Additional Common Bean in the Diet of Malawian Children Does Not Affect Linear Growth, but Reduces Intestinal Permeability

Impact of Harvest Lentil Vegetable Blend and Nutrition Education on Child Growth, Caregivers' Nutrition Knowledge, and WASH Practices

OBJECTIVE

To assess the changes in child nutrition status, caregivers' knowledge, and water, sanitation, and hygiene (WASH) practices following the provision of Harvest Lentil Vegetable Blend to children and a nutrition education intervention to their caregivers.

DESIGN

Three-week pretest-posttest study.

SETTING

Turkana, Kenya.

PARTICIPANTS

Children aged 6-59 months (n = 162) and their caregivers (n = 127) completed the intervention, representing > 70% retention.

INTERVENTIONS

Provision of Harvest Lentil Vegetable Blend to children and nutrition education intervention for caregivers on child feeding and WASH practices.

MAIN OUTCOMES MEASURES

Children's anthropometric measurements, caregivers' nutrition knowledge, and WASH practices.

ANALYSIS

Wilcoxon signed rank and McNemar tests.

RESULTS

At baseline, 19%, 24%, and 35% of children were stunted, underweight, and wasted, respectively. At the endpoint, the weight-for-age z-scores increased by 0.61 (P = 0.04) for children 6-12 months and by 0.31 (P = 0.03) for children 13-47 months. Weight-for-height z-scores increased by 0.84 (P = 0.04) among children 6-12 months and by 0.42 (P = 0.04) among children 13-47 months. The proportion of caregivers who reported washing hands after defecation and before cooking increased by 37% and 26%, respectively (P = 0.001).

CONCLUSIONS AND IMPLICATIONS

An on-site feeding program that used nutrient-dense supplemental food was associated with positive changes in children's nutrition status within a short duration. Nutrition education intervention increased the proportion of caregivers who practiced some key WASH practices.

IMPACT OF NUTRITIONAL SUPPLEMENTATION ON ENVIRONMENTAL ENTERIC DYSFUNCTION (EED) IN CHILDREN LIVING IN RURAL AREAS: A SYSTEMATIC REVIEW

BACKGROUND

A staggering 99% of infant undernutrition mortality comes from Sub-Saharan Africa and South Asia. Despite multiple interventions focusing on nutrition adequacy, 2.7 million children worldwide remain associated with undernutrition-related mortality. The lack of impact from multiple interventions toward undernutrition reflects a strong reason to believe that EED is the missing link that sustains undernutrition in low-to-middle-income countries (LMICs). EED is a sub-clinical condition caused by repeated oral enteropathogenic and non-pathogenic fecal microbes exposure that causes intestinal villous malformation, multi-omics changes, chronic intestinal and systemic inflammation, and gut dysbiosis. EED impacts the absorptive capacity and the integrity of the gut, causing a cycle of undernutrition in children. There is currently no protocol for the diagnosis and treatment of EED, hence EED is widely believed to be highly prevalent and underdiagnosed in LMICs.

OBJECTIVE

To our knowledge, this is the first systematic review to study the impact of nutritional interventions on EED. Previous studies yielded inconsistent results, hence the synthesis of this information is essential in attaining a deeper understanding of EED to formulate new targets of intervention against child undernutrition.

METHODS

This systematic review is registered to PROSPERO (CRD42022363157) in accordance to PRISMA, using keywords referring to nutrient supplementation, EED, and child growth failure.

RESULTS

Eleven articles were eligible for review, comprising randomized controlled trials performed mainly in the African continent, with a total of 5689 healthy children eligible for analysis.

CONCLUSION

The systematic review illustrates that nutritional interventions have a minimal impact on EED biomarkers and linear growth and reflects the importance of understanding better the mechanisms causing EED and its consequences. It appears that the anabolic contribution of nutrition intervention to child growth is negated by EED.

The double burden of malnutrition in individuals: Identifying key challenges and re-thinking research focus

The 'double burden of malnutrition' is a global health challenge that increasingly affects populations in both low- and middle-income countries (LMICs). This phenomenon refers to the coexistence of undernutrition and overweight or obesity, as well as other diet-related non-communicable diseases, in the same population, household or even individual. While noteworthy progress has been made in reducing undernutrition in some parts of the world, in many of these areas, the prevalence of overweight and obesity is increasing, particularly in urban areas, resulting in greater numbers of people who were undernourished in childhood and have overweight or obesity in adulthood. This creates a complex and challenging situation for research experts and policymakers who must simultaneously address the public health burdens of undernutrition and overweight/obesity. This review identifies key challenges and limitations in the current research on the double burden of malnutrition in individuals, including the need for a more comprehensive and nuanced understanding of the drivers of malnutrition, the importance of context-specific interventions and the need for greater attention to the food environment and food systems. We advocate for the re-evaluation of research strategies and focus, with a greater emphasis on multidisciplinary and systems approaches and greater attention to the synergistic relationship between the biological, environmental, commercial and socio-economic determinants of malnutrition. Addressing these key challenges can enable us to better comprehend and tackle the multifaceted and dynamic issues of the double burden of malnutrition, particularly in individuals and work towards more effective and sustainable solutions.

Formulation and acceptability of local nutrient-dense foods for young children: A formative study for the Child Health, Agriculture and Integrated Nutrition (CHAIN) Trial in rural Zimbabwe

Stunting affects almost one-quarter of children globally, leading to reduced human capacity and increased long-term risk of chronic disease. Despite intensive infant and young child feeding (IYCF) interventions, many children do not meet their requirements for essential nutrients. This study aimed to assess the feasibility of implementing an IYCF intervention utilizing nutrient-dense powders from egg, biofortified sugar beans and Moringa oleifera leaf in rural Zimbabwe. A mixed-methods formative study was conducted comprising the following: (i) a recipe formulation trial, (ii) trials of improved practices to assess acceptability of the intervention, and (iii) a participatory message formulation process to develop counselling modules for the IYCF-plus intervention. Twenty-seven mother-baby pairs were recruited between November 2019 and April 2020. Key domains affecting IYCF practices that emerged were time, emotional and physical space, cultural and religious beliefs, indigenous knowledge systems and gender dynamics. Household observations and sensory evaluation indicated high acceptability of the new ingredients. Recipe formulation and participatory message formulation by participants instilled community ownership and served to demystify existing misconceptions about the new food products. Families noted the potential for intervention sustainability because the foods could be grown locally. Supplementing complementary foods with nutrient-dense local food ingredients as powders has the potential to sustainably address nutrient-gaps in the diets of young children living in rural lower- and middle-income countries. Comprehensive IYCF counselling utilizing a gender-lens approach, family support and indigenous knowledge systems or resources are key elements to support positive behaviour change in complementary feeding interventions.

NAD+ precursors and bile acid sequestration treat preclinical refractory environmental enteric dysfunction

Environmental enteric dysfunction (EED) is a diffuse small bowel disorder associated with poor growth, inadequate responses to oral vaccines, and nutrient malabsorption in millions of children worldwide. We identify loss of the small intestinal Paneth and goblet cells that are critical for innate immunity, reduced villous height, increased bile acids, and dysregulated nicotinamide adenine dinucleotide (NAD+) synthesis signaling as potential mechanisms underlying EED and which also correlated with diminished length-for-age z score. Isocaloric low-protein diet (LPD) consumption in mice recapitulated EED histopathology and transcriptomic changes in a microbiota-independent manner, as well as increases in serum and fecal bile acids. Children with refractory EED harbor single-nucleotide polymorphisms in key enzymes involved in NAD+ synthesis. In mice, deletion of Nampt, the gene encoding the rate-limiting enzyme in the NAD+ salvage pathway, from intestinal epithelium also reduced Paneth cell function, a deficiency that was further aggravated by LPD. Separate supplementation with NAD+ precursors or bile acid sequestrant partially restored LPD-associated Paneth cell defects and, when combined, fully restored all histopathology defects in LPD-fed mice. Therapeutic regimens that increase protein and NAD+ contents while reducing excessive bile acids may benefit children with refractory EED.

Child Health, Agriculture and Integrated Nutrition (CHAIN): protocol for a randomised controlled trial of improved infant and young child feeding in rural Zimbabwe

INTRODUCTION

Over one-quarter of children in sub-Saharan Africa are stunted; however, commercial supplements only partially meet child nutrient requirements, cannot be sustainably produced, and do not resolve physiological barriers to adequate nutrition (eg, inflammation, microbiome dysbiosis and metabolic dysfunction). Redesigning current infant and young child feeding (IYCF) interventions using locally available foods to improve intake, uptake and utilisation of nutrients could ameliorate underlying pathogenic pathways and improve infant growth during the critical period of complementary feeding, to reduce the global burden of stunting.

METHODS AND ANALYSIS

Child Health Agriculture Integrated Nutrition is an open-label, individual household randomised trial comparing the effects of IYCF versus 'IYCF-plus' on nutrient intake during infancy. The IYCF intervention comprises behaviour change modules to promote infant nutrition delivered by community health workers, plus small-quantity lipid-based nutrient supplements from 6 to 12 months of age which previously reduced stunting at 18 months of age by ~20% in rural Zimbabwe. The 'IYCF-plus' intervention provides these components plus powdered NUA-45 biofortified sugar beans, whole egg powder, moringa leaf powder and provitamin A maize. The trial will enrol 192 infants between 5 and 6 months of age in Shurugwi district, Zimbabwe. Research nurses will collect data plus blood, urine and stool samples at baseline (5-6 months of age) and endline (9-11 months of age). The primary outcome is energy intake, measured by multipass 24-hour dietary recall at 9-11 months of age. Secondary outcomes include nutrient intake, anthropometry and haemoglobin concentration. Nested laboratory substudies will evaluate the gut microbiome, environmental enteric dysfunction, metabolic phenotypes and innate immune function. Qualitative substudies will explore the acceptability and feasibility of the IYCF-plus intervention among participants and community stakeholders, and the effects of migration on food production and consumption.

ETHICS AND DISSEMINATION

This trial is registered at ClinicalTrials.gov (NCT04874688) and was approved by the Medical Research Council of Zimbabwe (MRCZ/A/2679) with the final version 1.4 approved on 20 August 2021, following additional amendments. Dissemination of trial results will be conducted through the Community Engagement Advisory Board in the study district and through national-level platforms.

TRIAL REGISTRATION NUMBER

NCT04874688.

Development of Food Multi-Mix Using a Linear Programming Approach to Fill the Nutrient Gap of Amino Acids and Micronutrients for Stunted Non-Wasted Children

Food-based approaches using locally available food escalates the feasibility and the sustainability of nutrition intervention. A complementary feeding recommendation (CFR) integrated with the food multi-mix (FMM) formulation was targeted to fulfill micronutrient and amino acid requirements for stunted non-wasted (SNW) children aged 12-23 months living in agricultural areas. A seven-day estimated food record (EFR) of 87 children was used to design the CFR and 4 identified underutilized foods were integrated as the FMM. A linear programming approach using Optifood was applied to optimize the CFR and FMM. CFR alone successfully fulfills the vitamin C, riboflavin, iron, and zinc, but it cannot fulfill calcium, thiamin, niacin, vitamin B6, folate, vitamin B12, and histidine. With the incorporation of the selected underutilized cowpea, buncis batik, wader fish, and cows' milk in the FMM development, the nutrients that are challenging in CFR development, can be fulfilled. Therefore, these findings present evidence that food multi-mix developed based on locally available nutrient-dense food sources can help to meet the nutrient gaps, which often remained even after a complementary feeding diet is optimized. Efficacy study using the developed CFR and FMM is recommended to assess effect in improving intake of micronutrients and amino acids and improving the linear growth of stunted, non-wasted children.

Acceptability of orange corn-common bean as an alternative to corn-soybean complementary porridge in Malawi

This study assessed the acceptability of porridge from a corn-common bean flour blend to increase the diversity of complementary foods in Malawi. Porridges prepared using commercial corn-soybean flour (C-CSB), homemade orange corn-soybean flour (H-CSB), and orange corn-common bean flour (CCBB) were evaluated by 101 pairs of mothers and their respective children aged from 6 to 24 months. A home use test (HUT) setup was used in this study, and the flours were given sequentially to participating households following a randomized complete block design. Each sample type was evaluated for 3 days in a row followed by a 1-day break (washout period) between sample types. Based on aggregate mean scores, all the samples were liked by both the children and their mothers. However, clustering results revealed two distinct consumer segments for mothers as well as for children. Most of the mothers (59.4% in cluster 1) liked all the samples, while the minority (cluster 2) were neutral (neither like nor dislike) regarding the H-CSB porridge. Likewise, most children (66.3% in cluster 2) liked all the samples, while the rest in cluster 1 did not like CCBB porridge. Infants (≤12 months) and those from food-insecure households, respectively, were 5.42 and 6.75 times more likely to like the CCBB porridge than their counterparts. The study has demonstrated the potential of introducing CCBB complementary porridge in Malawi and possibly in other countries with similar food preferences and socioeconomic stature. PRACTICAL APPLICATION: The study provides a solution to the limited diversity of complementary foods in sub-Saharan Africa and Malawi in particular. The findings can help food scientists, nutritionists, marketers, and policymakers develop strategies for promoting the consumption of orange corn-common bean porridge. Furthermore, the findings can inform decisions on commercializing orange corn-common bean flour by flour processors.

Design Factors for Food Supplementation and Nutrition Education Interventions That Limit Conclusions about Effectiveness for Wasting Prevention: A Scoping Review of Peer-Reviewed Literature

We conducted a scoping review to characterize the evidence base for the effectiveness of food supplementation (FS), nutrition education (NE), or FS/NE interventions to prevent wasting among children aged 6 to 59 mo. We aimed to identify gaps in peer-reviewed literature and to develop recommendations for strengthening study designs. We identified 56 unique studies (FS = 21, NE = 19, FS/NE = 16) for which we assessed intervention design factors, implementation context, evaluation methods, and wasting impact. Compared with studies focused on stunting, fewer wasting-focused studies reported weight-for-height z score (WHZ). Midupper arm circumference (MUAC) was more commonly reported in wasting-focused studies (71.4%) than those focused on stunting (36.8%) or wasting and stunting (30.4%). FS studies measured anthropometry (mean, 95% CI) more frequently at every 11.3 (7.8, 14.8) wk than NE interventions at 36.3 (8.8, 62.1) wk (P = 0.036), but not FS/NE interventions at 25.8 (5.6, 49.1) wk (P = 0.138). NE interventions tended to be of longer duration than FS or FS/NE interventions. Only 6 studies followed and measured children after the intervention period ended. Across all studies, 45% reported a significant effect on wasting; these included FS, NE, and FS/NE interventions. The lack of comparability across studies limits conclusions about the effectiveness of specific types of interventions. To build a more unified evidence base for wasting prevention we recommend that future studies 1) report on a consistent set of metrics, including MUAC; 2) attempt to measure change in wasting incidence using more frequent measures; 3) measure wasting prevalence among the general population; 4) follow children postintervention to assess relapse; 5) measure food insecurity and diet quality; and 6) use harmonized protocols across multiple settings. Such efforts to improve study comparability will strengthen the evidence base, may help unite divergent professional communities, and ultimately accelerate progress toward eliminating child undernutrition.

Investigating the infant gut microbiota in developing countries: worldwide metagenomic meta-analysis involving infants living in sub-urban areas of Côte d'Ivoire

In recent decades, infants' gut microbiota has aroused constant scientific interest, primarily due to early- and long-term repercussions on the host health. In this context, nutritional challenges such as those found in less developed countries can influence infants' gut microbiota development, thus generating potentially critical health outcomes. However, comprehensive investigations regarding species-level differences in the infant gut microbiota's composition between urbanized and rural countries are still missing. In this study, 16S rRNA and Shallow Shotgun metagenomics sequencing were exploited to dissect the microbial community's species-level composition of 11 faecal samples collected from infants living in a semi-urban area of Sub-Saharan Africa, i.e. Côte d'Ivoire. Moreover, the generated data were coupled with those retrieved from public available metagenomic repositories, including two rural communities and 13 urban communities of industrialized countries. The meta-analysis led to the identification of Infant Species Community States Type (ISCSTs) and microbial species covariances, which were exploited to reveal key signatures of infants living in rural and semi-urban societies. Remarkably, analysis of rural and semi-urban datasets revealed shifts from ISCSTs prevalent in urbanized populations with putative health implications. Thus, indicating the need for population-wide investigations aimed to define the factors determining such potentially harmful gut microbial communities' signatures.

Modifying gut integrity and microbiome in children with severe acute malnutrition using legume-based feeds (MIMBLE): A pilot trial

Case fatality among African children with severe acute malnutrition remains high. We report a 3-arm pilot trial in 58 Ugandan children, comparing feeds targeting disordered gastrointestinal function containing cowpea (CpF, n = 20) or inulin (InF, n = 20) with conventional feeds (ConF, n = 18). Baseline measurements of gut permeability (lactulose:mannitol ratio 1.19 ± SD 2.00), inflammation (fecal calprotectin 539.0 μg/g, interquartile range [IQR] 904.8), and satiety (plasma polypeptide YY 62.6 pmol/l, IQR 110.3) confirm gastrointestinal dysfunction. By day 28, no differences are observable in proportion achieving weight gain >5 g/kg/day (87%, 92%, 86%; p > 0.05), mortality (16%, 30%, 17%; p > 0.05), or edema resolution (83%, 54%, 91%; p > 0.05) among CpF, InF, and ConF. Decreased fecal bacterial richness from day 1 (abundance-based coverage estimator [ACE] 53.2) to day 7 (ACE 40.8) is observed only in ConF (p = 0.025). Bifidobacterium relative abundance increases from day 7 (5.8% ± 8.6%) to day 28 (10.9% ± 8.7%) in CpF (corrected p = 1.000). Legume-enriched feeds support aspects of gut function and the microbiome. Trial registration PACTR201805003381361.

Impact of diet and the bacterial microbiome on the mucous barrier and immune disorders

The prevalence of chronic immune and metabolic disorders is increasing rapidly. In particular, inflammatory bowel diseases, obesity, diabetes, asthma and chronic obstructive pulmonary disease have become major healthcare and economic burdens worldwide. Recent advances in microbiome research have led to significant discoveries of associative links between alterations in the microbiome and health, as well as these chronic supposedly noncommunicable, immune/metabolic disorders. Importantly, the interplay between diet, microbiome and the mucous barrier in these diseases has gained significant attention. Diet modulates the mucous barrier via alterations in gut microbiota, resulting in either disease onset/exacerbation due to a "poor" diet or protection against disease with a "healthy" diet. In addition, many mucosa-associated disorders possess a specific gut microbiome fingerprint associated with the composition of the mucous barrier, which is further influenced by host-microbiome and inter-microbial interactions, dietary choices, microbe immigration and antimicrobials. Our review focuses on the interactions of diet (macronutrients and micronutrients), gut microbiota and mucous barriers (gastrointestinal and respiratory tract) and their importance in the onset and/or progression of major immune/metabolic disorders. We also highlight the key mechanisms that could be targeted therapeutically to prevent and/or treat these disorders.

Campylobacter Colonization, Environmental Enteric Dysfunction, Stunting, and Associated Risk Factors Among Young Children in Rural Ethiopia: A Cross-Sectional Study From the Campylobacter Genomics and Environmental Enteric Dysfunction (CAGED) Project

Livestock farming provides a possible mechanism by which smallholder farmers can meet their household need for animal source foods (ASF), which may reduce the risk of stunting. However, direct/indirect contacts with domestic animals may increase colonization by Campylobacter spp., which has been associated with Environmental Enteric Dysfunction (EED) and stunting. A cross-sectional study involving 102 randomly selected children between 12 and 16 months of age was conducted in rural eastern Ethiopia to establish prevalence rates of Campylobacter colonization, EED, and stunting, and evaluate potential risk factors. Data were collected between September and December 2018. The prevalence of EED and stunting was 50% (95% CI: 40-60%) and 41% (95% CI: 32-51%), respectively. Among enrolled children, 56% had consumed some ASF in the previous 24 h; 47% had diarrhea and 50% had fever in the past 15 days. 54, 63, 71 or 43% of households owned at least one chicken, cow/bull, goat, or sheep; 54 (53%) households kept chickens indoors overnight and only half of these confined the animals. Sanitation was poor, with high levels of unimproved latrines and open defecation. Most households had access to an improved source of drinking water. The prevalence of Campylobacter colonization was 50% (95% CI: 41-60%) by PCR. In addition to the thermotolerant species Campylobacter jejuni, Campylobacter coli and Campylobacter upsaliensis, non-thermotolerant species related to Campylobacter hyointestinalis and Campylobacter fetus were frequently detected by Meta-total RNA sequencing (MeTRS). Current breastfeeding and ASF consumption increased the odds of Campylobacter detection by PCR, while improved drinking water supply decreased the odds of EED. No risk factors were significantly associated with stunting. Further studies are necessary to better understand reservoirs and transmission pathways of Campylobacter spp. and their potential impact on child health.

Nutritional Support in Malnourished Children With Compromised Gastrointestinal Function: Utility of Peptide-Based Enteral Therapy

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.

Amino Acid Digestibility of Extruded Chickpea and Yellow Pea Protein is High and Comparable in Moderately Stunted South Indian Children with Use of a Dual Stable Isotope Tracer Method

BACKGROUND

Legumes are an excellent plant source of the limiting indispensable amino acid (IAA) lysine in vegetarian, cereal-based diets. However, their digestibility is poor largely because of their antiprotease content. Extrusion can enhance digestibility by inactivating trypsin inhibitors and thus potentially improve the protein quality of legumes.

OBJECTIVE

We measured the digestibility of extruded chickpea and yellow pea protein with use of a dual stable isotope method in moderately stunted South Indian primary school children.

METHODS

Twenty-eight moderately stunted children (height-for-age z scores <-2.0 SD and >-3.0 SD) aged 6-11 y from low to middle socioeconomic status were randomly assigned to receive a test protein (extruded intrinsically [2H]-labeled chickpea or yellow pea) along with a standard of U-[13C]-spirulina protein to measure amino acid (AA) digestibility with use of a dual stable isotope method. Individual AA digestibility in the test protein was calculated by the ratios of AA enrichments in the test protein to the standard protein in the food and their appearance in blood plasma collected at 6 and 6.5 h during the experiment, representing a plateau state.

RESULTS

The mean AA digestibility of extruded chickpea and yellow pea protein in moderately stunted children (HAZ; -2.86 to -1.2) was high and similar in both extruded test proteins (89.0% and 88.0%, respectively, P = 0.83). However, lysine and proline digestibilities were higher in extruded chickpea than yellow pea (79.2% compared with 76.5% and 75.0% compared with 72.0%, respectively, P < 0.02).

CONCLUSION

Extruded chickpea and yellow pea protein had good IAA digestibility in moderately stunted children, which was 20% higher than an earlier report of their digestibility when pressure-cooked, measured by the same method in adults. Higher digestibility of lysine and proline highlights better retention of these AA in chickpea during extrusion-based processing. Extrusion might be useful for developing high-quality protein foods from legumes. This trial was registered at www.ctri.nic.in as CTRI/2018/03/012439.

Effects of improved water, sanitation, and hygiene and improved complementary feeding on environmental enteric dysfunction in children in rural Zimbabwe: A cluster-randomized controlled trial

BACKGROUND

Environmental enteric dysfunction (EED) may be an important modifiable cause of child stunting. We described the evolution of EED biomarkers from birth to 18 months in rural Zimbabwe and tested the independent and combined effects of improved water, sanitation, and hygiene (WASH), and improved infant and young child feeding (IYCF), on EED.

METHODOLOGY AND FINDINGS

The Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial was a 2x2 factorial cluster-randomised trial of improved IYCF and improved WASH on child stunting and anaemia at 18 months of age. 1169 infants born to HIV-negative mothers provided plasma and faecal specimens at 1, 3, 6, 12, and 18 months of age. We measured EED biomarkers that reflect all domains of the hypothesized pathological pathway. Markers of intestinal permeability and intestinal inflammation declined over time, while markers of microbial translocation and systemic inflammation increased between 1-18 months. Markers of intestinal damage (I-FABP) and repair (REG-1β) mirrored each other, and citrulline (a marker of intestinal epithelial mass) increased from 6 months of age, suggesting dynamic epithelial turnover and regeneration in response to enteric insults. We observed few effects of IYCF and WASH on EED after adjustment for multiple comparisons. The WASH intervention decreased plasma IGF-1 at 3 months (β:0.89, 95%CI:0.81,0.98) and plasma kynurenine at 12 months (β: 0.92, 95%CI:0.87,0.97), and increased plasma IGF-1 at 18 months (β:1.15, 95%CI:1.05,1.25), but these small WASH effects did not translate into improved growth.

CONCLUSIONS

Overall, we observed dynamic trends in EED but few effects of IYCF or WASH on biomarkers during the first 18 months after birth, suggesting that these interventions did not impact EED. Transformative WASH interventions are required to prevent or ameliorate EED in low-income settings.

Environmental enteric dysfunction: a review of potential mechanisms, consequences and management strategies

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.

Leaky gut: mechanisms, measurement and clinical implications in humans

The objectives of this review on 'leaky gut' for clinicians are to discuss the components of the intestinal barrier, the diverse measurements of intestinal permeability, their perturbation in non-inflammatory 'stressed states' and the impact of treatment with dietary factors. Information on 'healthy' or 'leaky' gut in the public domain requires confirmation before endorsing dietary exclusions, replacement with non-irritating foods (such as fermented foods) or use of supplements to repair the damage. The intestinal barrier includes surface mucus, epithelial layer and immune defences. Epithelial permeability results from increased paracellular transport, apoptosis or transcellular permeability. Barrier function can be tested in vivo using orally administered probe molecules or in vitro using mucosal biopsies from humans, exposing the colonic mucosa from rats or mice or cell layers to extracts of colonic mucosa or stool from human patients. Assessment of intestinal barrier requires measurements beyond the epithelial layer. 'Stress' disorders such as endurance exercise, non-steroidal anti-inflammatory drugs administration, pregnancy and surfactants (such as bile acids and dietary factors such as emulsifiers) increase permeability. Dietary factors can reverse intestinal leakiness and mucosal damage in the 'stress' disorders. Whereas inflammatory or ulcerating intestinal diseases result in leaky gut, no such disease can be cured by simply normalising intestinal barrier function. It is still unproven that restoring barrier function can ameliorate clinical manifestations in GI or systemic diseases. Clinicians should be aware of the potential of barrier dysfunction in GI diseases and of the barrier as a target for future therapy.

Development of Acute Malnutrition Despite Nutritional Supplementation in Malawi

Malnutrition in children is most often attributed to inadequate nutrient intake. Utilizing data from 2 prospective, randomized controlled trials of complimentary feeding with supplemental legumes (n = 693, ages 6-24 months) in 2 Malawian villages, Masenjere, and Limera, we document a high rate 70/693 (10.1%) of acute malnutrition (AM). Risks for AM in this setting, as determined by Cox regression analysis, include study village (hazard ratio [HR] 3.0), prior malnutrition (HR 4.12), stunting (HR 2.87), and a marker of food insecurity (HR 1.89). Comparison of Masenjere to Limera demonstrate adequate and similar nutritional intake yet an increased rate of AM in Masenjere, 56 of 400 (14.0%) versus 14 of 293 (4.8%), and stunting, 140 of 400 (35%) versus 80 of 293 (27%), environmental enteric dysfunction 246 of 400 (71%) versus 181/293 (67%), and infectious symptoms (cough and diarrhea). Masenjere did have cleaner water and less food insecurity 200 of 399 (50.5%) versus 204 of 293 (69.6%). These findings suggest adequate complementary nutrient intake does not protect young children against AM.

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.

Consumption of Animal-Source Protein is Associated with Improved Height-for-Age z Scores in Rural Malawian Children Aged 12⁻36 Months

Linear growth faltering, caused by insufficient diet, recurrent infections and environmental enteric dysfunction (EED), continues to plague young children in low- and middle-income countries (LMICs). Diets in LMICs are primarily plant based, and thus have poor-quality protein and low levels of essential micronutrients. The aim of this study was to assess the association of the type and protein quality of food consumed with stunting, EED and acute malnutrition in children aged 6⁻36 months in Limera and Masenjere, two rural Southern Malawian communities. This is a secondary analysis of two randomized controlled trials that tested the effects of common bean and cowpea flour on stunting in children aged 6⁻36 months. We used data from two interactive 24-h dietary recalls conducted 12 weeks after enrolment into each trial. Food intakes were compared between the regions using Chi-square and Student's t-test. There were 355 children that participated in the dietary recalls. The diets of children were of poor quality, but the children from Limera consumed more fish (54% vs. 35%, p = 0.009) and more bioavailable protein (26.0 ± 10.3 g/day vs. 23.1 ± 8.1 g/day, p = 0.018, respectively) than children in Masenjere. Food type and protein quality were not associated with any of the outcomes except an association between animal protein consumption and improvement in height-for-age z scores in children aged 12⁻36 months (p = 0.047). These findings support the notion that animal-source food (ASF) consumption in this vulnerable population promotes linear growth.

Detection and interpretation of fecal host mRNA in rural Malawian infants aged 6-12 months at risk for environmental enteric dysfunction

Recent studies have suggested that environmental enteric dysfunction can be assessed in rural African children by measuring levels of fecal mRNA transcripts. The field collection of fecal samples is less invasive and cumbersome than administration of the lactulose:mannitol test, which is typically used to assess environmental enteric dysfunction. This study sought to determine if, as in children aged 12-60 months, an array of seven fecal host transcripts (CD53, CDX1, HLA-DRA, TNF, S100A8, MUC12, and REG1A) could predict environmental enteric dysfunction in rural African infants. Host fecal transcript abundance was correlated to the percentage of lactulose (%L) excreted in the urine for 340 samples from Malawian children aged 6-12 months. Permeability was categorized as not severe (%L < 0.45) and severe (%L ≥ 0.45). This study found the prevalence of severe environmental enteric dysfunction to be 114/834 (14%), lower than what was previously reported for 12-60 months old children, 595/1521 (39%, P = 0.001). In linear regression analysis with the seven host transcripts, two were associated with %L: β coefficients of -1.843 ( P = 0.035) and 0.215 ( P = 0.006) for CDX1 and REG1A, respectively. The seven fecal host transcripts in a random forest model did not predict severe environmental enteric dysfunction. Future models utilizing different transcripts identified from an untargeted, agnostic assessment of all potential host transcripts could provide accurate predictions of environmental enteric dysfunction in infants. Impact statement Environmental enteric dysfunction (EED) is associated with reduced linear growth. The dual sugar absorption test has been used as a non-invasive method to determine the gut health of individuals. Alternative methods using fecal host mRNAs as predictors of the gut health are promising. In older children, we have determined that seven transcripts can predict the gut health in a random forest model. Our current study determined that the host fecal mRNA is abundant in infants and toddlers alike. Severe EED in rural Malawian children is less prevalent in infants than in young children. REG1A and CDX1 are associated with gut health. Fecal host mRNA may well be a means to assess gut health in African infants, but the panel of transcripts used to do this will differ from that in older children.

Milk Powder Added to a School Meal Increases Cognitive Test Scores in Ghanaian Children

Background

The inclusion of milk in school feeding is accepted as good nutritional practice, but specific benefits remain uncertain.

Objective

The objective was to determine whether consumption of 8.8 g milk protein/d given as milk powder with a multiple micronutrient-enriched porridge resulted in greater increases in linear growth and Cambridge Neuropsychological Test Automated Battery (CANTAB) scores in Ghanaian schoolchildren when compared with 1 of 3 control groups.

Methods

A randomized, double-blind, placebo-controlled clinical trial in healthy children aged 6-9 y was conducted comparing 8.8 g milk protein/d with 4.4 g milk protein/d or 4.4 g milk protein + 4.4 g rice protein/d (isonitrogenous, half of the protein from milk and half from rice) or a non-nitrogenous placebo. Primary outcomes were changes in length after 9 mo and CANTAB scores after 4.5 mo; secondary outcomes were body-composition measures. Supplements were added to porridge each school day and consumed for 9 mo. Anthropometric and body-composition measures and CANTAB tests were completed upon enrollment and after 4.5 and 9 mo. Group results were compared by using ANCOVA for anthropometric measures and the Kruskal-Wallis test for CANTAB scores.

Results

Children receiving 8.8 g milk protein/d showed greater increases on percentage correct in Pattern Recognition Memory (mean ± SD: 5.5% ± 16.8%; P < 0.05) and Intra/Extradimensional Set Shift completed stages compared with all other food groups (0.6 ± 2.3; P < 0.05). No differences were seen in linear growth between the groups. The children receiving either 4.4 or 8.8 g milk protein/d had a higher fat-free body mass index than those who received no milk, with an effect size of 0.34 kg/m2.

Conclusion

Among schoolchildren, the consumption of 8.8 g milk protein/d improved executive cognitive function compared with other supplements and led to the accretion of more lean body mass, but not more linear growth. This trial was registered at www.clinicaltrials.gov">www.clinicaltrials.gov as NCT02757508.

EB 2017 Article: Interpretation of the lactulose:mannitol test in rural Malawian children at risk for perturbations in intestinal permeability

The dual sugar absorption test, specifically the lactulose:mannitol test, is used to assess gut health. Lactulose absorption is said to represent gut damage and mannitol absorption is used as a measure of normal small bowel function and serves as normalizing factor for lactulose. A underappreciated limitation of this common understanding of the lactulose:mannitol test is that mannitol is not absorbed to any substantial extent by a transcellular process. Additionally, this interpretation of lactulose:mannitol is not consistent with current understanding of paracellular pathways, where three pathway types exist: pore, leak, and unrestricted. Pore and leak pathways are regulated biological constructions of the small bowel barrier, and unrestricted pathways represent micropathological damage. We analyzed 2334 lactulose:mannitol measurements rigorously collected from 622 young rural Malawian children at high risk for poor gut health in light of the pathway model. An alternative method of normalizing for gut length utilizing autopsy data is described. In our population, absorbed lactulose and mannitol are strongly correlated, r = 0.68 P <0.0001, suggesting lactulose and mannitol are traversing the gut barrier via the same pathways. Considering measurements where pore pathways predominate, mannitol flux is about 14 times that of lactulose. As more leak pathways are present, this differential flux mannitol:lactulose falls to 8:1 and when increased numbers of unrestricted pathways are present, the differential flux of mannitol:lactulose is 6:1. There was no substantial correlation between the lactulose:mannitol and linear growth. Given that mannitol will always pass through a given pathway at a rate at least equal to that of lactulose, and lactulose absorption is a composite measure of flux through both physiologic and pathologic pathways, we question the utility of the lactulose:mannitol test. We suggest using lactulose alone is as informative as lactulose:mannitol in a sugar absorption testing in subclinical gut inflammation. Impact statement Our work integrates the standard interpretation of the lactulose:mannitol test (L:M), with mechanistic insight of intestinal permeability. There are three paracellular pathways in the gut epithelium; pore, leak, and unrestricted. Using thousands of L:M measurements from rural Malawian children at risk for increased intestinal permeability, we predict the differential flux of L and M through the pathways. Our findings challenge the traditional notions that little L is absorbed through a normal epithelial barrier and that M is a normalizing factor for L. Our observations are consistent with pore pathways allowing only M to pass. And that substantial amounts of L and M pass through leak pathways which are normal, regulated, cell-junctional adaptations. So M is a composite measure of all pathways, and L is not a measure solely of pathologic gut damage. Using L alone as a probe will yield more information about gut health than L:M.