Randomized clinical study: Partially hydrolyzed guar gum (PHGG) versus placebo in the treatment of patients with irritable bowel syndrome

Nutr Metab (Lond). 2016 Feb 6:13:10. doi: 10.1186/s12986-016-0070-5. eCollection 2016.


Background: The treatment of Irritable bowel syndrome (IBS) is still challenging. Partially hydrolyzed guar gum (PHGG) is a known prebiotic fiber. To assess the effects of PHGG on clinical symptoms of IBS patients in a prospective randomized double blind placebo-controlled study.

Methods: Suitable IBS patients were recruited into an 18-week-long study (2 weeks of run-in, 12 weeks of treatment and 4 weeks of follow-up). They were blindly randomized to receive 6 gr of PHGG or placebo. Treatment efficacy was evaluated by the Francis Severity IBS score, the IBS quality-of-life scores and scored parameters of weekly journal of symptoms. Deltas of changes between the final and baseline scores were compared between two groups.

Results: Of 121 patients who underwent randomization, 108 patients (49 in the PHGG group and 59 in the placebo group) had all the data needed for intention-to-treat analysis. A 12-week administration of PHGG led to a significant improvement of journal bloating score in the PHGG group versus placebo (-4.1±13.4 versus -1.2±11.9, P=0.03), as well as in bloating+gasses score (-4.3±10.4 versus -1.12±10.5, P = 0.035). The effect lasted for at least 4 weeks after the last PHGG administration. PHGG had no effect on other journal reported IBS symptoms or on Severity and Quality of life scores. There were no significant side effects associated with PHGG ingestion. The rate of dropouts was significantly higher among patients in the placebo group compared with the PHGG group (49.15% versus 22.45%, respectively, P = 0.01).

Conclusions: The results of this study support the administration of 6 g/day PHGG for IBS patients with bloating.

Trial registration: NCT01779765.

Keywords: Fibers; Irritable bowel syndrome (IBS); Partially hydrolyzed guar gum (PHGG); Prebiotics.

Associated data

  • ClinicalTrials.gov/NCT01779765