The probiotic Bifido­bacterium bifidum MIMBb75 is a normal GI tract inhabitant (along with several hundred other commensal organisms). This strain, found in some probiotic formulations, decreases overall symptoms in patients with irritable bowel symptoms and is an inexpensive and safe alternative to medications.

The German investigators conducting this study recruited 132 adults with mild to moderate irritable bowel syndrome (IBS; Rome III criteria) to participate in the study. Placebo and control groups were well matched for IBS subtype, with 23% of control patients having the diarrhea-predominant type, 15% having the constipation-predominant type, and 62% having the alternating type. During the first two weeks, patients did not receive any treatment but kept symptom diaries. Patients with at least two days of mild to moderate pain during the second week of the study (n = 122) were randomly assigned (allocation concealment not specified) to receive four weeks of treatment with placebo (maltodextrin, which uncommonly causes diarrhea) or B bifidum 1 billion units followed by two weeks of observation without treatment.

The main outcome was a rating on a seven-point scale asking about symptoms in the past 24 hours. Scores at baseline were approximately 2.8 of a possible 6 in both groups (moderate symptoms). After treatment, these scores dropped by an average 0.88 in the treated group as compared with 0.16 in the placebo group (P < .0001). Differences in scores appeared in the first week of treatment and continued throughout the treatment period. The% of patients experiencing an improvement of at least 1 point on the Likert scale in at least two of the four weeks was significantly higher in the treatment group (57% vs 21%; P = .0001). Scores were not significantly different in the two weeks after treatment was discontinued.

Source: Guglielmetti S, Mora D, Gschwender M, Popp K. Randomised clinical trial: “Bifidobacterium bifidum MIMBb75 Significantly Alleviates Irritable Bowel Syndrome and Improves Quality of Life--A Double-Blind, Placebo Controlled Study.” Alimen Pharmacol Ther. 2011;33(10):1123-1132.

 From the November 11, 2011, Prepared Foods' Daily News.