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OBJECTIVES Stunting, the most common form of childhood undernutrition, is associated with environmental enteropathy (EE). Enteric infections are believed to play a role in the pathophysiology of EE and stunting though the exact mechanism remains undetermined. The FUT2 (secretor) and FUT3 (Lewis) genes have been shown to be associated with some symptomatic enteric infections in both children and adults. These genes are responsible for the presence of histo-blood group antigens (HBGAs) in various secretions and epithelial surfaces.We evaluated whether the secretor and Lewis status influences asymptomatic enteric infections and thus EE severity on duodenal biopsies of stunted children. METHODS In this case-control study, we used saliva samples to determine the secretor and Lewis status of stunted children (cases, n = 113) enrolled in a nutritional rehabilitation program and from their well-nourished counterparts (controls, n = 42). Where available, saliva was also collected from the mothers. Baseline stool samples were used to detect asymptomatic enteropathogen carriage. Duodenal biopsies were collected from a subgroup of stunted children (n = 77) who had an upper GI endoscopy done as part of the evaluation process for their non-response to nutritional therapy. RESULTS The proportion of secretors was similar between the cases and the controls (82% vs 81%, p = 0.81). The stunted children had significantly higher rates of carrying multiple enteropathogens, but this was not associated with their sector status nor that of their mothers. The secretor status was also not associated with mucosal morphometry of duodenal biopsies. CONCLUSION This case-control analysis in Zambian children does not support the hypothesis that fucosylation status determines asymptomatic enteropathogen carriage in stunting.

Poor food hygiene is likely to be an important contributor to high rates of infectious diseases in resource-poor settings. According to some estimates, up to 70% of diarrheal episodes in developing countries are caused by pathogens transmitted through food.1,2 Children are particularly vulnerable to diarrheal infections during the weaning period3–5 when protection from breast milk reduces and complementary food is introduced. High rates of diarrheal infections contribute to problems of undernutrition,6–8 where a quarter of stunting can be attributed to a child having five or more episodes of diarrhea before 2 years of age.5 Environmental enteropathy arising from subclinical exposures to fecal pathogens7 may be a further cause of poor growth in children residing in unhygienic environments. Although poor food hygiene has often been implicated as a source of diarrhea pathogens in industrialized countries,9–12 there have been few studies of microbial food contamination, and even fewer studies on interventions to improve this situation, in the low-income countries that have the highest disease burdens. Preparing and serving uncontaminated food is difficult in such contexts mostly because water may not be available on tap, sanitation facilities may be substandard or absent, surfaces are hard to clean, cleaning products are scarce, and refrigerators uncommon despite high ambient temperatures. Such studies as there are point to high levels of microbial contamination in foods fed to young children3,13–18 and food preparation as a risk factor for diarrheal diseases,10,17,19 including cholera. Improving food hygiene is therefore a priority for infectious disease control. However, before we can intervene on the scale that is required, we need to better understand the behaviors that cause risk and their determinants. This formative research study thus used a variety of theory-based methods to investigate food hygiene behavior in a rural hill area of Nepal. The objective was to identify key food hygiene behaviors and their determinants to inform the design of an intervention for trial and potential scale-up.

Environmental enteric dysfunction (EED) is a syndrome characterized by impairments of digestion and absorption and intestinal barrier failure in people living in insanitary or tropical environments. There is substantial evidence that it contributes to impaired linear growth of millions of children in low- and middle-income countries, to slowed neurocognitive development, and to diminished responses to oral vaccines. It represents the functional consequences of environmental enteropathy, an asymptomatic inflammatory disorder of the mucosa, and there is considerable overlap with the enteropathy observed in severe clinical malnutrition. The majority of studies of EED have employed functional tests based on lactulose permeation to define the presence of abnormal leak in the gut. However, where intestinal biopsies can safely be collected the opportunity then arises to study the underlying enteropathy in cellular and molecular detail, as well as to measure important functional elements such as enzyme expression. The purpose of this narrative review is to summarize the current understanding of environmental enteropathy obtained from small intestinal biopsies, and prospects for future work. We review histology, electron microscopy, transcription and protein expression, physiological measures, and the microbiome. We conclude that while noninvasive biomarkers of enteropathy and intestinal dysfunction permit large-scale studies of unquestionable value, intestinal biopsies are still required to investigate pathophysiology in depth.

Sometimes referred to as hidden hunger, micronutrient deficiencies persist on a global scale. For some micronutrients this appears to be due to inadequate intake, for others intake may not match increased requirements. However, for most micronutrient deficiencies there is uncertainty as to the dominant driver, and the question about the contribution of malabsorption is open. Environmental enteropathy (EE), formerly referred to as tropical enteropathy and also referred to as environmental enteric dysfunction, is an asymptomatic disorder of small intestinal structure and function which is very highly prevalent in many disadvantaged populations. Recent studies of the pathology and microbiology of this disorder suggest that it is driven by very high pathogen burdens in children and adults living in insanitary environments and is characterised by major derangements of the epithelial cells of the intestinal mucosa. Transcriptomic data suggest that it may lead to impaired digestion and absorption of macronutrients. Given the very high prevalence of EE, marginal malabsorption could have large impacts at population scales. However, the relative contributions of inadequate soil and crop micronutrient contents, inadequate intake, malabsorption and increased requirements are unknown. Malabsorption may compromise attempts to improve micronutrient status, but with the exception of zinc there is currently little evidence to confirm that malabsorption contributes to micronutrient deficiency. Much further research is required to understand the role of malabsorption in hidden hunger, especially in very disadvantaged populations where these deficiencies are most prevalent.

Environmental enteropathy is a major contributor to growth faltering in millions of children in Africa and South Asia. We carried out a longitudinal, observational and interventional study in Lusaka, Zambia, of 297 children with stunting (aged 2–17 months at recruitment) and 46 control children who had good growth (aged 1–5 months at recruitment). Control children contributed data only at baseline. Children were provided with nutritional supplementation of daily cornmeal-soy blend, an egg and a micronutrient sprinkle, and were followed up to 24 months of age. Children whose growth did not improve over 4–6 months of nutritional supplementation were classified as having non-responsive stunting. We monitored microbial translocation from the gut lumen to the bloodstream in the cohort with non-responsive stunting (n = 108) by measuring circulating lipopolysaccharide (LPS), LPS-binding protein and soluble CD14 at baseline and when non-response was declared. We found that microbial translocation decreased with increasing age, such that LPS declined in 81 (75%) of 108 children with non-responsive stunting, despite sustained pathogen pressure and ongoing intestinal epithelial damage. We used confocal laser endomicroscopy and found that mucosal leakiness also declined with age. However, expression of brush border enzyme, nutrient transporter and mucosal barrier genes in intestinal biopsies did not change with age or correlate with biomarkers of microbial translocation. We propose that environmental enteropathy arises through adaptation to pathogen-mediated epithelial damage. Although environmental enteropathy reduces microbial translocation, it does so at the cost of impaired growth. The reduced epithelial surface area imposed by villus blunting may explain these findings., Studying the intestinal pathology of undernourished children in Zambia with persistent stunting reveals that adaptation to pathogen exposure in early life may explain why children with stunting do not respond well to nutrient supplementation.

Quantifying the contribution of individual exposure pathways to a child's total ingestion of fecal matter could help prioritize interventions to reduce environmental enteropathy and diarrhea. This study used data on fecal contamination of drinking water, food, soil, hands, and objects and second-by-second data on children's contacts with these environmental reservoirs in rural Bangladesh to assess the relative contribution of different pathways to children's ingestion of fecal indicator bacteria and if ingestion decreased with the water, sanitation, and hygiene interventions implemented in the WASH Benefits Trial. Our model estimated that rural Bangladeshi children

Background Early-life malnutrition may have long-lasting effects on microbe-host interactions that affect health and disease susceptibility later in life. Diet quality and quantity in conjunction with toxin and pathogen exposure are key contributors to microbe-host physiology and malnutrition. Consequently, it is important to consider both diet- and microbe-induced pathologies as well as their interactions underlying malnutrition. Main Body Gastrointestinal immunity and digestive function are vital to maintain a symbiotic relationship between the host and microbiota. Childhood malnutrition can be impacted by numerous factors including gestational malnutrition, early life antibiotic use, psychological stress, food allergy, hygiene, and exposure to other chemicals and pollutants. These factors can contribute to reoccurring environmental enteropathy, a condition characterized by the expansion of commensal pathobionts and environmental pathogens. Reoccurring intestinal dysfunction, particularly during the critical window of development, may be a consequence of diet-microbe interactions and may lead to life-long immune and metabolic programming and increased disease risk. We provide an overview of the some key factors implicated in the progression of malnutrition (protein, fat, carbohydrate, iron, vitamin D, and vitamin B12) and discuss the microbiota during early life that may contribute health risk later in life. Conclusion Identifying key microbe-host interactions, particularly those associated with diet and malnutrition requires well-controlled dietary studies. Furthering our understanding of diet-microbe-host interactions will help to provide better strategies during gestation and early life to promote health later in life.

OBJECTIVE: Determine the minimum dosage of alanyl-glutamine (Ala-Gln) required to improve gut integrity and growth in children at risk of environmental enteropathy (EE).METHODS: This was a double-blinded randomized placebo-controlled dose-response trial. We enrolled 140 children residing in a low-income community in Fortaleza, Brazil. Participants were 2 to 60 months old and had weight-for-age (WAZ), height-for-age (HAZ), or weight-for-height (WHZ) z-scores less than -1. We randomized children to 10 days of nutritional supplementation: Ala-Gln at 3 g/day, Ala-Gln at 6 g/day, Ala-Gln at 12 g/day, or an isonitrogenous dose of glycine (Gly) placebo at 12.5 g/day. Our primary outcome was urinary lactulose-mannitol excretion testing. Secondary outcomes were anthropometry, fecal markers of inflammation, urine metabolic profiles, and malabsorption (spot fecal energy).RESULTS: Of 140 children, 103 completed 120 days of follow-up (24% dropout). In the group receiving the highest dose of Ala-Gln, we detected a modest improvement in urinary lactulose excretion from 0.19% on day 1 to 0.17% on day 10 (P = 0.05). We observed significant but transient improvements in WHZ at day 10 in 2 Ala-Gln groups, and in WHZ and WAZ in all Ala-Gln groups at day 30. We detected no effects on fecal inflammatory markers, diarrheal morbidity, or urine metabolic profiles; but did observe modest reductions in fecal energy and fecal lactoferrin in participants receiving Ala-Gln.CONCLUSIONS: Intermediate dose Ala-Gln promotes short-term improvement in gut integrity and ponderal growth in children at risk of EE. Lower doses produced improvements in ponderal growth in the absence of enhanced gut integrity.

The relationship between environmental factors and child health is not well understood in rural Pakistan. This study characterized the environmental factors related to the morbidity of acute respiratory infections (ARIs), diarrhea, and growth using geographical information systems (GIS) technology. Anthropometric, address and disease prevalence data were collected through the SEEM (Study of Environmental Enteropathy and Malnutrition) study in Matiari, Pakistan. Publicly available map data were used to compile coordinates of healthcare facilities. A Pearson correlation coefficient (r) was used to calculate the correlation between distance from healthcare facilities and participant growth and morbidity. Other continuous variables influencing these outcomes were analyzed using a random forest regression model. In this study of 416 children, we found that participants living closer to secondary hospitals had a lower prevalence of ARI (r = 0.154, p &lt, 0.010) and diarrhea (r = 0.228, p &lt, 0.001) as well as participants living closer to Maternal Health Centers (MHCs): ARI (r = 0.185, p &lt, 0.002) and diarrhea (r = 0.223, p &lt, 0.001) compared to those living near primary facilities. Our random forest model showed that distance has high variable importance in the context of disease prevalence. Our results indicated that participants closer to more basic healthcare facilities reported a higher prevalence of both diarrhea and ARI than those near more urban facilities, highlighting potential public policy gaps in ameliorating rural health.

OBJECTIVES We measured fractional absorption of zinc (FAZ) in children with environmental enteropathy (EE) and carried out transcriptomic analysis of biopsies from these children in order to compare FAZ to histology of intestinal biopsies, expression of zinc transporter genes, and biomarkers of enteropathy. METHODS Fractional absorption of a standardized aqueous dose of zinc was measured by a dual isotope ratio technique in a cohort of children aged between 9 and 24 months in Lusaka, Zambia, who all had non-responsive stunting. Gene expression analysis was carried out on biopsies through RNA sequencing using an Illumina HiSeq2000 platform. RESULTS All 33 children had histological features of environmental enteropathy and plasma zinc concentrations below the lower limit of normal. Measured FAZ ranged from 0.18-0.93; all values >0.55 were observed in girls. FAZ was negatively correlated with faecal myeloperoxidase (MPO) (ρ = -0.51, n = 17; P = 0.04) and faecal calprotectin (ρ = -0.50, n = 16; P = 0.05), but not blood biomarkers. Of 41 genes with known roles in zinc metabolism, only three metallothionein genes were significantly correlated with FAZ. CONCLUSIONS Zinc homeostasis is impaired in children with environmental enteropathy, and was inversely correlated with mucosal inflammation. Reduced FAZ without specific changes in expression of most zinc transporter genes could be explained by reduced absorptive surface area due to villus/microvillus atrophy.

Background Environmental enteropathy (EE) refers to villus blunting, reduced absorption, and microbial translocation in children and adults in tropical or deprived residential areas. In previous work we observed an effect of micronutrients on villus height (VH). Objective We aimed to determine, in a randomized controlled trial, if amino acid (AA) or multiple micronutrient (MM) supplementation can improve intestinal structure or barrier dysfunction in Zambian adults with EE. Methods AA (tryptophan, leucine, and glutamine) and/or MM supplements were given for 16 wk in a 2 × 2 factorial comparison against placebo. Primary outcomes were changes in VH, in vivo small intestinal barrier dysfunction assessed by confocal laser endomicroscopy (CLE), and mechanistic (or mammalian) target of rapamycin complex 1 (MTORC1) nutrient responsiveness in lamina propria CD4+ lymphocytes. Results Over 16 wk AA, but not MM, supplementation increased VH by 16% (34.5 μm) compared with placebo (P = 0.04). Fluorescein leak, measured by CLE, improved only in those allocated to both AA and MM supplementation. No effect was seen on MTORC1 activation, but posttreatment MTORC1 and VH were correlated (ρ = 0.51; P = 0.001), and change in MTORC1 was correlated with change in VH in the placebo group (ρ = 0.63; P = 0.03). In secondary analyses no effect was observed on biomarkers of microbial translocation. Metabolomic analyses suggest alterations in a number of microbial- and host-derived metabolites including the leucine metabolite β-hydroxy-β-methylbutyrate, which was increased by AA supplementation and correlated with VH. Conclusions In this phase 2 trial, AA supplementation protected against a decline in VH over the supplementation period, and improved barrier function when combined with micronutrients. Leucine and MTORC1 metabolism may be involved in the mechanism of effect. This trial was registered at www.pactr.org as PACTR201505001104412

Background Environmental enteric dysfunction (EED) is thought to increase the risk of micronutrient deficiencies, but few studies adjust for dietary intakes and systemic inflammation. Objective We tested whether EED is associated with micronutrient deficiency risk independent of diet and systemic inflammation, and whether it mediates the relation between intake and micronutrient status. Methods Using data from 1283 children in the MAL-ED (Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health) birth cohort we evaluated the risk of anemia, low retinol, zinc, and ferritin, and high transferrin receptor (TfR) at 15 mo. We characterized gut inflammation and permeability by myeloperoxidase (MPO), neopterin (NEO), and α-1-antitrypsin (AAT) concentrations from asymptomatic fecal samples averaged from 9 to 15 mo, and averaged the lactulose:mannitol ratio z-score (LMZ) at 9 and 15 mo. Nutrient intakes from complementary foods were quantified monthly from 9 to 15 mo and densities were averaged for analyses. α-1-Acid glycoprotein at 15 mo characterized systemic inflammation. Relations between variables were modeled using a Bayesian network. Results A greater risk of anemia was associated with LMZ [1.15 (95% CI: 1.01, 1.31)] and MPO [1.16 (1.01, 1.34)]. A greater risk of low ferritin was associated with AAT [1.19 (1.03, 1.37)] and NEO [1.22 (1.04, 1.44)]. A greater risk of low retinol was associated with LMZ [1.24 (1.08, 1.45)]. However, MPO was associated with a lower risk of high transferrin receptor [0.86 (0.74, 0.98)], NEO with a lower risk of low retinol [0.75 (0.62, 0.89)], and AAT with a lower risk of low plasma zinc [0.83 (0.70, 0.99)]. Greater nutrient intake densities (vitamins A and B6, calcium, protein, and zinc) were negatively associated with EED. Inverse associations between nutrient densities and micronutrient deficiency largely disappeared after adjustment for EED, suggesting that EED mediates these associations. Conclusions EED is independently associated with an increased risk of low ferritin, low retinol, and anemia. Greater nutrient density from complementary foods may reduce EED, and the control of micronutrient deficiencies may require control of EED.

BackgroundMetabolic syndrome is a cluster of risk factors for cardiovascular disease thought to afflict over a billion people worldwide and is increasingly being identified in younger age groups and socio-economically disadvantaged settings in the global south. Enteropathogen exposure and environmental enteropathy in infancy may lead to metabolic syndrome by disrupting the metabolic profile in a way that is detectable in cardiometabolic markers later in childhood.Methods217 subjects previously enrolled in a birth cohort in Amazonian Peru were followed up annually from ages 2 to 5 years. Blood samples collected in later childhood were analyzed for a panel of 37 cardiometabolic biomarkers, including adipokines, apolipoproteins, cytokines, and other analytes. These were matched to extant early-life markers of enteropathy ascertained between birth and 2 years of age. Multivariate and multivariable regression models were fitted to test for associations adjusting for confounders.ResultsFecal and urinary markers of intestinal permeability and inflammation (myeloperoxidase, lactulose and mannitol) measured from birth to 2 years of age were independently associated with later serum concentrations of soluble CD40-ligand, a proinflammatory cytokine correlated with adverse metabolic outcomes. Fecal myeloperoxidase was also strongly, directly associated with later levels of the anti-inflammatory adipocytokine omentin-1. Cumulative enteric protozoa exposure before 2 years of age showed stronger associations with later cardiometabolic markers than enteric viruses and bacteria and overall diarrheal episodes.ConclusionEarly-life markers of enteric infection and enteropathy were associated with numerous changes in adipokine, apolipoprotein and cytokine profiles later in childhood consistent with those of an adverse cardiometabolic disease risk profile in this Peruvian birth cohort. Markers of intestinal permeability and inflammation measured in urine (lactulose, mannitol) and stool (myeloperoxidase, protozoal infections) during infancy, may predict disruptions to cytokine and adipocytokine production in later childhood that are precursors to metabolic syndrome in adulthood. Chronic enteric infections, such as by protozoan pathogens, may be more important drivers of these changes than symptomatic diarrhea or growth faltering.FundingBill & Melinda Gates Foundation OPP1066146 and OPP1152146.

Background Environmental enteropathy is an example of a poorly-understood intestinal disorder affecting millions of children worldwide, characterized by malabsorption and stunting. Although there is increasing interest in non-invasive means of assessing intestinal structure and function, the potential value of intestinal biopsy for histology, immunostaining, RNA sequencing and epigenetic work means that endoscopic biopsy remains extremely valuable. We here report our experience in the BEECH (Biomarkers of Environmental Enteropathy in CHildren) study of stunting in Zambia, in the belief that it may help address the knowledge gap regarding the safety of endoscopic biopsy in vulnerable young children. Methods We report our experience of safety in 119 children undergoing endoscopic biopsy in the BEECH study in Lusaka Children’s Hospital, Lusaka, and discuss ethical considerations in this light. Results Upper gastrointestinal endoscopy was performed on children with stunting (length-for-age z score -2 or less) not responsive to nutritional interventions. Conscious sedation was provided by anaesthetists. Of 119 children, 5 (4%) developed transient desaturation, but no serious adverse events were experienced; no clinical, demographic or anaesthetic characteristics were identified as predictive of desaturation. Two children derived clinically useful information from the endoscopy, one life-saving. Of 105 lactase tests, 59 (54%) showed hypolactasia. Discussion Children with stunting underwent endoscopy safely, and some derived clinical benefit. Safety and the possibility of clinical benefit are usually felt to be preconditions for the ethical justification for endoscopy for research in children, and we believe that these conditions were met in this study.

A child’s diet contains nutrients and other substances that influence intestinal health. The present study aimed to evaluate the relations between complementary feeding, intestinal barrier function and environmental enteropathy (EE) in infants. Data from 233 children were obtained from the Brazilian site of the Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development Project cohort study. Habitual dietary intake from complementary feeding was estimated using seven 24-h dietary recalls, from 9 to 15 months of age. Intestinal barrier function was assessed using the lactulose–mannitol test (L–M), and EE was determined as a composite measure using faecal biomarkers concentrations – α-1-antitrypsin, myeloperoxidase (MPO) and neopterin (NEO) at 15 months of age. The nutrient adequacies explored the associations between dietary intake and the intestinal biomarkers. Children showed adequate nutrient intakes (with the exception of fibre), impaired intestinal barrier function and intestinal inflammation. There was a negative correlation between energy adequacy and L–M (ρ = −0·19, P < 0·05) and between folate adequacy and NEO concentrations (ρ = −0·21, P < 0·01). In addition, there was a positive correlation between thiamine adequacy and MPO concentration (ρ = 0·22, P < 0·01) and between Ca adequacy and NEO concentration (ρ = 0·23; P < 0·01). Multiple linear regression models showed that energy intakes were inversely associated with intestinal barrier function (β = −0·19, P = 0·02), and fibre intake was inversely associated with the EE scores (β = −0·20, P = 0·04). Findings suggest that dietary intake from complementary feeding is associated with decreased intestinal barrier function and EE in children.

The difference noted in Rotavirus vaccine efficiency between high and low income countries correlates with the lack of universal access to clean water and higher standards of hygiene. Overcoming these obstacles will require great investment and also time, therefore more effective vaccines should be developed to meet the needs of those who would benefit the most from them. Increasing our current knowledge of mucosal immunity, response to Rotavirus infection and its modulation by circadian rhythms could point at actionable pathways to improve vaccination efficacy, especially in the case of individuals affected by environmental enteropathy. Also, a better understanding and validation of Rotavirus entry factors as well as the systematic monitoring of dominant strains could assist in tailoring vaccines to individual’s needs. Another aspect that could improve vaccine efficiency is targeting to M cells, for which new ligands could potentially be sought. Finally, alternative mucosal adjuvants and vaccine expression, storage and delivery systems could have a positive impact in the outcome of Rotavirus vaccination.

Despite nutrition interventions, stunting thought to be secondary to underlying environmental enteropathy (EE) remains pervasive among infants residing in resource-poor countries and remains poorly characterized. From a birth cohort of 380 children, 65 malnourished infants received 12 weeks of nutritional supplementation with ready-to-use therapeutic food (RUTF). Eleven children with insufficient response to RUTF underwent upper endoscopy with duodenal biopsies, which were compared with U.S., age-matched specimens for healthy, celiac disease, non-celiac villous atrophy, non-celiac intraepithelial lymphocytosis, and graft-versus-host disease patients. Of the 11 children biopsied, EE was found in 10 (91%) with one subject with celiac disease. Morphometry demonstrated decreased villus-to-crypt (V:C) ratios in EE relative to healthy and non-celiac lymphocytosis patients. Environmental enteropathy villus volumes were significantly decreased relative to healthy controls. In EE, average CD3+ cells per 100 epithelial cells and per 1,000 µm2 of lamina propria and the number of lamina propria CD20+ B-cell aggregates were increased relative to all other groups. Our results indicate that V:C ratios are reduced in EE but are less severe than in celiac disease. Environmental enteropathy intraepithelial and lamina propria T lymphocytosis is of greater magnitude than that in celiac disease. The increases in lamina propria B and T lymphocytes suggest that non-cytolytic lymphocytic activation may be a more prominent feature of EE relative to celiac disease. These results provide new insights into shared yet distinct histological and immunological features of EE and celiac disease in children.

Striking histopathological overlap between distinct but related conditions poses a disease diagnostic challenge. There is a major clinical need to develop computational methods enabling clinicians to translate heterogeneous biomedical images into accurate and quantitative diagnostics. This need is particularly salient with small bowel enteropathies; environmental enteropathy (EE) and celiac disease (CD). We built upon our preliminary analysis by developing an artificial intelligence (AI)-based image analysis platform utilizing deep learning convolutional neural networks (CNNs) for these enteropathies.Data for the secondary analysis was obtained from three primary studies at different sites. The image analysis platform for EE and CD was developed using CNNs including one with multizoom architecture. Gradient-weighted class activation mappings (Grad-CAMs) were used to visualize the models' decision-making process for classifying each disease. A team of medical experts simultaneously reviewed the stain color normalized images done for bias reduction and Grad-CAMs to confirm structural preservation and biomedical relevance, respectively.Four hundred and sixty-one high-resolution biopsy images from 150 children were acquired. Median age (interquartile range) was 37.5 (19.0-121.5) months with a roughly equal sex distribution; 77 males (51.3%). ResNet50 and shallow CNN demonstrated 98% and 96% case-detection accuracy, respectively, which increased to 98.3% with an ensemble. Grad-CAMs demonstrated models' ability to learn different microscopic morphological features for EE, CD, and controls.Our AI-based image analysis platform demonstrated high classification accuracy for small bowel enteropathies which was capable of identifying biologically relevant microscopic features and emulating human pathologist decision-making process. Grad-CAMs illuminated the otherwise "black box" of deep learning in medicine, allowing for increased physician confidence in adopting these new technologies in clinical practice.

The Study of Environmental Enteropathy (EE) and Malnutrition in Pakistan (SEEM) is a community intervention trial designed to understand the pathophysiology of EE and its associated clinical phenotypes in children less than two years of age. Undernutrition is the underlying cause of three million deaths annually, accounting for 45% of all deaths among children under five years of age. Linear growth stunting affects a further 165 million. In Pakistan, where our study is focused, an estimated one in three children are underweight and nearly half are stunted. This manuscript summarizes the challenges faced by the field team and the solutions employed for achieving our research objectives at the rural field site, Matiari. Our study design involved a longitudinal collection of field data and biological samples which required constant engagement of field staff with the participating families. Challenges faced in SEEM included: 1) quality assurance parameters of anthropometry data; 2) 24-hour food recall data collection; 3) clinical management of acutely sick children enrolled in our study; 4) obtaining informed consent for upper gastrointestinal endoscopy (an invasive procedure); and 5) biological sample collection (blood, urine, stool) from malnourished children at the community level. We accomplished our goal of enrolling 350 malnourished children and 50 well-nourished children with a more than 95% success rate of collecting blood, urine and stool specimens. We collected 72% microbiome stool samples within 30 minutes of the child passing stool. We conducted an upper gastrointestinal biopsy in 63 children. Broadly, solutions to these challenges included good governance, the establishment of credibility, and the development of a longitudinal bidirectional relationship embedded in trust and effective communication with the caretakers of the children enrolled in our study. Continuous monitoring, regular training of staff, and effective teamwork were key factors that led to the successful execution of our study.

Background Chronic childhood malnutrition, as manifested by stunted linear growth, remains a persistent barrier to optimal child growth and societal development. Environmental enteric dysfunction (EED) is a significant underlying factor in the causal pathway to stunting, delayed cognitive development, and ultimately morbidity and mortality. Effective therapies against EED and stunting are lacking and further clinical trials are warranted to effectively identify and operationalize interventions. Methods/design A prospective randomized placebo-controlled parallel-group randomized controlled trial will be conducted to determine if a daily supplement of lactoferrin and lysozyme, two important proteins found in breast milk, can decrease the burden of EED and stunting in rural Malawian children aged 12–23 months old. The intervention and control groups will have a sample size of 86 subjects each. All field and laboratory researchers will be blinded to the assigned intervention group, as will the subjects and their caregivers. The percentage of ingested lactulose excreted in the urine (Δ%L) after 4 h will be used as the biomarker for EED and linear growth as the measure of chronic malnutrition (stunting). The primary outcomes of interest will be change in Δ%L from baseline to 8 weeks and to 16 weeks. Intention-to-treat analyses will be used. Discussion A rigorous clinical trial design will be used to assess the biologically plausible use of lactoferrin and lysozyme as dietary supplements for children at high risk for EED. If proven effective, these safe proteins may serve to markedly reduce the burden of childhood malnutrition and improve survival. Trial Registration Clinicaltrials.gov, NCT02925026. Registered on 4 October 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-2278-8) contains supplementary material, which is available to authorized users.

As the cause of approximately 500,000 deaths in 20151 resulting from 1.7 billion episodes2 globally, early childhood diarrhea has been a major focus of global health efforts to improve child health in low-resource settings. However, as we have witnessed substantial reductions in diarrhea-related mortality and learned how to provide appropriate oral rehydration therapy, diarrhea has revealed itself to be only one, though particularly visible, consequence of exposure to enteropathogens in environments with poor sanitation and hygiene. A potentially more widespread and debilitating consequence for long-term development is environmental enteropathy (EE, also termed environmental enteric dysfunction, EED), a chronic condition of the small intestine that is commonly considered a “subclinical” problem and often involves enteric infections without overt symptoms.3 However, since it lacks definition as a “disease” and is challenging to diagnose, its magnitude and importance are only beginning to be appreciated. Growing evidence for the diverse effects of EE on child development have revealed the “subclinical” designation to be a misnomer. There is a largely under-recognized range of potential impacts of common enteric infections and enteropathy that extend far beyond the typical assumption that they mainly cause diarrhea or other intestinal complaints like abdominal pain, nausea, or vomiting. Recognized examples of non-intestinal outcomes associated with enteric infections include associations of toxoplasmosis with birth defects and congenital brain damage (“TORCH” syndrome)4 and of Campylobacter infections with Guillain-Barre Syndrome.5 However, as research studies include detection of wider arrays of bacterial, viral, and parasitic pathogens and longer term follow-up, potential effects of enteric infections and enteropathy on vaccine responses,6,7 child growth,8,9 cognitive development,10,11 and even later life obesity, diabetes, and metabolic syndrome are increasingly being recognized.12–15 Here, we review the evolving challenges to defining EE and enteric infections, current evidence for the magnitude and determinants of its burden, new assessment tools, and relevant interventions.

Background: Environmental enteropathy (EE) is a common intestinal condition among children living in low- and middle-income countries and is associated with diminished enteric immunity to gastrointestinal pathogens, and possibly to oral vaccine antigens. The goal of this study was to examine associations between biomarkers of EE and immunogenicity to the pentavalent rotavirus vaccine (RV5). Methods: Infants were recruited 1 day before their first RV5 immunization in León, Nicaragua, from public health rosters. Infants provided a preimmunization blood and stool sample, and a second blood sample 1 month after receipt of RV5. We measured immunoglobin A (IgA) seroconversion to the first dose of RV5 and concentrations of 4 previously identified fecal biomarkers of EE (alpha-1 antitrypsin, neopterin, myeloperoxidase and calprotectin). We then assessed associations between concentrations of these biomarkers, both individually and as combined scores, and seroconversion to the first dose of RV5. Results: Of the 43 enrolled infants, 24 (56%) seroconverted after the first dose of RV5. As compared with infants who seroconverted, those who did not seroconvert had higher median concentrations of both myeloperoxidase (3.1 vs. 1.1 μg/mL, P = 0.002) and calprotectin (199.1 vs. 156.2 μg/mL, P = 0.03). Further, those who did not seroconvert had a higher median combined score of the 4 biomarkers as compared with those who seroconverted (6.5 vs. 4.5, P = 0.017). Conclusions: We found an association between biomarkers of EE and seroconversion to the first dose of RV5. It is possible that interventions that prevent or ameliorate EE may also improve oral rotavirus vaccine response.

Rotavirus gastroenteritis is a leading global cause of mortality and morbidity in young children due to diarrhea and dehydration. Over 85% of deaths occur in developing countries. In industrialised countries, 2 live oral rotavirus vaccines licensed in 2006 quickly demonstrated high effectiveness, dramatically reducing severe rotavirus gastroenteritis admissions in many settings by more than 90%. In contrast, the same vaccines reduced severe rotavirus gastroenteritis by only 30–60% in developing countries, but have been proven life-saving. Bridging this “efficacy gap” offers the possibility to save many more lives of children under the age of 5. The reduced efficacy of rotavirus vaccines in developing settings may be related to differences in transmission dynamics, as well as host luminal, mucosal and immune factors. This review will examine strategies currently under study to target the issue of reduced efficacy and effectiveness of oral rotavirus vaccines in developing settings.

BACKGROUND Environmental enteric dysfunction (EED) and linear growth stunting affect many rural agrarian children in the developing world and contribute to the persistently high rates of stunting that are observed worldwide. Effective interventions to consistently ameliorate EED are lacking. OBJECTIVE We tested whether a bundle of safe and affordable interventions would decrease EED and stunting over 12-24 wk in a cohort of rural Malawian children 12-35 mo old. METHODS This was a randomized, double-blind, placebo-controlled clinical trial in which the intervention group received a single dose of albendazole and 14 d of zinc at enrollment and after 20 wk. The intervention group also received a daily multiple micronutrient powder throughout the 24 wk of study. The primary outcomes were improvements in EED, as measured by the urinary lactulose-to-mannitol ratio (L:M ratio) from dual-sugar absorption testing, and linear growth. Urinary L:M ratios and anthropometric measurements were evaluated after 12 and 24 wk of intervention and compared with a placebo group that did not receive any of these interventions. RESULTS A total of 254 children were enrolled at a mean age of 24 mo; 55% were female. Their mean weight-for-age z score was -1.5, and their mean length-for-age z score was -0.9. After 12 and 24 wk of study, increases in the L:M ratio did not differ between the intervention group (0.071 and 0.088 units, respectively) and the placebo group (0.073 and 0.080 units, respectively) (P = 0.87 and 0.19, respectively). Relative changes in length and weight also did not differ significantly between groups at any time point. CONCLUSION The combined usage of albendazole, zinc, and a daily multiple micronutrient powder did not decrease EED or stunting in this population of agrarian children 12-35 mo old in rural Malawi. Alternative interventions to improve these diseases should be investigated. This trial was registered at clinicaltrials.gov as NCT02253095.

Water, sanitation, and hygiene interventions are increasingly recognized as essential for improving nutritional outcomes in children. Emerging literature describes the negative effects of poor sanitation on child growth. However, limited evidence has shown a link between water quality and nutritional outcomes. Similar to poor sanitation, it is plausible that water contaminated with E. coli could affect the nutritional status of children through various possible biological pathways, such as repeated episodes of diarrhea, environmental enteropathy, parasites, or other mechanisms that inhibit nutrient uptake and absorption. This study explores the relationship between contaminated water and stunting prevalence among children younger than age five years, using unique cross-sectional data from the 2012–13 Bangladesh Multiple Indicator Cluster Survey, which was one of the first nationally representative surveys to include water quality testing for E. coli. E. coli contamination in drinking water is measured at household and source points. Stunting is measured using height-for-age z-scores for children under five, where a child is considered stunted when he or she is two or more standard deviations below the median of the World Health Organization reference population. The results of multiple probit regression models indicate a 6 percent increase in the prevalence of stunting in children who are exposed to highly contaminated drinking water at household point compared with those exposed to low-to-medium contamination. When contamination is measured at the source level, the association is greater, with a 9 percent increase in the likelihood of stunting when exposed to a high level of contamination.

Celiac Disease (CD) and Environmental Enteropathy (EE) are common causes of malnutrition and adversely impact normal childhood development. CD is an autoimmune disorder that is prevalent worldwide and is caused by an increased sensitivity to gluten. Gluten exposure destructs the small intestinal epithelial barrier, resulting in nutrient mal-absorption and childhood under-nutrition. EE also results in barrier dysfunction but is thought to be caused by an increased vulnerability to infections. EE has been implicated as the predominant cause of under-nutrition, oral vaccine failure, and impaired cognitive development in low-and-middle-income countries. Both conditions require a tissue biopsy for diagnosis, and a major challenge of interpreting clinical biopsy images to differentiate between these gastrointestinal diseases is striking histopathologic overlap between them. In the current study, we propose a convolutional neural network (CNN) to classify duodenal biopsy images from subjects with CD, EE, and healthy controls. We evaluated the performance of our proposed model using a large cohort containing 1000 biopsy images. Our evaluations show that the proposed model achieves an area under ROC of 0.99, 1.00, and 0.97 for CD, EE, and healthy controls, respectively. These results demonstrate the discriminative power of the proposed model in duodenal biopsies classification.

Recent evidence suggests that enteropathy of the gut due to environmental conditions (i.e., environmental enteropathy [EE]) in young children is negatively associated with linear growth. Using a case-control study design, we examined the potential determinants of stunting in stunted and non-stunted children 22-28 months of age. Potential determinants included inflammation biomarkers C-reactive protein, alpha-1-acid glycoprotein (AGP), and endotoxin-core antibody (EndoCAb) measured in serum samples; enteropathy markers alpha-1-antitrypsin, neopterin, myeloperoxidase (MPO) measured in stools samples; and demographic, health, feeding, and household characteristics. We also explored the determinants of EE by testing associations of composite EE scores and individual biomarkers with potential risk factors. Fifty-two percent of children (n = 310) were found to be stunted, and mean height-for-age Z scores (HAZ) were -1.22 (standard deviation [SD] +/- 0.56) among non-stunted (control) children and -2.82 (SD +/- 0.61) among stunted (case) children. Child HAZ was significantly (P < 0.05) and inversely associated with AGP, and child stunting was significantly positively associated (P < 0.05) with low dietary diversity, severe household hunger, and absence of soap in the household. Alpha-1-acid glycoprotein and EndoCAb concentrations were also significantly higher (P < 0.05) among children in households with no soap. Our study documented a seemingly localized cultural practice of young children (25%) being fed their dirty bathwater, which was associated with significantly higher concentrations of MPO (P < 0.05). Alpha-1-acid glycoprotein showed the most consistent associations with child growth and hygiene practices, but fecal EE biomarkers were not associated with child growth. The lack of retrospective data in our study may explain the null findings related to fecal EE biomarkers and child growth.

Physicians use biopsies to distinguish between different but histologically similar enteropathies. The range of syndromes and pathologies that could cause different gastrointestinal conditions makes this a difficult problem. Recently, deep learning has been used successfully in helping diagnose cancerous tissues in histopathological images. These successes motivated the research presented in this paper, which describes a deep learning approach that distinguishes between Celiac Disease (CD) and Environmental Enteropathy (EE) and normal tissue from digitized duodenal biopsies. Experimental results show accuracies of over 90% for this approach. We also look into interpreting the neural network model using Gradient-weighted Class Activation Mappings and filter activations on input images to understand the visual explanations for the decisions made by the model.

Background: Environmental enteropathy (EE) is associated with chronic undernutrition. Efforts to identify minimally invasive biomarkers of EE reveal an expanding number of candidate analytes. An analytic strategy is reported to select among candidate biomarkers and systematically express the strength of each marker's association with linear growth in infancy and early childhood. Methods: 180 analytes were quantified in fecal, urine and plasma samples taken at 7, 15 and 24 months of age from 258 subjects in a birth cohort in Peru. Treating the subjects' length-for-age Z-score (LAZ-score) over a 2-month lag as the outcome, penalized linear regression models with different shrinkage methods were fitted to determine the best-fitting subset. These were then included with covariates in linear regression models to obtain estimates of each biomarker's adjusted effect on growth. Findings: Transferrin had the largest and most statistically significant adjusted effect on short-term linear growth as measured by LAZ-score - a coefficient value of 0.76 (0.48, 1.05) for each log2 increase in plasma transferrin concentration relative to the sample mean. Other biomarkers with large effect size estimates included 4-hydroxyproline, tumor necrosis factor receptor 2, beta-2-microglobulin, proline, serum amyloid P-component and adiponectin. The selected subset explained up to 26.0% of the variability in LAZ-score. Interpretation: Penalized regression modeling approaches can be used to select subsets from large panels of candidate biomarkers of EE. There is a need to systematically express the strength of association of biomarkers with linear growth or other select outcomes to compare results across studies. Funding: Bill & Melinda Gates Foundation. Declaration of Interest: The authors report no conflicts of interest. The information has not previously been presented in any meetings. Ethical Approval: Ethical approval for MAL-ED was given by the Johns Hopkins Institutional Review Board as well as the Ethics Committee of Asociacion Benefica PRISMA, and the Regional Health Department of Loreto.

BACKGROUND Antibodies to LPS and flagellin have been described as indirect measures of increased gastrointestinal permeability and may be markers of environmental enteric dysfunction (EED), which is a condition associated with poor child growth. OBJECTIVE We assessed whether LPS- and flagellin-specific immunoglobulin (Ig) concentrations were associated with poor growth in young Tanzanian children at risk of EED. DESIGN Blood samples were obtained from 590 children at 6 wk, 6 mo, and 12 mo of age. Serum LPS- and flagellin-specific Ig concentrations (IgA and IgG) were measured with the use of an ELISA. Growth was measured on a monthly basis for 18 mo. RESULTS Anti-LPS and anti-flagellin IgA and IgG concentrations increased over the first year of life and were higher than concentrations (measured at 9 mo of age) in healthy controls. Children with anti-flagellin IgA, anti-LPS IgA, anti-flagellin IgG, and anti-LPS IgG concentrations in the highest quartile at 6 wk of age were 2.02 (95% CI: 1.11, 3.67), 1.84 (95% CI: 1.03, 3.27), 1.94 (95% CI: 1.04, 3.62), and 2.31 (95% CI: 1.25, 4.27) times, respectively, more likely to become underweight (weight-for-age z score

Although there has been a decline in rates of child stunting in Bangladesh, more than one‐third of under‐five children still suffer from impaired linear growth. Results of the demographic health surveys since 2004 show that the rate of stunting decreased by only 1.5 percentage points per year (NIPORT, Mitra and Associates & ICF International, 2015). This is not anticipated, given the impressive results the country has demonstrated in reducing infant and maternal mortality over the past two decades (NIPORT, MEASURE Evaluation, and ICDDR,B 2012). Stunting seems to be pervasive throughout the country and is very high in children in slum settlements. Poverty and lack of education are associated with stunting in Bangladesh as elsewhere; however, 21% children from households belonging to the richest wealth quintiles are also stunted. About one‐third of children of literate mothers also suffer from stunting. Therefore, the aetiology of stunting is still not clear, although data from Bangladesh suggest that factors associated with the condition include poor maternal nutrition, low birthweight (LBW), severe food insecurity, inappropriate complementary feeding, poverty, illiteracy, poor sanitation, and hygiene practices (Ahmed et al, 2012; Psaki et al., 2014). There is increasing evidence that environmental enteropathy, a condition where the small intestinal mucosa is colonized and damaged by pathogenic bacteria, is one cause of malabsorption of nutrients and stunting. This happens when hygiene and sanitation practices are poor and young children are chronically exposed to bacteria in the environment.

The incidence of Antimicrobial Resistance (AMR) has been growing globally, posing threat to medical practice. Around this instance, environmental enteropathy remains one of the major causes of infant mortality. In the past few decades, great efforts have been laid to foster gut health. Efforts have been focused on understanding the role of exogenous factors such as sanitation, exclusive breast feeding, consumption of probiotic nutrition, etc. Antibiotics, while treating the disease successfully, diminishes the gut micro biome and possess the threat of developing resistance. A complementary way of enhance gut health is to build a healthy gut micro biome environment which requires a great insight in understanding the host-microbiome interactions. Precise engineering of bacteriophages to develop novel models to understand, describe, probe and modify gut function by building a healthy micro biome environment will yield decade’s worth progress in the field of biotechnology. The objective of this article is to introduce the hypothesis of tuning gut microbiota using bacteriophages and to familiarize the physiology of a bacteriophage, to elaborate its current implications, challenges faced on its application, future scope and to motivate new researchers to bring out novel strategies to mitigate the burden and spread of Environmental Enteric Dysfunction (EED) by establishing a healthy micro biome using bacteriophage- mediated micro biome engineering which proves complementary to nutritional and chemotherapeutic approaches.

Objective To describe the case of two siblings with severe protein-calorie malnutrition due to abuse by starvation. Cases description The two patients were simultaneously referred to the Hospital Municipal, where they were admitted to the Pediatric Gastroenterology clinic of a university hospital for diagnostic investigation of the cause of severe malnutrition and screening tests for Celiac Disease, Cystic Fibrosis and Environmental enteropathy among others. The exams were all normal, and after detailed research on the interactions of this family, we reached the conclusion that the malnutrition was due to abuse by starvation. The children spent approximately two months in the hospital, receiving a high-protein and high-calorie diet, with significant nutritional recovery. Comments Abuse by starvation, although rare, should always be considered of as one of the causes of child malnutrition and pediatrician should be aware of the child's development, as well as the family interactions, to prevent more severe nutritional and emotional consequences in the future.

IntroductionEnvironmental enteropathy (EE) is suspected to be a cause of growth faltering in children with sustained exposure to enteric pathogens, typically in resource-limited settings. A major hindrance to EE research is the lack of sensitive, non-invasive biomarkers. Current biomarkers measure intestinal permeability and inflammation, but not the functional capacity of the gut. Australian researchers have demonstrated proof of concept for an EE breath test based on using naturally 13C-enriched sucrose, derived from maize, to assay intestinal sucrase activity, a digestive enzyme that is impaired in villus blunting. Here, we describe a coordinated research project to optimise, validate and evaluate the usability of a breath test protocol based on highly enriched 13C-sucrose to quantify physiological dysfunction in EE in relevant target populations.Methods and analysisWe use the 13C-sucrose breath test (13C-SBT) to evaluate intestinal sucrase activity in two phases. First, an optimisation and validation phase will (1) confirm that a 13C-SBT using highly enriched sucrose tracers reports similar information to the naturally enriched 13C-SBT; (2) examine the dose–response relationship of the test to an intestinal sucrase inhibitor; (3) validate the 13C-SBT in paediatric coeliac disease (4) validate the highly enriched 13C-SBT against EE defined by biopsy in adults and (5) validate the 13C-SBT against EE defined by the urinary lactulose:rhamnose ratio (LR) among children in Peru. Second, a cross-sectional study will be conducted in six resource-limited countries (Bangladesh, India, Jamaica, Kenya, Peru and Zambia) to test the usability of the optimised 13C-SBT to assess EE among 600 children aged 12–15 months old.Ethics and disseminationEthical approval will be obtained from each participating study site. By working as a consortium, the test, if shown to be informative of EE, will demonstrate strong evidence for utility across diverse, low-income and middle-income country paediatric populations.Trial registration numberNCT04109352; Pre-results.

Campylobacterinfections are among the leading bacterial causes of diarrhea and of ‘environmental enteropathy’ (EE) and growth failure worldwide. However, the lack of an inexpensive small animal model of enteric disease withCampylobacterhas been a major limitation for understanding its pathogenesis, interventions or vaccine development. We describe a robust standard mouse model that can exhibit reproducible bloody diarrhea or growth failure, depending on the zinc or protein deficient diet and on antibiotic alteration of normal microbiota prior to infection. Zinc deficiency and the use of antibiotics create a niche forCampylobacterinfection to establish by narrowing the metabolic flexibility of these mice for pathogen clearance and by promoting intestinal and systemic inflammation. Several biomarkers and intestinal pathology in this model also mimic those seen in human disease. This model provides a novel tool to testing specific hypotheses regarding disease pathogenesis as well as vaccine development that is currently in progress.Author SummaryCampylobacter jejunihas been identified as one of the leading causes of enteropathy and diarrhea. In developing countries, these repeated enteric infections often result in growth deficits and cognitive impairment. There is a lack of small animal models ofCampylobacterinfection. This is a major hurdle in understanding the pathogenesis ofCampylobacterinfection in order to lead to therapeutic treatments and vaccines. We have developed a highly reproducible mouse model ofCampylobacterinfection that has clinical outcomes that match those of malnourished children. We hope that these insights intoCampylobactersusceptibility will lead to the development of treatments against this major cause of diarrheal illness.

It is appropriate that we begin the clinical part of this conference with a discussion of acquired monosaccharide intolerance. This disease is the most severe form of carbohydrate malabsorption and maldigestion that can afflict an infant. The following article describes the pathophysiology of the disease, as well as its treatment, much of which was based on studies done by the Section of Pediatric Gastroenterology and Nutrition at Baylor College of Medicine. Acquired monosaccharide intolerance has almost disappeared from the United States but remains a problem in the developing world where it is included as part of the diagnosis of environmental enteropathy. Present research on this disease seems to sometimes duplicate what is already known.

Environmental enteropathy (EE) is characterised by subclinical inflammation and hyperpermeability of the small intestine, hypothesised to be caused by recurrent ingestion of faecal bacteria. It has been suggested that EE may be a contributor to malnutrition and growth delays seen in children living in unsanitary conditions. We measured putative faecal EE markers myeloperoxidase (MPO) (ng/mL) and alpha-1-antitrypsin (AAT) (mg/g) in stool samples collected from 133 children aged 1-5 years in 16 communities enrolled in the WASH for WORMS randomised controlled trial in Timor-Leste. Samples were collected two years after a community-wide water, sanitation and hygiene (WASH) intervention that was integrated with regular deworming. Mixed effects multivariable linear regression models were used to examine the impact of the study intervention and of various WASH and infection-related factors on EE biomarkers. Children who lived in communities that received both the WASH intervention and deworming had similar AAT values as those who lived in communities that received only deworming (regression coefficient -0.14, p = 0.583), but they had a trend towards lower MPO values (coeff -0.51, p = 0.055). Younger children showed significantly higher MPO levels (coeff: -0.29, p = 0.002). No WASH variables or parasitic infections were associated with AAT levels. Household water being stored in covered containers was associated with lower MPO levels (coeff -1.75, p = 0.046). We found little evidence that a community-based WASH intervention had an impact on EE over a two-year period.

Oral vaccines are less immunogenic when given to infants in low-income compared with high-income countries, limiting their potential public health impact. Here, we review factors that might contribute to this phenomenon, including transplacental antibodies, breastfeeding, histo blood group antigens, enteric pathogens, malnutrition, microbiota dysbiosis and environmental enteropathy. We highlight several clear risk factors for vaccine failure, such as the inhibitory effect of enteroviruses on oral poliovirus vaccine. We also highlight the ambiguous and at times contradictory nature of the available evidence, which undoubtedly reflects the complex and interconnected nature of the factors involved. Mechanisms responsible for diminished immunogenicity may be specific to each oral vaccine. Interventions aiming to improve vaccine performance may need to reflect the diversity of these mechanisms.

OBJECTIVES Environmental enteropathy (EE) is likely associated with growth retardation in children, but the association between EE and length velocity z score (LVZ) has not been investigated. The objective of the study was to assess associations between fecal markers for intestinal inflammation and LVZ and whether these associations were influenced by micronutrient adequacy among 9 to 24 months old children in Bhaktapur, Nepal. METHODS Data were divided into 5 time slots (9-12, 12-15, 15-18, 18-21, and 21-24 months). Anthropometric measurement and dietary assessment (by 24 hour recall) were performed monthly. Mean nutrient density adequacy was calculated based on nutrient density adequacy of 10 micronutrients (thiamin, riboflavin, niacin, vitamin B6, folate, vitamin C, vitamin A, calcium, iron, and zinc). Anti-1-antitrypsin (AAT), myeloperoxidase (MPO), and neopterin (NEO) were measured in stool samples collected at the beginning of each time slot. An EE score was calculated based on all 3 fecal markers. Associations between AAT, MPO, NEO and EE score and LVZ were assessed by multiple linear regression analyses and Generalized Estimating Equations models. RESULTS Associations between fecal markers and EE score and LVZ were generally weak. EE score and MPO for 3-month and MPO for 6-month growth periods were significantly associated with LVZ from 9 to 24 months. These associations were slightly modified by mean nutrient density adequacy. CONCLUSIONS EE score and MPO were significantly associated with LVZ in 9 to 24 months old Nepali children. Further studies to establish the usefulness of AAT, MPO, and NEO in assessing EE and growth retardation are warranted.

Background Recurrent infections and inflammation contribute to growth faltering in low-income countries. n-3 (ω-3) Long-chain polyunsaturated fatty-acids (LC-PUFAs) may improve immune maturation, resistance to infections, and growth in young children who are at risk. Objective We evaluated the independent and combined effects of fish oil (500 mg n-3 LC-PUFAs/d) supplementation to lactating mothers and their breastfed children, aged 6-24 mo, on child morbidity, systemic inflammation, and growth in southwest Ethiopia. Design A 4-arm double-blind randomized controlled trial was conducted by enrolling 360 mother-infant pairs with infants 6-12 mo old. Study arms were both the lactating mother and child receiving fish oil intervention (MCI), only the lactating mother receiving fish oil intervention and child receiving placebo control (MI), only the child receiving intervention and mother receiving placebo control (CI), and both mother and child receiving a placebo supplement or control (C). The primary study outcome was linear growth using monthly changes in length-for-age z score. Anthropometric measurements were taken monthly, and hemoglobin, C-reactive protein, and blood LC-PUFAs were measured at baseline and after 6 and 12 mo of follow-up. Weekly morbidity surveillance was conducted throughout the study. Results Fish-oil supplementation significantly increased blood n-3 LC-PUFA concentration (P

Environmental enteropathy (EE) or environmental enteric dysfunction (EED) is a poorly defined condition of the small intestine usually associated with gut inflammation and increased gut permeability. This condition is common in less developed settings and has been hypothesized to be linked to the high enteropathogen load in infants in developing countries, which leads to chronic enteric T-cell–mediated inflammation.1 This, in turn, has been linked with linear growth failure, impaired cognition, and suboptimal response to oral vaccines.2 Although studies, such as the “Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and Consequences for Child Health and Development” (MAL-ED), have looked at biomarkers of EE among children in deprived settings, there are few studies evaluating differences, if any, in the levels of proposed biomarkers of EE or EED in children living in different environments in the same geographic location. The MAL-ED study looked at the role played by enteropathogen infection in malnutrition, gut inflammation, and other long-term health outcomes by focusing on resource-deprived settings with high incidence of diarrheal disease.3 However, this and other such studies have not evaluated heterogeneity in enteropathogen exposure and its consequences in communities with varying access to clean water and sanitation. In the following study, we compared the prevalence of asymptomatic enteropathogens and biomarkers of gut inflammation as a component of EE/EED,4 among infants and children living in different environmental conditions in southern India.

Undernutrition is estimated to be an underlying cause of over half of all deaths in young children globally. There is a growing body of literature suggesting that increased exposure to enteric pathogens is responsible for environmental enteropathy (EE), a disorder associated with impaired growth in children. To determine if household unsanitary environmental conditions were significantly associated with EE and stunting in children, we conducted a cohort of 216 children (≤ 30 months) in rural Bangladesh. Stool was analyzed for four fecal markers of EE: alpha-1-antitrypsin, myeloperoxidase, and neopterin combined to form an EE disease activity score, and calprotectin. We observed a significant association between having an animal corral in a child's sleeping room and elevated EE scores (1.0 point difference, 95% confidence interval [CI]: 0.13, 1.88) and a two times higher odds of stunting (height-for-age z-score < −2) (odds ratio [OR]: 2.53, 95% CI: 1.08, 5.43) after adjusting for potential confounders. In addition, children of caregivers with visibly soiled hands had significantly elevated fecal calprotectin (μg/g) (384.1, 95% CI: 152.37, 615.83). These findings suggest that close contact with animals and caregiver hygiene may be important risk factors for EE in young children. These findings are consistent with the hypothesis that unsanitary environmental conditions can lead to EE in susceptible pediatric populations.

SUMMARYExposure to animal livestock has been linked to zoonotic transmission, especially of gastrointestinal pathogens. Exposure to animals may contribute to chronic asymptomatic intestinal infection, environmental enteropathy and child under-nutrition in low-income settings. We conducted a cohort study to explore the effect of exposure to cows on growth and endemic diarrhoea in children aged

Recent evidence suggests that establishment of a healthy gut microbiota shortly after birth is important to achieve optimal growth and development of children. Being born into a resource-poor environment presents challenges to the establishment of a healthy gut microbial flora in the newborn. Among these challenges are births that occur at home, traditional pre-lacteal feeding of newborns leading to failure to initiate lactation, poor sanitation and water quality, early environmental exposure to, and infection with, enteric or other pathogens, suboptimal breast feeding duration and intensity, deficiencies in weaning and childhood diets contributing to micro- and macro-nutrient deficiencies, and the frequent use of antibiotics. These factors should be considered in the design and implementation of preventive and therapeutic interventions aimed at improving the health and development of these children.

Background Environmental enteropathy (EE) is subclinical, diffuse villous atrophy characterized by T cell infiltration of the small intestinal mucosa associated with nutrient malabsorption and stunting. EE is assessed by the lactulose:mannitol (L:M) test, whereby nonmetabolized sugars are ingested and quantified in the urine. Multiple micronutrient (MN) deficiency morphologically mimics EE, and ω-3 (n-3) polyunsaturated fatty acids reduce mucosal inflammation in Crohn disease. Objective We tested the hypothesis that supplementary MNs, with or without fish oil (FO), would improve L:M in rural Malawian children aged 1-3 y compared with a control (C) group receiving a placebo. Methods The MNs and FO provided the Recommended Dietary Intake for 26 vitamins, minerals, eicosapentaenoic acid, and docosahexaenoic acid. This was a 3-arm, randomized, double-blind, placebo-controlled clinical trial, with the primary outcomes being the change in L:M (ΔL:M) after 12 and 24 wk of supplementation. Comparisons were made for ΔL:M after 12 and 24 wk within each group by using a Wilcoxon matched pairs signed rank test, because the data are not normally distributed. Results A total of 230 children had specimens adequate for analysis; all had an abnormal baseline L:M, defined as >0.10. After 12 wk, children who received MNs + FO had a ΔL:M [mean (95% CI)] of -0.10 (-0.04, -0.15; P = 0.001), and children receiving only MNs had ΔL:M of -0.12 (-0.03, -0.21; P = 0.002). After 24 wk, children who received MNs + FO had a ΔL:M of -0.09 (-0.03, -0.15; P = 0.001); children receiving only MNs had a ΔL:M of -0.11 (-0.02, -0.20; P = 0.001), and the C group had ΔL:M of -0.07 (0.02, -0.16); P = 0.002). Linear growth was similar in all groups, ∼4.3 cm over 24 wk. Conclusion Although the effect was modest, these data suggest MNs can transiently ameliorate EE in rural African children. The trial was registered at clinicaltrials.gov as NCT01593033.

Objective To validate a method for measuring endotoxin-core antibodies (EndoCAb) from dried blood spots (DBS)—drops of capillary whole blood collected and dried on filter paper—as an indicator of environmental enteropathy (EE) in infancy and early childhood. Methods A commercially available enzyme immunoassay kit was adapted for use with DBS, with optimized steps for sample elution. Technical validation included analysis of linearity/recovery, precision and reliability, lower limit of detection, and correspondence between matched plasma and DBS samples. Validation in a field-based setting was implemented with samples from Peruvian infants (n = 82; age = 2–33 months) collected at two time points six months apart. Results A high correspondence between plasma and DBS levels of EndoCAb was observed (R2 = 0.93, P

The early to middle childhood years are a critical period for child neurodevelopment. Nutritional deficiencies, infection, and inflammation are major contributors to impaired child neurodevelopment in these years, particularly in low-resource settings. This review identifies global research priorities relating to nutrition, infection, and inflammation in early to middle childhood neurodevelopment. The research priority areas identified include: (1) assessment of how nutrition, infection, or inflammation in the preconception, prenatal, and infancy periods (or interventions in these periods) affect function in early to middle childhood; (2) assessment of whether effects of nutritional interventions vary by poverty or inflammation; (3) determination of the feasibility of preschool- and school-based integrated nutritional interventions; (4) improved assessment of the epidemiology of infection- and inflammation-related neurodevelopmental impairment (NDI); (5) identification of mechanisms through which infection causes NDI; (6) identification of noninfectious causes of inflammation-related NDI and interventions for causes already identified (eg, environmental factors); and (7) studies on the effects of interactions between nutritional, infectious, and inflammatory factors on neurodevelopment in early to middle childhood. Areas of emerging importance that require additional study include the effects of maternal Zika virus infection, childhood environmental enteropathy, and alterations in the child’s microbiome on neurodevelopment in early to middle childhood. Research in these key areas will be critical to the development of interventions to optimize the neurodevelopmental potential of children worldwide in the early to middle childhood years.

Objective To characterise childhood mouthing behaviours and to investigate the association between object-to-mouth and food-to-mouth contacts, diarrhoea prevalence and environmental enteropathy. Methods A prospective cohort study was conducted of 216 children ≤30 months of age in rural Bangladesh. Mouthing contacts with soil and food and objects with visible soil were assessed by 5-h structured observation. Stool was analysed for four faecal markers of intestinal inflammation: alpha-1-antitrypsin, myeloperoxidase, neopterin and calprotectin. Results Overall 82% of children were observed mouthing soil, objects with visible soil, or food with visible soil during the structured observation period. Sixty two percent of children were observed mouthing objects with visible soil, 63% were observed mouthing food with visible soil, and 18% were observed mouthing soil only. Children observed mouthing objects with visible soil had significantly elevated faecal calprotectin concentrations (206.81 μg/g, 95% confidence interval [CI]: 6.27, 407.36). There was also a marginally significant association between Escherichia coli counts in soil from a child's play space and the prevalence rate of diarrhoea (diarrhoea prevalence ratio: 2.03, 95% CI 0.97, 4.25). Conclusion These findings provide further evidence to support the hypothesis that childhood mouthing behaviour in environments with faecal contamination can lead to environmental enteropathy in susceptible paediatric populations. Furthermore, these findings suggest that young children mouthing objects with soil, which occurred more frequently than soil directly (60% vs. 18%), was an important exposure route to faecal pathogens and a risk factor for environmental enteropathy.

Kwashiorkor and marasmus, collectively termed severe acute malnutrition (SAM), account for at least 10% of all deaths among children under 5 years of age worldwide, virtually all of them in low-income and middle-income countries. A number of risk factors, including seasonal food insecurity, environmental enteropathy, poor complementary feeding practices, and chronic and acute infections, contribute to the development of SAM. Careful anthropometry is key to making an accurate diagnosis of SAM and can be performed by village health workers or even laypeople in rural areas. The majority of children can be treated at home with ready-to-use therapeutic food under the community-based management of acute malnutrition model with recovery rates of approximately 90% under optimal conditions. A small percentage of children, often those with HIV, tuberculosis or other comorbidities, will still require inpatient therapy using fortified milk-based foods.