Myths vs facts: LCT and Darmgesundheit

The LCT gene encodes lactase, the enzyme that breaks down lactose (milk sugar). A common myth is that a single LCT variant (e.g., rs4988235) fully determines dairy tolerance. Fact: Genetics influence lactase persistence, but gut health depends on microbiome, diet, inflammation, and more. Many people with 'lactose intolerance' tolerate small amounts or fermented dairy. Another myth: lactose intolerance is a disease – it is a normal adult state in most of the world. The gut microbiota can adapt, so symptoms are not purely genetic. A DNA test offers clues, not a diagnosis. For persistent issues, consult a doctor. Evidence for the LCT–gut health link is moderate: strong for lactose digestion, but weaker for overall gut health due to multifactorial influences.