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BackgroundCommon bean and cowpea contain about 25% protein and 25% fiber, and are recommended as complementary foods in sub-Saharan Africa.ObjectiveThe objective of this study was to determine if a daily legume supplement given to Malawian infants aged 6 to 12 mo alters the 16S configuration of the fecal microbiota as read out by amplicon sequence variants (ASVs).MethodsThis study was conducted within the context of a randomized, double-blind, controlled clinical trial to assess whether cowpea or common bean supplementation reduced intestinal permeability or increased linear growth. There were 2 village clusters in which the study was conducted. Fresh stool collections were flash frozen from 236 infants at ≤6 time points. The stools were sequenced using Earth Microbiome project protocols and data were processed using Qiime and Qiita, open-source, validated software packages. α-diversity was measured using the Faith's test. The 16S configuration was characterized by determining the weighted UniFrac distances of the ASVs and comparing them using permutational multivariate ANOVA.ResultsAmong the 1249 samples analyzed, the α-diversity of the fecal microbiome was unchanged among subjects after initiation of legume supplementation. Neither cowpea nor common bean altered the overall 16S configuration at any age. The 16S configuration differed between children with adequate and poor linear growth aged from 6 to 9 mo, but no specific ASVs differed in relative abundance. The 16S configuration differed between children with normal and abnormal intestinal permeability at 9 mo, but no specific ASVs differed in relative abundance. Among categorical characteristics of the population associated with different 16S configurations, village cluster was most pronounced.ConclusionLegume supplementation in breastfed, rural African infants did not affect the structure of the gut microbial communities until the children were aged 9 mo. This trial was registered at clinicaltrials.gov as NCT02472262.

Undernourished children exhibit impaired development of their gut microbiota. Transplanting microbiota from 6- and 18-month-old healthy or undernourished Malawian donors into young germ-free mice that were fed a Malawian diet revealed that immature microbiota from undernourished infants and children transmit impaired growth phenotypes. The representation of several age-discriminatory taxa in recipient animals correlated with lean body mass gain; liver, muscle, and brain metabolism; and bone morphology. Mice were cohoused shortly after receiving microbiota from healthy or severely stunted and underweight infants; age- and growth-discriminatory taxa from the microbiota of the former were able to invade that of the latter, which prevented growth impairments in recipient animals. Adding two invasive species, Ruminococcus gnavus and Clostridium symbiosum, to the microbiota from undernourished donors also ameliorated growth and metabolic abnormalities in recipient animals. These results provide evidence that microbiota immaturity is causally related to undernutrition and reveal potential therapeutic targets and agents.

To gain insights into the interrelationships among childhood undernutrition, the gut microbiota, and gut mucosal immune/barrier function, we purified bacterial strains targeted by immunoglobulin A (IgA) from the fecal microbiota of two cohorts of Malawian infants and children. IgA responses to several bacterial taxa, including Enterobacteriaceae, correlated with anthropometric measurements of nutritional status in longitudinal studies. The relationship between IgA responses and growth was further explained by enteropathogen burden. Gnotobiotic mouse recipients of an IgA(+) bacterial consortium purified from the gut microbiota of undernourished children exhibited a diet-dependent enteropathy characterized by rapid disruption of the small intestinal and colonic epithelial barrier, weight loss, and sepsis that could be prevented by administering two IgA-targeted bacterial species from a healthy microbiota. Dissection of a culture collection of 11 IgA-targeted strains from an undernourished donor, sufficient to transmit these phenotypes, disclosed that Enterobacteriaceae interacted with other consortium members to produce enteropathy. These findings indicate that bacterial targets of IgA responses have etiologic, diagnostic, and therapeutic implications for childhood undernutrition.

Gut microbial communities represent one source of human genetic and metabolic diversity. To examine how gut microbiomes differ among human populations, here we characterize bacterial species in fecal samples from 531 individuals, plus the gene content of 110 of them. The cohort encompassed healthy children and adults from the Amazonas of Venezuela, rural Malawi and US metropolitan areas and included mono- and dizygotic twins. Shared features of the functional maturation of the gut microbiome were identified during the first three years of life in all three populations, including age-associated changes in the genes involved in vitamin biosynthesis and metabolism. Pronounced differences in bacterial assemblages and functional gene repertoires were noted between US residents and those in the other two countries. These distinctive features are evident in early infancy as well as adulthood. Our findings underscore the need to consider the microbiome when evaluating human development, nutritional needs, physiological variations and the impact of westernization.

Breastfeeding provides optimal infant nutrition; however, <50% of infants are exclusively breastfed (EBF) for 6 months. We aimed to describe breastfeeding practices and their effects on growth and mortality among a high-risk mother-infant cohort in rural Sierra Leone. This was a secondary analysis of data from a randomized nutrition intervention trial among undernourished pregnant women. The study's primary outcomes were infant weight and length gains at 6 weeks of age. We included 1270 singleton infants in the analysis, with 1092 (85.6%) having 24-week outcome data. At 6 weeks, 88% were EBF, but the rate of EBF decreased to 17% at 24 weeks. The EBF infants at 6 weeks had improved length (difference of 0.9 mm/week; 95% CI 0.4 to 1.3; p < 0.001) and weight (difference of 40 g/week; 95% CI 24 to 53; p < 0.001) gains compared to the non-EBF infants. At 12 weeks, the EBF infants had improved weight (difference of 12 g/week; 95% CI 2 to 22; p = 0.024) gain. The EBF infants had lower mortality than the infants who were not EBF (hazard ratio of 0.39; 95% CI 0.18 to 0.84; p = 0.017). In summary, the infants who were EBF had greater weight and length gain and reduced mortality than those who were not EBF. Efforts to improve breastfeeding should thus be prioritized to improve infant health. [ABSTRACT FROM AUTHOR]

Background Innovations for undernourished pregnant women that improve newborn survival and anthropometry are needed to achieve the Sustainable Development Goals 1 and 3. This study tested the hypothesis that a combination of a nutritious supplementary food and several proven chemotherapeutic interventions to control common infections would increase newborn weight and length in undernourished pregnant women. Methods and findings This was a prospective, randomized, controlled clinical effectiveness trial of a ready-to-use supplementary food (RUSF) plus anti-infective therapies compared to standard therapy in undernourished pregnant women in rural Sierra Leone. Women with a mid-upper arm circumference (MUAC) [less than or equal to]23.0 cm presenting for antenatal care at one of 43 government health clinics in Western Rural Area and Pujehun districts were eligible for participation. Standard of care included a blended corn/soy flour and intermittent preventive treatment for malaria in pregnancy (IPTp). The intervention replaced the blended flour with RUSF and added azithromycin and testing and treatment for vaginal dysbiosis. Since the study involved different foods and testing procedures for the intervention and control groups, no one except the authors conducting the data analyses were blinded. The primary outcome was birth length. Secondary outcomes included maternal weight gain, birth weight, and neonatal survival. Follow-up continued until 6 months postpartum. Modified intention to treat analyses was undertaken. Participants were enrolled and followed up from February 2017 until February 2020. Of the 1,489 women enrolled, 752 were allocated to the intervention and 737 to the standard of care. The median age of these women was 19.5 years, of which 42% were primigravid. Twenty-nine women receiving the intervention and 42 women receiving the standard of care were lost to follow-up before pregnancy outcomes were obtained. There were 687 singleton live births in the intervention group and 657 in the standard of care group. Newborns receiving the intervention were 0.3 cm longer (95% confidence interval (CI) 0.09 to 0.6; p = 0.007) and weighed 70 g more (95% CI 20 to 120; p = 0.005) than those receiving the standard of care. Those women receiving the intervention had greater weekly weight gain (mean difference 40 g; 95% CI 9.70 to 71.0, p = 0.010) than those receiving the standard of care. There were fewer neonatal deaths in the intervention (n = 13; 1.9%) than in the standard of care (n = 28; 4.3%) group (difference 2.4%; 95% CI 0.3 to 4.4), (HR 0.62 95% CI 0.41 to 0.94, p = 0.026). No differences in adverse events or symptoms between the groups was found, and no serious adverse events occurred. Key limitations of the study are lack of gestational age estimates and unblinded administration of the intervention. Conclusions In this study, we observed that the addition of RUSF, azithromycin, more frequent IPTp, and testing/treatment for vaginal dysbiosis in undernourished pregnant women resulted in modest improvements in anthropometric status of mother and child at birth, and a reduction in neonatal death. Implementation of this combined intervention in rural, equatorial Africa may well be an important, practical measure to reduce infant mortality in this context. Trial registration ClinicalTrials.gov NCT03079388., Author(s): David Taylor Hendrixson 1, Kristie Smith 1, Patrick Lasowski 1, Meghan Callaghan-Gillespie 1, Jacklyn Weber 1, Peggy Papathakis 2, Per Ole Iversen 3, Aminata Shamit Koroma 4, Mark J. [...]

Objective: To assess the effectiveness of outpatient management with ready-to-use and supplementary foods for infants under 6 months (u6m) of age who were unable to be treated as inpatients due to social and economic barriers. Design: Review of operational acute malnutrition treatment records. Setting: Twenty-one outpatient therapeutic feeding clinics in rural Malawi. Participants: Infants u6m with acute malnutrition treated as outpatients because of barriers to inpatient treatment. The comparison group consisted of acutely malnourished children 6–9 months of age who were being treated at the same time in the same location in the context of two different randomised clinical trials. Results: A total of 323 infants u6m were treated for acute malnutrition (130 severe and 193 moderate). A total of 357 infants 6–9 months old with acute malnutrition (seventy-four severe and 283 moderate) were included as contemporaneous controls. Among infants u6m with severe acute malnutrition, 98 (75·4 %) achieved nutritional recovery; in comparison, 56 (75·7 %) of those with severe acute malnutrition 6–9 months old recovered. Among infants u6m with moderate acute malnutrition, 157 (81·3 %) recovered; in comparison, 241 (85·2 %) of those aged 6–9 months recovered. Conclusions: In a rural Malawian population of infants u6m who had generally already stopped exclusive breast-feeding and were now acutely malnourished, treatment with therapeutic or supplementary foods under the community management of acute malnutrition model was safe and effective. In settings where social and financial factors make hospital admission challenging, consideration should be given to lowering the recommended age of ready-to-use therapeutic and supplementary foods to infants u6m. [ABSTRACT FROM AUTHOR]

Undernutrition during pregnancy in adolescence confers a high risk of maternal morbidity and adverse birth outcomes, particularly in low‐resource settings. In a secondary analysis, we hypothesized that younger undernourished pregnant adolescents (<18 years) would benefit more than undernourished pregnant adults (>20 years) from the intervention of supplementary food and anti‐infective treatments. The original trial in Sierra Leone enrolled 236 younger adolescents (<18 years), 454 older adolescents (aged 18–19 years), and 741 adults (≥20 years), all with a mid‐upper arm circumference ≤23 cm. Younger adolescents had lower final fundal height as well as smaller newborns (−0.3 kg; 95% confidence interval [CI], −0.3, −0.2; p < 0.001) and shorter newborns (−1.1 cm; 95% CI, −1.5, −0.7; p < 0.001) than adults. The intervention's effect varied significantly between maternal age groups: adults benefited more than younger adolescents with respect to newborn birth weight (difference in difference, 166 g; 95% CI, 26, 306; interaction p = 0.02), birth length (difference in difference, 7.4 mm; 95% CI, 0.1, 14.8; interaction p = 0.047), and risk for low birth weight (<2.5 kg) (interaction p = 0.019). The differences in response persisted despite adjustments for maternal anthropometry, the number of prior pregnancies, and human immunodeficiency virus status. Older adolescents similarly benefited more than younger adolescents, though differences did not reach statistical significance. In conclusion, newborns born to younger adolescent mothers had worse outcomes than those born to adult mothers, and adults and their newborns benefited more from the intervention than younger adolescents. Key messages: We performed secondary data analysis of a randomized controlled trial of a combined nutrition and anti‐infective intervention for undernourished pregnant women, investigating the effect of maternal age on maternal and newborn outcomes and response to the intervention.Despite achieving similar gestational weight gain, younger adolescent mothers (<18 years) had newborns with lower birth weights, lengths, and mid‐upper arm circumferences, as well as higher proportions of low birth weight and stunted newborns when compared with adult mothers (≥20 years).Younger adolescent mothers also derived less benefit from the combined intervention than adult mothers with respect to the rate of weight gain during pregnancy, infant birth weight, length, and rate of low birth weight (<2.5 kg).Further work is needed to identify interventions that benefit undernourished pregnant adolescents and their newborns. [ABSTRACT FROM AUTHOR]