Randomized Controlled Trial on the Effect of Partially Hydrolyzed Guar Gum Supplementation on Diarrhea Frequency and Gut Microbiome Count Among Pelvic Radiation Patients

BACKGROUND: Radiation therapy is the treatment of pelvic cancers, with diarrhea often being the most frequent acute side effect. This study aimed to determine the efficacy of partially hydrolyzed guar gum (PHGG) usage in reducing radiotherapy-induced diarrhea and improving bacterial count, nutrition status, and quality of life (QoL) among cancer patients.

METHODS: Adult patients undergoing pelvic radiation were recruited and randomly assigned to receive supplementation of either 10 g of PHGG or placebo (maltodextrin) twice daily, 14 days prior and 14 days during pelvic radiation. Diarrhea frequency, fecal samples, nutrition status, and QoL were assessed at baseline and days 14, 28 (2 weeks after pelvic radiation), and 45 (at the completion of pelvic radiation, 2 weeks' postsupplementation).

RESULTS: A total of 30 patients (mean age 56.5 ± 10.8 years, 75% malnourished) participated. The mean of diarrhea frequency in the intervention group (IG) was higher compared with the control group (CG) from days 14 and 28 but reduced at day 45. There was a significant intervention effect after controlling for confounders (ie, baseline diarrhea, age, nutrition status) (P < .05). Bifidobacterium count increased by double among the IG at 14 days of PHGG supplementation, whereas such trend was not observed in the CG.

CONCLUSION: Supplementation of PHGG potentially increased the bifidobacterial count and seemed to have post-supplementation effects by reducing the frequency of diarrhea upon the completion of pelvic radiation treatment.