When is Kefir Check actually useful?

Based on the provided context, there is no specific information about a 'Kefir Check'. In general, such a test might be useful for individuals interested in monitoring gut health or tolerance to fermented dairy. However, evidence for direct health benefits from kefir checks is limited; many claims rely on individual responses rather than robust clinical studies. Without concrete data from the context, the assessment remains cautious: usefulness depends heavily on personal circumstances and should not be taken as a medical diagnosis.