SERPINA1 and gastroenteritis: Concurrent findings show that several fecal biomarkers, namely myeloperoxidase (MPO; indicates intestinal inflammation), neopterin (NEO; indicates intestinal inflammation), and alpha-1 antitrypsin (AAT; indicates loss of enteric proteins and intestinal permeability), are associated with EED and thus have been proposed as noninvasive alternatives for the diagnosis of EED.11