Undernutrition, Vitamin A and Iron Deficiency Are Associated with Impaired Intestinal Mucosal Permeability in Young Bangladeshi Children Assessed by Lactulose/Mannitol Test

Consumption of a multi-deficient diet causes dynamic changes in the intestinal morphofunctional barrier, body composition and impaired physical development in post-weaning mice

Few studies have focused on nutrient-deficient diets and associated pathobiological dynamics of body composition and intestinal barrier function. This study evaluated the impact of a nutrient-deficient diet on physical development and intestinal morphofunctional barrier in mice. C57BL/6 (21 days of age) mice were fed a Northeastern Brazil regional basic diet (RBD) or a control diet for 21 d. The animals were subjected to bioimpedance analysis, lactulose test, morphometric analysis and quantitative reverse transcription-PCR to evaluate tight junctions and intestinal transporters. RBD feeding significantly reduced weight (P < 0·05) from day 5, weight gain from day 3 and tail length from day 14. The intake of RBD reduced total body water, extracellular fluid, fat mass and fat-free mass from day 7 (P < 0·05). RBD induced changes in the jejunum, with an increase in the villus:crypt ratio on day 7, followed by reduction on days 14 and 21 (P < 0·05). Lactulose:mannitol ratio increased on day 14 (P < 0·05). Changes in intestinal barrier function on day 14 were associated with reductions in claudin-1 and occludin, and on day 21, there was a reduction in the levels of claudin-2 and occludin. SGLT-1 levels decreased on day 21. RBD compromises body composition and physical development with dynamic changes in intestinal barrier morphofunctional. RBD is associated with damage to intestinal permeability, reduced levels of claudin-1 and occludin transcripts and return of bowel function in a chronic period.

Fecal Markers of Environmental Enteric Dysfunction and their Relation to Faltering Growth in a Sample of Egyptian Children

BACKGROUND: Chronic malnutrition is a long-term health condition that has threatening effects on children’s health. Environmental enteric dysfunction (EED) is a subclinical disorder affecting the small intestine that may occur due to exposure to environmental pathogens and toxins. AIM: The present research was intended to detect the value of fecal biomarkers of intestinal epithelial damage alpha-1anti-trypsin (AAT) and intestinal inflammation Myeloperoxidase (MPO) and Neopetrin (NEO), also to quantify their association with faltering growth in stunted and underweight children. PATIENTS AND METHODS: This case–control study included 105 children with moderate malnutrition as a case group and 100 children of normal body weight and height as a control group. Quantification of fecal markers levels of intestinal permeability AAT and intestinal inflammation (NEO and MPO) along with serum micronutrients levels (iron and zinc) in children with malnutrition in comparison to controls. RESULTS: Fecal markers of intestinal permeability AAT and intestinal inflammation NEO had statistically significant higher levels in children with malnutrition, while serum micronutrients (iron and zinc) had statistically significant lower levels in children with malnutrition. CONCLUSION: Faltering growth is associated with elevated fecal markers of intestinal permeability AAT and intestinal inflammation NEO. EED may be a cause for faltering growth.

Effect of topical applications of sunflower seed oil on systemic fatty acid levels in under-two children under rehabilitation for severe acute malnutrition in Bangladesh: a randomized controlled trial

Background

Children with severe acute malnutrition (SAM) have inadequate levels of fatty acids (FAs) and limited capacity for enteral nutritional rehabilitation. We hypothesized that topical high-linoleate sunflower seed oil (SSO) would be effective adjunctive treatment for children with SAM.

Methods

This study tested a prespecified secondary endpoint of a randomized, controlled, unblinded clinical trial with 212 children with SAM aged 2 to 24 months in two strata (2 to < 6 months, 6 to 24 months in a 1:2 ratio) at Dhaka Hospital of icddr,b, Bangladesh between January 2016 and December 2017. All children received standard-of-care management of SAM. Children randomized to the emollient group also received whole-body applications of 3 g/kg SSO three times daily for 10 days. We applied difference-in-difference analysis and unsupervised clustering analysis using t-distributed stochastic neighbor embedding (t-SNE) to visualize changes in FA levels in blood from day 0 to day 10 of children with SAM treated with emollient compared to no-emollient.

Results

Emollient therapy led to systematically higher increases in 26 of 29 FAs over time compared to the control. These effects were driven primarily by changes in younger subjects (27 of 29 FAs). Several FAs, especially those most abundant in SSO showed high-magnitude but non-significant incremental increases from day 0 to day 10 in the emollient group vs. the no-emollient group; for linoleic acid, a 237 μg/mL increase was attributable to enteral feeding and an incremental 98 μg/mL increase (41%) was due to emollient therapy. Behenic acid (22:0), gamma-linolenic acid (18:3n6), and eicosapentaenoic acid (20:5n3) were significantly increased in the younger age stratum; minimal changes were seen in the older children.

Conclusions

SSO therapy for SAM augmented the impact of enteral feeding in increasing levels of several FAs in young children. Further research is warranted into optimizing this novel approach for nutritional rehabilitation of children with SAM, especially those < 6 months.

Trial registration

ClinicalTrials.gov: NCT02616289.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-021-00707-3.

Extracellular vesicles isolated from milk can improve gut barrier dysfunction induced by malnutrition

Malnutrition impacts approximately 50 million children worldwide and is linked to 45% of global mortality in children below the age of five. Severe acute malnutrition (SAM) is associated with intestinal barrier breakdown and epithelial atrophy. Extracellular vesicles including exosomes (EVs; 30-150 nm) can travel to distant target cells through biofluids including milk. Since milk-derived EVs are known to induce intestinal stem cell proliferation, this study aimed to examine their potential efficacy in improving malnutrition-induced atrophy of intestinal mucosa and barrier dysfunction. Mice were fed either a control (18%) or a low protein (1%) diet for 14 days to induce malnutrition. From day 10 to 14, they received either bovine milk EVs or control gavage and were sacrificed on day 15, 4 h after a Fluorescein Isothiocyanate (FITC) dose. Tissue and blood were collected for histological and epithelial barrier function analyses. Mice fed low protein diet developed intestinal villus atrophy and barrier dysfunction. Despite continued low protein diet feeding, milk EV treatment improved intestinal permeability, intestinal architecture and cellular proliferation. Our results suggest that EVs enriched from milk should be further explored as a valuable adjuvant therapy to standard clinical management of malnourished children with high risk of morbidity and mortality.

Retinoids delay cell cycle progression and promote differentiation of intestinal epithelial cells exposed to nutrient deprivation

OBJECTIVE

Vitamin A is commonly recommended as a treatment for diarrhea and undernutrition; however, little is known about the underlying cellular mechanisms. The aim of this study was to investigate the modulation of cell cycle by vitamin A derivatives (retinyl palmitate or retinol) in undernourished intestinal epithelial crypts (IEC-6).

METHODS

IEC-6 cells were exposed to nutrient deprivation (no serum and no glutamine) and supplemented with retinyl palmitate or retinol at a range of 2 to 20 μM. Proliferation, apoptosis/necrosis, cell cycle process, and gene transcription were assessed.

RESULTS

Nutrient deprivation for 6, 12, 24, or 48 h decreased cell proliferation, and retinyl palmitate further decreased it after 24 and 48 h. Apoptosis rates were reduced by undernourishment and further reduced by retinyl palmitate after 48 h; whereas necrosis rates were unaltered. Undernourishment induced overall cell quiescence, increased percentage of cells in G0/G1 phase and decreased percentage of cells in S phase after 12 h and in G2/M phases at 6, 12, and 24 h after treatment. Both retinoids also showed cell quiescence induction with less cells in G2/M phases after 48 h, whereas only retinol showed significant modulation of G0/G1 and S phases. Both retinoids also increased markers of cell differentiation Fabp and Iap gene transcriptions in about fivefold rates after 42 h. Furthermore, specific gene transcriptions related to MAP kinase signaling pathway regulation of cell differentiation and cell cycle regulation were triggered by retinoids in undernourished IEC-6, with higher levels of expression for Atf2 and C-jun genes.

CONCLUSIONS

These findings indicated that both vitamin A derivatives induce further survival mechanisms in undernourished intestinal epithelial crypt cells. These mechanisms include increased cell quiescence, decreased apoptosis, increased cell differentiation, and transcription of genes related to MAP kinase signaling pathway.

Evaluating association of vaccine response to low serum zinc and vitamin D levels in children of a birth cohort study in Dhaka

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MAL-ED Bangladesh birth cohort data used in the analysis.

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Relationship between vaccine titers and micronutrient data explored.

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Positive association found between serum zinc level and tetanus vaccine titer.

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The finding implicates the importance of improving zinc nutrition status of the children.

Background

Vaccine-preventable infectious diseases are often responsible for childhood morbidity and high rates of mortality. Immune response to the vaccine is associated with multiple factors in early childhood and measured by antibody titers. Among them, micronutrient deficiencies such as vitamin D and zinc deficiencies are the most important in resource-limited settings like Bangladesh.

Objective

We aimed to evaluate the association of vaccine response to low serum zinc and vitamin D levels in children.

Methods

We evaluated vaccine response for measles and poliovirus, tetanus and pertussis toxoid, and Ig A antibody levels to rotavirus by ELISA and serum vitamin D and zinc at 7 and 15 months in the MAL-ED birth cohort of the Bangladesh site. By using population-specific generalized estimating equations (GEE), the association between each explanatory variable and the binary outcome variable was examined longitudinally where the dependent variable was vaccine titers and the independent variables were low serum vitamin D and zinc levels.

Results

The GEE multivariable model identified a positive association between serum zinc level and tetanus vaccine titer (OR: 1.84; 95% CI: 1.07–3.17 and p value = 0.028) after adjusting for age, gender, birth weight, WAMI score, diarrhea, ALRI, exclusive breastfeeding, serum ferritin, serum retinol and undernutrition (stunting, wasting, underweight). No association was found between the rest of the vaccine titers with serum vitamin D and zinc level (p > 0.05).

Conclusion

In the MAL-ED birth cohort, where children were followed for five years, serum zinc level had a positive impact on tetanus vaccine titers.

Fecal MicroRNAs as Potential Biomarkers for Screening and Diagnosis of Intestinal Diseases

MicroRNAs (miRNAs) are a class of conserved endogenous, small non-coding RNA molecules with a length of 18–25 nucleotides that regulate gene expression by RNA interference processes, including mRNA chopping, mRNA deadenylation, and translation inhibition. miRNAs maintain the physiological functions of the intestine and are instrumental in gut pathogenesis. miRNAs play an important role in intercellular communication and are present in all body fluids, including stools with different composition and concentrations. However, under diseased conditions, miRNAs are aberrantly expressed and act as negative regulators of gene expression. The stable and differentially expressed miRNAs in stool enables miRNAs to be used as potential biomarkers for screening of various intestinal diseases. In this review, we summarize the expressed miRNA profile in stool and highlight miRNAs as biomarkers with potential clinical and diagnostic applications, and we aim to address the prospects for recent advanced techniques for screening miRNA in diagnosis and prognosis of intestinal disorders.

Rapid HPLC method for monitoring of lactulose production with a high yield

An HPLC method suitable for rapid monitoring of lactulose production by isomerization from lactose was developed. The separation of lactose and lactulose under hydrophilic interaction liquid chromatography (HILIC) mode was achieved with resolution 1.5 within 5 min. Since isocratic elution was used, there is no extra time necessary for the column equilibration. Application of the method was illustrated on monitoring lactulose isomerization with catalysis of sodium hydroxide in the presence of sodium tetraborate at 70 °C (pH = 11). The conversion yield obtained for lactulose was 86%, and corresponding purity 76%. For the first time, a polyhydroxy stationary phase for separation of lactose and lactulose is reported.

Zinc Absorption and Endogenous Fecal Zinc Losses in Bangladeshi Toddlers at Risk for Environmental Enteric Dysfunction

OBJECTIVES

Environmental enteric dysfunction (EED) impairs zinc absorption from food, and zinc deficiency may contribute to the poor growth associated with EED. We examined zinc absorption from a standardized aqueous zinc dose, and habitual daily endogenous fecal zinc excretion (EFZ) and compared these outcomes between children grouped by the lactulose to mannitol ratio (L:M).

METHODS

Bangladeshi toddlers (18-24 months) with low (<0.09) and high (≥0.09) L:M were administered isotope-labeled 3 mg aqueous zinc in the fasted state. Fractional absorption of zinc (FAZ) and EFZ were measured by dual stable isotope tracer method and an isotope dilution method, respectively. Secondary aims included examining relationships of biomarkers of systemic and intestinal inflammation and gut function with FAZ and EFZ.

RESULTS

Forty children completed the study; nearly all had evidence of EED. No differences in zinc homeostasis measurements (mean ± SD) were observed between high and low L:M groups: FAZ was 0.38 ± 0.19 and 0.31 ± 0.19, respectively; both figures were within estimated reference range. Means of EFZ were 0.73 ± 0.27 and 0.76 ± 0.20 mg/day for high and low L:M, respectively, and were 10% to 15% above estimated reference range. Regression analyses indicated that biomarkers of systemic inflammation were directly associated with increasing FAZ, consistent with increased gut permeability. Biomarkers of intestinal inflammation were negatively associated with EFZ, consistent with low-zinc intake and chronic deficiency.

CONCLUSIONS

In these children at risk of EED, endogenous zinc losses were not markedly increased. Results suggest that efforts to improve zinc status in EED should focus on substantially improving zinc intakes.

Supplementation With Lactoferrin and Lysozyme Ameliorates Environmental Enteric Dysfunction: A Double-Blind, Randomized, Placebo-Controlled Trial

INTRODUCTION

Environmental enteric dysfunction (EED) predisposes children throughout the developing world to high rates of systemic exposure to enteric pathogens and stunting. Effective interventions that treat or prevent EED may help children achieve their full physical and cognitive potential. The objective of this study is to test whether 2 components of breast milk would improve a biomarker of EED and linear growth during the second year of life.

METHODS

A prospective, randomized, double-blind, placebo-controlled clinical trial among children aged 12-23 months was conducted in rural Malawi. The experimental group received a daily supplement of 1.5 g of lactoferrin and 0.2 g of lysozyme for 16 weeks. The primary outcome was an improvement in EED, as measured by the change in the percentage of ingested lactulose excreted into the urine (Δ%L).

RESULTS

Among 214 children who completed the study, there was a significant difference in Δ%L between the control and experimental groups over 8 weeks (an increase of 0.23% vs 0.14%, respectively; P = 0.04). However, this relative improvement was not as strongly sustained over the full 16 weeks of the study (an increase of 0.16% vs 0.11%, respectively; P = 0.17). No difference in linear growth over this short period was observed. The experimental intervention group had significantly lower rates of hospitalization and the development of acute malnutrition during the course of the study (2.5% vs 10.3%, relative risk 0.25; P < 0.02).

DISCUSSION

Supplementation with lactoferrin and lysozyme in a population of agrarian children during the second year of life has a beneficial effect on gut health. This intervention also protected against hospitalization and the development of acute malnutrition, a finding with a significant clinical and public health importance. This finding should be pursued in larger studies with longer follow-up and optimized dosing.

Zinc Absorption from Micronutrient Powders Is Low in Bangladeshi Toddlers at Risk of Environmental Enteric Dysfunction and May Increase Dietary Zinc Requirements

Background

Environmental enteric dysfunction (EED), a chronic inflammatory disorder of the small bowel, is suspected to impair absorption of micronutrients, including zinc.

Objective

The objective of this study was to compare zinc absorption from micronutrient powder (MNP) over a range of zinc doses in young children screened for EED with use of the lactulose:mannitol ratio (L:M).

Methods

Bangladeshi children aged 18-24 mo, grouped according to high and low L:M (≥0.09 and <0.09, respectively), were randomly assigned to MNP with 0, 5, 10, or 15 mg Zn/sachet (10 subjects per dose per L:M group). Over a day, fractional absorption of zinc was measured from an MNP-fortified meal and from unfortified meals with stable isotope tracers; total daily absorbed zinc (TAZ, milligrams per day) was determined as the primary outcome. Secondary outcomes included investigation of relations of TAZ to intake, to physiologic requirement, and to other variables, including biomarkers of systemic and intestinal inflammation, using nonlinear models. TAZ was also compared with published data on child zinc absorption.

Results

In 74 subjects who completed the study, zinc absorption did not differ by L:M grouping. Most biomarkers of intestinal inflammation were elevated in both L:M groups. For combined L:M groups, mean ± SD TAZ for each MNP dose (0, 5, 10, and 15 mg/sachet) was 0.57 ± 0.30, 0.68 ± 0.31, 0.90 ± 0.43, and 1.0 ± 0.39 mg/d, respectively (P = 0.002), and exceeded the estimated physiologic requirement only for the 10- and 15-mg MNP doses. Zinc absorption was notably lower at all intake levels compared with published data (P < 0.0001) and was inversely related to serum α-1 acid glycoprotein and to fecal Entamoeba histolytica (P = 0.02).

Conclusion

Results indicate impaired absorption of zinc, which may predispose to zinc deficiency in young children with evidence of enteropathy. These findings suggest that current doses of zinc in MNP may be insufficient to yield zinc-related preventative benefits in similar settings. This study is registered at clinicaltrials.gov as NCT02758444.

Modulation of Intestinal Immune and Barrier Functions by Vitamin A: Implications for Current Understanding of Malnutrition and Enteric Infections in Children

The micronutrient vitamin A refers to a group of compounds with pleiotropic effects on human health. These molecules can modulate biological functions, including development, vision, and regulation of the intestinal barrier. The consequences of vitamin A deficiency and supplementation in children from developing countries have been explored for several years. These children live in an environment that is highly contaminated by enteropathogens, which can, in turn, influence vitamin A status. Vitamin A has been described to modulate gene expression, differentiation and function of diverse immune cells; however, the underlying mechanisms are not fully elucidated. This review aims to summarize the most updated advances on elucidating the vitamin A effects targeting intestinal immune and barrier functions, which may help in further understanding the burdens of malnutrition and enteric infections in children. Specifically, by covering both clinical and in vivo/in vitro data, we describe the effects of vitamin A related to gut immune tolerance/homeostasis, intestinal barrier integrity, and responses to enteropathogens in the context of the environmental enteric dysfunction. Some of the gaps in the literature that require further research are also highlighted.

Children living in the slums of Bangladesh face risks from unsafe food and water and stunted growth is common

AIM

This study investigated the microbial quality of food and water consumed by children in four slums in Dhaka, the capital of Bangladesh, together with the associated risk factors.

METHODS

This cross-sectional study took place from December 2015 to May 2016 and focused on 360 children under the age of five. We recorded household food security, namely adequate food for a healthy life, socio-economic and nutritional status, hygiene and feeding practices. Food and water samples were analysed.

RESULTS

We found that 63% of the children were malnourished and 58% were stunted. Yeast and moulds were detected in 86% of the food samples and coliforms in 73%. All the water samples were contaminated with faecal coliforms, yeasts and moulds and Staphylococcus. Food insecurity affected 83% of households. Children were twice as likely to be malnourished if they were born with a perceived low birthweight or their mothers did not wash their hands with soap after cleaning the child's bottom following defecation. Exclusively breastfed children were less likely to develop malnutrition.

CONCLUSION

Children from the Dhaka slums were frequently stunted and malnourished and contaminated food and water was common. Integrated efforts are essential to create public awareness about hygiene.

Micronutrient adequacy is poor, but not associated with stunting between 12-24 months of age: A cohort study findings from a slum area of Bangladesh

The prevalence of stunting among children below 5 years of age is higher in the slum-dwelling population of Bangladesh compared to that in both urban and rural areas. Studies have reported that several factors such as inadequate nutrition, low socio-economic status, poor hygiene and sanitation and lack of maternal education are the substantial predictors of childhood stunting. Almost all these factors are universally present in the slum-dwelling population of Bangladesh. However, few studies have prospectively examined such determinants of stunting among slum populations. In this paper, we reveal the findings of a cohort study with an aim to explore the status of micronutrient adequacy among such vulnerable children and establish its association with stunting along with other determinants. Two-hundred-sixty-five children were enrolled and followed since birth until 24 months of age. We collected anthropometric, morbidity and dietary intake data monthly. We used the 24-hour multiple-pass recall approach to collect dietary intake data from the age of 9 months onward. Micronutrient adequacy of the diet was determined by the mean adequacy ratio (MAR) which was constructed from the average intake of 9 vitamins and 4 minerals considered for the analysis. We used generalized estimating equation (GEE) regression models to establish the determinants of stunting between 12–24 months of age in our study population. The prevalence of low-birth-weight (LBW) was about 28.7% and approximately half of the children were stunted by the age of 24 months. The average micronutrient intake was considerably lower than the recommended dietary allowance and the MAR was only 0.48 at 24 months of age compared to the optimum value of 1. However, the MAR was not associated with stunting between 12–24 months of age. Rather, LBW was the significant determinant (AOR = 3.03, 95% CI: 1.69–5.44) after adjusting for other factors such as age (AOR = 2.12, 95% CI: 1.45–3.11 at 24 months and AOR = 1.97, 95% CI: 1.49–2.59 at 18 months, ref: 12 months) and sex (AOR = 1.98, 95% CI: 1.17–3.33, ref: female). Improving the nutritional quality of complementary food in terms of adequacy of micronutrients is imperative for optimum growth but may not be adequate to mitigate under-nutrition in this setting. Further research should focus on identifying multiple strategies that can work synergistically to diminish the burden of stunting in resource-poor settings.

Campylobacter jejuni and associated immune mechanisms: short-term effects and long-term implications for infants in low-income countries

PURPOSE OF REVIEW

Campylobacter jejuni is recognized as one of the most common causes of food-borne gastrointestinal illness worldwide, resulting in a self-limiting dysentery in developed countries. However, it is increasingly gaining attention due to its association with postinfectious complications such as Guillain-Barré Syndrome and recently recognized importance in early childhood diarrhea in developing countries. We hypothesize that the inflammation mediated by C. jejuni infection causes environmental enteric dysfunction, and with contribution from diet and the host, microbiome may be responsible for growth faltering in children and developmental disability.

RECENT FINDINGS

Diet plays a major role in the impact of C. jejuni infection, both by availability of micronutrients for the bacteria and host as well as shaping the microbiome that affords resistance. Early childhood repeated exposure to the bacterium results in inflammation that affords long-term immunity but, in the short term, can lead to malabsorption, oral vaccine failure, cognitive delay and increased under-5 mortality.

SUMMARY

As interest in C. jejuni increases, our understanding of its virulence mechanisms has improved. However, much work remains to be done to fully understand the implications of immune-mediated inflammation and its potential role in diseases such as environmental enteric dysfunction.

A test of the optimal iron hypothesis among breastfeeding Ariaal mothers in northern Kenya

OBJECTIVE

The optimal iron hypothesis posits a trade-off in iron nutrition-iron deficiency restricts iron available to infectious agents, protecting against severe infection, but also compromises immune defense-such that mild-to-moderate iron deficiency may be more adaptive than either iron-replete or severe deficiency in environments with high infectious disease load. This hypothesis has not been tested among adults.

MATERIALS AND METHODS

A secondary analysis of data and specimens from 220 lactating mothers in northern Kenya was conducted. Elevated serum C-reactive protein (CRP > 2 or >5 mg/l) was utilized to identify prevalent subclinical infection/inflammation. Iron deficiency was identified with transferrin receptor in archived dried blood spots (TfR > 5.0 mg/l). The absence of iron deficiency or anemia (Hemoglobin < 12 g/l) defined the iron replete state. Iron-deficient erythropoiesis (IDE, mild-to-moderate iron deficiency) was defined as iron deficiency without anemia; iron deficiency anemia (IDA, severe iron deficiency) as iron deficiency with anemia; and noniron-deficiency anemia (NIDA) as anemia without iron deficiency.

RESULTS

The prevalence of elevated inflammation (subclinical infection) was lowest in IDE. In logistic regression, IDE was inversely associated with inflammation (for CRP > 2 mg/l: adjusted odds ratio, aOR = 0.30; p = 0.02; for CRP > 5 mg/l: aOR = 0.27; p = 0.10), compared to the iron replete state. The protective effect of IDE differed in the presence of vitamin A deficiency or underweight.

CONCLUSIONS

We interpret these patterns as tentative support for the optimal iron hypothesis in breastfeeding women in the infectious disease ecology of northern Kenya. Iron deficiency may interact in important ways with other forms of malnutrition that are known to affect immune protection.