What should I know about ist kefir gesund guide?

Your question about whether kefir is healthy is valid, but the provided context contains no information about kefir, probiotics, or diet. Therefore, I can only share general evidence-based knowledge: Kefir is a fermented milk drink rich in probiotic bacteria and yeasts. Studies suggest benefits for gut health, lactose digestion, and possibly immune modulation. However, the evidence is mostly mechanistic or observational; large randomized controlled trials are lacking. For individuals with lactose intolerance, kefir may be better tolerated due to reduced lactose content from fermentation. Important: Kefir is not a medicine and should not replace medical treatment. Quality varies widely between commercial and homemade versions. Without specific sources from the context, the evidence level is best described as 'practice' (practice-based). For personalized advice, biomarkers such as gut microbiome analysis or lactose tolerance tests would be more relevant than DNA tests.