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Inadequate diet and frequent symptomatic infections are considered major causes of growth stunting in low-income countries, but interventions targeting these risk factors have achieved limited success. Asymptomatic infections can restrict growth, but little is known about their role in global stunting prevalence. We investigated factors related to length-for-age Z-score (LAZ) at 24 months by constructing an interconnected network of various infections, biomarkers of inflammation (as assessed by alpha-1-acid glycoprotein [AGP]), and growth (insulin-like growth factor 1 [IGF-1] and collagen X biomarker [CXM]) at 18 months, as well as other children, maternal, and household level factors. Among 604 children, there was a continuous decline in mean LAZ and increased mean length deficit from birth to 24 months. At 18 months of age, the percentage of asymptomatic children who carried each pathogen was: 84.5% enterovirus, 15.5% parechovirus, 7.7% norovirus, 4.6% rhinovirus, 0.6% rotavirus, 69.6% Campylobacter, 53.8% Giardia lamblia, 11.9% malaria parasites, 10.2% Shigella, and 2.7% Cryptosporidium. The mean plasma IGF-1 concentration was 12.5 ng/ml and 68% of the children had systemic inflammation (plasma AGP concentration >1 g/L). Shigella infection was associated with lower LAZ at 24 months through both direct and indirect pathways, whereas enterovirus, norovirus, Campylobacter, Cryptosporidium, and malaria infections were associated with lower LAZ at 24 months indirectly, predominantly through increased systemic inflammation and reduced plasma IGF-1 and CXM concentration at 18 months. publishedVersion

Author(s): Kortekangas, Emma; Kamng'ona, Arox W; Fan, Yue-Mei; Cheung, Yin Bun; Ashorn, Ulla; Matchado, Andrew; Poelman, Basho; Maleta, Kenneth; Dewey, Kathryn G; Ashorn, Per | Abstract: BackgroundGut microbiota composition is associated with child health, but the effect of the environment on microbiota composition is not well understood. Few studies have been conducted in low-income settings where childhood malnutrition is common and possibly related to microbiota composition.ObjectivesTo investigate whether gut microbiota composition in young children and their mothers is associated with different environmental exposures in rural Malawi. We hypothesized that more adverse environmental exposures would be associated with lower levels of microbiota maturity and diversity.MethodsFaecal samples from up to 631 children and mothers participating in a nutrition intervention trial were collected at 1, 6, 12, 18, and 30nmonths (children) and at 1nmonth (mothers) after birth and analysed for microbiota composition with 16S rRNA sequencing. Bacterial OTU and genus abundances, measures of microbiota maturity and diversity, and UniFrac distances were compared between participants with different environmental exposures. The exposure variables included socio-economic status, water source, sanitary facility, domestic animals, maternal characteristics, season, antibiotic use, and delivery mode.ResultsMeasures of microbiota maturity and diversity in children were inversely associated with maternal education at 6, 18, and 30nmonths and did not otherwise differ consistently between participants with different environmental exposures. Phylogenetic distance was related to season of stool sample collection at all time points. At the level of individual OTUs and genera, season of stool sample collection, type of water source, and maternal education showed most associations with child gut microbiota, while HIV status was the most important predictor of relative OTU and genus abundances in mothers.ConclusionThe results do not support the hypothesis that adverse environmental exposures are broadly associated with lower microbiota maturity and diversity but suggest that environmental exposures influence the abundance of several bacterial OTUs and genera and that low maternal education is associated with higher microbiota maturity and diversity.

Environmental enteric dysfunction (EED) is common in low- and middle-income countries and associated with childhood undernutrition. The composition of gut microbiota has been implicated in the pathogenesis of EED. Our aim was to assess the associations between gut microbiota and EED biomarkers in rural Malawian children. We hypothesized that there would be an inverse association between microbiota maturity and diversity and fecal concentrations of EED biomarkers.We used data from fecal samples collected at 6, 18 and 30 months from 611 children who were followed up during a nutrition intervention trial. The primary time point for analysis was 18 months. Microbiota data were obtained through 16S rRNA sequencing and variables included microbiota maturity and diversity, phylogenetic dissimilarity and relative abundances of individual taxa. EED biomarkers included calprotectin (marker of inflammation), alpha-1 antitrypsin (intestinal permeability) and REG1B (intestinal damage).There was an inverse association between microbiota maturity and diversity and fecal concentrations of all 3 EED biomarkers at 18 months (p≤0.001). The results were similar at 30 months, while at 6 months inverse associations were found only with calprotectin and alpha-1 antitrypsin concentrations. At 18 months, EED biomarkers were not associated with phylogenetic dissimilarity, but at 6 and 30 months several associations were observed. Individual taxa predicting EED biomarker concentrations at 18 months included several Bifidobacterium and Enterobacteriaceae taxa as well as potentially displaced oral taxa.Our findings support the hypothesis of an inverse association between microbiota maturity and diversity and EED in rural Malawian children.Chronic childhood undernutrition is an important public health concern that affects about 150 million children, mostly in low- and middle-income countries. Undernutrition is caused by insufficient nutrient intake and frequent infections, but there are also other underlying factors. One of these is a condition called environmental enteric dysfunction (EED), which is characterized by intestinal inflammation and damage without apparent clinical symptoms. EED is thought to be caused by the ingestion of pathogenic bacteria that leads to changes in the intestine such as increased permeability and decreased absorptive capacity. This might make the intestinal wall vulnerable to bacterial invasion and reduce the absorption of nutrients. Besides potentially pathogenic bacteria, there are many commensal bacteria in the gastrointestinal tract that have beneficial functions and that interact with the immune system. The aim of our study was to assess the associations between all these bacteria, that is the intestinal microbiota and biomarkers of EED. We used data from fecal samples collected from young children participating in a nutrition intervention trial in rural Malawi. Our findings support an inverse association between the diversity and maturity of the intestinal microbiota and biomarkers of EED. Additionally, we identified the differences at the level of individual bacterial taxa (groups of bacteria defined by genetic similarity) between participants with different levels of EED biomarkers. Due to the type of study, we cannot determine whether the observed associations represent a causal relationship between the intestinal microbiota and EED. This as well as the exact mechanisms behind these associations should be assessed in further studies.

INTRODUCTION: Small-quantity (SQ) lipid-based nutrient supplements (LNSs) may influence infants' plasma fatty acid (FA) profiles, which could be associated with short- and long-term outcomes. OBJECTIVES: We aimed to determine the impact of SQ-LNS consumption on infants' plasma FA profiles in Ghana and Malawi. METHODS: Ghanaian (n = 1320) and Malawian (n = 1391) women ≤20 weeks pregnant were assigned to consume 60 mg iron and 400 μg folic acid daily until delivery [iron and folic acid (IFA) group], multiple-micronutrient supplements (MMNs) until 6 months postpartum (MMN group), or SQ-LNSs (∼7.8 linoleic acid:α-linolenic acid ratio) until 6 months postpartum (LNS group). LNS group infants received SQ-LNS from 6 to 18 months of age. We compared infant plasma FAs by intervention group in subsamples (n = 379 in Ghana; n = 442 in Malawi) at 6 and 18 months using ANOVA and Poisson regression models. Main outcomes were mean percentage compositions (%Cs; percentage of FAs by weight) of α-linolenic acid (ALA), linoleic acid (LA), EPA, DHA, and arachidonic acid (AA). RESULTS: At 6 months, LNS infants had greater mean ± SD ALA %Cs in Ghana (0.23 ± 0.08; IFA, 0.21 ± 0.06; MMN, 0.21 ± 0.07; P = 0.034) and Malawi (0.42 ± 0.16; IFA, 0.38 ± 0.15; MMN, 0.38 ± 0.14; P = 0.034) and greater AA values in Ghana (6.25 ± 1.24; IFA, 6.12 ± 1.13; MMN, 5.89 ± 1.24; P = 0.049). At 18 months, LNS infants had a tendency towards greater ALA (0.32 ± 0.16; IFA, 0.24 ± 0.08; MMN, 0.24 ± 0.10; P = 0.06) and LA (27.8 ± 3.6; IFA, 26.9 ± 2.9; MMN, 27.0 ± 3.1; P = 0.06) in Ghana, and greater ALA (0.45 ± 0.18; IFA, 0.39 ± 0.18; MMN, 0.39 ± 0.18; P

We tested the hypotheses that a more mature or diverse gut microbiota will be positively associated with infant growth and inversely associated with inflammation. We characterized gut microbiota from the stool samples of Malawian infants at 6 mo (n = 527), 12 mo (n = 632) and 18 mo (n = 629) of age. Microbiota diversity and maturity measurements were based on Shannon diversity index and microbiota for age Z-score (MAZ), respectively. Growth was calculated as change in Z-scores for weight-for-age (WAZ), length-for-age (LAZ) and head circumference-for-age (HCZ) from 6 to 12 mo and 12 to 18 mo. Biomarkers of inflammation (alpha-1-acid glycoprotein (AGP) and C-reactive protein (CRP)) were measured at 6 and 18 mo. Multivariable models were used to assess the association of each independent variable with each outcome. Microbiota diversity and maturity were related to growth in weight from 6 to 12 mo, but not to growth in length or head circumference or to growth from 12 to 18 mo. Microbiota diversity and maturity may also be linked to inflammation, but findings were inconsistent.

Author(s): Wessells, K Ryan; Arnold, Charles D; Stewart, Christine P; Prado, Elizabeth L; Abbeddou, Souheila; Adu-Afarwuah, Seth; Arnold, Benjamin F; Ashorn, Per; Ashorn, Ulla; Becquey, Elodie; Brown, Kenneth H; Byrd, Kendra A; Campbell, Rebecca K; Christian, Parul; Fernald, Lia CH; Fan, Yue-Mei; Galasso, Emanuela; Hess, Sonja Y; Huybregts, Lieven; Jorgensen, Josh M; Kiprotich, Marion; Kortekangas, Emma; Lartey, Anna; Le Port, Agnes; Leroy, Jef L; Lin, Audrie; Maleta, Kenneth; Matias, Susana L; Mbuya, Mduduzi NN; Mridha, Malay K; Mutasa, Kuda; Naser, Abu Mohd; Paul, Rina R; Okronipa, Harriet; Ouedraogo, Jean-Bosco; Pickering, Amy J; Rahman, Mahbubur; Schulze, Kerry; Smith, Laura E; Weber, Ann M; Zongrone, Amanda; Dewey, Kathryn G | Abstract: ABSTRACTBackgroundSmall-quantity lipid-based nutrient supplements (SQ-LNS) have been shown to reduce the prevalence of anemia and iron deficiency among infants and young children, but effects on other micronutrients are less well known. Identifying subgroups who may experience greater benefits from SQ-LNS, or who are more likely to respond to the intervention, may facilitate the development of public health policies and programs.ObjectiveOur objective was to identify study-level and individual-level modifiers of the effect of SQ-LNS on child hematological and micronutrient status outcomes.MethodsWe conducted a two-stage meta-analysis of individual participant data from 13 randomized controlled trials of SQ-LNS provided to children 6 to 24 months of age in low- and middle-income countries (n = 15,946). Outcomes were hemoglobin (Hb), inflammation-adjusted plasma ferritin, soluble transferrin receptor, zinc, retinol and retinol binding protein (RBP), and erythrocyte zinc protoporphyrin, and respective dichotomous outcomes indicative of anemia and micronutrient deficiency. We generated study-specific estimates of SQ-LNS vs. control, including main effects and subgroup estimates for individual-level effect modifiers, and pooled the estimates using fixed-effects models. We used random effects meta-regression to examine potential study-level effect modifiers.ResultsProvision of SQ-LNS decreased the prevalence of anemia (Hb l 110 g/L) by 16% (relative reduction), iron deficiency (plasma ferritin l 12 µg/L) by 56% and iron deficiency anemia (IDA; Hb l 110 g/L and plasma ferritin l 12 µg/L) by 64%. We observed positive effects of SQ-LNS on hematological and iron status outcomes within all subgroups of the study-level and individual-level effect modifiers, but effects were larger in certain subgroups. For example, effects of SQ-LNS on anemia and iron status were greater in trials that provided SQ-LNS for g 12 months and provided 9 mg/d vs. l 9 mg iron/d, and among later-born (vs. first-born) children. There was no effect of SQ-LNS on plasma zinc or retinol, but there was a 7% increase in plasma RBP and a 56% reduction in vitamin A deficiency (RBP l 0.70 µmol/L), with little evidence of effect modification by individual-level characteristics.ConclusionsSQ-LNS provided to infants and young children 6-24 months of age can substantially reduce the prevalence of anemia, iron deficiency, and IDA across a range of individual, population and study design characteristics. Policy-makers and program planners should consider SQ-LNS within intervention packages to prevent anemia and iron deficiency. This study was registered at www.crd.york.ac.uk/PROSPERO as CRD42020156663.

Author(s): Maleta, Kenneth; Fan, Yue-Mei; Luoma, Juho; Ashorn, Ulla; Bendabenda, Jaden; Dewey, Kathryn G; Hyoty, Heikki; Knip, Mikael; Kortekangas, Emma; Lehto, Kirsi-Maarit; Matchado, Andrew; Nkhoma, Minyanga; Nurminen, Noora; Parkkila, Seppo; Purmonen, Sami; Veijola, Riitta; Oikarinen, Sami; Ashorn, Per | Abstract: BackgroundInsulin-like growth factor I (IGF-I) is the most important hormonal promoter of linear growth in infants and young children.ObjectivesThe objectives of this study were to compare plasma IGF-I concentration in a low- compared with a high-income country and characterize biological pathways leading to reduced IGF-I concentration in children in a low-income setting.MethodsWe analyzed plasma IGF-I concentration from 716 Malawian and 80 Finnish children at 6-36 mo of age. In the Malawian children, we studied the association between IGF-I concentration and their environmental exposures; nutritional status; systemic and intestinal inflammation; malaria parasitemia and viral, bacterial, and parasitic enteric infections; as well as growth at 18 mo of age. We then conducted a pathway analysis to identify direct and indirect associations between these predictors and IGF-I concentration.ResultsThe mean IGF-I concentrations were similar in Malawi and Finland among 6-mo-old infants. At age 18 mo, the meann±nSD concentration was almost double among the Finns compared with the Malawians [24.2n±n11.3 compared with 12.5n±n7.7 ng/mL, age- and sex-adjusted difference in mean (95% CI): 11.8 (9.9, 13.7) ng/mL; Pnln0.01]. Among 18-mo-old Malawians, plasma IGF-I concentration was inversely associated with systemic inflammation, malaria parasitemia, and intestinal Shigella, Campylobacter, and enterovirus infection and positively associated with the children's weight-for-length z score (WLZ), female sex, maternal height, mother's education, and dry season. Seasonally, mean plasma IGF-I concentration was highest in June and July and lowest in December and January, coinciding with changes in children's length gain and preceded by ∼2 mo by the changes in their WLZ.ConclusionsThe mean plasma IGF-I concentrations are similar in Malawi and Finland among 6-mo-old infants. Thereafter, mean concentrations rise markedly in Finland but not in Malawi. Systemic inflammation and clinically nonapparent infections are strongly associated with lower plasma IGF-I concentrations in Malawi through direct and indirect pathways.

Author(s): Kamng'ona, Arox W; Young, Rebecca; Arnold, Charles D; Patson, Noel; Jorgensen, Josh M; Kortekangas, Emma; Chaima, David; Malamba, Chikondi; Ashorn, Ulla; Cheung, Yin B; Ashorn, Per; Maleta, Kenneth; Dewey, Kathryn G | Abstract: BACKGROUND:Diet may alter the configuration of gut microbiota, but the impact of prenatal and postnatal nutritional interventions on infant gut microbiota has not been investigated. OBJECTIVE:We evaluated whether providing lipid-based nutrient supplements (LNSs) to mother-infant dyads promotes a more diverse and mature infant gut microbiota, compared to maternal supplementation with multiple micronutrients (MMN) or iron and folic acid (IFA). METHODS:We enrolled 869 pregnant women in a randomized trial in Malawi. There were 3 study groups, with women receiving 1 MMN capsule daily during pregnancy and 6nmo postpartum, or 1 LNS sachet (20 g) daily during pregnancy and 6nmo postpartum, or 1 IFA capsule daily (during pregnancy) then a placebo daily (postpartum). Infants in the LNS group received LNS from 6 to 18nmo; infants in the other groups did not receive supplements. The infants' fecal microbiota were characterized by PCR amplification and sequencing of the bacterial 16S rRNA gene (variable region 4). The primary outcomes were microbiota α diversity and maturation [as microbiota-for-age z score (MAZ)]. Specific associations of taxa with intervention were established with indicator species analysis (ISA). RESULTS:Primary outcomes did not differ between IFA and MMN groups, so these groups were combined (IFAn+nMMN). Meann±nSD α diversity was higher in the LNS group at 18nmo for Shannon index [3.01n±n0.57 (LNS) compared with 2.91n±n0.60 (IFAn+nMMN), Pn=n0.032] and Pielou's evenness index [0.61n±n0.08 (LNS) compared with 0.60n±n0.09 (IFAn+nMMN), Pn=n0.043]; no significant differences were observed at 1, 6, 12, or 30nmo. MAZ and β diversity did not differ at any age. We found 10 and 3 operational taxonomic units (OTUs) positively associated with LNS and IFAn+nMMN, respectively; however, these associations became nonsignificant following false discovery rate correction at 10%. CONCLUSIONS:Prenatal and postnatal LNS intake promoted infant gut microbiota diversity at 18nmo, after 12nmo of child supplementation, but did not alter microbiota maturation. This trial was registered at clinicaltrials.gov as NCT01239693.

Objectives The determinants of gut microbiota composition and its effects on common childhood illnesses are only partly understood, especially in low-income settings. The aim of the present study was to investigate whether morbidity predicts gut microbiota composition in Malawian children and whether microbiota predicts subsequent morbidity. We tested the hypothesis that common infectious disease symptoms would be predictive of lower microbiota maturity and diversity. Methods We used data from 631 participants in a randomized-controlled nutrition intervention trial, in which a small-quantity lipid-based nutrient supplement was provided to pregnant and lactating mothers and their children at 6 to 18 months of age. Fecal samples were collected from the children at 6, 12, 18, and 30 months of age and analyzed using 16S rRNA sequencing. Microbiota variables consisted of measures of microbiota diversity (Shannon Index), microbiota maturity (microbiota-for-age z score), and the relative abundances of taxa. Morbidity variables included gastrointestinal and respiratory symptoms and fever. Results Diarrhea and respiratory symptoms from 11 to 12 months were predictive of lower microbiota-for-age z score and higher Shannon Index, respectively (P = 0.035 and P = 0.023). Morbidity preceding sample collection was predictive of the relative abundances of several bacterial taxa at all time points. Higher microbiota maturity and diversity at 6 months were predictive of a lower incidence rate of fever in the subsequent 6 months (P = 0.007 and P = 0.031). Conclusions Our findings generally do not support the hypothesis that morbidity prevalence predicts a subsequent decrease in gut microbiota maturity or diversity in rural Malawian children. Certain morbidity symptoms may be predictive of microbiota maturity and diversity and relative abundances of several bacterial taxa. Furthermore, microbiota diversity and maturity may be associated with the subsequent incidence of fever.

BackgroundEarly development of neurocognitive functions in infants can be compromised by poverty, malnutrition and lack of adequate stimulation. Optimal management of neurodevelopmental problems in infants requires assessment tools that can be used early in life, and are objective and applicable across economic, cultural and educational settings.Objective and designThe present study examined the feasibility of infrared eye tracking as a novel and highly automated technique for assessing visual-orienting and sequence-learning abilities as well as attention to facial expressions in young (9-month-old) infants. Techniques piloted in a high-resource laboratory setting in Finland (N=39) were subsequently field-tested in a community health centre in rural Malawi (N=40).ResultsParents' perception of the acceptability of the method (Finland 95%, Malawi 92%) and percentages of infants completing the whole eye-tracking test (Finland 95%, Malawi 90%) were high, and percentages of valid test trials (Finland 69–85%, Malawi 68–73%) satisfactory at both sites. Test completion rates were slightly higher for eye tracking (90%) than traditional observational tests (87%) in Malawi. The predicted response pattern indicative of specific cognitive function was replicated in Malawi, but Malawian infants exhibited lower response rates and slower processing speed across tasks.ConclusionsHigh test completion rates and the replication of the predicted test patterns in a novel environment in Malawi support the feasibility of eye tracking as a technique for assessing infant development in low-resource setting. Further research is needed to the test–retest stability and predictive validity of the eye-tracking scores in low-income settings.

Aim The timing and frequency of stunting and possible catch-up growth are ambiguous in low-income settings. This study explored the timing and extent of becoming stunted and nonstunted between birth and 15 years of age in a resource-poor area of Malawi, south-east Africa. Methods We followed 767 children from the foetal period until 15 years of age and examined the transition between stunted and nonstunted status and the pubertal stage at 15 years of age. We also plotted smoothed curves for the mean absolute deficits in centimetres and height-for-age standard deviation scores (HAZ) according to the World Health Organization's 2006 and 2007 references. Results Most two-year olds (80%) were stunted (HAZ