Partially hydrolysed guar gum (PHGG)
What it is
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
Time of day & tips
Dissolves completely in any cold or hot beverage without changing taste or texture. Start at 3 g and increase to 5–7 g over two weeks to minimise initial bloating. Take at any time of day.
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