Evidence check: Leaky Gut Test in the context of blood sugar

The scientific evidence for 'leaky gut' tests (e.g., zonulin, LPS-binding protein) in relation to blood sugar is weak to conflicting. While animal and small human studies suggest increased intestinal permeability may be linked to systemic inflammation and insulin resistance, there are no standardized, validated biomarkers or established clinical cutoffs. Most commercial tests lack approval from medical societies and are not recommended for routine use. A positive result does not reliably predict blood sugar dysregulation, nor does a negative result rule out metabolic issues. For blood sugar assessment, validated measures like fasting glucose, HbA1c, and oral glucose tolerance tests remain the gold standard. Evidence grade: mixed/unclear. Caveat: do not base dietary or therapeutic decisions solely on leaky gut test results.