Soluble Fiber May Benefit IBS Sufferers
Lee Swanson Research Update
Adding soluble fiber to the diet may improve symptoms associated with irritable bowel syndrome (IBS), but insoluble fiber may worsen the effects, according to a new study.
Sufferers of IBS assigned to receive a soluble fiber supplement (psyllium) experienced a 90-point reduction in the severity of their symptoms, almost double the levels observed in the placebo group.
Reductions of 58 points in the severity of symptoms in the group assigned bran were noted, but this group experienced a high level of early drop-out following a worsening of IBS.
“In this randomized trial in primary care patients with irritable bowel syndrome, psyllium resulted in a significantly greater proportion of patients reporting adequate relief of symptoms compared with placebo supplementation,” researchers wrote in the British Medical Journal.
The precise numbers of people living with IBS in the United States are not known, as many people with mild symptoms do not consult a physician, but it is believed to be between 15 and 30 million.
The long-term condition, from which more women suffer than men, involves abdominal discomfort accompanied by diarrhea or constipation. Although it is not life-threatening and does not lead to other, more serious health conditions, IBS is untreatable. At present, intervention involves management of symptoms.
Led by Dr. C. Bijkerk from the University Medical Center Utrecht in the Netherlands, the researchers recruited 275 people with IBS between the ages of 18 and 65 and randomly assigned them to one of three groups. The first received daily supplements of soluble fiber (10 g psyllium). The second group received insoluble fiber (10 g bran) and the third group received a placebo (10 g rice flour) for three months.
As the name suggests, soluble fibers can dissolve in water and are found in fruits and vegetables. On the other hand, insoluble fibers contain cellulose, hemicellulose and lignin and cannot be dissolved in water and are commonly associated with cereals.
Only 64%, 56% and 56% of the participants of each group finished the study. Of these, the severity of IBS symptoms decreased by 90 points in the psyllium group, compared with 49 and 58 points in the placebo and bran groups, respectively.
British Medical Journal Published online ahead of print.