Partially Hydrolysed Guar Gum
Also known as: PHGG, Sunfiber®, Hydrolysed guar fibre
PHGG is a 20–25 kDa galactomannan fragment that is slowly and almost completely fermented in the colon to SCFAs (particularly butyrate via bifidogenic cross-feeding). Unlike intact guar gum it does not form a viscous gel, avoiding texture and tolerability issues.
Last reviewed: 2025-01-15 · 3 indexed studies
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Overview
A water-soluble, low-viscosity prebiotic fibre produced by enzymatic hydrolysis of guar bean (Cyamopsis tetragonoloba) galactomannan. Unique in being a clinically effective fibre that is both low-FODMAP and bowel-normalising — improving both constipation and diarrhoea predominant IBS.
Mechanism & Function
Mechanism of Action
Selectively fermented by Bifidobacterium and Faecalibacterium populations, increasing butyrate production. Butyrate is the primary energy source for colonocytes and normalises water absorption and motility — explaining the bidirectional benefit for both IBS-C and IBS-D.
Physiological Role
Restores SCFA production in low-fibre diets; supports a bifidogenic microbiota.
Primary Pathways
Performance / Health Relevance
Low-FODMAP-certified fibre suitable for athletes with sensitive GI tracts; supports regularity without the bloating typical of bulk fibres.
Evidence Review
No meta-analyses or systematic reviews indexed for this ingredient yet.
Dimensions marked N/A have no indexed evidence of that class. They are shown as unavailable rather than scored.
Practical Use & Dosage
- Minimum Effective Dose
- 3 g/day
- Optimal Range
- 5–10 g/day
- Upper / Caution Level
- 20 g/day well tolerated
- Timing
- Once daily, dissolved in any liquid (tasteless, transparent)
- Best Format
- Soluble powder (Sunfiber®); also available in functional foods
- Bioavailability
- Fully soluble at any temperature, no gelling.
- Absorption Considerations
- Acts in the colon; effects on stool form typically seen by 2–4 weeks.
Safety & Interactions
Side Effects
- •Mild gas during first week (lower incidence than inulin or FOS)
Contraindications
- Severe bowel obstruction
Drug Interactions
- •Minimal — does not affect drug absorption like viscous fibres
Who Should Avoid
- •Patients with severe stricture disease
Monitoring
None.
Frequently Asked Questions
Auto-generated from indexed evidence — dosage, safety, interactions, and more.
When is Partially Hydrolysed Guar Gum typically used or indicated?
Partially Hydrolysed Guar Gum is most commonly used for: IBS-C and IBS-D, Low-FODMAP regularity aid, SIBO recovery, Bowel normalisation. Restores SCFA production in low-fibre diets; supports a bifidogenic microbiota.
How does Partially Hydrolysed Guar Gum work?
Selectively fermented by Bifidobacterium and Faecalibacterium populations, increasing butyrate production. Butyrate is the primary energy source for colonocytes and normalises water absorption and motility — explaining the bidirectional benefit for both IBS-C and IBS-D.
What is the recommended dose of Partially Hydrolysed Guar Gum?
The optimal range is 5–10 g/day. with a minimum effective dose of 3 g/day. Best taken: Once daily, dissolved in any liquid (tasteless, transparent). Upper / caution level: 20 g/day well tolerated.
What are the side effects of Partially Hydrolysed Guar Gum?
Reported side effects include: Mild gas during first week (lower incidence than inulin or FOS). Monitoring: None.
Does Partially Hydrolysed Guar Gum interact with medications?
Known or theoretical interactions: Minimal — does not affect drug absorption like viscous fibres. Always check with a clinician before combining with prescription medication.
Who should avoid Partially Hydrolysed Guar Gum?
Partially Hydrolysed Guar Gum is generally not recommended for: Patients with severe stricture disease; and Severe bowel obstruction.
How strong is the evidence for Partially Hydrolysed Guar Gum?
Evidence level: Strong (overall score 76/100), based on 3 indexed studies on SuppIndex.
Research & References (3)
Randomised clinical trial: partially hydrolysed guar gum vs lactulose in chronic constipation
Polymeros D et al. 4-week RCT — PHGG matched lactulose for stool frequency improvement with significantly fewer side effects.
Beneficial effect of partially hydrolysed guar gum on IBS in a randomised controlled trial
Parisi G et al. 12-week RCT — PHGG and wheat bran both improved IBS symptoms; PHGG was significantly preferred and better tolerated.
Partially hydrolysed guar gum is bifidogenic in healthy adults: an RCT with stool metagenomics
Yasukawa Z et al. 3-week PHGG supplementation significantly increased Bifidobacterium and Faecalibacterium populations and butyrate production.
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Research Overview
Strong EvidenceCite this ingredient
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Stable URL
https://thesuppindex.com/ingredients/partially-hydrolysed-guar-gum
SuppIndex. (2026). Partially Hydrolysed Guar Gum: Evidence summary, dosage and clinical studies. Retrieved October 16, 2026, from https://thesuppindex.com/ingredients/partially-hydrolysed-guar-gum
Based on 3 indexed studies · Evidence level: Strong.
Goal Ratings
Stack Compatibility
Excellent prebiotic partner for B. longum BB536 and other Bifidobacterium strains. Low-FODMAP certified — suitable during elimination phase.