warum vertrage ich plötzlich keinen kaffee mehr — can a microbiome test help?

Sudden coffee intolerance can have several causes, not all of which can be clarified by a microbiome test. Genetic factors often play a role: variants in the CYP1A2 gene affect caffeine metabolism – slow metabolizers may experience jitters, palpitations, or sleep disturbances after coffee. Histamine intolerance (DAO gene variants) can also make coffee problematic as a histamine liberator. A microbiome test can show the composition of gut flora, but a direct link to coffee intolerance is not well supported by evidence. Changes in the microbiome due to antibiotics, diet shifts, or stress might contribute to symptoms like bloating or heartburn after coffee, but the evidence for a specific 'coffee dysbiosis' is weak. A more useful first step would be a food diary, an elimination trial, or a genetic test for caffeine metabolism. A microbiome test can provide additional hints about general dysbiosis but does not replace medical evaluation for new-onset intolerances.