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Moderate evidenceGut health

Partially Hydrolyzed Guar Gum

A low-viscosity soluble fiber that is unusually well tolerated for a fermentable fiber. Small randomized trials support modest benefits in IBS and constipation.

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What the science says

  • IBS symptoms Moderate evidence

    A randomized, placebo-controlled trial in IBS patients found improvement in symptom scores with PHGG, and older randomized comparisons found it at least as good as wheat bran with fewer complaints. Trials are small and mostly single-center.

  • Constipation and stool form Moderate evidence

    A randomized placebo-controlled trial in long-term care residents reduced constipation, and a randomized, double-blind trial in healthy adults improved fecal characteristics and shifted the gut microbiota.

  • Tolerability compared with other fibers Limited evidence

    Trials consistently report low rates of gas and bloating relative to inulin or FOS, but this comes from adverse-event reporting rather than from head-to-head tolerability studies.

Dosage & safety

Studied doseTrials used roughly 5–7 g per day (some up to 11 g), stirred into liquid. It dissolves without thickening, which is why it is used in drinks and tube feeds.
SafetyUsually well tolerated; mild gas early on. Like all soluble fibers, take it separated by a couple of hours from medications to avoid interfering with absorption, and with adequate fluid.

How to take it

TimingTiming does not matter.
With food?Either way; stir it into water or any drink.
Worth knowingUnlike psyllium it does not thicken, so it mixes into coffee or soup without changing the texture.

Interactions

With medications

  • oral medications generally

    Soluble fiber can slow or reduce absorption of a drug taken at the same time. separate by at least 2 hours

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Does partially hydrolyzed guar gum help IBS?

PHGG has moderate evidence for IBS: a randomized placebo-controlled trial improved symptom scores, and older comparisons found it at least as good as wheat bran with fewer complaints. Trials are small and mostly single-center.

Does PHGG help constipation?

Partially hydrolyzed guar gum reduced constipation in a placebo-controlled trial in long-term care residents and improved stool characteristics in healthy adults, which is moderate evidence.

How much partially hydrolyzed guar gum per day?

Trials used roughly 5–7 g of PHGG per day, some up to 11 g, stirred into liquid. It dissolves without thickening, so it mixes into coffee or soup.

Does PHGG cause gas or interact with medications?

PHGG is usually well tolerated, with mild gas early on and reportedly less than inulin or FOS. Like other soluble fibers, separate it from oral medications by at least 2 hours.

Scientific references

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