Pathobiome driven gut inflammation in Pakistani children with Environmental Enteric Dysfunction

Abstract

Environmental Enteric Dysfunction (EED) is an acquired small intestinal inflammatory condition underlying high rates of stunting in children <5 years of age in low- and middle-income countries. Children with EED are known to have repeated exposures to enteropathogens and environmental toxins that leads to malabsorptive syndrome. We aimed to characterize association of linear growth faltering with enteropathogen burden and subsequent changes in EED biomarkers. In a longitudinal birth cohort (n = 272), monthly anthropometric measurements (Length for Age Z score- LAZ) of asymptomatic children were obtained up to 18 months. Biological samples were collected at 6 and 9 months for the assessment of biomarkers. A customized TaqMan array card was used to target 40 enteropathogens in fecal samples. Linear regression was applied to study the effect of specific enteropathogen infection on change in linear growth (ΔLAZ). Presence of any pathogen in fecal sample correlated with serum flagellin IgA (6 mo, r = 0.19, p = 0.002), fecal Reg 1b (6 mo, r = 0.16, p = 0.01; 9mo, r = 0.16, p = 0.008) and serum Reg 1b (6 mo, r = 0.26, p<0.0001; 9 mo, r = 0.15, p = 0.008). At 6 months, presence of Campylobacter [β (SE) 7751.2 (2608.5), p = 0.003] and ETEC LT [β (SE) 7089.2 (3015.04), p = 0.019] was associated with increase in MPO. Giardia was associated with increase in Reg1b [β (SE) 72.189 (26.394), p = 0.006] and anti-flic IgA[β (SE) 0.054 (0.021), p = 0.0091]. Multiple enteropathogen infections in early life negatively correlated with ΔLAZ, and simultaneous changes in gut inflammatory and permeability markers. A combination vaccine targeting enteropathogens in early life could help in the prevention of future stunting.

Gut integrity and duodenal enteropathogen burden in undernourished children with environmental enteric dysfunction

“…On the other hand, lactulose levels were marginally higher in controls while no difference was observe in the L:R ratio. This can be explained by the fact that alterations in gut barrier function are expected in even asymptomatic healthy children as they are equally exposed to varying degrees of chronic inflammation due to pathogen burden, oro-fecal contamination and exposure to environmental toxins [ 6 ]. In our study, we did not observe age-dependent or gender-dependent effect on gut-permeability measurements ( S6 Table ).…”

“…This case-control study is a part of a larger community-based intervention study called “Study of environmental enteropathy and malnutrition (SEEM), Pakistan” [ 6 ]. In the SEEM study, a birth cohort of 50 newborns was followed for six months and recruited as controls based on at least 2 consecutive months of weight for height Z score (WHZ) > 0 and height for age Z score (HAZ) > −1.0 between birth and 6 months of age.…”

“…To explore the enteric pathogen panel that included viruses, bacteria, and protozoa, Taqman Array Card (TAC) was customized to detect microbial pathogens in the duodenal aspirate (manufactured by Life Technologies, Thermo fisher, US). This card was customized to detect common enteropathogens as listed in the S7 Table at the Houpt Laboratory, University of Virginia, Charlottesville, VA [ 6 ].…”

“…Currently, intestinal biopsies are being assessed across global sites in Asia and Africa to devise a diagnostic criterion for EED using features similar to those for Marsh Scoring of celiac disease [5,6]. In adults, Kelly et al demonstrated defects in the duodenal epithelial lining that led to diminished barrier integrity and associated microbial translocation [7] suggesting an inter-relationship between enteropathogen burden and intestinal permeability.…”

“…Currently, intestinal biopsies are being assessed across global sites in Asia and Africa to devise a diagnostic criterion for EED using features similar to those for Marsh Scoring of celiac disease [ 5 , 6 ]. In adults, Kelly et al .…”