What to watch with LCT and gut health?

The question about LCT (lactase gene) and gut health is not covered in the provided knowledge context. In general: LCT variants (e.g., rs4988235) determine adult lactose digestion. Individuals with the lactose-intolerance genotype (C/C) produce little lactase after weaning, leading to bloating, diarrhea, and abdominal pain upon lactose consumption. The gut microbiota ferments undigested lactose, exacerbating symptoms. A direct-to-consumer DNA test for LCT can offer clues but does not replace clinical diagnosis (e.g., hydrogen breath test). Clinical relevance is moderate: many tolerate small amounts of lactose or fermented dairy. Evidence is robust (human studies, guidelines) but absent from the given context, so the evidence level is marked 'unclear'. Safety note: persistent gut issues warrant medical evaluation before dietary changes.