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PHGG (partially hydrolysed guar gum)

The gentle, low-gas fibre — great for sensitive guts and IBS, and certified low-FODMAP.

Reviewed by Bodil Isaksson, Licensed Biomedical Scientist (Sweden)Last reviewed July 2026Supplement guide

SupplementsFiberSoluble fibreIBSLow-FODMAP

PHGG (sold as Sunfiber) is guar-bean fibre broken down into a non-thickening, fully soluble form. That makes it unusually easy on the gut — its main selling point.

Key takeaways

  • Well tolerated and certified low-FODMAP — much less bloating/gas than inulin.
  • Eases IBS symptoms and can regulate stool both ways (constipation and diarrhoea).1
  • Fermentable — acts as a mild prebiotic, raising beneficial bacteria and SCFAs.
  • Dissolves clear and tasteless in water or food — convenient for daily use.

What it is

Guar gum (from the guar bean) that has been partially hydrolysed so it no longer thickens liquids. It stays fully soluble and is slowly fermented in the colon.

The evidence

Clinical studies show PHGG improves IBS symptoms and normalises bowel habit, with high tolerability and a prebiotic shift in the microbiome.1 It is a common choice when other fibres cause too much gas.

Dose

5–7 g/day, stirred into water or food. Because it’s gentle you can usually reach the full dose quickly.

Safety

Excellent tolerability; minimal gas. As with any fibre, take with adequate fluid and space out from medicines.

Bottom line: the fibre for sensitive guts — low-FODMAP, low-gas, and good for IBS in either direction; less potent for cholesterol than viscous fibres.

References

Adult research summary for education, not a prescription.

  1. Giannini EG, Mansi C, Dulbecco P, Savarino V. Role of partially hydrolyzed guar gum in the treatment of irritable bowel syndrome. Nutrition, 2006;22(3):334–42. (Narrative review — no systematic review of PHGG in IBS has been published.) pubmed.ncbi.nlm.nih.gov

This article summarises nutrition science for education. It is not a substitute for individual medical advice; consult a professional before starting a supplement, in pregnancy, or alongside medication.