Most Australian adults fall short of the recommended fibre intake of about 25 g (women) and 30 g (men) per day. Food should be the first port of call, but supplements can help fill the gap. The three main types behave quite differently.

Psyllium husk forms a gel in the gut. It’s well supported for relieving constipation, can also help with loose stools, and has good evidence for modestly lowering LDL cholesterol. It’s often the best-tolerated all-rounder.

Inulin is a prebiotic fibre that feeds beneficial gut bacteria. That fermentation can cause gas and bloating, especially at higher doses, and it may not suit people with irritable bowel syndrome or those following a low-FODMAP diet.

Guar gum (often sold as partially hydrolysed guar gum, or PHGG) is fermentable but generally gentler than inulin. Some studies show benefits for both constipation and diarrhoea in IBS.

Whichever you choose, start with a small dose and increase slowly over a couple of weeks, and drink plenty of water. Take fibre supplements at least two hours apart from medications, as they can affect absorption.

Bottom line: Psyllium suits most people. Inulin and guar gum suit specific goals, but go slowly.