For a few hundred dollars you can put your poo in an envelope and post it off to a laboratory. In return you’ll get a report (sometimes generated by AI) outlining your food sensitivities, metabolic fitness, and what pathogens or fungi you’re harbouring.

These at-home gut microbiome tests or “GI mapping” kits are frequently promoted by influencers as a way to “hack your health” and “take control” through analysing some of the trillions of organisms that live in your digestive tract.

But how much can an at-home gut test really tell you, and are they actually worth doing?

Prof Rupert Leong, a gastroenterologist and microbiome researcher based at Macquarie university hospital, is increasingly seeing patients alarmed by gut microbiome reports they don’t understand.

Leong said depending on what is being analysed, gut microbiome testing can be “very powerful and accurate” in detecting microbial markers. But interpreting what those markers mean for an individual remains a major challenge, and different labs vary in their methodology, leading to differing results.

“We are still in the infancy of understanding how to interpret them,” he said.

If a gut microbiome test is ordered by a specialist doctor or accredited dietitian with a clear clinical reason, sent to a reputable lab,........

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