Environmental enteric dysfunction and water, sanitation, and hygiene conditions in childhood chronic malnutrition: a systematic review

Abstract

Objective: To synthesize the evidence on the association between poor water, sanitation, and hygiene conditions and environmental enteric dysfunction, as well as their relationship with chronic malnutrition or linear growth faltering in children under 5 years of age.

Methods: Systematic review without meta-analysis, reported according to PRISMA 2020. Original studies published in Spanish or English from January 2020 up to the search date were identified through searches in PubMed/MEDLINE, Embase, Scopus, Web of Science, and LILACS. Studies in children aged 0–59 months evaluating environmental exposures or environmental enteric dysfunction measured by biomarkers, permeability tests, or intestinal histomorphology were included. Selection was performed by two reviewers and synthesis was narrative.

Results: Nineteen studies were included. Evidence showed a biologically plausible, but non-uniform, association between unfavorable environmental exposure, environmental enteric dysfunction, and impaired linear growth. Combined nutrition and water, sanitation, and hygiene interventions did not produce consistent additive benefits. Comparability was limited by heterogeneity in biomarkers, exposure pathways, and settings, and the greatest vulnerability was concentrated in the prenatal period and the first 6 months of life.

Conclusions: The association was biologically supported, but depended on context, exposure pathway, and diagnostic method. More targeted interventions and longitudinal biomarkers with greater clinical utility are needed.