Changes in intestinal microbiota and biochemical parameters in patients with inflammatory bowel disease and irritable bowel syndrome induced by the prolonged addition of soluble fibers to usual drug therapy

Objectives : Partially hydrolyzed guar gum (PHGG) is a soluble dietary fiber ; in addition to improving bowel movements, it maintains intestinal health by producing short-chain fatty acids. However, majority of clinical studies on PHGG have been concluded within a month and excluded usual drug therapy. Hence, this study aimed to determine the effects of long-term consumption of PHGG, in combination with drug therapy, on gut bacteria ratios, laboratory values for inflammatory response, and fecal characteristics. Methods and Results : The study was performed in patients with irritable bowel syndrome (IBS), Crohn's disease (CD), and ulcerative colitis (UC), by the administration of PHGG for six months while they continued their usual treatment. PHGG treatment caused significant changes in patients with IBS, including an increase in the abundance of short-chain fatty acid-producing bacteria, a significant decrease in Bacteroides abundance, and normalization of the Bristol scale of stool. In patients with UC, non-significant normalization of soft stools and decrease in fecal calprotectin were observed. Adverse events were not observed in any of the groups. Conclusion : Thus, it would be beneficial to include PHGG in the usual drug therapies of patients with IBS. J. Med. Invest. 71 : 121-128, February, 2024