Kefir Darm: which blood markers matter?

Kefir is often promoted for gut health, but which blood markers actually matter? The evidence is mixed. Potential markers include inflammatory markers (hs-CRP, IL-6, TNF-α), gut permeability markers (zonulin, LPS), lipid profile (LDL, HDL, triglycerides), and fasting glucose/insulin. Some small studies show modest improvements in inflammatory markers after kefir consumption, while others find no significant change. The evidence is best described as 'mechanistic' to 'mixed' – many studies lack robust controls or are underpowered. Additionally, the effect depends on kefir composition, baseline microbiota, and overall diet. No single blood marker reliably captures gut health improvements from kefir. A comprehensive assessment including stool markers (e.g., calprotectin) and clinical symptoms is more informative. Caution: Blood markers alone cannot diagnose 'leaky gut' or dysbiosis. Always consult a physician for interpretation.