Environmental enteropathy (EE) is a syndrome affecting the gut characterised by villus blunting, reduced nutrient absorption and microbial translocation in children and adults experiencing a high burden of enteric infection due to inadequate access to clean water and sanitation.

We will conduct coordinated randomised controlled trials in six countries to determine if supplementation with indispensable amino acids (IAAs) can improve intestinal barrier dysfunction in six geographically diverse populations of 18–36 months old children with stunting or severe stunting. All trials will measure the same primary outcomes while secondary outcomes will be measured on a per-trial basis using standardised protocols across the project. The primary endpoint will be change in gut permeability as assessed by the lactulose/rhamnose ratio. Secondary endpoints include changes in amino acid and carbohydrate absorption using novel, isotope tracer tests. Other prespecified outcome measures include changes in EE biomarkers and child weight. IAA supplementation will be given daily for 28 days and evaluation of the major endpoints will be at baseline and after 28 days of supplementation.

Ethical approval will be obtained from the Research Ethics Committee at each participating site. Caregivers will provide written informed consent for each participant. Findings will be disseminated through peer-reviewed journals, conference presentations and face-to-face meetings with participant caregivers.

CTRI: CTRI/2024/06/069187 (India); ClinicalTrials.gov (NCT06617130, Malawi; NCT06676215, Philippines and NCT07256028, Morocco); Ongoing (Zambia); Ongoing (Morocco); PACTR: (PACTR202311714091884, Ghana).