wie lange nichts essen vor blutabnahme — can a microbiome test help?

The question of how long to fast before a blood draw is medically clear: for fasting blood values (glucose, triglycerides, LDL cholesterol), 8–12 hours of fasting is usually required. A microbiome test cannot replace or influence this requirement. Microbiome tests analyze the composition of gut bacteria, not acute metabolic parameters in the blood. Even if a microbiome test suggests altered digestion, it does not change the need for fasting before blood collection. The evidence for microbiome tests predicting blood lipid levels is weak and purely mechanistic. Rely on your doctor's fasting instructions, not a stool test.