What role does FT4 play in Darmgesundheit?

FT4 (free thyroxine) is a thyroid hormone that can indirectly influence gut health. Thyroid hormones regulate basal metabolic rate, gut motility, and intestinal barrier function. Hypothyroidism (low FT4) is associated with constipation, dysbiosis, and increased intestinal permeability, while hyperthyroidism (high FT4) can cause diarrhea and accelerated transit. The provided context lacks direct studies on FT4 and gut health; evidence comes from clinical observations and mechanistic models. Importantly, FT4 is not measured in typical consumer DNA tests (e.g., MyBody-X) – it is a blood biomarker that should only be assessed by a physician. Its effect on the microbiome is indirect and highly individual. Interpreting FT4 values without clinical context is not meaningful. Evidence: mechanistic/unclear.