Evidence check: Progesteron in the context of Darmgesundheit

Progesterone is a sex hormone primarily known for its role in the menstrual cycle and pregnancy, but it also has direct and indirect effects on gut health. Mechanistically, progesterone relaxes smooth muscle, slowing gut motility – this explains common constipation during the luteal phase or pregnancy. It also modulates immune function and may influence intestinal permeability ('leaky gut'). Some research suggests bidirectional interactions with the gut microbiome: certain bacteria can metabolize progesterone, and progesterone may alter microbial composition. However, the evidence base is largely mechanistic, derived from in vitro or animal studies. High-quality human trials demonstrating a causal link between progesterone levels and specific gut disorders are lacking. Consumer tests for progesterone (e.g., saliva or blood) measure only a single time point, which fluctuates greatly with the cycle, and cannot assess gut health. Hormone testing should always be interpreted by a physician. Overall, the progesterone–gut connection is biologically plausible but not sufficiently evidence-based to guide clinical or dietary recommendations.