Partially Hydrolyzed Guar Gum (PHGG)

Supplements · Digestive Health · Supplement, Typed Supps

A processed form of guar bean fiber that dissolves easily and helps with constipation and bloating, without the thick gel texture of regular guar gum.

Stage by stage

Intake (Powder, dissolved in liquid): Mixed into water or a drink; dissolves without becoming thick or gel-like.
Stomach and small intestine (Minimal digestion): Passes through largely undigested, reaching the colon mostly intact.
Colon (Bacterial fermentation): Fermented by gut bacteria, producing short-chain fatty acids and increasing bacterial mass.
Stool bulking (Bowel regularity): The combined effect bulks and softens stool, supporting more regular bowel movements.

What the evidence supports

Improving constipation and stool frequency — moderate evidence. A systematic review and meta-analysis found PHGG improved constipation to a degree similar in magnitude to laxatives across several trials, with a typical effective dose around 5-7g/day.
Improving IBS-related constipation specifically — moderate evidence. A randomized, placebo-controlled trial found a higher rate of treatment responders (an increase of at least one spontaneous bowel movement per week) in the PHGG group than placebo among IBS patients (roughly 34% vs 18%).
Improving overall IBS symptom severity and quality of life beyond bloating — insufficient evidence. In the same trial, bloating scores improved significantly versus placebo, but other individual IBS symptoms and overall severity/quality-of-life scores did not differ significantly from placebo.

Typical dose

5-7g/day, taken with fluids, is the range used in most constipation and IBS trials

Upper limit: No established UL

Timing

Take daily with plenty of fluids; increase the dose gradually to reduce initial gas.

Time to effect

Several weeks: Improvements in bowel-movement frequency have generally been measured after several weeks of consistent daily use in trials.

Common myth

“PHGG will fix all my IBS symptoms.” In reality: Trial evidence supports a real benefit for constipation and bloating specifically — the same trial that found this did not find a significant improvement in overall IBS severity or quality of life, so its benefit scope is narrower than "fixing IBS" broadly.