Prebiotics or probiotics for constipation-predominant irritable bowel syndrome? Original paper

In this randomized controlled trial in participants with constipation-predominant irritable bowel syndrome, supplementing with either a probiotics supplement containing Bifidobacterium animalis subsp. lactis BLa80 or acacia fiber increased stool frequency compared to a placebo.

Whether supplementing with acacia fiber (AF; part of the legume family Fabaceae) or a probiotics supplement containing Bifidobacterium animalis subsp. lactis BLa80 (BLa80) improves symptoms in people with constipation-predominant irritable bowel syndrome (IBS-C).

The primary outcome was stool frequency. The secondary outcomes were stool consistency, stool mass, IBS severity, constipation symptoms, quality of life, and anxiety and depression scores. All of the outcomes were assessed using different questionnaires.

180 participants (average age of 37; 156 women, 20 men) with IBS-C.

A 4-week randomized controlled trial was performed. The participants took either AF (10 grams), BLa80 (4 grams, providing 2x10¹¹ CFUs per gram) or a placebo daily.

The participants reported their dietary intake (including fluid intake) and adherence to the intervention in an app daily.

Compared to the placebo group, stool frequency increased in the AF group (+0.14 stools per day) and the BLa80 (+0.09 stools per day) group.

For the secondary outcomes, IBS symptom severity improved in the BLa80 group compared to the placebo group. The number of participants who had a clinically meaningful improvement in IBS symptom severity was 53% in the BLa80 group and 29% in the placebo group. There was no significant change in the AF group for this outcome. None of the remaining outcomes differed between groups.

The study was funded by the companies that manufacture the supplements that were used. Also, one of the researchers was employed by the company that manufactures the acacia fiber supplement.