Cluster Bean

Partially-Hydrolyzed Guar Gum from Cyamopsis tetragonoloba

Evidence: Strong

PHGG from Cluster Bean is a non-FODMAP fiber. We use it as one of our backbone fibers in All-in-One Gut Essentials because it provides reliable nutrition for good gut bacteria while minimizing irritating gas.

It's a highly-fermentable shorter-chain galactomannan fiber, notable for its high solubility. Since it's a shorter chain of non-digestible, fermenting fibers, it ferments faster and earlier in the colon than Acacia Gum, markedly enhancing Bifidobacterium populations and promoting short-chain fatty acid synthesis, particularly butyrate and acetate. Despite fermenting relatively quickly, it does not result in rapid or significant gas production proportionate to the SCFAs produced. It also supports gut motility and improves stool consistency.

There are 135 peer-reviewed scientific studies on this ingredient.

Selected study:

1. Abe, A., Morishima, S., Kapoor, M. P., Inoue, R., Tsukahara, T., Naito, Y., & Ozeki, M. (2023). Partially hydrolyzed guar gum is associated : With improvement in gut health, sleep, and motivation among healthy subjects. Journal of Clinical Biochemistry and Nutrition, 72(2), 189. https://doi.org/10.3164/jcbn.22-75

Study summary: 

Study type & size: Randomized, double-blind, placebo-controlled parallel single-center randomized clinical trial (RCT); 60 Japanese adults with mild constipation were randomized, 51 completed the protocol for efficacy analysis.

Intervention: PHGG 3 g/day or 5 g/day vs maltodextrin placebo for 8 weeks.

Key benefits observed:

• Gut function – 5 g/day increased weekly bowel frequency (+1.15 bowels/wk) and improved “excretory feeling” versus placebo; stool smell also softened in both PHGG groups.
• Microbiota – Both doses markedly suppressed mucin-degrading “harmful” genera Dorea and Ruminococcus torques, while 5 g/day enriched beneficial SCFA-producers (Bacteroides, Paraprevotella, Sellimonas).
• Quality of life – At 5 g/day, scores for “refreshment on waking”, “fatigue on waking” and “motivation toward work/study” improved significantly by week 8 vs placebo, even amid pandemic-related stress.

Proposed mechanisms: PHGG resists digestion, is fermented to Short-Chain Fatty Acids (SCFAs), and selectively lowers mucolytic bacteria that erode the gut-mucus layer; this may tighten the gut barrier, dampen systemic/neuro-inflammation and positively influence the brain–gut axis, explaining sleep and motivation gains.

Safety / side-effects: No serious adverse events or drop-outs related to PHGG; authors reported “no adverse effect” and good overall tolerability.

Evidence: Benefits were dose-dependent and clinically modest yet extend beyond bowel regularity to mood-related endpoints, with an excellent safety profile at up to 5 g/day.