warum vertrage ich plötzlich keinen kaffee mehr — what are common causes?

Sudden coffee intolerance can have many causes not solely explained by genetic tests. The provided context contains no direct information on caffeine metabolism (e.g., CYP1A2) or caffeine sensitivity (ADORA2A). Genetic variants in these genes can influence caffeine processing, but evidence is often weak and not clinically actionable. Other common causes include: altered gut microbiome (e.g., after antibiotics), stress, hormonal changes (e.g., pregnancy), medication interactions, or developing gastric irritation. The variants mentioned in the context (COMT, ADRB2, NQO1) have no proven link to sudden coffee intolerance. Consumer DNA tests tend to overstate clinical relevance. If symptoms persist, consult a doctor to rule out organic causes. Evidence: unclear, as the context does not provide specific studies.