Thinking about trying one of those at-home gut microbiome tests? A new study suggests you may want to read the results with caution.Growing interest in gut health has fueled a surge in at-home tests that examine your gut bacteria — and turn the results into personalized health reports.Researchers analyzed 21 direct-to-consumer gut microbiome kits from seven different companies.All of the kits tested the exact same combined stool sample from an individual donor — but the results didn’t match.The reported levels of certain bacteria varied widely. One example: the genus Clostridium, which includes harmful bacteria like C. diff.While data from the American Gut Project shows average levels just over 2.5%, one company reported five times that amount — and three others didn’t detect it at all in at least one sample.Even more surprising, researchers say, when three identical samples were sent to the same company, one was labeled “unhealthy” — while the other two were labeled “healthy.”The authors believe differences in sampling, processing, and analysis methods likely explain the inconsistencies.They suggest standardizing testing procedures could help improve accuracy. Source: Communications BiologyAuthor Affiliations: National Institute of Standards and Technology, University of Maryland School of Medicine, The NEST: A Biotechnology Consulting Firm, University of Maryland School of Law.Sign up for our weekly HealthDay newsletter