wann am besten kefir trinken — when to see a doctor?

The optimal time to drink kefir and when to see a doctor cannot be determined from the provided context. General advice suggests consuming kefir on an empty stomach in the morning or with meals to aid digestion, but evidence is weak and individual. A doctor should be consulted if you experience persistent digestive issues, lactose intolerance symptoms, or adverse reactions after kefir consumption. The available context covers DNA and microbiome tests, not kefir specifically. Therefore, evidence is unclear. Caveat: kefir is a food, not a treatment; seek medical advice for any concerning symptoms.