Explainer 1 min read

Psyllium Husk and PHGG: What Each Fibre Actually Does

Psyllium husk works fast and works well for many people. PHGG (partially hydrolysed guar gum) takes a different route to a similar result, and it's one of the fibres in our own blend.

Reviewed by our gut-microbiome scientists Built on 10+ years of MIT research

The short answer

Psyllium husk forms a gel that bulks and softens stool, relieving constipation and diarrhoea for many people. PHGG works differently. It's slowly fermented by your gut bacteria, easing symptoms while also feeding your microbiome, which is why it's one of the fibres we use.

Psyllium is well tolerated by most people, including many with IBS.
PHGG is slowly fermented in the colon, giving it both symptom-relief and prebiotic benefits.
We include PHGG in our Gut Health blend for exactly this reason.

Psyllium husk: fast, mechanical relief

Psyllium husk absorbs water and forms a gel in your gut, bulking and softening stool. It works quickly and is well tolerated by most people, including many with IBS. What it doesn't do much of is feed your gut bacteria. It passes through largely unfermented.

PHGG: relief that also feeds your gut bacteria

Partially hydrolysed guar gum (PHGG), sometimes sold under the brand name Sunfiber, takes a slower route. Your gut bacteria ferment it gradually, easing bloating and irregularity while also producing the compounds that support a healthy gut lining. It's one of the five fibres in our Gut Health blend for exactly this reason.

Psyllium husk

Bulks and softens

Forms a gel in the gut, relieving symptoms quickly. Passes through largely unfermented, so it doesn't feed your gut bacteria much.

PHGG (Sunfiber)

Relieves and feeds

A slowly fermented fibre that eases bloating and irregularity while also feeding beneficial gut bacteria. It's one of the five fibres in our Gut Health blend.

Psyllium and PHGG aren't competing solutions. They just work differently. Fast, mechanical relief is psyllium's strength. Relief that also feeds your gut bacteria is why PHGG is part of our blend.

Already part of the blend

PHGG is one of the five prebiotic fibres in our Gut Health blend, chosen because it eases digestive symptoms while also feeding your gut bacteria, not just one or the other. One spoonful, stirred into whatever you're already having.

Researched with

Not sure which fibres you need?

Six questions about your digestion, energy and diet. We'll point you to the right blend.

Take the gut quiz Takes about a minute

Keep reading

Gut Health 30 Jul 2026

From Biohacking to Bioharmony: the softer wellness trend of 2026

Forget the numbers and the spreadsheets. Wellness in 2026 is all about going with the flow.

Beat seasonal allergies and ease inflammation

Gut Health 16 Jul 2026

Beat the seasonal allergies and ease inflammation

Ah summer - sunshine, beach days, and unfortunately also seasonal allergies. But fret not! Here are some of our favourite foods to ease inflammation, support your immune system and alleviate those pesky symptoms.

Gut Health 09 Jul 2026

High protein or high fibre? What should I be focusing on?

Social media is obsessed with protein. From shakes to bars, it’s the nutrient everyone’s talking about. But here’s the catch. Only around 10% of people are actually protein deficient. Instead, we continue to ignore a nutrient that 90% of us are deficient in. That’s right, it’s time fibre had its moment.