Assessing environmental enteric dysfunction via multiplex assay and its relation to growth and development among HIV-exposed uninfected Tanzanian infants.

Background: Environmental enteric dysfunction (EED) may contribute to poor growth and development in young children. While validated EED biomarkers are currently lacking, multiplex assays are able to capture multiple domains of the condition. The purpose of this exploratory study was to examine the relationship between biomarkers of EED and subsequent growth and development among Tanzanian HIV-exposed uninfected (HEU) infants. Methodology: We enrolled 467 infants of mothers living with HIV who had participated in a trial of vitamin D₃ supplementation during pregnancy. Infant serum samples collected at 6 weeks (n = 365) and 6 months (n = 266) were analyzed for anti-flagellin and anti-lipopolysaccharide (LPS) IgA and IgG via ELISA as well as the 11-plex Micronutrient and EED Assessment Tool (MEEDAT), which incorporates two biomarkers of EED [intestinal fatty acid-binding protein (I-FABP) and soluble CD14 (sCD14)]. Outcomes were 12-month growth [length-for-age z-score (LAZ), weight-for-length z-score (WLZ), and weight-for-age z-score (WAZ)] and development [Caregiver Reported Early Development Instruments (CREDI) z-scores] and were assessed using linear regression. Findings: In primary analyses, higher quartiles of 6-month anti-LPS IgG concentrations were significantly associated with lower LAZ at 12 months (p_trend = 0.040). In secondary analyses, higher log₂-transformed 6-week anti-flagellin IgA and 6-month anti-LPS IgA concentrations were significantly associated with lower LAZ at 12 months. No associations were observed between I-FABP or sCD14 and infant growth. However, higher log₂-transformed 6-week sCD14 concentrations were significantly associated with lower overall CREDI z-scores, while higher log₂-transformed 6-month I-FABP concentrations were significantly associated with higher overall CREDI z-scores. Conclusions: Unlike anti-flagellin and anti-LPS Igs, MEEDAT's biomarkers of EED (I-FABP and sCD14) were not associated with subsequent linear growth among HEU infants in Tanzania. The relationship between EED and infant development warrants further study. Author summary: Growth failure can begin in utero and worsen during early infancy; environmental enteric dysfunction (EED) has been hypothesized as an important causal factor. EED is an acquired, subclinical condition of the small intestine associated with chronic exposure to an unhygienic environment where enteric pathogens persist. Histologic features include mucosal inflammation, villous blunting, altered barrier integrity, and reduced intestinal absorptive capacity. Despite EED's purported link to poor health and nutrition outcomes in young children in low- and middle- income countries (LMICs), our knowledge of EED is relatively limited and is hindered by the lack of validated biomarkers across EED's various domains. In this exploratory study, we examined the relationship between biomarkers of EED, including ones in the 11-plex Micronutrient and EED Assessment Tool (MEEDAT), and growth and development in HIV-exposed uninfected (HEU) Tanzanian infants. Overall, we found that certain anti-flagellin and anti-LPS Igs assessed at 6 weeks and 6 months were significantly associated with reduced linear growth at 12 months. EED biomarkers in MEEDAT were significantly associated with subsequent developmental, but not growth, outcomes. [ABSTRACT FROM AUTHOR]