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1.
Cell ; 164(5): 859-71, 2016 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-26898329

RESUMO

Identifying interventions that more effectively promote healthy growth of children with undernutrition is a pressing global health goal. Analysis of human milk oligosaccharides (HMOs) from 6-month-postpartum mothers in two Malawian birth cohorts revealed that sialylated HMOs are significantly less abundant in those with severely stunted infants. To explore this association, we colonized young germ-free mice with a consortium of bacterial strains cultured from the fecal microbiota of a 6-month-old stunted Malawian infant and fed recipient animals a prototypic Malawian diet with or without purified sialylated bovine milk oligosaccharides (S-BMO). S-BMO produced a microbiota-dependent augmentation of lean body mass gain, changed bone morphology, and altered liver, muscle, and brain metabolism in ways indicative of a greater ability to utilize nutrients for anabolism. These effects were also documented in gnotobiotic piglets using the same consortium and Malawian diet. These preclinical models indicate a causal, microbiota-dependent relationship between S-BMO and growth promotion.


Assuntos
Desenvolvimento Infantil , Desnutrição/dietoterapia , Leite Humano/química , Leite/química , Oligossacarídeos/metabolismo , Animais , Bacteroides fragilis/genética , Bifidobacterium/classificação , Bifidobacterium/genética , Química Encefálica , Modelos Animais de Doenças , Escherichia coli/genética , Fezes/microbiologia , Vida Livre de Germes , Humanos , Lactente , Malaui , Masculino , Metabolômica , Camundongos , Camundongos Endogâmicos C57BL , Microbiota
2.
Malar J ; 22(1): 266, 2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37697296

RESUMO

BACKGROUND: The complex interaction between malaria and undernutrition leads to increased mortality and morbidity rate among young children in malaria-endemic regions. Results from previous interventions suggest that improving nutritional status of young children may reduce the burden of malaria. This study tested a hypothesis that provision of lipid-based nutrient supplements (LNS) or corn-soy blend (CSB) supplementation to 6-18-month-old children in Malawi would reduce the prevalence of asymptomatic malaria among them. METHODS: A total of 840 6-month-old children were enrolled in a randomized trial. The participants received 12-month supplementation with three different daily dietary supplementations: CSB, soy-LNS, or milk-LNS, and one control group without supplementation. The prevalence rate of asymptomatic Plasmodium falciparum was determined by real-time PCR from the participant's dried blood spots (DBS) collected at the baseline and every 3 months. The global null hypothesis was tested using modified Poisson regression to estimate the prevalence ratio (PR) between the control group and three intervention groups at all ages combined. All the models were adjusted for malaria at baseline, season of DBS sample collection, site of enrolment, and household asset Z-score. RESULTS: All children combined, the prevalence of P. falciparum was 14.1% at enrollment, 8.7% at 9 months, 11.2% at 12 months, 13.0% at 15 months and 22.4% at 18 months of age. Among all samples that were taken after enrolment, the prevalence was 12.1% in control group, 12.2% in milk-LNS, 14.0% in soy-LNS, and 17.2% in CSB group. Compared to children in the control group the prevalence ratio of positive malaria tests was 1.19 (95% CI 0.81-1.74; P = 0.372) in the milk-LNS group, 1.32 (95% CI 0.88-1.96; P = 0.177) in the soy-LNS group and 1.72 (95% CI 1.19-2.49; P = 0.004) in the CSB group. CONCLUSION: The study findings do not support a hypothesis that LNS or CSB supplementation would reduce the prevalence of asymptomatic malaria among Malawian children. In contrast, there was a signal of a possible increase in malaria prevalence among children supplemented with CSB.


Assuntos
Malária Falciparum , Malária , Humanos , Criança , Pré-Escolar , Lactente , Malaui/epidemiologia , Prevalência , Suplementos Nutricionais , Malária/epidemiologia , Malária/prevenção & controle , Malária Falciparum/epidemiologia , Malária Falciparum/prevenção & controle , Zea mays
3.
Matern Child Nutr ; 19(1): e13417, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36111423

RESUMO

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.


Assuntos
Criptosporidiose , Cryptosporidium , Malária , Pré-Escolar , Humanos , Lactente , Infecções Assintomáticas/epidemiologia , Biomarcadores , Cryptosporidium/metabolismo , Transtornos do Crescimento/epidemiologia , Inflamação , Fator de Crescimento Insulin-Like I
4.
J Nutr ; 152(1): 286-301, 2022 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-34543432

RESUMO

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 < 0.001) and LA (29.7 ± 3.5; IFA, 28.7 ± 3.3; MMN, 28.6 ± 3.4; P = 0.011) in Malawi. The prevalence of ALA below the population-specific 10th percentile was lower in the LNS group compared to the MMN group, but not the IFA group. Groups did not differ significantly in plasma EPA or DHA levels. CONCLUSIONS: SQ-LNS increased infants' plasma essential FA levels in Ghana and Malawi, which may have implications for health and developmental outcomes. These trials were registered at clinicaltrials.gov as NCT00970866 and NCT01239693.


Assuntos
Fenômenos Fisiológicos da Nutrição Materna , Micronutrientes , Suplementos Nutricionais , Ácidos Graxos Essenciais , Feminino , Gana , Humanos , Lactente , Lipídeos , Malaui , Nutrientes , Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto
5.
J Trop Pediatr ; 68(2)2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-35149871

RESUMO

BACKGROUND: 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. METHODS: 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). RESULTS: 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. CONCLUSIONS: 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.


Assuntos
Microbioma Gastrointestinal , Criança , Fezes/microbiologia , Microbioma Gastrointestinal/genética , Humanos , Inflamação , Permeabilidade , Filogenia , RNA Ribossômico 16S/genética
6.
Matern Child Nutr ; 18(3): e13331, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35128820

RESUMO

Lipid-based nutrient supplements (LNS) have been found to improve child growth and reduce child mortality. However, the mechanistic pathways for these improvements warrant exploration. One potential pathway is linked to improvement in intestinal health. Our study aimed to test a hypothesis that small-quantity LNS (SQ-LNS) could reduce the levels of intestinal inflammation, repair and permeability of children. As intestinal health markers we measured fecal calprotectin, regenerating 1B protein (REG1B) and alpha-1-antitrypsin concentrations at 18 months of age (after 12 months of supplementation) and 1 year later (12 months after cessation of supplementation). In this analysis, we included data of 735 children who participated in a randomised dietary supplementation trial in rural Malawi; 243 children who received 20 g/day SQ-LNS from 6 to 18 months of age were in the SQ-LNS group, while the others who received no dietary supplementation during this period were in the control group. At 18 months of age, the mean concentrations of calprotectin, REG1B and alpha-1-antitrypsin were 241, 105 µg/g and 7.1 mg/dl, respectively, in the SQ-LNS group, and 224, 105 µg/g and 7.4 mg/dl, respectively, in the control group, and did not differ between the SQ-LNS and control groups. We conclude that SQ-LNS provision did not have an impact on children's intestinal health in rural Malawi.


Assuntos
Suplementos Nutricionais , Nutrientes , Criança , Humanos , Lactente , Complexo Antígeno L1 Leucocitário , Lipídeos , Malaui , Micronutrientes , População Rural
7.
J Nutr ; 151(4): 1029-1037, 2021 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-33561214

RESUMO

BACKGROUND: Vitamin A (VA) deficiency is prevalent in preschool-aged children in sub-Saharan Africa. OBJECTIVES: We assessed the effect of small-quantity lipid-based nutrient supplements (SQ-LNS) given to women during pregnancy and lactation and their children from 6 to 18 mo of age on women's plasma and milk retinol concentrations in Malawi, and children's plasma retinol concentration in Malawi and Ghana. METHODS: Pregnant women (≤20 wk of gestation) were randomized to receive daily: 1) iron and folic acid (IFA) during pregnancy only; 2) multiple micronutrients (MMN; 800 µg retinol equivalent (RE)/capsule), or 3) SQ-LNS (800 µg RE/20g) during pregnancy and the first 6 mo postpartum. Children of mothers in the SQ-LNS group received SQ-LNS (400 µg RE/20 g) from 6 to 18 mo of age; children of mothers in the IFA and MMN groups received no supplement. Plasma retinol was measured in mothers at ≤20 and 36 wk of gestation and 6 mo postpartum, and in children at 6 and 18 mo of age. Milk retinol was measured at 6 mo postpartum. VA status indicators were compared by group. RESULTS: Among Malawian mothers, geometric mean (95% CI) plasma retinol concentrations at 36 wk of gestation and 6 mo postpartum were 0.97 µmol/L (0.94, 1.01 µmol/L) and 1.35 µmol/L (1.31, 1.39 µmol/L), respectively; geometric mean (95% CI) milk retinol concentration at 6 mo postpartum was 1.04 µmol/L (0.97, 1.13 µmol/L); results did not differ by intervention group. Geometric mean (95% CI) plasma retinol concentrations for Malawian children at 6 and 18 mo of age were 0.78 µmol/L (0.75, 0.81 µmol/L) and 0.81 µmol/L (0.78, 0.85 µmol/L), respectively, and for Ghanaian children they were 0.85 µmol/L (0.82, 0.88 µmol/L) and 0.88 µmol/L (0.85, 0.91 µmol/L), respectively; results did not differ by intervention group in either setting. CONCLUSIONS: SQ-LNS had no effect on VA status of mothers or children, possibly because of low responsiveness of the VA status indicators.


Assuntos
Suplementos Nutricionais , Lipídeos/administração & dosagem , Leite Humano/metabolismo , Vitamina A/sangue , Vitamina A/metabolismo , Adolescente , Adulto , Feminino , Gana/epidemiologia , Humanos , Lactente , Fenômenos Fisiológicos da Nutrição do Lactente , Recém-Nascido , Lactação , Malaui/epidemiologia , Fenômenos Fisiológicos da Nutrição Materna , Mães , Estado Nutricional , Gravidez , Prevalência , Deficiência de Vitamina A/sangue , Deficiência de Vitamina A/dietoterapia , Deficiência de Vitamina A/epidemiologia , Adulto Jovem
8.
Public Health Nutr ; 24(10): 3049-3057, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33054890

RESUMO

OBJECTIVES: Inadequate iodine intake during pregnancy increases the risk of neonatal morbidity and mortality. We aimed to evaluate whether prenatal supplements containing iodine affect urinary iodine concentrations (UIC) of pregnant women in Malawi. DESIGN: A randomised controlled trial. Pregnant women (n 1391) were assigned to consume 60 mg/d Fe and 400 µg/d folic acid (IFA) or 18 vitamins and minerals including 250 µg/d iodine (MMN) or 20 g/d small-quantity lipid-based nutrient supplements (SQ-LNS) with similar nutrient contents as MMN group, plus macronutrients (LNS) until childbirth. In a sub-study (n 317), we evaluated group geometric mean urinary iodine concentration (UIC) (µg/L) at 36 weeks of gestation controlling for baseline UIC and compared median (baseline) and geometric mean (36 weeks) UIC with WHO cut-offs: UIC < 150, 150-249, 250-499 and ≥500 reflecting insufficient, adequate, above requirements and excessive iodine intakes, respectively. SETTING: Mangochi District, Malawi. PARTICIPANTS: Women ≤20 weeks pregnant. RESULTS: Groups had comparable background characteristics. At baseline, overall median (Q1, Q3) UIC (319 (167, 559)) suggested iodine intakes above requirements. At 36 weeks, the geometric mean (95 % CI) UIC of the IFA (197 (171, 226)), MMN (212 (185, 243)) and LNS (220 (192, 253)) groups did not differ (P = 0·53) and reflected adequate intakes. CONCLUSIONS: In this setting, provision of supplements containing iodine at the recommended dose to pregnant women with relatively high iodine intakes at baseline, presumably from iodised salt, has no impact on the women's UIC. Regular monitoring of the iodine status of pregnant women in such settings is advisable. Clinicaltrials.gov identifier: NCT01239693.


Assuntos
Ácido Fólico , Iodo , Suplementos Nutricionais , Feminino , Humanos , Recém-Nascido , Ferro , Lipídeos , Malaui , Fenômenos Fisiológicos da Nutrição Materna , Micronutrientes , Gravidez
9.
J Paediatr Child Health ; 57(3): 388-394, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33112481

RESUMO

AIM: This study was designed to determine whether faecal regenerating 1B protein (REG1B) concentration is associated with physical growth among 6-30-month-old children in rural Malawi. METHODS: This was a secondary analysis from a randomised controlled trial in rural Malawi in which we followed-up 790 live-born infants from birth to 30 months of age. We collected anthropometric data at the age of 6, 12, 18, 24 and 30 months. We measured faecal REG1B concentration by enzyme-linked immunosorbent assay (ELISA) technique using stool samples collected at 6, 18 and 30 months of age. We assessed the association between faecal REG1B concentration and children's physical growth using linear regression and longitudinal data analysis. RESULTS: Of 790 live-born infants enrolled, 694 (87%) with at least one faecal REG1B concentration measurement were included in the analysis. Faecal REG1B concentration was not associated with the children's concurrent length-for-age z-score (LAZ), weight-for-age z-score (WAZ), weight-for-length z-score (WLZ) and mid-upper arm circumference-for-age z-score (MUACZ) at any time point (P > 0.05), nor with a change in their anthropometric indices in the subsequent 6-month period (P > 0.05). CONCLUSIONS: Faecal REG1B concentration is not associated with LAZ, WAZ, WLZ and MUACZ among 6-30-month-old infants and children in rural Malawi.


Assuntos
Estatura , Litostatina , População Rural , Antropometria , Peso Corporal , Criança , Pré-Escolar , Fezes , Feminino , Crescimento , Humanos , Lactente , Malaui , Masculino , Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto
10.
Paediatr Perinat Epidemiol ; 34(2): 161-170, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32011017

RESUMO

BACKGROUND: Gut 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. OBJECTIVES: To 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. METHODS: Faecal samples from up to 631 children and mothers participating in a nutrition intervention trial were collected at 1, 6, 12, 18, and 30 months (children) and at 1 month (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. RESULTS: Measures of microbiota maturity and diversity in children were inversely associated with maternal education at 6, 18, and 30 months 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. CONCLUSION: The 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.


Assuntos
Bactérias , Transtornos da Nutrição Infantil , Escolaridade , Exposição Ambiental , Fezes/microbiologia , Microbioma Gastrointestinal/fisiologia , Transtornos da Nutrição do Lactente , Adulto , Bactérias/classificação , Bactérias/isolamento & purificação , Transtornos da Nutrição Infantil/diagnóstico , Transtornos da Nutrição Infantil/epidemiologia , Pré-Escolar , Exposição Ambiental/análise , Exposição Ambiental/estatística & dados numéricos , Feminino , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Humanos , Lactente , Transtornos da Nutrição do Lactente/diagnóstico , Transtornos da Nutrição do Lactente/epidemiologia , Malaui/epidemiologia , Masculino , Avaliação Nutricional , Apoio Nutricional , Fatores Socioeconômicos
11.
J Pediatr Gastroenterol Nutr ; 69(4): 431-437, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31436705

RESUMO

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.


Assuntos
Diarreia Infantil/epidemiologia , Trato Gastrointestinal/microbiologia , Infecções Respiratórias/epidemiologia , Diarreia Infantil/microbiologia , Feminino , Humanos , Lactente , Malaui/epidemiologia , Masculino , Serviços de Saúde Materno-Infantil , Microbiota/genética , Prevalência , Estudos Prospectivos , RNA Ribossômico 16S/genética , População Rural
12.
Acta Paediatr ; 108(10): 1833-1840, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31038225

RESUMO

AIM: Despite high pathogen burden and malnutrition in low-income settings, knowledge on relationship between asymptomatic viral or parasitic infections, nutrition and growth is insufficient. We studied these relationships in a cohort of six-month-old Malawian infants. METHODS: As part of a nutrient supplementation trial for 12 months, we documented disease symptoms of 840 participant daily and anthropometric measurements every three months. Stool specimens were collected every six months and analysed for Giardia lamblia, Cryptosporidium species and enterovirus, rotavirus, norovirus, parechovirus and rhinovirus using polymerase chain reaction (PCR). The prevalence of the microbes was compared to the children's linear growth and the dietary. RESULTS: The prevalence of the microbes was similar in every intervention group. All age groups combined, children negative for G. lamblia had a mean standard deviation (SD) of -0.01 (0.49) change in length-for-age Z-score (LAZ), compared to -0.12 (0.045) among G. lamblia positive children (difference -0.10, 95% CI -0.21 to -0.00, p = 0.047). The LAZ change difference was also statistically significant (p = 0.042) at age of 18-21 months but not at the other time points. CONCLUSION: Asymptomatic G. lamblia infection was mainly associated with growth reduction in certain three-month periods. The result refers to the chronic nature of G. lamblia infection.


Assuntos
Fezes/parasitologia , Giardia lamblia/isolamento & purificação , Giardíase/complicações , Transtornos do Crescimento/parasitologia , Infecções Assintomáticas/epidemiologia , Suplementos Nutricionais , Fezes/virologia , Feminino , Giardíase/epidemiologia , Transtornos do Crescimento/dietoterapia , Transtornos do Crescimento/virologia , Humanos , Lactente , Malaui/epidemiologia , Masculino
13.
Appl Environ Microbiol ; 84(6)2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-29305501

RESUMO

The bacterial community found in the vagina is an important determinant of a woman's health and disease status. A healthy vaginal microbiota is associated with low species richness and a high proportion of one of a number of different Lactobacillus spp. When disrupted, the resulting abnormal vaginal microbiota is associated with a number of disease states and poor pregnancy outcomes. Studies up until now have concentrated on relatively small numbers of American and European populations that may not capture the full complexity of the community or adequately predict what constitutes a healthy microbiota in all populations. In this study, we sampled and characterized the vaginal microbiota found on vaginal swabs taken postpartum from a cohort of 1,107 women in rural Malawi. We found a population dominated by Gardnerella vaginalis and devoid of the most common vaginal Lactobacillus species, even if the vagina was sampled over a year postpartum. This Lactobacillus-deficient anaerobic community, commonly labeled community state type (CST) 4, could be subdivided into four further communities. A Lactobacillus iners-dominated vaginal microbiota became more common the longer after delivery the vagina was sampled, but G. vaginalis remained the dominant organism. These results outline the difficulty in all-encompassing definitions of what a healthy or abnormal postpartum vaginal microbiota is. Previous identification of community state types and associations among bacterial species, bacterial vaginosis, and adverse birth outcomes may not represent the complex heterogeneity of the microbiota present. (This study has been registered at ClinicalTrials.gov as NCT01239693.)IMPORTANCE A bacterial community in the vaginal tract is dominated by a small number of Lactobacillus species, and when not present there is an increased incidence of inflammatory conditions and adverse birth outcomes. A switch to a vaginal bacterial community lacking in Lactobacillus species is common after pregnancy. In this study, we characterized the postpartum vaginal bacterial community of a large group of women from a resource-poor, undersampled population in rural Malawi. The majority of women were found to have a Lactobacillus-deficient community, and even when sampled a year after delivery the majority of women still did not have Lactobacillus present in their vaginal microbiota. The effect of becoming pregnant again for those who do not revert to a Lactobacillus-dominant community is unknown, and this could suggest that not all Lactobacillus-deficient community structures are adverse. A better understanding of this complex community state type is needed.


Assuntos
Gardnerella vaginalis/isolamento & purificação , Lactobacillus/isolamento & purificação , Microbiota , Vaginose Bacteriana/epidemiologia , Adulto , Feminino , Gardnerella vaginalis/metabolismo , Humanos , Incidência , Lactobacillus/metabolismo , Perda de Seguimento , Malaui/epidemiologia , Período Pós-Parto , Gravidez , Estudos Prospectivos , RNA Bacteriano/genética , RNA Bacteriano/isolamento & purificação , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/isolamento & purificação , População Rural , Fatores Socioeconômicos , Vagina/microbiologia , Adulto Jovem
14.
J Nutr ; 147(10): 1867-1874, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28794206

RESUMO

BACKGROUND: Human milk oligosaccharides (HMOs) and bioactive proteins are beneficial to infant health. Recent evidence suggests that maternal nutrition may affect the amount of HMOs and proteins in breast milk; however, the effect of nutrient supplementation on HMOs and bioactive proteins has not yet been well studied. OBJECTIVE: We aimed to determine whether lipid-based nutrient supplements (LNSs) affect milk bioactive protein and HMO concentrations at 6 mo postpartum in women in rural Malawi. These are secondary outcomes of a previously published randomized controlled trial. METHODS: Women were randomly assigned to consume either an iron and folic acid capsule (IFA) daily from ≤20 wk gestation until delivery, followed by placebo daily from delivery to 6 mo postpartum, or a multiple micronutrient (MMN) capsule or LNS daily from ≤20 wk gestation to 6 mo postpartum. Breast milk concentrations of total HMOs, sialylated HMOs, fucosylated HMOs, lactoferrin, lactalbumin, lysozymes, antitrypsin, immunoglobulin A, and osteopontin were analyzed at 6 mo postpartum (n = 647). Between-group differences in concentrations and in proportions of women classified as having low concentrations were tested. RESULTS: HMO and bioactive protein concentrations did not differ between groups (P > 0.10 for all comparisons). At 6 mo postpartum, the proportions of women with low HMOs or bioactive proteins were not different between groups except for osteopontin. A lower proportion of women in the IFA group had low osteopontin compared with the LNS group after adjusting for covariates (OR: 0.5; 95% CI: 0.3, 0.9; P = 0.016). CONCLUSION: The study findings do not support the hypothesis that supplementation with an LNS or MMN capsule during pregnancy and postpartum would increase HMO or bioactive milk proteins at 6 mo postpartum among Malawian women. This trial was registered at clinicaltrials.gov as NCT01239693.


Assuntos
Suplementos Nutricionais , Lipídeos/administração & dosagem , Micronutrientes/administração & dosagem , Proteínas do Leite/análise , Leite Humano/química , Oligossacarídeos/análise , Adulto , Feminino , Humanos , Lactação , Gravidez
15.
J Pediatr Gastroenterol Nutr ; 64(4): 610-615, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27403608

RESUMO

OBJECTIVES: The aim of the study was to assess the effect of nutritional supplementation with lipid-based nutrient supplements (LNS) and corn-soy blend flour on Bifidobacterium and Staphylococcus aureus gut microbiota composition in Malawian infants. In addition, the microbiota changes over time were characterized in the study infants. METHODS: Healthy 6-month-old Malawian infants were randomly assigned to 1 of 4 intervention schemes for a 6-month period. Infants in the control group were not provided with any supplementary food. Infants in other 3 groups received either micronutrient-fortified corn-soy blend, micronutrient-fortified LNS with milk protein base, or micronutrient-fortified LNS with soy protein base between 6 and 12 months of age. Fecal bifidobacteria and S aureus gut microbiota at 6 and 12 months of age were analyzed by quantitative real-time polymerase chain reaction method. RESULTS: There was no difference in change in bacterial prevalence or counts between the intervention groups during the 6-month study period. When looking at the total study population, higher counts of total bacteria (P = 0.028), Bifidobacterium genus (P = 0.027), B catenulatum (P = 0.031), and lower counts of B infantis (P < 0.001), B lactis (P < 0.001), B longum (P < 0.001), and S aureus (P < 0.001) were detected in the children's stools at 12 months rather than at 6 months of age. CONCLUSIONS: The dietary supplementation did not have an effect on the Bifidobacterium and S aureus microbiota composition of the study infants. The fecal bifidobacterial diversity of the infants, however, changed toward a more adult-like microbiota profile within the observed time.


Assuntos
Bifidobacterium , Gorduras na Dieta , Suplementos Nutricionais , Alimentos Fortificados , Microbioma Gastrointestinal , Alimentos Infantis , Staphylococcus aureus , Bifidobacterium/isolamento & purificação , Fezes/microbiologia , Feminino , Seguimentos , Humanos , Lactente , Malaui , Masculino , Micronutrientes , Avaliação de Resultados em Cuidados de Saúde , Reação em Cadeia da Polimerase em Tempo Real , Método Simples-Cego , Staphylococcus aureus/isolamento & purificação
16.
Trop Med Int Health ; 21(2): 283-90, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26644222

RESUMO

OBJECTIVES: To examine whether two forms of lipid-based nutrient supplements (LNS) or a micronutrient-fortified corn-soya blend were associated with development of the gut microbiota in Malawian infants, to assess the microbiota profiles at the age of 6 and 18 months and to follow the changes during the 12-month period. METHODS: This was a substudy of a 4-arm randomised controlled trial conducted in rural Malawi. Infants at the age of 6 months were randomised to receive no supplement during the primary follow-up period (control), 54 g/day of micronutrient-fortified LNS with milk protein base (milk LNS), 54 g/day of micronutrient-fortified LNS with soya protein base (soya LNS), or 71 g/day of micronutrient-fortified corn-soya blend for 12 months. Stool samples were collected at baseline (6 months) and end of trial (18 months). The 16S rRNA gene was amplified and subjected to multiplex sequencing. RESULTS: A total of 213 infants had paired microbiota data at 6 and 18 months of age. The Dirichlet-multinomial test showed no significant difference in microbiota profile between the four intervention groups at either age (each P > 0.10). Bifidobacterium longum was most abundant at both ages. Lactobacillus ruminis, Shigella and Salmonella were present. The abundance of Prevotella and Faecalibacterium increased with age (each P < 0.001), while Bifidobacteriaceae and Enterobacteriaceae exhibited significant decrease (each P < 0.001). CONCLUSIONS: Nutritional supplementation by LNS or corn-soya blend for twelve months did not affect the gut microbiota profile in the rural Malawian context.


Assuntos
Bactérias/efeitos dos fármacos , Proteínas Alimentares/farmacologia , Suplementos Nutricionais , Microbioma Gastrointestinal/efeitos dos fármacos , Lipídeos/farmacologia , Micronutrientes/farmacologia , Animais , Bactérias/crescimento & desenvolvimento , Feminino , Alimentos Fortificados , Humanos , Lactente , Alimentos Infantis , Malaui , Masculino , Leite/química , População Rural , Glycine max/química , Zea mays/química
17.
Malar J ; 14: 193, 2015 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-25957793

RESUMO

BACKGROUND: Malaria and undernutrition frequently coexist, especially in pregnant women and young children. Nutrient supplementation of these vulnerable groups might reduce their susceptibility to malaria by improving immunity. METHODS: Antibody immunity to antigens expressed by a placental-binding parasite isolate, a non-placental binding parasite isolate, merozoites and schizonts at enrolment (before 20 gestation weeks) and at 36 gestation weeks were measured in 1,009 Malawian pregnant women receiving a daily lipid-based nutrient supplement, multiple micronutrients or iron and folic acid, who were participants in a randomized clinical trial assessing the effects of nutrient supplementation on pregnancy outcomes and child development (registration ID: NCT01239693). RESULTS: Antibodies to placental-binding isolates significantly increased while antibodies to most merozoite antigens declined over pregnancy. Overall, after adjustment for covariates, the type of supplementation did not influence antibody levels at 36 gestation weeks or the rate of change in antibody levels from enrolment to 36 weeks. A negative association between maternal body mass index and opsonizing antibodies to placental-binding antigens (coefficient (95% CI) -1.04 (-1.84, -0.24), was observed. Similarly, women with higher socioeconomic status had significantly lower IgG and opsonizing antibodies to placental-binding antigens. Neither of these associations was significantly influenced by the supplementation type. CONCLUSIONS: In the current cohort nutrient supplementation did not affect anti-malarial antibody responses, but poor and undernourished mothers should be a priority group in future trials.


Assuntos
Imunidade Adaptativa/efeitos dos fármacos , Anticorpos Antiprotozoários/sangue , Suplementos Nutricionais/análise , Metabolismo dos Lipídeos/efeitos dos fármacos , Malária/dietoterapia , Plasmodium/imunologia , Adolescente , Adulto , Estudos de Coortes , Feminino , Ácido Fólico/administração & dosagem , Ácido Fólico/metabolismo , Humanos , Ferro/administração & dosagem , Ferro/metabolismo , Malária/parasitologia , Malaui , Merozoítos/imunologia , Micronutrientes/administração & dosagem , Micronutrientes/metabolismo , Gravidez , Resultado da Gravidez , Esquizontes/imunologia , Adulto Jovem
18.
Am J Clin Nutr ; 119(1): 221-231, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37890672

RESUMO

BACKGROUND: Copper (Cu), an essential trace mineral regulating multiple actions of inflammation and oxidative stress, has been implicated in risk for preterm birth (PTB). OBJECTIVES: This study aimed to determine the association of maternal Cu concentration during pregnancy with PTB risk and gestational duration in a large multicohort study including diverse populations. METHODS: Maternal plasma or serum samples of 10,449 singleton live births were obtained from 18 geographically diverse study cohorts. Maternal Cu concentrations were determined using inductively coupled plasma mass spectrometry. The associations of maternal Cu with PTB and gestational duration were analyzed using logistic and linear regressions for each cohort. The estimates were then combined using meta-analysis. Associations between maternal Cu and acute-phase reactants (APRs) and infection status were analyzed in 1239 samples from the Malawi cohort. RESULTS: The maternal prenatal Cu concentration in our study samples followed normal distribution with mean of 1.92 µg/mL and standard deviation of 0.43 µg/mL, and Cu concentrations increased with gestational age up to 20 wk. The random-effect meta-analysis across 18 cohorts revealed that 1 µg/mL increase in maternal Cu concentration was associated with higher risk of PTB with odds ratio of 1.30 (95% confidence interval [CI]: 1.08, 1.57) and shorter gestational duration of 1.64 d (95% CI: 0.56, 2.73). In the Malawi cohort, higher maternal Cu concentration, concentrations of multiple APRs, and infections (malaria and HIV) were correlated and associated with greater risk of PTB and shorter gestational duration. CONCLUSIONS: Our study supports robust negative association between maternal Cu and gestational duration and positive association with risk for PTB. Cu concentration was strongly correlated with APRs and infection status suggesting its potential role in inflammation, a pathway implicated in the mechanisms of PTB. Therefore, maternal Cu could be used as potential marker of integrated inflammatory pathways during pregnancy and risk for PTB.


Assuntos
Nascimento Prematuro , Gravidez , Feminino , Humanos , Recém-Nascido , Cobre , Idade Gestacional , Nascido Vivo , Inflamação , Fatores de Risco
19.
PLoS Genet ; 6(9): e1001146, 2010 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-20941391

RESUMO

The relative contribution of genetic risk factors to the progression of subclinical atherosclerosis is poorly understood. It is likely that multiple variants are implicated in the development of atherosclerosis, but the subtle genotypic and phenotypic differences are beyond the reach of the conventional case-control designs and the statistical significance testing procedures being used in most association studies. Our objective here was to investigate whether an alternative approach--in which common disorders are treated as quantitative phenotypes that are continuously distributed over a population--can reveal predictive insights into the early atherosclerosis, as assessed using ultrasound imaging-based quantitative measurement of carotid artery intima-media thickness (IMT). Using our population-based follow-up study of atherosclerosis precursors as a basis for sampling subjects with gradually increasing IMT levels, we searched for such subsets of genetic variants and their interactions that are the most predictive of the various risk classes, rather than using exclusively those variants meeting a stringent level of statistical significance. The area under the receiver operating characteristic curve (AUC) was used to evaluate the predictive value of the variants, and cross-validation was used to assess how well the predictive models will generalize to other subsets of subjects. By means of our predictive modeling framework with machine learning-based SNP selection, we could improve the prediction of the extreme classes of atherosclerosis risk and progression over a 6-year period (average AUC 0.844 and 0.761), compared to that of using conventional cardiovascular risk factors alone (average AUC 0.741 and 0.629), or when combined with the statistically significant variants (average AUC 0.762 and 0.651). The predictive accuracy remained relatively high in an independent validation set of subjects (average decrease of 0.043). These results demonstrate that the modeling framework can utilize the "gray zone" of genetic variation in the classification of subjects with different degrees of risk of developing atherosclerosis.


Assuntos
Doenças das Artérias Carótidas/genética , Doenças das Artérias Carótidas/patologia , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único/genética , Adolescente , Adulto , Doenças das Artérias Carótidas/diagnóstico por imagem , Criança , Pré-Escolar , Progressão da Doença , Epistasia Genética , Finlândia , Seguimentos , Humanos , Pessoa de Meia-Idade , Fatores de Risco , Túnica Íntima/diagnóstico por imagem , Túnica Íntima/patologia , Túnica Média/diagnóstico por imagem , Túnica Média/patologia , Ultrassonografia , Adulto Jovem
20.
Am J Trop Med Hyg ; 108(4): 768-776, 2023 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-36780896

RESUMO

Maternal malaria and infections during pregnancy are risk factors for fetal growth restriction. We assessed the impact of preventive treatment in pregnancy on maternal malaria and fetal growth. Between 2003 and 2006, we enrolled 1,320 pregnant Malawian women, 14-26 gestation weeks, in a randomized trial and treated them with two doses of sulfadoxine-pyrimethamine (SP, control) at enrollment and between 28-34 gestation weeks; with monthly SP from enrollment until 37 gestation weeks; or with monthly SP and azithromycin twice, at enrollment and between 28 and 34 gestation weeks (AZI-SP). Participants were seen at 4-week intervals until 36 completed gestation weeks and weekly thereafter. At each visit, we collected dried blood spots for real-time polymerase chain reaction diagnosing of malaria parasitemia and, in a random subgroup of 341 women, we measured fetal biparietal diameter and femur length with ultrasound. For the monthly SP versus the control group, the odds ratios (OR) (95% CI) of malaria parasitemia during the second, third, and both trimesters combined were 0.79 (0.46-1.37), 0.58 (0.37-0.92), and 0.64 (0.42-0.98), respectively. The corresponding ORs for the AZI-SP versus control group were 0.47 (0.26-0.84), 0.51 (0.32-0.81), and 0.50 (0.32-0.76), respectively. Differences between the AZI-SP and the monthly SP groups were not statistically significant. The interventions did not affect fetal biparietal diameter and femur length growth velocity. The results suggest that preventive maternal treatment with monthly SP reduced malaria parasitemia during pregnancy in Malawi and that the addition of azithromycin did not provide much additional antimalarial effect.


Assuntos
Antimaláricos , Malária , Complicações Parasitárias na Gravidez , Feminino , Gravidez , Humanos , Azitromicina/uso terapêutico , Parasitemia/tratamento farmacológico , Complicações Parasitárias na Gravidez/prevenção & controle , Pirimetamina/uso terapêutico , Malária/prevenção & controle , Antimaláricos/uso terapêutico , Combinação de Medicamentos , Desenvolvimento Fetal
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