Labelled Carbon Sucrose Breath Test (13C-SBT) as a Marker of Environmental Enteropathy

Validation and Field-applicability of a 13C-Sucrose Breath Test to Assess Carbohydrate Uptake and Utilization in Environmental Enteropathy Among Children in Resource Poor Settings: A Multi-site Prospective Study

Linear growth failure, a manifestation of chronic undernutrition in early childhood, is a recalcitrant problem in resource constrained settings. The underlying causes of growth failure are multifactorial, but persistent and recurrent infection and inflammation of the gastrointestinal tract and immune activation, a condition commonly referred to as environmental enteropathy, is an important contributor. A highly enriched 13C-Sucrose Breath Test, a measure of sucrase-isomaltase activity, will be evaluated as a non-invasive biomarker of environmental enteropathy, and more specifically of intestinal brush border enzyme activity in 6 resource poor countries (Bangladesh, India, Jamaica, Kenya, Peru and Zambia) in 100 volunteers aged 12-15 months (total n=600) and evaluated relative to the lactose rhamnose test and linear and ponderal growth over a 3-6 month period following biomarker assessment. Field usability will also be assessed.

Environmental enteropathy is associated with linear and ponderal growth shortfalls in young children in resource constrained settings. However, the physiological alterations of intestinal function that accompany both the demonstrable evidence of inflammation and architectural changes seen in biopsies from effected children have yet to be elucidated, and this knowledge gap limits the development of effective strategies to optimally manage the condition. Furthermore, a limited number of non-invasive assays exist with which to assess the presence of environmental enteropathy in low resource settings. This study aims 1) to determine if sucrose-isomaltase enzyme is altered in children with environmental enteropathy by using a 13C-Sucrose breath test 2) to determine if the test is able to be employed in resource limited settings.

Inclusion Criteria:

All children will be recruited and enrolled through convenience sampling, either at the community level (if the study site has previously censused the community) or through child clinic visits.

Exclusion Criteria:

1. Severe acute malnutrition
2. HIV positive
3. Weight for height Z >+2
4. Known medical illness contributing to growth failure