Partially hydrolysed guar gum (PHGG)

Tier 2 — promising · IBS · Prebiotic · Gut regularity

A water-soluble prebiotic fibre that normalises bowel habits in both constipation and diarrhoea-predominant IBS. Unlike psyllium, PHGG dissolves completely without thickening and is tasteless. A 2024 systematic review of 12 trials confirmed significant improvements in IBS symptom scores. Well tolerated with less bloating than other prebiotic fibres due to slow fermentation.

Dose: 5–7 g/day dissolved in any liquid; start at 3 g/day and increase over 1–2 weeks