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Ehsan L, Coomes D, Kelly P, Greene AR, Ali SA, Mulenga C, Denno DM, VanBuskirk K, Raghib MF, Mahfuz M, Moore SR, Hossain MS, Ahmed T, Sullivan PB, Moskaluk CA, Syed S. Duodenal quantitative mucosal morphometry in children with environmental enteric dysfunction: a cross-sectional multi-country analysis. Am J Clin Nutr 2024:S0002-9165(24)00450-7. [PMID: 38685382 DOI: 10.1016/j.ajcnut.2024.04.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 03/08/2024] [Accepted: 04/24/2024] [Indexed: 05/02/2024] Open
Abstract
BACKGROUND Environmental enteric dysfunction (EED), a chronic inflammatory condition of the small intestine, is an important driver of childhood malnutrition globally. Quantifying intestinal morphology in EED allows for exploration of its association with functional and disease outcomes. OBJECTIVE We sought to define morphometric characteristics of childhood EED and determine whether morphology features were associated with disease pathophysiology. METHODS Morphometric measurements and histology were assessed on duodenal biopsy slides for this cross-sectional study from children with EED in Bangladesh, Pakistan, and Zambia (n=69), and those with no pathologic abnormality (NPA; n=8) or celiac disease (n=18) in North America. Immunohistochemistry was also conducted on 46, 8, and 18 biopsy slides, respectively. Linear mixed-effects regression models were used to reveal morphometric differences between EED compared to NPA or celiac disease, and identify associations between morphometry and histology or immunohistochemistry amongst children with EED. RESULTS In duodenal biopsies, median EED villus height (248 μm), crypt depth (299 μm), and villus:crypt (V:C) ratio (0.9) values ranged between those of NPA (396 μm villus height; 246 μm crypt depth; 1.6 V:C ratio) and celiac disease (208 μm villus height; 365 μm crypt depth; 0.5 V:C ratio). Among EED biopsy slides, morphometric assessments were not associated with histologic parameters or immunohistochemical markers, other than pathologist determined subjective semi-quantitative villus architecture. CONCLUSIONS Morphometric analysis of duodenal biopsy slides across geographies identified morphologic features of EED, specifically short villi, elongated crypts, and a smaller V:C ratio relative to NPA slides; although not as severe as in celiac slides. Morphometry did not explain other EED features, suggesting that EED histopathologic processes may be operating independently of morphology. While acknowledging the challenges with obtaining relevant tissue, these data form the basis for further assessments of the role of morphometry in EED.
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Affiliation(s)
- Lubaina Ehsan
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, VA, USA; Department of Pediatric and Adolescent Medicine, Homer Stryker M.D. School of Medicine, Western Michigan University, Kalamazoo, MI, USA
| | - David Coomes
- Department of Epidemiology, University of Washington, Seattle, WA, USA
| | - Paul Kelly
- Blizard Institute, Barts & The London School of Medicine, Queen Mary University of London, London, UK; Tropical Gastroenterology and Nutrition Group, University of Zambia School of Medicine, Lusaka, Zambia
| | - Adam R Greene
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, VA, USA
| | - S Asad Ali
- Department of Paediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Chola Mulenga
- Tropical Gastroenterology and Nutrition Group, University of Zambia School of Medicine, Lusaka, Zambia
| | - Donna M Denno
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | | | - Muhammad Faraz Raghib
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, VA, USA
| | - Mustafa Mahfuz
- Nutritional and Clinical services Division, International Centre for Diarrhoeal Disease Research (icddr,b), Dhaka, Bangladesh
| | - Sean R Moore
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, VA, USA
| | - M Shabab Hossain
- International Centre for Diarrhoeal Disease Research (icddr,b), Dhaka, Bangladesh
| | - Tahmeed Ahmed
- International Centre for Diarrhoeal Disease Research (icddr,b), Dhaka, Bangladesh
| | - Peter B Sullivan
- Department of Paediatrics, Children's Hospital, University of Oxford, Oxford, UK
| | | | - Sana Syed
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, VA, USA; School of Data Science, University of Virginia, Charlottesville, VA, USA.
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2
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Brouwer AF, Lee GO, Van Wyk H, Schillinger RJ, Edwards CA, Morrison DJ. A Model-Based 13C-Sucrose Breath Test Diagnostic for Gut Function Disorders Characterized by a Loss of Sucrase-Isomaltase Enzymatic Activity. J Nutr 2024; 154:815-825. [PMID: 37995914 PMCID: PMC10942859 DOI: 10.1016/j.tjnut.2023.11.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/30/2023] [Accepted: 11/03/2023] [Indexed: 11/25/2023] Open
Abstract
BACKGROUND Environmental enteric dysfunction (EED) causes malnutrition in children in low-resource settings. Stable-isotope breath tests have been proposed as noninvasive tests of altered nutrient metabolism and absorption in EED, but uncertainty over interpreting the breath curves has limited their use. The activity of sucrose-isomaltase, the glucosidase enzyme responsible for sucrose hydrolysis, may be reduced in EED. We previously developed a mechanistic model describing the dynamics of the 13C-sucrose breath test (13C-SBT) as a function of underlying metabolic processes. OBJECTIVES This study aimed to determine which breath test curve dynamics are associated with sucrose hydrolysis and with the transport and metabolism of the fructose and glucose moieties and to propose and evaluate a model-based diagnostic for the loss of activity of sucrase-isomaltase. METHODS We applied the mechanistic model to 2 sets of exploratory 13C-SBT experiments in healthy adult participants. First, 19 participants received differently labeled sucrose tracers (U-13C fructose, U-13C glucose, and U-13C sucrose) in a crossover study. Second, 16 participants received a sucrose tracer accompanied by 0, 100, and 750 mg of Reducose, a sucrase-isomaltase inhibitor. We evaluated a model-based diagnostic distinguishing between inhibitor concentrations using receiver operator curves, comparing with conventional statistics. RESULTS Sucrose hydrolysis and the transport and metabolism of the fructose and glucose moieties were reflected in the same mechanistic process. The model distinguishes these processes from the fraction of tracer exhaled and an exponential metabolic process. The model-based diagnostic performed as well as the conventional summary statistics in distinguishing between no and low inhibition [area under the curve (AUC): 0.77 vs. 0.66-0.79] and for low vs. high inhibition (AUC 0.92 vs. 0.91-0.99). CONCLUSIONS Current summary approaches to interpreting 13C breath test curves may be limited to identifying only gross gut dysfunction. A mechanistic model-based approach improved interpretation of breath test curves characterizing sucrose metabolism.
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Affiliation(s)
- Andrew F Brouwer
- Department of Epidemiology, University of Michigan, Ann Arbor, MI, USA.
| | - Gwenyth O Lee
- Rutgers Global Health Institute, Rutgers University, New Brunswick, NJ, USA
| | - Hannah Van Wyk
- Department of Epidemiology, University of Michigan, Ann Arbor, MI, USA
| | - Robert J Schillinger
- Scottish Universities Environmental Research Centre, University of Glasgow, East Kilbride, United Kingdom; School of Medicine, Dentistry and Nursing, University of Glasgow, Glasgow, United Kingdom
| | - Christine A Edwards
- School of Medicine, Dentistry and Nursing, University of Glasgow, Glasgow, United Kingdom
| | - Douglas J Morrison
- Scottish Universities Environmental Research Centre, University of Glasgow, East Kilbride, United Kingdom
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Crane RJ, Parker EP, Fleming S, Gwela A, Gumbi W, Ngoi JM, de Laurent ZR, Nyatichi E, Ngari M, Wambua J, Uhlig HH, Berkley JA. Cessation of exclusive breastfeeding and seasonality, but not small intestinal bacterial overgrowth, are associated with environmental enteric dysfunction: A birth cohort study amongst infants in rural Kenya. EClinicalMedicine 2022; 47:101403. [PMID: 35497062 PMCID: PMC9046123 DOI: 10.1016/j.eclinm.2022.101403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 03/31/2022] [Accepted: 04/01/2022] [Indexed: 12/18/2022] Open
Abstract
Background Environmental Enteric Dysfunction (EED) is a chronic intestinal inflammatory disorder of unclear aetiology prevalent amongst children in low-income settings and associated with stunting. We aimed to characterise development of EED and its putative risk factors amongst rural Kenyan infants. Methods In a birth cohort study in Junju, rural coastal Kenya, between August 2015 and January 2017, 100 infants were each followed for nine months. Breastfeeding status was recorded weekly and anthropometry monthly. Acute illnesses and antibiotics were captured by active and passive surveillance. Intestinal function and small intestinal bacterial overgrowth (SIBO) were assessed by monthly urinary lactulose mannitol (LM) and breath hydrogen tests. Faecal alpha-1-antitrypsin, myeloperoxidase and neopterin were measured as EED biomarkers, and microbiota composition assessed by 16S sequencing. Findings Twenty nine of the 88 participants (33%) that underwent length measurement at nine months of age were stunted (length-for-age Z score <-2). During the rainy season, linear growth was slower and LM ratio was higher. In multivariable models, LM ratio, myeloperoxidase and neopterin increased after cessation of continuous-since-birth exclusive breastfeeding. For LM ratio this only occurred during the rainy season. EED markers were not associated with antibiotics, acute illnesses, SIBO, or gut microbiota diversity. Microbiota diversified with age and was not strongly associated with complementary food introduction or linear growth impairment. Interpretation Our data suggest that intensified promotion of uninterrupted exclusive breastfeeding amongst infants under six months during the rainy season, where rainfall is seasonal, may help prevent EED. Our findings also suggest that therapeutic strategies directed towards SIBO are unlikely to impact on EED in this setting. However, further development of non-invasive diagnostic methods for SIBO is required. Funding This research was funded in part by the Wellcome Trust (Research Training Fellowship to RJC (103376/Z/13/Z)). EPKP was supported by the MRC/DfID Newton Fund (MR/N006259/1). JAB was supported by the MRC/DFiD/Wellcome Trust Joint Global Health Trials scheme (MR/M007367/1) and the Bill & Melinda Gates Foundation (OPP1131320). HHU was supported by the NIHR Oxford Biomedical Research Centre (IS-BRC-1215-20008).
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Affiliation(s)
- Rosie J. Crane
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, New Richards Building, Old Road Campus, Roosevelt Drive, Oxford OX3 7LG, UK
- KEMRI Wellcome Trust Research Programme, PO Box 80108-230, Kilifi, Kenya
| | - Edward P.K. Parker
- Department of Clinical Research, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Simon Fleming
- Royal Cornwall Hospitals NHS Trust, Treliske, Truro TR1 3LQ, UK
| | - Agnes Gwela
- KEMRI Wellcome Trust Research Programme, PO Box 80108-230, Kilifi, Kenya
| | - Wilson Gumbi
- KEMRI Wellcome Trust Research Programme, PO Box 80108-230, Kilifi, Kenya
| | - Joyce M. Ngoi
- KEMRI Wellcome Trust Research Programme, PO Box 80108-230, Kilifi, Kenya
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, PO Box LG54, Accra, Ghana
| | | | - Emily Nyatichi
- KEMRI Wellcome Trust Research Programme, PO Box 80108-230, Kilifi, Kenya
| | - Moses Ngari
- KEMRI Wellcome Trust Research Programme, PO Box 80108-230, Kilifi, Kenya
- The Childhood Acute Illness and Nutrition (CHAIN) Network, P.O Box 43640 – 00100, Nairobi, Kenya
| | - Juliana Wambua
- KEMRI Wellcome Trust Research Programme, PO Box 80108-230, Kilifi, Kenya
| | - Holm H. Uhlig
- Translational Gastroenterology Unit, University of Oxford, Oxford OX3 9DU, UK
- Department of Paediatrics, University of Oxford, Oxford OX3 9DU, UK
- NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK
| | - James A. Berkley
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, New Richards Building, Old Road Campus, Roosevelt Drive, Oxford OX3 7LG, UK
- KEMRI Wellcome Trust Research Programme, PO Box 80108-230, Kilifi, Kenya
- The Childhood Acute Illness and Nutrition (CHAIN) Network, P.O Box 43640 – 00100, Nairobi, Kenya
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Otiti MI, Kariuki S, Wang D, Hall LJ, Ter Kuile FO, Allen S. PRObiotics and SYNbiotics to improve gut health and growth in infants in western Kenya (PROSYNK Trial): study protocol for a 4-arm, open-label, randomised, controlled trial. Trials 2022; 23:284. [PMID: 35410317 PMCID: PMC8996226 DOI: 10.1186/s13063-022-06211-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 03/26/2022] [Indexed: 11/10/2022] Open
Abstract
Background Malnutrition amongst under-fives remains common in resource-poor countries and is resistant to current interventions. New opportunities have emerged to target “environmental enteric dysfunction” (EED) that refers to the abnormal gut structure and function that results from colonisation of the gut with pathogenic microbes and compromises nutrition and growth in early life. Although the gut microbiome may provide a defence against ingested gut pathogens through colonisation resistance, its development is adversely affected by multiple environmental factors. Dietary supplements of pro- or synbiotics may build the resilience of the gut microbiome against these environmental factors and boost colonisation resistance. We aim to assess whether dietary supplementation of newborns in rural Kenya with pro/synbiotics prevents or ameliorates EED and improves growth. Methods Six hundred newborns less than 4 days old will be recruited from Homa Bay County Teaching and Referral Hospital, western Kenya. Newborns will be randomly allocated, stratified by HIV exposure, in a 1:1:1:1 ratio to one of 4 study arms to receive either of two synbiotics, a probiotic or no supplement. Supplements will be given daily for 10 days and then weekly until 6 months of age. Participants will be followed until the age of 2 years. The primary outcome is systemic inflammation at 6 months assessed by plasma alpha-1-acid glycoprotein. Secondary outcomes include biomarkers of gut health and growth, anthropometric indices, morbidity and mortality. Discussion As dietary supplements with pro- or synbiotics may improve gut health and can be administered in early life, our findings may inform the package of interventions to prevent malnutrition and improve growth in Africa and similar low-resource settings. Trial registration Pan African Clinical Trials Registry, Trial number: PACTR202003893276712. Date: 02/03/2020 https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=9798 Supplementary Information The online version contains supplementary material available at 10.1186/s13063-022-06211-1.
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Affiliation(s)
- Peter B Sullivan
- Department of Paediatrics, University of Oxford, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
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Fahim SM, Hossain MS, Sen S, Das S, Hosssain M, Ahmed T, Rahman SMM, Rahman MK, Alam S. Nutrition and Food Security in Bangladesh: Achievements, Challenges, and Impact of the COVID-19 Pandemic. J Infect Dis 2021; 224:S901-S909. [PMID: 34668556 PMCID: PMC8687095 DOI: 10.1093/infdis/jiab473] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Bangladesh has experienced remarkable transformation in demographic, health, and nutritional status of the population. The changes have exposed the population to a number of challenges, the detrimental effect of which on health and nutrition is likely to be increased by the coronavirus disease 2019 (COVID-19) pandemic. We provide an overview of health and nutritional challenges in Bangladesh in relation to demographic transition and the COVID-19 pandemic. METHODS We identified and reviewed recent reports, published articles, and pertinent gray literature on nutrition and food security in Bangladesh to provide historical and contextual information. RESULTS The review identifies the progress as well as existing burden regarding nutrition and food security in Bangladesh and highlights the challenges in the coming days in regard to population growth and the COVID-19 pandemic. The country is on track to reduce all forms of childhood undernutrition, while the proportion of nutrition-related noncommunicable diseases is rising owing to changes in dietary intake, low physical activity, and sedentary lifestyle. CONCLUSIONS Despite remarkable progress, health and nutritional status of the population in Bangladesh faces challenges, particularly in relation to demographic transition and compounded by the COVID-19 pandemic, which require concerted attention from policymakers as well as stakeholders.
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Affiliation(s)
- Shah Mohammad Fahim
- Nutrition and Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Md Shabab Hossain
- Nutrition and Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Shimul Sen
- General Economics Division, Bangladesh Planning Commission, Government of Bangladesh, Dhaka, Bangladesh
| | - Subhasish Das
- Nutrition and Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Muttaquina Hosssain
- Nutrition and Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Tahmeed Ahmed
- Nutrition and Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
- Department of Global Health, University of Washington, Seattle, Washington, USA
- Department of Public Health Nutrition, James P. Grant School of Public Health, BRAC University, Dhaka, Bangladesh
| | - S M Mustafizur Rahman
- National Nutrition Services, Ministry of Health and Family Welfare, Government of Bangladesh, Dhaka, Bangladesh
| | - Md Khalilur Rahman
- Bangladesh National Nutrition Council, Ministry of Health and Family Welfare, Government of Bangladesh, Dhaka, Bangladesh
| | - Shamsul Alam
- General Economics Division, Bangladesh Planning Commission, Government of Bangladesh, Dhaka, Bangladesh
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7
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Zhao X, Setchell KDR, Huang R, Mallawaarachchi I, Ehsan L, Dobrzykowski III E, Zhao J, Syed S, Ma JZ, Iqbal NT, Iqbal J, Sadiq K, Ahmed S, Haberman Y, Denson LA, Ali SA, Moore SR. Bile Acid Profiling Reveals Distinct Signatures in Undernourished Children with Environmental Enteric Dysfunction. J Nutr 2021; 151:3689-3700. [PMID: 34718665 PMCID: PMC8643614 DOI: 10.1093/jn/nxab321] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 08/20/2021] [Accepted: 08/30/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Intestinal inflammation and malabsorption in environmental enteric dysfunction (EED) are associated with early childhood growth faltering in impoverished settings worldwide. OBJECTIVES The goal of this study was to identify candidate biomarkers associated with inflammation, EED histology, and as predictors of later growth outcomes by focusing on the liver-gut axis by investigating the bile acid metabolome. METHODS Undernourished rural Pakistani infants (n = 365) with weight-for-height Z score (WHZ) < -2 were followed up to the age of 24 mo and monitored for growth, infections, and EED. Well-nourished local children (n = 51) were controls, based on consistent WHZ > 0 and height-for-age Z score (HAZ) > -1 on 2 consecutive visits at 3 and 6 mo. Serum bile acid (sBA) profiles were measured by tandem MS at the ages of 3-6 and 9 mo and before nutritional intervention. Biopsies and duodenal aspirates were obtained following upper gastrointestinal endoscopy from a subset of children (n = 63) that responded poorly to nutritional intervention. BA composition in paired plasma and duodenal aspirates was compared based on the severity of EED histopathological scores and correlated to clinical and growth outcomes. RESULTS Remarkably, >70% of undernourished Pakistani infants displayed elevated sBA concentrations consistent with subclinical cholestasis. Serum glycocholic acid (GCA) correlated with linear growth faltering (HAZ, r = -0.252 and -0.295 at the age of 3-6 and 9 mo, respectively, P <0.001) and biomarkers of inflammation. The proportion of GCA positively correlated with EED severity for both plasma (rs = 0.324 P = 0.02) and duodenal aspirates (rs = 0.307 P = 0.06) in children with refractory wasting that underwent endoscopy, and the proportion of secondary BA was low in both undernourished and EED children. CONCLUSIONS Dysregulated bile acid metabolism is associated with growth faltering and EED severity in undernourished children. Restoration of intestinal BA homeostasis may offer a novel therapeutic target for undernutrition in children with EED. This trial was registered at clinicaltrials.gov as NCT03588013.
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Affiliation(s)
- Xueheng Zhao
- Division of Pathology & Laboratory Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | | | - Rong Huang
- Division of Pathology & Laboratory Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | | | - Lubaina Ehsan
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, VA, USA
| | - Edward Dobrzykowski III
- Division of Pathology & Laboratory Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA,Division of Human Genetics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Junfang Zhao
- Division of Pathology & Laboratory Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Sana Syed
- Division of Pediatric Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, University of Virginia, Charlottesville, VA, USA,Departments of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Jennie Z Ma
- Department of Public Health Sciences, University of Virginia, Charlottesville, VA, USA
| | - Najeeha T Iqbal
- Departments of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan,Departments of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan
| | - Junaid Iqbal
- Departments of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan,Departments of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan
| | - Kamran Sadiq
- Departments of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Sheraz Ahmed
- Departments of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Yael Haberman
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA,Department of Pediatrics, Sheba Medical Center, Tel-HaShomer, affiliated with the Tel-Aviv University, Israel,Division of Gastroenterology, Hepatology, and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Lee A Denson
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA,Division of Gastroenterology, Hepatology, and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Syed Asad Ali
- Departments of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
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8
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Zambrana LE, Weber AM, Borresen EC, Zarei I, Perez J, Perez C, Rodríguez I, Becker-Dreps S, Yuan L, Vilchez S, Ryan EP. Daily Rice Bran Consumption for 6 Months Influences Serum Glucagon-Like Peptide 2 and Metabolite Profiles without Differences in Trace Elements and Heavy Metals in Weaning Nicaraguan Infants at 12 Months of Age. Curr Dev Nutr 2021; 5:nzab101. [PMID: 34514286 PMCID: PMC8421236 DOI: 10.1093/cdn/nzab101] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/09/2021] [Accepted: 07/16/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Environmental enteric dysfunction (EED) is associated with chronic gut inflammation affecting nutrient absorption and development of children, primarily in low- and middle-income countries. Several studies have shown that rice bran (RB) supplementation provides nutrients and modulates gut inflammation, which may reduce risk for undernutrition. OBJECTIVE The aim was to evaluate the effect of daily RB dietary supplementation for 6 mo on serum biomarkers in weaning infants and associated changes in serum and stool metabolites. METHODS A 6-mo randomized-controlled dietary intervention was conducted in a cohort of weaning 6-mo-old infants in León, Nicaragua. Anthropometric indices were obtained at 6, 8, and 12 mo. Serum and stool ionomics and metabolomics were completed at the end of the 6-mo intervention using inductively coupled plasma MS and ultra-high performance LC-tandem MS. The ɑ1-acid glycoprotein, C-reactive protein, and glucagon-like peptide 2 (GLP-2) serum EED biomarkers were measured by ELISA. RESULTS Twenty-four infants in the control group and 23 in the RB group successfully completed the 6-mo dietary intervention with 90% dietary compliance. RB participants had higher concentrations of GLP-2 as compared with control participants at 12 mo [median (IQR): 743.53 (380.54) pg/mL vs. 592.50 (223.59) pg/mL; P = 0.04]. Metabolite profiles showed significant fold differences of 39 serum metabolites and 44 stool metabolites from infants consuming RB compared with control, and with significant metabolic pathway enrichment scores of 4.7 for the tryptophan metabolic pathway, 5.7 for polyamine metabolism, and 5.7 for the fatty acid/acylcholine metabolic pathway in the RB group. No differences were detected in serum and stool trace elements or heavy metals following daily RB intake for 6 mo. CONCLUSIONS RB consumption influences a suite of metabolites associated with growth promotion and development, while also supporting nutrient absorption as measured by changes in serum GLP-2 in Nicaraguan infants. This clinical trial was registered at https://clinicaltrials.gov as NCT02615886.
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Affiliation(s)
- Luis E Zambrana
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA
- Center of Infectious Diseases, Department of Microbiology and Parasitology, Faculty of Medical Sciences, National Autonomous University of Nicaragua, León (UNAN-León), León, Nicaragua
| | - Annika M Weber
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA
| | - Erica C Borresen
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA
| | - Iman Zarei
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA
| | - Johann Perez
- Center of Infectious Diseases, Department of Microbiology and Parasitology, Faculty of Medical Sciences, National Autonomous University of Nicaragua, León (UNAN-León), León, Nicaragua
| | - Claudia Perez
- Center of Infectious Diseases, Department of Microbiology and Parasitology, Faculty of Medical Sciences, National Autonomous University of Nicaragua, León (UNAN-León), León, Nicaragua
| | - Iker Rodríguez
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA
- Biotic Products Development Center, National Polytechnic Institute, Morelos, Mexico
| | - Sylvia Becker-Dreps
- Departments of Family Medicine and Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Lijuan Yuan
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Samuel Vilchez
- Center of Infectious Diseases, Department of Microbiology and Parasitology, Faculty of Medical Sciences, National Autonomous University of Nicaragua, León (UNAN-León), León, Nicaragua
| | - Elizabeth P Ryan
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA
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Krishinchand H, Naidoo K, Mahabeer P, Archary M. Paediatric Enterobacteriaceae infections in hospitalised children in Durban, KwaZulu-Natal. S Afr J Infect Dis 2021. [DOI: 10.4102/sajid.v36i1.279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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10
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Selimoglu MA, Kansu A, Aydogdu S, Sarioglu AA, Erdogan S, Dalgic B, Yuce A, Cullu Cokugras F. Nutritional Support in Malnourished Children With Compromised Gastrointestinal Function: Utility of Peptide-Based Enteral Therapy. Front Pediatr 2021; 9:610275. [PMID: 34164352 PMCID: PMC8215107 DOI: 10.3389/fped.2021.610275] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 05/07/2021] [Indexed: 12/20/2022] Open
Abstract
This review focuses on nutritional support in malnourished children with compromised gastrointestinal function addressing the interplay between malnutrition and gastrointestinal dysfunction, and the specific role of peptide-based enteral therapy in pediatric malnutrition. Malnutrition is associated with impaired gut functions such as increased intestinal permeability, malabsorption, and diarrhea, while pre-existing functional gastrointestinal disorders may also lead to malnutrition. Presence of compromised gastrointestinal function in malnourished children is critical given that alterations such as malabsorption and increased intestinal permeability directly interfere with efficacy of nutritional support and recovery from malnutrition. Appropriate nutritional intervention is the key step in the management of malnutrition, while alterations in gastrointestinal functions in malnourished children are likely even in those with mild degree malnutrition. Therefore, nutritional therapy in children with compromised gastrointestinal function is considered to involve gut-protective interventions that address the overlapping and interacting effects of diarrhea, enteropathy and malnutrition to improve child survival and developmental potential in the long-term. Peptide-based enteral formulas seem to have clinical applications in malnourished children with compromised gastrointestinal function, given their association with improved gastrointestinal tolerance and absorption, better nitrogen retention/ balance, reduced diarrhea and bacterial translocation, enhanced fat absorption, and maintained/restored gut integrity as compared with free amino acid or whole-protein formulas.
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Affiliation(s)
- Mukadder Ayse Selimoglu
- Department of Pediatric Gastroenterology, Atasehir and Bahcelievler Memorial Hospitals, Istanbul, Turkey
| | - Aydan Kansu
- Department of Pediatric Gastroenterology, Ankara University School of Medicine, Ankara, Turkey
| | - Sema Aydogdu
- Department of Pediatric Gastroenterology, Ege University Faculty of Medicine, Izmir, Turkey
| | | | | | - Buket Dalgic
- Department of Pediatric Gastroenterology, Gazi University Faculty of Medicine, Ankara, Turkey
| | - Aysel Yuce
- Department of Pediatric Gastroenterology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Fugen Cullu Cokugras
- Department of Pediatric Gastroenterology, Istanbul University Cerrahpasa Faculty of Medicine, Istanbul, Turkey
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Lee GO, Schillinger R, Shivakumar N, Whyte S, Huq S, Ochieng Konyole S, Chileshe J, Paredes-Olortegui M, Owino V, Yazbeck R, Kosek MN, Kelly P, Morrison D. Optimisation, validation and field applicability of a 13C-sucrose breath test to assess intestinal function in environmental enteropathy among children in resource poor settings: study protocol for a prospective study in Bangladesh, India, Kenya, Jamaica, Peru and Zambia. BMJ Open 2020; 10:e035841. [PMID: 33203623 PMCID: PMC7674092 DOI: 10.1136/bmjopen-2019-035841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
INTRODUCTION Environmental 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 ANALYSIS We 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 DISSEMINATION Ethical 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 NUMBER NCT04109352; Pre-results.
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Affiliation(s)
- Gwenyth O Lee
- Department of Epidemiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Robert Schillinger
- Scottish Universities Environmental Research Centre, University of Glasgow, Glasgow, UK
| | - Nirupama Shivakumar
- Division of Nutrition, Saint John's Research Institute, Bangalore, Karnataka, India
| | - Sherine Whyte
- Caribbean Institute for Health Research (formerly, Tropical Medicine Research Institute), University of the West Indies at Mona, Mona, Saint Andrew, Jamaica
| | - Sayeeda Huq
- Nutrition and Clinical Services Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | | | - Justin Chileshe
- Department of Nutritional Sciences, Masinde Muliro University of Science and Technology, Kakamega, Kenya
| | - Maribel Paredes-Olortegui
- Research and Development Area, Asociaciόn Benéfica Proyectos de Informática, Salud, Medicina, y Agricultura (A.B. PRISMA), Iquitos, Loreto, Peru
| | - Victor Owino
- Nutritional and Health Related Environmental Studies Section, Division of Human Health, International Atomic Energy Agency, Vienna, Austria
| | - Roger Yazbeck
- Department of Surgery, College of Medicine and Public Health, Flinders University, Adelaide, South Australia, Australia
- Flinders Centre for Innovation in Cancer, Flinders University, Adelaide, South Australia, Australia
| | - Margaret N Kosek
- Research and Development Area, Asociaciόn Benéfica Proyectos de Informática, Salud, Medicina, y Agricultura (A.B. PRISMA), Iquitos, Loreto, Peru
- Division of Infectious Diseases & International Health, University of Virginia, Charlottesville, Virginia, USA
| | - Paul Kelly
- Blizard Institute, Barts and The London School of Medicine, London, UK
- Tropical Gastroenterology and Nutrition group, University of Zambia School of Medicine, Lusaka, Lusaka, Zambia
| | - Douglas Morrison
- Scottish Universities Environmental Research Centre, University of Glasgow, Glasgow, UK
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12
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Passarelli S, Ambikapathi R, Gunaratna NS, Madzorera I, Canavan CR, Noor AR, Worku A, Berhane Y, Abdelmenan S, Sibanda S, Munthali B, Madzivhandila T, Sibanda LM, Geremew K, Dessie T, Abegaz S, Assefa G, Sudfeld C, McConnell M, Davison K, Fawzi W. A Chicken Production Intervention and Additional Nutrition Behavior Change Component Increased Child Growth in Ethiopia: A Cluster-Randomized Trial. J Nutr 2020; 150:2806-2817. [PMID: 32652012 PMCID: PMC7549301 DOI: 10.1093/jn/nxaa181] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/28/2020] [Accepted: 06/05/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Chicken production in the context of nutrition-sensitive agriculture may benefit child nutrition in low-income settings. OBJECTIVES This study evaluated effects of 1) a chicken production intervention [African Chicken Genetic Gains (ACGG)], and 2) the ACGG intervention with nutrition-sensitive behavior change communication (BCC) [ACGG + Agriculture to Nutrition (ATONU)], on child nutrition and health outcomes and hypothesized intermediaries. METHODS Forty ACGG villages received 25 genetically improved chickens and basic husbandry guidance; of these, 20 ACGG + ATONU villages in addition received a nutrition-sensitive behavior change and homegardening intervention; 20 control clusters received no intervention. We assessed effects of the interventions on height-for-age z scores (HAZ), weight-for-age z scores (WAZ), and weight-for-height z scores (WHZ) at 9 (midline) and 18 mo (endline) through unadjusted and adjusted ordinary least squares (OLS) regressions. We examined the interventions' effects on hypothesized intermediaries including egg production and consumption, dietary diversity, women's empowerment, income, child morbidities, anemia, and chicken management practices through OLS and log binomial models. RESULTS Data included 829 children aged 0-36 mo at baseline. ACGG + ATONU children had higher midline HAZ [mean difference (MD): 0.28; 95% CI: 0.02, 0.54] than controls. The ACGG group had higher HAZ (MD: 0.28; 95% CI: 0.05, 0.50) and higher WAZ (MD: 0.18; 95% CI: 0.01, 0.36) at endline than controls; after adjusting for potential baseline imbalance, effects were similar but not statistically significant. At endline, differences in ACGG + ATONU children's HAZ and WAZ compared with controls were similar in magnitude to those of ACGG, but not statistically significant. There were no differences in anthropometry between the intervention groups. ACGG + ATONU children had higher dietary diversity and egg consumption than ACGG children at endline. Both interventions showed improvements in chicken management practices. The interventions did not increase anemia, diarrhea, fever, or vomiting, and the ACGG + ATONU group at midline showed reduced risk of fever. CONCLUSIONS A chicken production intervention with or without nutrition-sensitive BCC may have benefited child nutrition and did not increase morbidity.This trial was registered at clinicaltrials.gov as NCT03152227.
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Affiliation(s)
- Simone Passarelli
- Department of Nutrition, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - Ramya Ambikapathi
- Department of Public Health, Purdue University, West Lafayette, IN, USA
| | | | - Isabel Madzorera
- Department of Nutrition, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - Chelsey R Canavan
- Department of Nutrition, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - Abdallah R Noor
- Department of Nutrition, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - Amare Worku
- Addis Continental Institute of Public Health, Addis Ababa, Ethiopia
| | - Yemane Berhane
- Addis Continental Institute of Public Health, Addis Ababa, Ethiopia
| | | | - Simbarashe Sibanda
- Food, Agriculture and Natural Resources Policy Analysis Network, Pretoria, South Africa
| | - Bertha Munthali
- Food, Agriculture and Natural Resources Policy Analysis Network, Pretoria, South Africa
| | | | - Lindiwe M Sibanda
- Food, Agriculture and Natural Resources Policy Analysis Network, Pretoria, South Africa
| | | | - Tadelle Dessie
- International Livestock Research Institute, Addis Ababa, Ethiopia
| | - Solomon Abegaz
- Ethiopian Institute of Agricultural Research, Addis Ababa, Ethiopia
| | - Getnet Assefa
- Ethiopian Institute of Agricultural Research, Addis Ababa, Ethiopia
| | - Christopher Sudfeld
- Department of Global Health and Population, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - Margaret McConnell
- Department of Global Health and Population, Harvard TH Chan School of Public Health, Boston, MA, USA
| | | | - Wafaie Fawzi
- Department of Global Health and Population, Harvard TH Chan School of Public Health, Boston, MA, USA
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13
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Liu TC, VanBuskirk K, Ali SA, Kelly MP, Holtz LR, Yilmaz OH, Sadiq K, Iqbal N, Amadi B, Syed S, Ahmed T, Moore S, Ndao IM, Isaacs MH, Pfeifer JD, Atlas H, Tarr PI, Denno DM, Moskaluk CA. A novel histological index for evaluation of environmental enteric dysfunction identifies geographic-specific features of enteropathy among children with suboptimal growth. PLoS Negl Trop Dis 2020; 14:e0007975. [PMID: 31929525 PMCID: PMC6980693 DOI: 10.1371/journal.pntd.0007975] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 01/24/2020] [Accepted: 12/06/2019] [Indexed: 02/06/2023] Open
Abstract
Background A major limitation to understanding the etiopathogenesis of environmental enteric dysfunction (EED) is the lack of a comprehensive, reproducible histologic framework for characterizing the small bowel lesions. We hypothesized that the development of such a system will identify unique histology features for EED, and that some features might correlate with clinical severity. Methods Duodenal endoscopic biopsies from two cohorts where EED is prevalent (Pakistan, Zambia) and North American children with and without gluten sensitive enteropathy (GSE) were processed for routine hematoxylin & eosin (H&E) staining, and scanned to produce whole slide images (WSIs) which we shared among study pathologists via a secure web browser-based platform. A semi-quantitative scoring index composed of 11 parameters encompassing tissue injury and response patterns commonly observed in routine clinical practice was constructed by three gastrointestinal pathologists, with input from EED experts. The pathologists then read the WSIs using the EED histology index, and inter-observer reliability was assessed. The histology index was further used to identify within- and between-child variations as well as features common across and unique to each cohort, and those that correlated with host phenotype. Results Eight of the 11 histologic scoring parameters showed useful degrees of variation. The overall concordance across all parameters was 96% weighted agreement, kappa 0.70, and Gwet’s AC 0.93. Zambian and Pakistani tissues shared some histologic features with GSE, but most features were distinct, particularly abundance of intraepithelial lymphocytes in the Pakistani cohort, and marked villous destruction and loss of secretory cell lineages in the Zambian cohort. Conclusions We propose the first EED histology index for interpreting duodenal biopsies. This index should be useful in future clinical and translational studies of this widespread, poorly understood, and highly consequential disorder, which might be caused by multiple contributing processes, in different regions of the world. The study of EED has been limited by the lack of a rigorously tested, reproducible histology index that can provide insight to the pathogenesis of this entity. In this study we report the first duodenal histology index that was developed using an unbiased approach, with excellent inter-observer reproducibility, for the study of EED. The EED histology index readily identified histologic features that are common or unique to cohorts of distinct geographic locations. Incorporating the histology index into future clinical studies will provide useful insight into the pathogenesis and for intervention strategy development.
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Affiliation(s)
- Ta-Chiang Liu
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Kelley VanBuskirk
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Syed A. Ali
- Department of Paediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - M. Paul Kelly
- Tropical Gastroenterology and Nutrition group, University of Zambia School of Medicine, Lusaka, Zambia
- Blizard Institute, Barts & The London School of Medicine, Queen Mary University of London, London, United Kingdom
| | - Lori R. Holtz
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Omer H. Yilmaz
- The David H. Koch Institute for Integrative Cancer Research at MIT, Cambridge, MA, Department of Pathology, Massachusetts General Hospital, Boston, MA, United States of America
| | - Kamran Sadiq
- Department of Paediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Najeeha Iqbal
- Department of Paediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Beatrice Amadi
- Tropical Gastroenterology and Nutrition group, University of Zambia School of Medicine, Lusaka, Zambia
| | - Sana Syed
- Department of Paediatrics and Child Health, Aga Khan University, Karachi, Pakistan
- Department of Pediatrics, University of Virginia, Charlottesville, VA, United States of America
| | - Tahmeed Ahmed
- Nutrition and Clinical Services Division (NCSD), International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
- James P. Grant School of Public Health, BRAC University, Dhaka, Bangladesh
| | - Sean Moore
- Department of Pediatrics, University of Virginia, Charlottesville, VA, United States of America
| | - I. Malick Ndao
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Michael H. Isaacs
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States of America
| | - John D. Pfeifer
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Hannah Atlas
- Departments of Pediatrics and Global Health, University of Washington, Seattle, WA, United States of America
| | - Phillip I. Tarr
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Donna M. Denno
- Departments of Pediatrics and Global Health, University of Washington, Seattle, WA, United States of America
| | - Christopher A. Moskaluk
- Department of Pathology, University of Virginia, Charlottesville, VA, United States of America
- * E-mail:
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14
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Tickell KD, Atlas HE, Walson JL. Environmental enteric dysfunction: a review of potential mechanisms, consequences and management strategies. BMC Med 2019; 17:181. [PMID: 31760941 PMCID: PMC6876067 DOI: 10.1186/s12916-019-1417-3] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 08/27/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Environmental enteric dysfunction (EED) is an acquired enteropathy of the small intestine, characterized by enteric inflammation, villus blunting and decreased crypt-to-villus ratio. EED has been associated with poor outcomes, including chronic malnutrition (stunting), wasting and reduced vaccine efficacy among children living in low-resource settings. As a result, EED may be a valuable interventional target for programs aiming to reduce childhood morbidity in low and middle-income countries. MAIN TEXT Several highly plausible mechanisms link the proposed pathophysiology underlying EED to adverse outcomes, but causal attribution of these pathways has proved challenging. We provide an overview of recent studies evaluating the causes and consequences of EED. These include studies of the role of subclinical enteric infection as a primary cause of EED, and efforts to understand how EED-associated systemic inflammation and malabsorption may result in long-term morbidity. Finally, we outline recently completed and upcoming clinical trials that test novel interventions to prevent or treat this highly prevalent condition. CONCLUSIONS Significant strides have been made in linking environmental exposure to enteric pathogens and toxins with EED, and in understanding the multifactorial mechanisms underlying this complex condition. Further insights may come from several ongoing and upcoming interventional studies trialing a variety of novel management strategies.
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Affiliation(s)
- Kirkby D Tickell
- Department of Global Health, University of Washington, 325 9th Avenue (Box 359931), Seattle, WA, 98104, USA. .,Department of Epidemiology, University of Washington, 1959 NE Pacific Street, Health Sciences Bldg, F-262, Box 357236, Seattle, WA, 98195, USA. .,The Childhood Acute Illness and Nutrition Network (CHAIN), Nairobi, Kenya.
| | - Hannah E Atlas
- Department of Global Health, University of Washington, 325 9th Avenue (Box 359931), Seattle, WA, 98104, USA
| | - Judd L Walson
- Department of Global Health, University of Washington, 325 9th Avenue (Box 359931), Seattle, WA, 98104, USA.,Department of Epidemiology, University of Washington, 1959 NE Pacific Street, Health Sciences Bldg, F-262, Box 357236, Seattle, WA, 98195, USA.,The Childhood Acute Illness and Nutrition Network (CHAIN), Nairobi, Kenya.,Department of Allergy and Infectious Disease, University of Washington, 325 9th Avenue (Box 359931), Seattle, WA, 98104, USA.,Department of Pediatrics, University of Washington, 325 9th Avenue (Box 359931), Seattle, WA, 98104, USA
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15
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Kuhlmann FM, Martin J, Hazen TH, Vickers TJ, Pashos M, Okhuysen PC, Gómez-Duarte OG, Cebelinski E, Boxrud D, del Canto F, Vidal R, Qadri F, Mitreva M, Rasko DA, Fleckenstein JM. Conservation and global distribution of non-canonical antigens in Enterotoxigenic Escherichia coli. PLoS Negl Trop Dis 2019; 13:e0007825. [PMID: 31756188 PMCID: PMC6897418 DOI: 10.1371/journal.pntd.0007825] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 12/06/2019] [Accepted: 10/02/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Enterotoxigenic Escherichia coli (ETEC) cause significant diarrheal morbidity and mortality in children of resource-limited regions, warranting development of effective vaccine strategies. Genetic diversity of the ETEC pathovar has impeded development of broadly protective vaccines centered on the classical canonical antigens, the colonization factors and heat-labile toxin. Two non-canonical ETEC antigens, the EtpA adhesin, and the EatA mucinase are immunogenic in humans and protective in animal models. To foster rational vaccine design that complements existing strategies, we examined the distribution and molecular conservation of these antigens in a diverse population of ETEC isolates. METHODS Geographically diverse ETEC isolates (n = 1159) were interrogated by PCR, immunoblotting, and/or whole genome sequencing (n = 46) to examine antigen conservation. The most divergent proteins were purified and their core functions assessed in vitro. RESULTS EatA and EtpA or their coding sequences were present in 57.0% and 51.5% of the ETEC isolates overall, respectively; and were globally dispersed without significant regional differences in antigen distribution. These antigens also exhibited >93% amino acid sequence identity with even the most divergent proteins retaining the core adhesin and mucinase activity assigned to the prototype molecules. CONCLUSIONS EtpA and EatA are well-conserved molecules in the ETEC pathovar, suggesting that they serve important roles in virulence and that they could be exploited for rational vaccine design.
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Affiliation(s)
- F. Matthew Kuhlmann
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
| | - John Martin
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, United States of America
- McDonnell Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Tracy H. Hazen
- Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Tim J. Vickers
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Madeline Pashos
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Pablo C. Okhuysen
- The Department of Infectious Diseases, Infection Control and Employee Health, University of Texas M.D. Anderson Cancer Center, Houston, Texas, United States of America
| | - Oscar G. Gómez-Duarte
- Department of Pediatrics, Division of Infectious Diseases, University at Buffalo, The State University of New York, Buffalo, New York, United States of America
| | | | - Dave Boxrud
- Minnesota Department of Health, St. Paul, Minnesota, United States of America
| | - Felipe del Canto
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Roberto Vidal
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Instituto Milenio de Inmunonología e Inmunoterapia, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Firdausi Qadri
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Makedonka Mitreva
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, United States of America
- McDonnell Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - David A. Rasko
- Department of Microbiology and Immunology and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - James M. Fleckenstein
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Medicine Service, Veterans Affairs Medical Center, St. Louis, Missouri, United States of America
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16
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Sullivan PB. Environmental enteric dysfunction: a socioeconomic problem looking for a medical solution? Am J Clin Nutr 2019; 110:1051-1052. [PMID: 31667510 DOI: 10.1093/ajcn/nqz225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Peter B Sullivan
- University of Oxford, Department of Pediatrics, Children's Hospital, Oxford, United Kingdom
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17
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Kastl AJ, Terry NA, Wu GD, Albenberg LG. The Structure and Function of the Human Small Intestinal Microbiota: Current Understanding and Future Directions. Cell Mol Gastroenterol Hepatol 2019; 9:33-45. [PMID: 31344510 PMCID: PMC6881639 DOI: 10.1016/j.jcmgh.2019.07.006] [Citation(s) in RCA: 163] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 07/17/2019] [Accepted: 07/17/2019] [Indexed: 02/07/2023]
Abstract
Despite growing literature characterizing the fecal microbiome and its association with health and disease, few studies have analyzed the microbiome of the small intestine. Here, we examine what is known about the human small intestinal microbiota in terms of community structure and functional properties. We examine temporal dynamics of select bacterial populations in the small intestine, and the effects of dietary carbohydrates and fats on shaping these populations. We then evaluate dysbiosis in the small intestine in several human disease models, including small intestinal bacterial overgrowth, short-bowel syndrome, pouchitis, environmental enteric dysfunction, and irritable bowel syndrome. What is clear is that the bacterial biology, and mechanisms of bacteria-induced pathophysiology, are enormously broad and elegant in the small intestine. Studying the small intestinal microbiota is challenged by rapidly fluctuating environmental conditions in these intestinal segments, as well as the complexity of sample collection and bioinformatic analysis. Because the functionality of the digestive tract is determined primarily by the small intestine, efforts must be made to better characterize this unique and important microbial ecosystem.
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Affiliation(s)
- Arthur J. Kastl
- Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania,Correspondence Address correspondence to: Arthur J. Kastl Jr, MD, Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, 3401 Civic Center Boulevard, 7NW, Philadelphia, Pennsylvania 19104. fax: (215) 590-3606.
| | - Natalie A. Terry
- Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Gary D Wu
- Division of Gastroenterology, Hepatology, and Nutrition, The University of Pennsylvania, Philadelphia, Pennsylvania
| | - Lindsey G. Albenberg
- Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
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18
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Abstract
Purpose of review Almost half of all childhood deaths worldwide occur in children with malnutrition, predominantly in sub-Saharan Africa and South Asia. This review summarizes the mechanisms by which malnutrition and serious infections interact with each other and with children's environments. Recent findings It has become clear that whilst malnutrition results in increased incidence, severity and case fatality of common infections, risks continue beyond acute episodes resulting in significant postdischarge mortality. A well established concept of a ‘vicious-cycle’ between nutrition and infection has now evolving to encompass dysbiosis and pathogen colonization as precursors to infection; enteric dysfunction constituting malabsorption, dysregulation of nutrients and metabolism, inflammation and bacterial translocation. All of these interact with a child's diet and environment. Published trials aiming to break this cycle using antimicrobial prophylaxis or water, sanitation and hygiene interventions have not demonstrated public health benefit so far. Summary As further trials are planned, key gaps in knowledge can be filled by applying new tools to re-examine old questions relating to immune competence during and after infection events and changes in nutritional status; and how to characterize overt and subclinical infection, intestinal permeability to bacteria and the role of antimicrobial resistance using specific biomarkers.
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19
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Allen SJ, Adepojou A, Akinyinka OO. Challenges and opportunities for paediatric gastroenterology in low- and middle-income countries: high time for action. Paediatr Int Child Health 2019; 39:4-6. [PMID: 30900525 DOI: 10.1080/20469047.2019.1568022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Stephen J Allen
- a Department of Clinical Sciences , Liverpool School of Tropical Medicine , Liverpool , UK.,b Department of Paediatric Gastroenterology , Alder Hey Children's NHS Foundation Trust , Liverpool , UK
| | - Akinlolu Adepojou
- b Department of Paediatric Gastroenterology , Alder Hey Children's NHS Foundation Trust , Liverpool , UK.,c Department of Paediatrics , University College Hospital; College Of Medicine, University of Ibadan , Ibadan , Nigeria
| | - Olusegun O Akinyinka
- d University of Ibadan , Ibadan , Nigeria.,e University College Hospital , Ibadan , Nigeria
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Bartelt LA, Bolick DT, Guerrant RL. Disentangling Microbial Mediators of Malnutrition: Modeling Environmental Enteric Dysfunction. Cell Mol Gastroenterol Hepatol 2019; 7:692-707. [PMID: 30630118 PMCID: PMC6477186 DOI: 10.1016/j.jcmgh.2018.12.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 12/12/2018] [Accepted: 12/13/2018] [Indexed: 12/12/2022]
Abstract
Environmental enteric dysfunction (EED) (also referred to as environmental enteropathy) is a subclinical chronic intestinal disorder that is an emerging contributor to early childhood malnutrition. EED is common in resource-limited settings, and is postulated to consist of small intestinal injury, dysfunctional nutrient absorption, and chronic inflammation that results in impaired early child growth attainment. Although there is emerging interest in the hypothetical potential for chemical toxins in the environmental exposome to contribute to EED, the propensity of published data, and hence the focus of this review, implicates a critical role of environmental microbes. Early childhood malnutrition and EED are most prevalent in resource-limited settings where food is limited, and inadequate access to clean water and sanitation results in frequent gastrointestinal pathogen exposures. Even as overt diarrhea rates in these settings decline, silent enteric infections and faltering growth persist. Furthermore, beyond restricted physical growth, EED and/or enteric pathogens also associate with impaired oral vaccine responses, impaired cognitive development, and may even accelerate metabolic syndrome and its cardiovascular consequences. As these potentially costly long-term consequences of early childhood enteric infections increasingly are appreciated, novel therapeutic strategies that reverse damage resulting from nutritional deficiencies and microbial insults in the developing small intestine are needed. Given the inherent limitations in investigating how specific intestinal pathogens directly injure the small intestine in children, animal models provide an affordable and controlled opportunity to elucidate causal sequelae of specific enteric infections, to differentiate consequences of defined nutrient deprivation alone from co-incident enteropathogen insults, and to correlate the resulting gut pathologies with their functional impact during vulnerable early life windows.
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Affiliation(s)
- Luther A Bartelt
- Division of Infectious Diseases, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Center for Gastrointestinal Biology and Disease, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
| | - David T Bolick
- Center for Global Health, Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia
| | - Richard L Guerrant
- Center for Global Health, Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia
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21
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Arndt MB, Walson JL. Enteric infection and dysfunction-A new target for PLOS Neglected Tropical Diseases. PLoS Negl Trop Dis 2018; 12:e0006906. [PMID: 30592716 PMCID: PMC6310236 DOI: 10.1371/journal.pntd.0006906] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Michael B. Arndt
- PATH, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
| | - Judd L. Walson
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
- Department of Epidemiology, University of Washington, Seattle, Washington, United States of America
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Department of Pediatrics, University of Washington, Seattle, Washington, United States of America
- Childhood Acute Illness and Nutrition Network, Nairobi, Kenya
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22
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Ickes SB, Hossain M, Ritter G, Lazarus M, Reynolds K, Nahar B, Ahmed T, Walson J, Denno DM. Systematic Review of Tools and Methods to Measure Appetite in Undernourished Children in the Context of Low- and Middle-Income Countries. Adv Nutr 2018; 9:789-812. [PMID: 30462177 PMCID: PMC6247147 DOI: 10.1093/advances/nmy042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Child undernutrition has multifactorial causes, ranging from food insecurity to etiologies refractory to conventional nutritional approaches, such as infections, environmental enteric dysfunction, and other conditions that lead to systemic inflammation. Poor appetite may be an important symptom of these causes and may be a useful marker of an undernourished child's ability to recover. We conducted a systematic review to characterize the methods and tools to measure appetite among children <5 y old in low- and middle-income countries. A systematic search of 8 databases identified 23 eligible studies published since 1995. Thirteen described methods based on direct feeding observation or quantification of nutrient intake from caregiver report, 16 described tools that assessed caregiver perceptions of appetite, and 6 reported assessments in both categories. Four studies that gauged caregiver perceptions assessed multiple appetite domains, whereas 12 assessed 1 domain-often with a single question. Only 6 studies reported validation processes, the most common of which compared an observed test meal with daily energy intake. No studies reported the use of a method or tool that was validated in multiple cultural or linguistic contexts. Although dietary intake measures and observed feeding tests have shown validity in some contexts, they are resource intensive. Subjective caregiver questionnaires may offer a more efficient appetite evaluation method, but they have been evaluated less consistently. A rigorously developed and validated tool to rapidly assess child appetite is needed and could be best addressed by a questionnaire that leverages the multiple domains of appetite. The application of interventions that target causes of undernutrition that are not amenable to food-based interventions in clinical or research contexts could be facilitated by an efficient appetite screening tool to identify appetite-related causes of undernutrition and to monitor children's response to such interventions.
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Affiliation(s)
- Scott B Ickes
- Departments of Health Services,Global Health,Program in Nutritional Sciences, University of Washington, Seattle, WA,Wheaton College Department of Applied Health Sciences, Wheaton, IL
| | - Muttaquina Hossain
- Nutrition and Clinical Services Division, International Centre for Diarrheal Diseases Research, Bangladesh (icddr,b)
| | - Gaelen Ritter
- Program in Nutritional Sciences, University of Washington, Seattle, WA
| | - Monica Lazarus
- Program in Nutritional Sciences, University of Washington, Seattle, WA
| | | | - Baitun Nahar
- Nutrition and Clinical Services Division, International Centre for Diarrheal Diseases Research, Bangladesh (icddr,b)
| | - Tahmeed Ahmed
- Global Health,Nutrition and Clinical Services Division, International Centre for Diarrheal Diseases Research, Bangladesh (icddr,b)
| | - Judd Walson
- Pediatrics,Global Health,Medicine,Epidemiology,Childhood Acute Illness and Nutrition Network, Nairobi, Kenya
| | - Donna M Denno
- Departments of Health Services,Pediatrics,Global Health,Childhood Acute Illness and Nutrition Network, Nairobi, Kenya,Address correspondence to DMD (e-mail: )
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23
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Marie C, Ali A, Chandwe K, Petri WA, Kelly P. Pathophysiology of environmental enteric dysfunction and its impact on oral vaccine efficacy. Mucosal Immunol 2018; 11:1290-1298. [PMID: 29988114 DOI: 10.1038/s41385-018-0036-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 04/03/2018] [Accepted: 04/11/2018] [Indexed: 02/08/2023]
Abstract
Environmental enteric dysfunction (EED) refers to a subclinical disorder of intestinal function common in tropical countries and in settings of poverty and economic disadvantage. The enteropathy that underlies this syndrome is characterized by mucosal inflammation and villus blunting mediated by T cell activation. Epithelial cell disruption and microbial translocation drive systemic inflammation. EED in young children is associated geographically with growth failure, malnutrition, and greatly impaired responses to oral vaccines, notably rotavirus and poliovirus vaccines. In this review, we describe the pathophysiology of EED and examine the evidence linking EED and oral vaccine failure. This evidence is far from conclusive. Although our understanding of EED is still sketchy, there is limited evidence of disturbed innate immunity, B cell disturbances including aggregation into lymphoid follicles, and autoantibody generation. Pathways of T cell activation and the possibility of dendritic cell anergy, which could help explain oral vaccine failure, require further work.
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Affiliation(s)
- Chelsea Marie
- The University of Virginia, Charlottesville, VA, USA
| | - Asad Ali
- Department of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Kanta Chandwe
- Tropical Gastroenterology and Nutrition group, University of Zambia School of Medicine, Lusaka, Zambia
| | | | - Paul Kelly
- Tropical Gastroenterology and Nutrition group, University of Zambia School of Medicine, Lusaka, Zambia. .,Barts & The London School of Medicine, Queen Mary University of London, London, E1 4AT, UK.
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24
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Church JA, Parker EPK, Kosek MN, Kang G, Grassly NC, Kelly P, Prendergast AJ. Exploring the relationship between environmental enteric dysfunction and oral vaccine responses. Future Microbiol 2018; 13:1055-1070. [PMID: 29926747 PMCID: PMC6136084 DOI: 10.2217/fmb-2018-0016] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 03/26/2018] [Indexed: 12/11/2022] Open
Abstract
Oral vaccines significantly underperform in low-income countries. One possible contributory factor is environmental enteric dysfunction (EED), a subclinical disorder of small intestinal structure and function among children living in poverty. Here, we review studies describing oral vaccine responses and EED. We identified eight studies evaluating EED and oral vaccine responses. There was substantial heterogeneity in study design and few consistent trends emerged. Four studies reported a negative association between EED and oral vaccine responses; two showed no significant association; and two described a positive correlation. Current evidence is therefore insufficient to determine whether EED contributes to oral vaccine underperformance. We identify roadblocks in the field and future research needs, including carefully designed studies those can investigate this hypothesis further.
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Affiliation(s)
- James A Church
- Zvitambo Institute for Maternal & Child Health Research, Harare, Zimbabwe
- Centre for Genomics & Child Health, Blizard Institute, Queen Mary University of London, UK
| | - Edward PK Parker
- Department of Infectious Disease Epidemiology, St Mary's Campus, Imperial College London, London, UK
| | - Margaret N Kosek
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Gagandeep Kang
- Department of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India
| | - Nicholas C Grassly
- Department of Infectious Disease Epidemiology, St Mary's Campus, Imperial College London, London, UK
| | - Paul Kelly
- Centre for Genomics & Child Health, Blizard Institute, Queen Mary University of London, UK
- Tropical Gastroenterology & Nutrition group, University of Zambia School of Medicine, Lusaka, Zambia
| | - Andrew J Prendergast
- Zvitambo Institute for Maternal & Child Health Research, Harare, Zimbabwe
- Centre for Genomics & Child Health, Blizard Institute, Queen Mary University of London, UK
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
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