At-Home Gut Microbiome Tests: What an International Expert Panel Says

Gut microbiome kits ask you to mail in a small stool sample. A few weeks later, you get a report on the bacteria in your gut, often with scores, charts and a list of foods or supplements to buy. If bloating or irregular bowels have worn you down, a detailed map can feel like progress. Here is what an international panel of microbiome experts concluded about these tests.

Who weighed in

In 2024, 69 experts from 18 countries, including gastroenterologists, microbiologists and data scientists, agreed on statements about microbiome testing in clinical care. Each statement needed at least 80% agreement.¹ They noted that direct-to-consumer tests have spread without agreed rules or proven clinical value.¹

What they concluded

• Not ready for routine use. There is currently insufficient evidence to widely recommend routine microbiome testing in clinical practice.¹
• Don’t self-order. Because evidence for clinical use is limited, they discourage patients from requesting microbiome tests directly without a clinical recommendation.¹
• No treatment advice in the report. They discourage testing providers from including post-test treatment advice.¹ Some consumer reports include diet plans or supplement suggestions.
• Be wary of certain scores. They discourage reporting the Firmicutes-to-Bacteroidetes ratio, say there’s insufficient evidence for any “dysbiosis index,” and say there generally isn’t enough information to set strict healthy ranges for individual species.¹

If you’ve already done a test

• Don’t change prescribed treatment or diet because of it. The panel says patients shouldn’t stop their usual therapy or diet before testing unless their doctor recommends it,¹ and the same caution makes sense afterward.
• You can ask for your raw data, which the panel says may be provided on request, for example for a second opinion.¹
• Bring the report to a clinician as background, not a diagnosis.

Symptoms that need a visit, not a kit

NIDDK lists anemia, rectal bleeding, bloody or black, tarry stools, and weight loss as symptoms that may point to something other than irritable bowel syndrome. Your doctor will also ask about family history of celiac disease, colon cancer and inflammatory bowel disease.² If any apply, book an appointment.

Before you order

Ask yourself what decision the result would change. If the honest answer is “I’d buy what the report recommends,” the panel’s view is that the report shouldn’t be making those recommendations.¹

Try: “I’ve been bloated most days for months. Would any tests help us find the cause, and is a microbiome test worth it in my case?”

Bloated by Dinner includes a Belly Clock log and a Test-It list with a visit script. Use them to track symptoms against meals and bring evidence-based questions to your visit. See the book.