Joint Research by Kyoto Prefectural University of Medicine, Yoshinoya, and Others Reveals Guar Bean Fiber May Improve Worker Productivity

A research group comprising Kyoto Prefectural University of Medicine Graduate School of Medical Science (Dept. of Molecular Immunology and Nutrition: Professor Yuji Naito, Dept. of Gastroenterology: Professor Tomohisa Takagi), Setsunan University (Faculty of Agriculture: Professor Ryo Inoue), International University of Health and Welfare (School of Medicine: Professor Tatsuo Shimozawa), Yoshinoya Holdings Co., Ltd. (President Tetsuya Naruse), and Taiyo Kagaku Co., Ltd. (Head Office: Yokkaichi, Mie; President: Nagayoshi Yamazaki) has revealed that continuous intake of guar bean dietary fiber, a known prebiotic, may improve the gut environment, reduce presenteeism (decreased work productivity), and enhance the quality of life (QOL) for office workers. The findings were presented on Saturday, May 16th at the 80th Annual Meeting of the Japanese Society of Nutrition and Food Science held in Sunport Takamatsu. Modern office workers are prone to digestive symptoms such as constipation and diarrhea due to long hours of desk work, mental stress, and irregular eating habits. These issues lead to presenteeism, where employees are present at work but their efficiency is reduced due to health problems, and this is noted as a factor that decreases corporate labor productivity. While guar bean dietary fiber (Partially Hydrolyzed Guar Gum, hereafter PHGG) had been reported to improve bowel movements and gut microbiota, this study, from the perspective of 'Health and Productivity Management,' comprehensively examined how PHGG intake affects actual labor productivity, sleep quality, and the gut environment. Over a two-month period from February to March 2025, 136 employees of Yoshinoya Holdings Co., Ltd. continuously consumed PHGG (6g/day). Evaluations of gut microbiota (16S rRNA analysis), digestive symptoms (Izumo Scale), labor productivity (WHO-HPQ: an index for presenteeism, etc.), and sleep quality (OSA-MA Sleep Inventory) were conducted before and after the PHGG intake. The results showed a significant increase in beneficial bacteria such as Bifidobacterium, which are involved in the production of short-chain fatty acids, and also confirmed improvements tailored to individual gut environments (such as improvement in those with a tendency for loose stools). Furthermore, a reduction in digestive symptoms such as constipation and heartburn was observed. Significant improvements were noted in items related to work performance and quality of life, including increased concentration at work, improved presenteeism, and reduced morning sleepiness. This study suggests that PHGG intake, by improving the gut environment, may contribute not only to physical well-being (digestive symptoms) but also broadly to psychological and performance aspects (labor productivity, sleep). 'Guar bean dietary fiber' is a low-viscosity dietary fiber obtained by enzymatically breaking down guar gum, which is extracted from guar beans.