids in addition to the symptomatic treatment depending on the predominant symptom, e.g. Imodium or Lomotil in IBS-diarrhea and laxatives in IBS-constipation. Zelnorm is effective for constipation predominant IBS. Antispasmodics and tricyclic anidepressants are frequently used.

   Several recent studies using probiotics for IBS have yielded promising results. The following study further strengthens the argument for inflammation and intestinal dysbiosis as a factor in pathogenesis and for the use of probiotics to relieve the symptoms.

   Whorwell and colleagues from the University of Manchester (U.K.) recently published their findings in the American Journal of Gastroenterology (July 2006). They examined the effect of an encapsulated formulation containing B. infantis and compared it to placebo. 362 patients with IBS were randomized to the probiotic or placebo for 4 weeks. IBS symptoms and quality of life were monitored.

   The study found that the probiotic treatment was superior to placebo in improving abdominal pain, bloating, bowel dysfunction, incomplete evacuation, straining, and the passage of gas at the end of the 4 weeks. In fact, the improvement in global symptom assessment exceeded placebo by more than twenty percent. The investigators did not find any significant adverse events as a result of the treatment.

   The authors concluded that B. infantis 35624 is a probiotic that relieves many of the symptoms of IBS. It can be delivered by a capsule making it stable, convenient to administer, and amenable to widespread use. The study found the positive effects of this probiotic to be dose dependent.