Environmental enteric dysfunction pathways and child stunting: A systematic review

Abstract

BackgroundEnvironmental enteric dysfunction (EED) is commonly defined as an acquired subclinical disorder of the small intestine, characterized by villous atrophy and crypt hyperplasia. EED has been proposed to underlie stunted growth among children in developing countries. A collection of biomarkers, organized into distinct domains, has been used to measure different aspects of EED. Here, we examine whether these hypothesized relationships, among EED domains and between each domain and stunting, are supported by data from recent studies.MethodologyA systematic literature search was conducted using PubMed, MEDLINE, EMBASE, Web of Science, and CINAHL between January 1, 2010 and April 20, 2017. Information on study objective, design, population, location, biomarkers, and results were recorded, as well as qualitative and quantitative definitions of EED. Biomarkers were organized into five EED domains, and the number of studies that support or do not support relationships among domains and between each domain with stunting were summarized.ResultsThere was little evidence to support the pathway from intestinal permeability to microbial translocation and from microbial translocation to stunting, but stronger support existed for the link between intestinal inflammation and systemic inflammation and for intestinal inflammation and stunting. There was conflicting evidence for the pathways from intestinal damage to intestinal permeability and intestinal damage to stunting.ConclusionsThese results suggest that certain EED biomarkers may require reconsideration, particularly those most difficult to measure, such as microbial translocation and intestinal permeability. We discuss several issues with currently used biomarkers and recommend further analysis of pathogen-induced changes to the intestinal microbiota as a pathway leading to stunting.

“If there is no water, we cannot feed our children”: The far‐reaching consequences of water insecurity on infant feeding practices and infant health across 16 low‐ and middle‐income countries

“…For instance, the use of unsafe water for formula preparation or hygiene practices (eg, poorly washed bottles) increases pathogen exposure and the risk of infectious disease, for example, cholera and diarrheal‐related mortality (Andresen, Rollins, Sturm, Conana, & Greiner, ; Ehiri et al, ; Fawzy et al, ; Peletz et al, ). Such water‐related infections, in turn, jeopardize the absorption of nutrients (Dewey & Mayers, ; Harper, Mutasa, Prendergast, Humphrey, & Manges, ; Mbuya & Humphrey, ). Few studies, though, have considered how other dimensions of water—for example, affordability, availability, accessibility, or stress related to water problems—may impact infant feeding.…”

Mechanisms linking height to early child development among infants and preschoolers in rural India

“…The integration of health into children's development is consistent with the bioecological theory of human development, which establishes the conceptual framework for the time‐dependent interactions influenced by genetics and environmental conditions that underlie children's development (Bronfenbrenner & Morris, ). Nutritional deficiencies and inflammatory processes have been associated with deficits to children's growth and health, and potentially to their development (Harper, Mutasa, Prendergast, Humphrey, & Manges, ). At the same time, there is strong evidence that maternal nurturance, characterized as a home environment with responsive parenting and opportunities for early learning, can promote children's early development through direct processes (Black, Walker, Fernald, Andersen, DiGirolamo, Lu, & Grantham‐McGregor, ; Britto, Lye, Proulx, Yousafzai, Matthews, Vaivada, & Bhutta, ).…”

Poultry husbandry, water, sanitation, and hygiene practices, and child anthropometry in rural Burkina Faso

“…Second, due to the observational nature of this study, we are limited to describing associations between WASH‐related indicators and nutrition outcomes and interpreting these associations where they exist as indications of possible pathways, or modifiable factors, through which future interventions may operate. Third, though we provide some insights on the potential links between poultry husbandry and child anthropometry, including the potential risks associated with poultry faeces, the mechanisms through which exposure to poultry faeces may be harmful to children's growth and development are still unclear and are the subject of ongoing further investigation (Harper, Mutasa, Prendergast, Humphrey, & Manges, ). Fourth, the indicators of cleanliness of mothers, children, and the household environment from the direct observations in this study likely suffer from considerable measurement error because of their reliance on observations and judgements made by survey enumerators (Ruel & Arimond, ).…”

“…One of the strengths of this study is the use of a wide range of non-standard WASH indicators-particularly those related to livestock and poultry-which allows us to document the extent of livestock contamination of the homestead environment and to explore the potential relationships with WASH practices and children's anthropometry. of ongoing further investigation (Harper, Mutasa, Prendergast, Humphrey, & Manges, 2018). Fourth, the indicators of cleanliness of mothers, children, and the household environment from the direct observations in this study likely suffer from considerable measurement error because of their reliance on observations and judgements made by survey enumerators (Ruel & Arimond, 2002).…”