Overview

Guar gum is an edible fibre derived from Cyamopsis tetragonolobus seeds, a leguminous plant cultivated primarily in India and Pakistan (Awan et al., 2024; Mudgil et al., 2014). The seeds of the guar plant are comprised of galactomannan, linear polysaccharides consisting of a mannose backbone and galactose side chains, responsible for guar gum’s thickening, emulsifying, and stabilizing properties (Awan et al., 2024; Mudgil et al., 2014; Thombare et al., 2016). Partially hydrolyzed guar gum (PHGG) is a water-soluble dietary fibre made from guar gum that has undergone partial enzymatic hydrolyzation, via microbial endo-β-mannanase, converting it to a low viscosity polysaccharide (Mudgil, 2018). PHGG moves through the upper gastrointestinal tract undigested and is fermented by colonic bacteria, resulting in the production of short-chain fatty acids (SCFA), such as butyrate, attributing PHGG’s use as a prebiotic (Sakai et al., 2022). 

Benefit Areas

Guar, also known as cluster bean, has been consumed as a food source by humans and animals for centuries (Anwan et al., 2024). Over the past decades, the research of guar gum and PHGG has demonstrated many health benefits, such as:

• PHGG reduces blood sugar and cholesterol levels and improves the blood lipid profile (Anwan et al., 2024; PDR, 2000; Mudgil, 2018) 
• PHGG increases satiety and delaying stomach emptying, which may help with weight management (Rao et al., 2015)
• PHGG contributes to gut health by improving bowel movements and stool formation via intestinal microbiota regulation and increasing SCFA production (Anwan et al., 2024; Yasukawa et al., 2019; Miyoshi et al., 2020; Inoue et al., 2019; Kato et al., 2023)
• PHGG influences immune function and prevents infections through increased production of immunoglobulin (Sakai et al., 2022)
• PHGG promotes increased levels of Bifidobacterium and Lactobacillus levels in the gut (Takahashi et al., 1994; Ohashi et al., 2015; Kapoor et al., 2020; Yasukawa et al., 2019)
• PHGG contributes to intestinal barrier maintenance (Hung et al., 2016; Kajiwara-Kubota et al., 2023) and suppresses the influx of inflammatory substances (Takayama et al., 2021; Sakakida et al., 2022) and inhibits systemic chronic inflammation (Okamura et al., 2022)
• PHGG contributes to mental health aspects such as sleep quality and motivation through the improvement of gut environment (Abe et al., 2023)

Sources

The manufacture of PHGG involves the guar endosperm, comprised of galactomannan, which is partially hydrolyzed to reduce the polymer chain length and molecular weight, creating a more soluble dietary fibre with a lower viscosity (Mudgil et al., 2014). PHGG has been accepted as a dietary fibre permitted for use by Health Canada’s Food Directorate as a novel fibre reducing postprandial blood glucose levels. In 2011, the European Food Safety Authority (EFSA) Panel on Dietetic Products, Nutrition and Allergies provided a Scientific Opinion on the substantiation of health claims related to PHGG and concluded that PHGG is sufficiently characterized. The United States (US) Food and Drug Administration (FDA) has affirmed guar gum as Generally Recognized As Safe (GRAS) in various food categories as an emulsifying, stabilizing, and thickening agent (US FDA a, 2024). In addition, guar gum and PHGG meet the US FDA’s definition of dietary fiber as “non-digestible soluble and insoluble carbohydrates (with 3 or more monomeric units), and lignin that are intrinsic and intact in plants; isolated or synthetic non-digestible carbohydrates (with 3 or more monomeric units) determined by FDA to have physiological effects that are beneficial to human health” permitted for use in food (US FDA b, 2024). 

Dose Range

The Physician’s Desk Reference (PDR) for Herbal Medicine suggests a daily dosage of guar gum as 5 g per tablet or granules, three times daily, for lowering postprandial serum glucose values, delaying stomach emptying into the duodenum, reducing glucosuria, improving HbA1c values, levelling blood sugar profile, lowering lipids, and regulating digestion. A systematic review and meta-analysis conducted by Kapoor et al. (2017) revealed that a daily dosage of 5-7 g PHGG per day is sufficient to prevent constipation.

Recent Research

Currently, there are three studies actively recruiting on ClinicalTrials.gov proposing PHGG for use as a dietary supplement or prebiotic for IBS, enteral tube feeding tolerance, and chronic inflammation in adults (ClinicalTrials.gov, 2024). Moreover, searching of “partially hydrolyzed guar gum” on PubMed retrieved one result published this year, investigating the regulatory pattern of PHGG in the fecal microbiota composition of different populations using in vitro fermentation, SCFA regulation, and metabolic gas differences.

An in vivo study conducted by Kato et al. (2023) investigated the effects of PHGG in a mouse model of influenza H1N1 virus infection. C57BL/6 mice, eight weeks of age, were fed normal diets with or without the addition of PHGG (500 mg/kg per day) for four weeks and were infected with H1N1 at ten weeks of age. It was observed that mice that were administered PHGG had improved body weight scores after losing weight due to the H1N1 infection. Improved intestinal atrophy and increased production of SCFAs were also observed in mice fed PHGG. H1N1 increased the serum concentrations of inflammatory cytokines including interferon-γ and interleukin-6. Anti-inflammatory cytokines such as interleukin-10 were observed to be inhibited by PHGG. In addition, PHGG administration reduced inflammatory gene expression in the lung and promoted both natural killer cell activity and regulatory T-cell differentiation in the spleen. This study demonstrated that the consumption of PHGG improves the gut environment and limited the inflammatory response to H1N1 infection. 

A randomized controlled clinical trial conducted by Zhou & Ho (2023) assessed if an individual’s baseline gut microbiota impacted their response to PHGG supplementation. 40 male and female participants, aged 32 to 69 years, diagnosed with IBS completed this study. Participants received 10 g of PHGG per day to be consumed with water at least 30 minutes before breakfast, for a period of three months. It was observed that participants with normal microbiota diversity (Shannon index ≥ 3) showed significant improvements to IBS symptom scores, quality-of-life, and better tolerated the PHGG supplement compared to participants with low microbiota diversity (Shannon index < 3). These findings suggest that an individual’s baseline gut microbiota has a substantial impact on their response to PHGG supplementation.

A narrative review article completed by Salvatore et al. (2024) analysed published scientific literature that focused on the effect of nutraceuticals in infantile colic, functional abdominal pain (FAP), and IBS in children and adolescents. It was observed that PHGG supplementation in 60 children with chronic abdominal pain or IBS significantly decreased IBS symptom scores and improved stool consistency. Further pediatric studies are encouraged to provide evidence of efficacy and safety of different prebiotics in infants and children with pain disorders of the gut-brain interaction.

How is guar gum and PHGG used in the marketplace?

According to Future Market Insights (2024), the guar gum market is estimated to reach $398 million USD in 2034, a 6% compound annual growth rate (CAGR) from the valuated $239.4 million USD in 2024. Key market drivers are attributed to an increase in guar gum use in food and beverage applications, increased interest in plant-based and clean-label packaging materials, and a desire to include guar gum in pharmaceutical applications as a controlled-drug delivery and/or release ingredient. PHGG is used in foods, beverages, dietary supplements, and clinical nutrition as a prebiotic that can support digestive health, improve bowel movements, reduce constipation, modulate the gut microbiota, have beneficial effects on blood sugar and cholesterol levels, assist in weight management, and improve immune function.