The current gold standard diagnostic test for EE is intestinal biopsy and histological analysis. Histological changes observed include: * Villous blunting * Crypt hypertrophy * Villous fusion * Mucosal inflammation However, this procedure is considered too invasive, complex and expensive to be implemented as standard of care. As a result, there are various research efforts underway to identify biomarkers associated with EE, which could serve as less invasive, yet representative, tools to screen for and identify EE from stool samples. In an effort to identify simple, accurate diagnostic tests for EE, the Bill and Melinda Gates Foundation (BMGF) has established an EE biomarkers consortium as part of their Global Grand Challenges initiative (specifically, the Discover Biomarkers of Gut Function challenge). So far, various biomarkers have been selected and studied based on the current understanding of EE pathophysiology: * Gut permeability/barrier function * Dual sugar permeability (lactose-to-mannitol ratio) * Intestinal inflammation * Alpha-1 anti-trypsin * Neopterin * Myeloperoxidase * Exocrine (hormonal) markers * Bacterial translocation markers * Endotoxin core antibody * Markers of systemic inflammation * Alpha-1 glycoprotein * C-reactive protein (CRP) It is postulated that the limited of understanding of EE is partially due to the paucity of reliable biomarkers, making it difficult for researchers to track the epidemiology of the condition and assess the efficacy of interventions. Classification In the 1960s, researchers reported a syndrome of non-specific histopathological and functional changes to the small intestine in individuals living in unsanitary conditions. This syndrome was observed predominantly in tropical regions across Latin America, sub-Saharan Africa and Asia. The geographic distribution of the syndrome lead to the original term of "tropical enteropathy" (sometimes also "tropical jejunopathy"). Following initial reports, further investigation revealed that these symptoms were not specific to tropical climates. For example, individuals in more wealthy tropical countries, such as Qatar and Singapore, did not exhibit these symptoms. Similarly, subsequent studies have shown this condition to be common across the developing world, closely associated with impoverished conditions but independent of climate or geography. As a result, the term<unk> " was introduced to specify that this condition is not only found in tropical areas and is believed to be caused by<unk>  factors.
Environmental enteropathy
Autoimmune enteropathy
Natural killer cell enteropathy
Tropical sprue
Congenital tufting enteropathy
Coeliac disease
Food protein-induced enterocolitis syndrome
Protein losing enteropathy