What to watch with Kefir Darm and longevity?

Kefir is often promoted as a probiotic food for gut health, and a healthy gut microbiome is linked to longevity. However, direct evidence for a life-extending effect of kefir in humans is weak. Most studies are mechanistic or animal-based. There are no randomized controlled trials showing that kefir alone extends lifespan. Instead, focus on an overall balanced diet rich in fiber, fermented foods, and low in processed products. DNA tests for longevity, as offered by some companies, are not clinically actionable (PMID: 38474735, 40079117). When choosing kefir, watch out for added sugars and opt for plain varieties. The evidence for kefir and longevity is currently 'mixed' – promising but not proven.