Partially hydrolyzed guar gum

Tier 3 — weak evidence · Soluble fibre · IBS · Prebiotic

Acid-hydrolysed galactomannan from guar bean. Unlike whole guar (which is too viscous and causes gut blockages historically), the partial-hydrolysate form is well tolerated and has small-RCT evidence in IBS-C, IBS-D, and functional constipation. Acts as a gentle prebiotic favouring Bifidobacterium and butyrate producers. Preferred over inulin/FOS in patients sensitive to fermentable fibres.

Dose: 5-7 g/day (gradually titrate from 2.5 g)