Myths vs facts: Stuhlprobe and Blutzucker

A common myth is that a stool sample can directly measure blood sugar levels. This is false: blood glucose is determined exclusively in blood (e.g., fasting plasma, HbA1c, continuous glucose monitoring). A stool sample, in contrast, analyzes gut microbiome composition, nutrient and mineral levels, and inflammatory markers in stool. However, there is scientific evidence that the gut microbiota can influence glucose metabolism – for instance via short-chain fatty acids that modulate insulin sensitivity. Studies show associations between certain bacteria (e.g., Bifidobacterium) and a more favorable blood sugar profile. These links are mechanistic and observational, not causal. A stool test can therefore provide indirect clues about metabolic risk, but it does not replace blood glucose measurement. MyBody-X’s Nährstoff | VitalCheck Complete offers an overview of minerals and vitamins from stool, not glucose. Anyone wanting to understand their blood sugar should rely on established blood parameters. The evidence for direct blood sugar diagnostics via stool is absent; the microbiome–glucose connection is promising but not yet ready for clinical decisions.