Soluble fibre (psyllium) is an effective treatment for irritable bowel syndrome (IBS), but insoluble fibre (bran) may worsen symptoms, according to the first trial of increasing dietary fibre in a primary care setting, published on bmj.

Irritable bowel syndrome is characterised by abdominal pain and an irregular bowel habit, and affects about 10% of the population. Increasing dietary fibre is recommended to help alleviate symptoms. However, there is limited evidence that fibre actually alleviates symptoms, and some studies have suggested that insoluble fibre may even worsen symptoms.

To resolve this uncertainty, Dr René Bijkerk from University Medical Center Utrecht and colleagues randomised 275 patients aged 18-65 years with irritable bowel syndrome to receive either 10 grams of psyllium (soluble fibre), bran (insoluble fibre), or placebo (rice flour) twice a day for 12 weeks.

Patients were assessed at one, two and three months for symptom relief, severity of abdominal pain and quality of life, using standard scoring scales.

Findings showed that psyllium was the most effective treatment for irritable bowel syndrome, with a significantly greater number of patients reporting adequate symptom relief and a reduction in symptom severity. After three months of treatment, symptom severity was reduced by 90 points in the psyllium group, 49 points in the placebo group, and 58 points in the bran group. However, no differences were reported between the groups in abdominal pain or quality of life.

Interestingly, bran showed no clinically relevant benefit. Many patients seemed not to tolerate bran and the dropout rate was highest in this group.

These results support the addition of soluble fibre such as psyllium, but not bran as an effective first treatment approach in the clinical management of irritable bowel syndrome, say the authors. Indeed, bran may worsen symptoms of irritable bowel syndrome and should be advised only with caution, they conclude.

Link to paper

Source
British Medical Journal