Impact of indispensable amino acid supplementation on gut function in children at high risk of environmental enteropathy: protocol for an international coordinated group of randomised controlled trials

Introduction 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. Methods and analysis 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.