Are gut microbiome tests accurate or useful?

Dear Anonymous,

They might be useful in the next five to 10 years when our understanding is more nuanced and we have more data, but I don’t think they offer much at this point. The gut microbiome — or the trillions of organisms that live in our gut— is like a fingerprint. It’s so individual, and we don’t know enough to look at the test results and say for sure that one microbiome is healthy and one is not. There’s also a lot of variation between the testing processes of different companies. 

Here’s how the tests generally work: 

• Stool sample. You’ll be directed to collect a stool sample and ship it to the company.  

• Analysis. The company will extract DNA from the sample to see which bacteria and other organisms are present. But it may not capture an accurate picture of the gut because some organisms adhere to the gut lining and don’t show up in stool, while other DNA may be from dead bacteria. 

• Report. You’ll receive an analysis that may tell you the overall diversity of the sample (a diverse gut is typically a good sign) or whether the findings are associated with a certain condition. Some companies will give you personalized nutrition advice based on the findings. Just make sure to review the company’s privacy policy because this information is highly personal and should remain confidential. 

Featured Expert

Dr. Rashmi Advani - Gastroenterologist at Cedars Sinai Medical Center in Los Angeles