Magen-Darm-Gesundheit: which blood markers matter?

The question about which blood markers matter for gastrointestinal health is not directly addressed in the provided context. The available information focuses on DNA tests (e.g., TCF7L2 for carbohydrate metabolism) and microbiome analyses (stool samples), not blood parameters. Clinically established blood markers for gut health include CRP (systemic inflammation), celiac serology (tTG IgA), vitamin B12, ferritin, and liver enzymes. However, these are not offered as blood tests in the referenced MyBody-X products. The evidence for the utility of individual blood markers in functional gastrointestinal disorders is mixed; routine screening without clinical indication is not recommended. Note: Blood tests should always be interpreted by a physician, especially when suspecting inflammatory bowel disease or malabsorption. Since the context provides no direct support, the evidence grade is marked as 'unclear'.