wann sollte man am besten kefir trinken — what does this mean exactly?

The optimal timing for drinking kefir is not clearly established by scientific evidence. Common wellness advice suggests consuming it in the morning on an empty stomach or before bed to support gut health. However, the provided context focuses on DNA tests, cortisol, and microbiome analyses, not on kefir specifically. Therefore, the evidence grade is 'unclear' or 'practice'. Caveat: Individual tolerance and health goals matter; for some, kefir on an empty stomach may cause discomfort. No specific studies or guidelines are available in the given context.