Risks and limits of Kefir Test

The so-called 'Kefir Test' is not a standardized medical test. It is typically a direct-to-consumer test that claims to assess tolerance or benefit of kefir based on DNA or microbiome data. Scientific evidence for such tests is very weak. Kefir contains live bacteria and yeasts that are generally safe for healthy individuals. However, kefir can cause bloating or diarrhea in people with lactose intolerance, histamine intolerance, or sensitive gut. A test predicting these reactions is not clinically validated. Limitations include lack of standardization, insufficient studies, and potential misinterpretation. Moreover, these tests often fail to distinguish between true allergy (IgE-mediated) and intolerance. Consumers should not rely solely on such results. If symptoms occur after kefir consumption, medical evaluation is recommended. The evidence is rated as 'marketing/unclear' because no validated studies exist.