IBS Relief From Soluble Fiber
Psyllium Fiber, but Not Bran, May Soothe Irritable Bowel
Aug. 28, 2009 -- Psyllium, the soluble fiber in Metamucil and other
products, can relieve abdominal pain and discomfort in some patients with
irritable bowel syndrome (IBS).
Bran, an insoluble fiber, did not help most patients and worsened symptoms
in many, according to the results of a 275-patient clinical trial.
"The results of this large-scale trial ... support the addition of soluble
fiber, such as psyllium, but not bran as an effective first treatment approach
in the clinical management of patients with irritable bowel syndrome," conclude
C.J. Bijkerk, MD, of University Medical Center, Utrecht, Netherlands, and
Study participants were randomly allocated to three groups. One group
received two 10-gram doses of psyllium a day, usually to be mixed with yogurt.
A second group received similar doses of bran, and a third group received a
non-fiber placebo (rice flour) to mix with their yogurt.
About 40% of the participants dropped out of the study; the dropout rate was
highest among those taking bran. Despite the blinded nature of the study, about
three-fourths of the patients figured out what it was they were getting.
After each month of the three-month study, patients were asked, "Did you
have adequate relief of irritable bowel syndrome-related abdominal pain or
discomfort in the past week?"
Patients receiving psyllium were more likely to say "yes" during the first
two months of the study. Those with constipation-predominant IBS were only
slightly more likely to report relief than were patients with
diarrhea-predominant or mixed-type IBS.
Those who received psyllium were also more likely to report significant
reduction in the severity of their symptoms.
"After three months of treatment, symptom severity in the psyllium group was
reduced by 90 points, compared with 49 points in the placebo group and 58
points in the bran group," Bijkerk and colleagues report.
The study appears in the Aug. 28 Online First issue of BMJ.