wie oft sollte man kefir trinken — can a DNA test help?

Kefir is a fermented dairy product rich in probiotics, often recommended for gut health. A common suggestion is to drink about one cup (200–250 ml) daily. The optimal frequency depends on your individual tolerance: some people tolerate kefir well, while others experience bloating, especially if they have lactose intolerance or irritable bowel syndrome. A DNA test can reveal genetic variants associated with lactose intolerance (e.g., LCT gene), but it cannot directly tell you how often to drink kefir. The available evidence includes one study (PMID:39641896) showing that small intestinal bacterial overgrowth (SIBO) can reduce lactase activity, and that treating SIBO improves lactose tolerance. This provides a mechanistic link but no specific dosage recommendation for kefir. For most people, moderate consumption is safe; if you experience bloating or diarrhea, reduce the amount or choose low-lactose versions. A DNA test alone does not replace personalized dietary advice. The evidence for genetically guided kefir intake is weak and relies mainly on association studies. Bottom line: kefir can be consumed daily, but listen to your body. A DNA test provides only one small piece of the puzzle.