Supplements for bloating: what I took and what the evidence says

The best-evidenced option here. A meta-analysis of 10 randomised trials found it superior to placebo for both global IBS symptoms (number needed to treat 4) and abdominal pain (number needed to treat 7). The ACG 2021 IBS guideline recommends it across all subtypes for short-term relief, though it grades the recommendation conditional and the evidence low quality. Two practical points that get lost: it has to be the enteric-coated capsule, since the coating is what gets it past the stomach, and peppermint tea is not a substitute. It also relaxes the lower oesophageal sphincter, so it can worsen reflux and heartburn, which is the most common reason people stop it.

Supported in IBS guidance from both the ACG and the British Society of Gastroenterology. The critical distinction is soluble versus insoluble: psyllium has evidence behind it, whereas insoluble wheat bran is not recommended and can make IBS symptoms worse. "Eat more fibre" is not a single instruction and giving it as one has probably harmed more people with IBS than it has helped. Start at a much lower dose than the label suggests and build up over weeks, because a fast increase reliably causes a bloating flare and most people quit during it.

Well established for chronic constipation and the usual first-line osmotic laxative. Honest caveat for this audience: it is good at the constipation and much less convincing for abdominal pain and bloating in constipation-predominant IBS. If your primary complaint is distension rather than infrequent stools, it may fix the wrong thing. Not habit-forming, despite the persistent belief that it is.

Works, for the specific problem of lactose intolerance, because it supplies the enzyme you are short of. That is what makes it different from broad-spectrum enzyme blends. It is only useful if lactose is genuinely one of your triggers, which is worth establishing rather than assuming, since lactose is one of six FODMAP groups and most people react to only one or two. See the FODMAP food list.

Targets galacto-oligosaccharides, the FODMAP group in beans, lentils and some brassicas. There are several positive randomised trials, including a double-blind placebo-controlled trial in children that found reduced global distress, fewer days with moderate to severe bloating and less flatulence, plus adult crossover work. The honest caveats: the trials are small, most of the core evidence dates to the mid-1990s, and reviewers consistently note design weaknesses and call for larger studies. It is cheap and low risk, and it is only relevant if GOS is actually your trigger, which makes it a good candidate for a proper single-variable test rather than daily use.

Works as an osmotic laxative and has some trial support for constipation. Reasonable, cheap, and easy to overdo, since the same mechanism produces diarrhoea. Needs care in kidney impairment, where magnesium can accumulate dangerously. Not a bloating treatment as such, and note that magnesium marketed for sleep or anxiety is being sold on much weaker grounds.

A nine-herb combination with genuine randomised evidence in functional dyspepsia and some in IBS, which puts it well ahead of most herbal products. It carries a real safety caveat: reports of liver injury led regulators to add hepatotoxicity warnings. Worth knowing before starting, and worth stopping for if you develop jaundice, dark urine or unexplained fatigue.

Decent evidence for nausea, including pregnancy-related nausea, and some effect on gastric emptying. That is not the same as evidence for bloating, and it is often sold as though it were. Low risk, low cost, modest expectations.

An anti-foaming agent that has been sold for decades and remains poorly supported by trials. It is essentially harmless and works for some people. Reasonable to try, unreasonable to build a routine around.

The multi-enzyme capsules sold for general digestion are not backed by good evidence. The exceptions are targeted and prove the point: lactase for lactose intolerance, alpha-galactosidase for GOS, and prescription pancreatic enzyme replacement for genuine exocrine pancreatic insufficiency, which is a diagnosed condition confirmed by a faecal elastase test. If you have real pancreatic insufficiency you need a prescription, not a supplement. See which gut tests are worth it.

The AGA declined to recommend probiotics for IBS in its 2020 guideline, and suggested that patients using them for conditions where evidence is lacking consider stopping. Strain matters enormously and a few specific strains have better data than the category average, so this deserves more nuance than one line. We gave it a page: do probiotics help bloating?

Sold on the theory that bloating reflects insufficient stomach acid. That theory is not supported for the population buying it, the recommended self-titration method has no validity, and deliberately adding acid is a poor idea if you have reflux or an undiagnosed ulcer. Genuine achlorhydria exists and is diagnosed properly.

Weak evidence for gas, and a genuine drawback: it is a non-selective adsorbent, so it can bind medications taken around the same time, including the contraceptive pill and thyroid replacement. That is a real interaction rather than a theoretical one.

No meaningful evidence for bloating. Erodes tooth enamel, and can worsen reflux in the people most likely to try it.

No evidence of benefit and documented harms, including electrolyte disturbance and dependence on stimulant laxatives. The candida version rests on a diagnosis that is not established in people with normal immune systems, which we covered in candida overgrowth and bloating.

The underlying biofilm science is real and more interesting than critics allow, but the supplement evidence is entirely laboratory work with no adequately powered human trials for gut symptoms. Some of these also have antiplatelet effects that matter around surgery or anticoagulants. Full write-up: gut biofilms.

Glutamine has the most behind it and that evidence sits mainly in critical illness, burns and chemotherapy-related mucosal injury rather than in ordinary gut symptoms. Collagen and bone broth are extrapolation: dietary protein is digested to amino acids and distributed by need. See leaky gut.

Effective short term and not intended as a daily habit. The old claim that they permanently destroy bowel function is overstated, but escalating dependence is a genuine pattern and long-term use should be a decision made with a clinician rather than drifted into.