Dietary Interventions and Irritable Bowel Syndrome – What Really Works?

Teodora Surdea-Blaga; Anamaria Cozma-Petrut; Dan Lucian Dumitraşcu


Curr Opin Gastroenterol. 2021;37(2):152-157. 

In This Article

Dietary Fiber Supplementation

Dietary fiber exhibits bulking-laxation activity, alters gut microbiota and modulates the production of fermentation by-products, effects that might be helpful in IBS.[31] Dietary fiber varies considerably in physical and chemical properties, hence, associated physiological effects are specific for each fiber type.[32] A recent meta-analysis showed that soluble fiber, particularly psyllium, was effective in IBS treatment, whereas insoluble fiber, particularly wheat bran, had no effect in treating IBS.[33] This evidence of efficacy, although considered of moderate quality, led the authors of the study to recommend psyllium for overall symptom improvement in IBS.[33] Nevertheless, the meta-analysis was unable to identify optimal dose and duration of fiber supplementation. Likewise, most RCTs included did not differentiate based on IBS subtype, suggesting more research is needed to understand which patients would benefit more from fiber supplementation. Available data suggest that psyllium has positive effects, especially in IBS-C.[31] Psyllium increases stool water and eases defecation.[12] Moreover, a double-blind RCT reported a decrease in gut bacterial species associated with hard stools following psyllium supplementation in constipated patients.[34]