wie gesund ist kefir — when to see a doctor?

Kefir is a fermented dairy product rich in probiotics, vitamins, and bioactive compounds. Current evidence suggests it may support gut health, improve lactose digestion, and have mild anti-inflammatory effects, but most studies are small or observational. The evidence level is 'human-moderate' to 'mixed'. You should see a doctor if you experience persistent digestive discomfort (bloating, diarrhea, cramps) after consuming kefir, if you have a weakened immune system (risk of opportunistic infections from live bacteria), or if you have a known intolerance to dairy or histamine. Also consult a physician if you are on immunosuppressants or have a central venous catheter. Kefir is a food, not a medicine; it cannot replace medical treatment for diagnosed conditions.