Should I take a gut health supplement? Read this first

Most people don’t need one. In the UK a gut health supplement is sold as a food, not a medicine, so nobody has to show it works before it reaches the shelf. There’s some evidence for probiotics in IBS and little for many other claims. If you’re tempted, ask a pharmacist or GP before you buy.

Most people get the nutrients they need from a varied and balanced diet, though some people do need a supplement for a specific reason. A gut capsule bought on the strength of its packaging is rarely that reason.

How are gut health supplements regulated in the UK?

As food. A food supplement is legally a concentrated source of a nutrient or other substance, sold in dose form to supplement a normal diet. It isn’t a medicinal product, and its use isn’t meant to treat or prevent disease.

That has consequences for what’s in the tub. Probiotics don’t go through the testing medicines do, and because of how they’re regulated, nobody can always be sure that a product contains the bacteria on its label, contains enough of them to have an effect, or that they survive long enough to reach your gut.

The label does have to carry a few things: the words “food supplement”, the recommended daily amount with a warning not to exceed it, and a statement that supplements shouldn’t be used as a substitute for a varied diet. That last line is worth reading twice.

What is a gut supplement allowed to claim?

Far less than the packaging tends to suggest. In Great Britain a health claim on food has to be authorised and listed on the official register, and “gut friendly” isn’t one of them. The word “probiotic” is itself treated as a health claim. Authorised claims about the immune system exist for named vitamins and minerals, such as vitamin C, vitamin D and zinc, and none exists for live cultures.

So if a probiotic pack mentions your immune system, look in the small print for an added vitamin or mineral, because that’s the only place an authorised immune claim can come from. The rules are set out in probiotic and live cultures on labels and what gut friendly means on a UK label.

Do probiotic supplements work for gut health?

For some people with IBS, possibly. For healthy people, probably not. There’s some evidence that probiotics may ease some IBS symptoms, and the 2021 guideline for UK gut specialists says probiotics as a group may help, while adding that it isn’t possible to recommend any specific species or strain. For someone who is healthy, the British Dietetic Association says a probiotic supplement is unlikely to be beneficial.

Part of the problem is that “probiotic” covers many different organisms. A type that helps with one problem won’t necessarily help with another, and the products that show promise in clinical trials can be a long way from what’s sold in shops.

The good, the bad and the verdict on a typical gut capsule

The good: for most people with a healthy immune system, probiotics appear safe, and some people with IBS find one helps.

The bad: you can’t be sure what’s inside or how much of it survives, the evidence depends on the strain, and the wording on the front can suggest far more than any authorised claim says.

The verdict: not something I’d buy on the strength of the label. If you have a gut condition and want to try a probiotic, ask a dietitian which one has the best evidence for your symptoms. For what it’s worth, I have no gut symptoms now and take no tablets. What I did change was how I eat: I prep my food and I take every break.

What about the other gut supplements on the shelf?

If the plan sold alongside the supplement is a three or seven day programme, does a gut reset work covers that half.

Who should talk to a doctor before taking one?

Anyone with an existing health condition or a weakened immune system should talk to a doctor before taking any probiotic supplement.

If you take any medicine, prescribed or bought, check with a pharmacist before adding a herbal product. Some don’t mix with common medicines, including metformin for diabetes, ramipril for blood pressure, the blood thinner warfarin and the combined pill. The combination can cause harmful effects or stop your medicine working.

What should I ask a pharmacist or GP?

A pharmacist is often the easiest person to ask, and checking how a product sits with your medicines is part of their job. Take the tub, or a photo of the label and ingredients.

• Does this interact with anything I already take?
• Is there evidence for this product for my symptom, or only for the claim on the front?
• Should my symptoms be checked by a GP before I try anything?
• If I try it and nothing changes, what should I do next?

If you’d like to practise spotting claims that sound official and aren’t, the label test quiz takes a few minutes.

When a supplement is the wrong question

Don’t let a supplement stand in for an appointment. See a GP if you feel bloated regularly, if you’ve tried changing your diet and keep feeling bloated, or if you have bloating with weight loss you can’t explain or with blood in your poo. If you have bloating with a swelling or lump in your tummy, or you cannot pee, poo or fart, ask for an urgent GP appointment or call 111.