Table 1.

Reference ranges for biomarkers, interpretation, and detection limits.

Biomarker	Ranges	Interpretation	Limit of Quantification
Calprotectin	<80 µg/g	Normal	Lower: ≤28.2 μg/g
	80–160 µg/g	Borderline/gray zone
	>160 µg/g	Elevated	Upper: ≥1002 μg/g
Zonulin	≤105 ng/mL	Normal	Lower: ≤0.241 ng/mL
	>105 ng/mL	Elevated	Upper: ≥170 ng/mL
sIgA	<510 µg/mL	Subnormal	Lower: ≤310 µg/mL
	510–2040 µg/mL	Normal
	>2040 µg/mL	Elevated	Upper: N/A a

Legend:^a—the upper limit was not available (N/A); samples above the reference standard curve values were diluted with wash buffer and measured again.