Psyllium husk vs. partially hydrolyzed guar gum

Psyllium husk and partially hydrolyzed guar gum (PHGG) are both soluble fibers sold as supplements, but they're processed to behave almost oppositely: psyllium is prized for staying thick and gel-like in water, while PHGG is guar gum deliberately broken down until it's nearly viscosity-free.

Where each comes from

Psyllium is the husk of the Plantago ovata seed, ground and minimally processed. PHGG starts as guar gum, extracted from the endosperm of the guar bean, and is then treated with an enzyme that partially hydrolyzes it — breaking it down specifically to reduce its naturally very high viscosity while keeping it soluble. That enzymatic step is the whole difference between guar gum and PHGG; psyllium doesn't go through an equivalent process.

Viscosity: the main practical difference

Psyllium forms a thick gel almost as soon as it's mixed into liquid, which is why every psyllium label warns to drink it promptly with a full glass of water before it thickens further. PHGG, by design, stays close to non-viscous even in solution — food science literature describes it as nearly viscosity-free compared to unmodified guar gum — which is part of why it's used in thin or clear formulations where psyllium's gel texture wouldn't work.

Fermentation: also different

The two fibers are also processed differently once they reach the colon. A lab fermentation study found psyllium's fermentation profile stayed largely unchanged even with an added probiotic bacterium, consistent with psyllium being mostly resistant to bacterial breakdown. Guar gum, including its partially hydrolyzed form, is generally described in the fiber literature as more extensively fermented by gut bacteria than psyllium — a compositional difference between the two fibers, not a statement about which is more effective for any particular use.

What's actually been tested, and at what dose

A small randomized trial gave long-term care residents 5 grams of PHGG a day, mixed with 200 mL of water, for four weeks — a considerably smaller daily gram amount than psyllium is typically studied at (see how much psyllium husk should you take a day for what's been tested for psyllium specifically). We haven't found a trial that tests psyllium and PHGG directly against each other, in the same study, at matched doses; the trials that exist for each test it against a placebo or water, not against the other fiber.

Where our fiber blend fits

Electric Tiger's Psyllium + Acai Fiber Blend is built around psyllium husk powder — a proprietary blend of 1,532 mg per two-capsule serving that also includes inulin, acai berry extract and seven other botanicals, as low as $14.87 a bottle on subscription. It's a psyllium-based product, not a PHGG one.

Questions people ask

Is psyllium husk or PHGG better?

There's no head-to-head trial to declare a winner — each has been tested against a placebo, not against the other. The two fibers behave differently (viscous and largely non-fermented vs. nearly non-viscous and more fermentable), so the more useful question is which mechanism you're looking for, not which one ranks higher in general.

Does PHGG cause less gas or bloating than psyllium?

PHGG's lower viscosity is often mentioned anecdotally as easier to tolerate, but we haven't found a direct comparative trial measuring gas or bloating between the two fibers to confirm that. See does psyllium husk cause diarrhea, gas or bloating for what's documented for psyllium specifically.

Related reading: psyllium husk vs. other fibers and psyllium husk side effects.