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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

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. publishedVersion

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. publishedVersion

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.

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

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.

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.

Environmental enteric dysfunction (EED) is common and contributes to linear growth faltering (stunting) and mortality among children in low-resource settings. A few studies on the environmental causes of EED have been conducted but the exact exposures that cause or predispose children to EED are context-specific and not clear. This study aimed to assess associations between selected environmental exposures and EED markers among 620 18-month-old children. This was a secondary analysis of data from Malawian children who participated in a randomized controlled trial (iLiNS-DYAD, registered at clinicaltrials.gov as NCT01239693) from birth to 18 months of age. Data on environmental exposures, including drinking water source, sanitation, exposure to animals, housing materials, season, residential area, and food insecurity were collected at enrolment. Biomarkers of EED included concentrations of calprotectin, regenerating 1B protein (REG1B), and alpha-1-antitrypsin from stool samples to assess intestinal inflammation, repair, and permeability, respectively. We performed bivariate and multivariable analyses to assess associations between environmental exposures and EED biomarkers. Adjusting for possible confounders, we did not find associations between the selected environmental exposures and the three biomarkers. These results do not provide support for our hypothesis that the studied adverse environmental exposures are associated with increased concentrations of children’s EED markers in rural Malawi. publishedVersion

ObjectiveTo estimate the degree of SARS-CoV-2 transmission among healthcare workers (HCWs) and general population in Kita region of Mali.DesignRoutine surveillance in 12 health facilities, HCWs serosurvey in five health facilities and community serosurvey in 16 villages in or near Kita town, Mali.SettingKita region, western Mali; local health centres around the central (regional) referral health centre.ParticipantsPatients in routine surveillance, HCWs in local health centres and community members of all ages in populations associated with study health centres.Main outcome measuresSeropositivity of ELISA test detecting SARS-CoV-2-specific total antibodies and real-time RT-PCR confirmed SARS-CoV-2 infection.ResultsFrom 2392 routine surveillance samples, 68 (2.8%, 95% CI: 2.2% to 3.6%) tested positive for SARS-CoV-2 by RT-PCR. The monthly positivity rate was 0% in June–August 2020 and gradually increased to 6% by December 2020 and 6.2% by January 2021, then declined to 5.5%, 3.3%, 3.6% and 0.8% in February, March, April and May 2021, respectively. From 397 serum samples collected from 113 HCWs, 175 (44.1%, 95% CI: 39.1% to 49.1%) were positive for SARS-CoV-2 antibodies. The monthly seroprevalence was around 10% from September to November 2020 and increased to over 40% from December 2020 to May 2021. For community serosurvey in December 2020, overall seroprevalence of SARS-CoV-2 antibodies was 27.7%. The highest age-stratified seroprevalence was observed in participants aged 60–69 years (45.5%, 95% CI: 32.3% to 58.6%). The lowest was in children aged 0–9 years (14.0%, 95% CI: 7.4% to 20.6%).ConclusionsSARS-CoV-2 in rural Mali is much more widespread than assumed by national testing data and particularly in the older population and frontline HCWs. The observation is contrary to the widely expressed view, based on limited data, that COVID-19 infection rates were lower in 2020–2021 in West Africa than in other settings.

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.

An unhealthy gut microbial community may act as a barrier to improvement in growth and health outcomes in response to nutritional interventions. The objective of this analysis was to determine whether the infant microbiota modified the effects of a randomized controlled trial of lipid-based nutrient supplements (LNS) in Malawi on growth and inflammation at 12 and 18 months, respectively. We characterized baseline microbiota composition of fecal samples at 6 months of age (n = 506, prior to infant supplementation, which extended to 18 months) using 16S rRNA gene sequencing of the V4 region. Features of the gut microbiota previously identified as being involved in fatty acid or micronutrient metabolism or in outcomes relating to growth and inflammation, especially in children, were investigated. Prior to correction for multiple hypothesis testing, the effects of LNS on growth appeared to be modified by Clostridium (p-for-interaction = 0.02), Ruminococcus (p-for-interaction = 0.007), and Firmicutes (p-for-interaction = 0.04) and effects on inflammation appeared to be modified by Faecalibacterium (p-for-interaction = 0.03) and Streptococcus (p-for-interaction = 0.004). However, after correction for multiple hypothesis testing these findings were not statistically significant, suggesting that the gut microbiota did not alter the effect of LNS on infant growth and inflammation in this cohort.

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.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.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.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.

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.

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.

Giardia lamblia and Cryptosporidium species belong to a complex group of pathogens that cause diseases hampering development and socioeconomic improvements in the developing countries. Both pathogens are recognized as significant causes of diarrhea and nutritional disorders. However, further studies are needed to clarify the role of parasitic infections, especially asymptomatic infections in malnutrition and stunting. We developed a high-throughput multiplex quantitative polymerase chain reaction (qPCR) method for G. lamblia and Cryptosporidium spp. detection in stool samples. The sensitivity and specificity of the method were ensured by analyzing confirmed positive samples acquired from diagnostics laboratories and participating in an external quality control round. Its capability to detect asymptomatic G. lamblia and Cryptosporidium spp. infections was confirmed by analyzing stool samples collected from 44 asymptomatic 6-month-old infants living in an endemic region in Malawi. Of these, five samples were found to be positive for G. lamblia and two for Cryptosporidium spp. In conclusion, the developed method is suitable for large-scale studies evaluating the occurrence of G. lamblia and Cryptosporidium spp. in endemic regions and for clinical diagnostics of these infections.

Microbiota and infant development Malnutrition in children is a persistent challenge that is not always remedied by improvements in nutrition. This is because a characteristic community of gut microbes seems to mediate some of the pathology. Human gut microbes can be transplanted effectively into germ-free mice to recapitulate their associated phenotypes. Using this model, Blanton et al. found that the microbiota of healthy children relieved the harmful effects on growth caused by the microbiota of malnourished children. In infant mammals, chronic undernutrition results in growth hormone resistance and stunting. In mice, Schwarzer et al. showed that strains of Lactobacillus plantarum in the gut microbiota sustained growth hormone activity via signaling pathways in the liver, thus overcoming growth hormone resistance. Together these studies reveal that specific beneficial microbes could potentially be exploited to resolve undernutrition syndromes. Science , this issue p. 10.1126/science.aad3311 , p. 854

Summary 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. PaperClip

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.

Sterol regulatory element-binding protein cleavage-activating protein (SCAP) and apolipoprotein E (apo E) regulate cellular and plasma lipid metabolism. Therefore, variations in the corresponding genes might influence weight reduction and obesity-associated metabolic changes. We investigated the relationships of SCAP (Ile796Val) and apo E polymorphisms on metabolic changes during weight reduction by using a 12-week very low-energy diet. Body composition, serum lipids, plasma glucose, and insulin were assessed in 78 healthy premenopausal women (initial body mass index, 34 +/- 4 kg/m(2); age, 40 +/- 4 years) before and after the intervention. The SCAP genotype groups did not differ in the responses of any parameters measured during weight reduction. Apo E did not differentiate the weight loss, but the changes in total and low-density lipoprotein cholesterol for the genotype groups apo E epsilon2/3, epsilon3/3, as well as epsilon3/4 and epsilon4/4 combined were -0.94 +/- 0.56 and -0.59 +/- 0.32, -0.71 +/- 0.49 and -0.49 +/- 0.45, and -0.55 +/- 0.47 and -0.37 +/- 0.39 mmol/L, respectively (P < .05 for both). In conclusion, neither the SCAP Ile796Val nor the apo E polymorphism was associated with weight loss in obese premenopausal women. However, the apo E-but not SCAP genotype-seems to be one of the modifying factors for serum cholesterol concentrations during very low-energy diet in obese premenopausal women.

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. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0707-2) contains supplementary material, which is available to authorized users.

Background The hepatic lipase (HL) gene C-480T promoter polymorphism affects gene transcription and enzyme activity and leads to CC, CT, and TT genotypes. Recently, HL expression was detected in macrophages. It has been postulated that HL might have a direct role in the pathogenesis of atherosclerosis without changes in the plasma profile. We hypothesized that the difference of plasma cholesterol level may not influence the effect of HL genotype on coronary reactivity. Methods A total of 108 young men (aged 34 ± 5 years) were genotyped and divided into three groups. These groups contained 45, 49 and 14 men having either normal (4.9 ± 1.2 mmol/L), mildly (5.5 ± 0.8 mmol/L) or severely (7.8 ± 1.9 mmol/L, subjects with familial hypercholesterolemia) elevated mean plasma cholesterol level, respectively. Myocardial blood flow (MBF) was measured at rest and during adenosine or dipyridamole-induced hyperemia with positron emission tomography using [15O] H2O. Results The effect of HL genotype on the indices of MBF was parallel within all cholesterol groups and therefore they were combined. In all subjects, basal flow did not differ between the genotypes. However, men with CC genotype had a significantly higher hyperemic blood flow (3.86 ± 1.26 mL g−1 min−1 versus 3.20 ± 1.38 mL g−1 min−1, p = 0.007), higher coronary flow reserve (CFR, 4.80 ± 1.77 versus 3.77 ± 1.43, p = 0.001) and lower coronary resistance during hyperemia (25.63 ± 9.98 mmHg min g mL−1 versus 35.00 ± 23.95 mmHg min g mL−1, p = 0.003) than T allele carriers. In multivariate regression analysis, after adjustment for age, body mass index, serum lipids, blood pressure, adenosine or dipyridamole administration, and study group, HL polymorphism was an independent predictor of blood flow during hyperemia (p = 0.016), coronary resistance (p = 0.014), and CFR (p = 0.005), respectively. Conclusions The HL C-480T polymorphism is associated with CFR, which is an early indicator of atherosclerosis, independently of the level of plasma cholesterol in young men.

The atheroprotective action of estrogen is mediated by estrogen receptors (ESR) 1 and 2, expressed in atherosclerotic lesions. The effects of hormone replacement therapy (HRT) and ESR1 PvuII genotypes on atherosclerosis have not previously been studied prospectively in postmenopausal women.We investigated the effect of HRT on the progression of atherosclerosis in a 5-year follow-up study of 88 postmenopausal women aged 45-71 years at baseline allocated into three groups based on the use of HRT. The HRT-EVP group (n=26) used sequential estradiol valerate (EV) plus progestin (P), the HRT-EV group EV alone (n=32), and a control group (n=30) was without HRT. The atherosclerosis severity score (AS) of the abdominal aorta and carotid arteries were determined by sonography and the ESR1 PvuII genotypes (P/P, P/p and p/p) by PCR.HRT, time and ESR1 PvuII genotype had a statistically significant or borderline significant main effect on AS during 5-year follow-up (P=0.004, P0.001 and P=0.090, respectively), when analyzed by repeated measures analysis of variance. There was a significant genotype-by-treatment (HRT-EVP and control groups) interaction for AS (P=0.034). In response to HRT-EVP, subjects with P/P, compared with those with P/p and p/p genotypes, had a less increase in AS (1.61+/-1.14 vs. 1.71+/-1.27 vs. 2.43+/-1.27). Baseline AS as covariate in similar model does not change the significant interaction effect between HRT-EVP and control groups (P=0.036). But this effect was not found between HRT-EV and control groups.Our results suggest that the effect of HRT-EVP in postmenopausal women on progression of AS may be determined in part by the genotype of ESR1 PvuII.

Upstream transcription factor 1 (USF1) allelic variants significantly influence future risk of cardiovascular disease and overall mortality in females. We investigated sex-specific effects of USF1 gene allelic variants on serum indices of lipoprotein metabolism, early markers of asymptomatic atherosclerosis and their changes during six years of follow-up. In addition, we investigated the cis-regulatory role of these USF1 variants in artery wall tissues in Caucasians. In the Cardiovascular Risk in Young Finns Study, 1,608 participants (56% women, aged 31.9 ± 4.9) with lipids and cIMT data were included. For functional study, whole genome mRNA expression profiling was performed in 91 histologically classified atherosclerotic samples. In females, serum total, LDL cholesterol and apoB levels increased gradually according to USF1 rs2516839 genotypes TT < CT < CC and rs1556259 AA < AG < GG as well as according to USF1 H3 (GCCCGG) copy number 0 < 1 < 2. Furthermore, the carriers of minor alleles of rs2516839 (C) and rs1556259 (G) of USF1 gene had decreased USF1 expression in atherosclerotic plaques (P = 0.028 and 0.08, respectively) as compared to non-carriers. The genetic variation in USF1 influence USF1 transcript expression in advanced atherosclerosis and regulates levels and metabolism of circulating apoB and apoB-containing lipoprotein particles in sex-dependent manner, but is not a major determinant of early markers of atherosclerosis.

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., Author Summary Although cardiovascular events, such as myocardial infarction and stroke, usually occur at later ages, it is known that the atherogenic process begins much earlier in life. Detection of subclinical atherosclerosis would therefore offer the means to identify individuals who are at increased risk of developing cardiovascular events. What remains unclear is the relative contribution of genetic variation to the development of the early stages of atherosclerosis. To address this question, we searched for combinations of both genetic and clinical determinants that are the most predictive of the progression of subclinical carotid atherosclerosis in a sample of 1,027 young adults, aged between 24–39 years, from the Finnish general population (The Cardiovascular Risk in Young Finns Study). We demonstrate here, for the first time in a population-based follow-up study, a predictive relationship between individual's genotypic variation and early signs of atherosclerosis, which cannot be explained by conventional cardiovascular risk factors, such as obesity and elevated blood pressure levels. The predictive modeling framework facilitates the usability of genetic information by identifying informative panels of variants, along with conventional risk factors, which may prove to be useful in early detection and management of atherosclerosis. The clinical implications of these findings remain to be studied.

The common C-480T polymorphism (rs1800588) of the hepatic lipase gene (LIPC) has been associated with high-density lipoprotein (HDL) cholesterol, atherosclerosis, and coronary artery disease. In this study, we examined whether the polymorphism is associated with serum lipid and lipoprotein concentrations, as well as with subclinical atherosclerosis in Young Finns. The participants comprised 2041 men and women (aged 24-39 years) enrolled in the Cardiovascular Risk in Young Finns Study with complete data concerning the rs1800588 polymorphism and serum lipids concentration. All participants underwent an ultrasound examination for brachial artery flow-mediated vasodilatation (FMD) and carotid artery intima-media thickness (IMT) measurement. The marker of arterial elasticity, carotid artery compliance (CAC), was also calculated by means of ultrasound and concomitant brachial blood pressure measurements. In all subjects, serum total cholesterol (p < 0.001), HDL cholesterol (p = 0.006), apolipoprotein AI (apoAI, p < 0.001), and triglyceride (p = 0.009) concentrations increased according to rs1800588 genotype in the order CC, CT, and TT. The same order applied only to apoAI after adjustment for age, body mass index, systolic and diastolic blood pressure, smoking, alcohol consumption, physical activity, diabetes, hypertension, contraceptive hormone use in women, and concentrations of glucose, insulin and C-reactive protein in men and women separately (p = 0.007 and p = 0.003, respectively). The polymorphism was also associated with HDL cholesterol, total cholesterol, and triglyceride levels in women (adjusted p = 0.004, p = 0.007 and 0.02, respectively), but not in men (p was not significant for all). No significant association between the rs1800588 and brachial FMD, carotid IMT, or CAC was found among the entire study population or among women or men separately, with or without adjustment for the above-mentioned factors. The rs1800588 is associated with serum lipid and apolipoprotein concentrations, especially in women, but does not seem to be a determinant of brachial artery FMD, carotid IMT, or CAC in young healthy adults.

ObjectiveTo compare whether serum lipids and their changes during a health education intervention are associated with the Leu7Pro polymorphism in the signal peptide part of neuropeptide Y (NPY) in children with normal weight and in those with overweight.DesignAn intervention study.SettingA family-based intervention of risk factors for prevention of CHD in Finland.SubjectsSubjects were 443 children with a family history of CVD participating in family-based health education. The children were divided into two groups according to NPY genotype: children with Leu7/Pro7 or Pro7/Pro7 genotype (n50) and children with Leu7/Leu7 genotype (n393). The final sample of the follow-up study included 353 (80 %) children (Pro7 allelle carriers,n43; Leu7/Leu7,n310).ResultsAt baseline, the Leu7Pro polymorphism was not associated with serum lipid values after adjustment for body weight in boys or girls. There was a significant interaction of NPY genotype group by time and body weight (P= 0·043 for three-way interaction: time × NPY genotype × body weight) in LDL-cholesterol (LDL-C) concentration among boys. LDL-C decreased among boys with normal weight in both NPY groups and in overweight boys with the Leu7/Leu7 genotype, whereas it increased in overweight boys with the Pro7 allele. Two-way interaction (time × NPY genotype) showed no significant differences in changes of serum lipids between the NPY genotype groups among boys or girls.ConclusionsThe Leu7Pro polymorphism may be associated with dietary response to LDL-C concentration in overweight boys with a family history of early-onset CVD.

Background The T allele of the hepatic lipase (HL) C-480T polymorphism was previously found to be associated with lower post-heparin plasma HL activity, atherosclerosis and risk of coronary artery disease. We studied the association of HL C-480T polymorphism with the extent of atherosclerosis at vessel-wall level in an autopsy series of middle-aged men. Materials and methods An autopsy cohort of 700 Caucasian Finnish men aged 33–70 years (mean 53 years), which comprised two autopsy series, collected 10 years apart during 1981–82 and 1991–92, were analysed. Areas of coronary wall covered with fatty streaks and fibrotic and complicated lesions were measured using computer-assisted planimetry and related to HL C-480T genotypes (CC, CT, and TT). Results There was a significant age–by–genotype interaction on the mean percentage area of fatty streaks (P = 0·01). The HL C-480T polymorphism was a significant explanatory factor for fatty streak area in men under 53 years of age with or without age, body mass index, hypertension, diabetes, smoking, alcohol consumption, apolipoprotein E genotype, and series number as covariates. Men carrying the TT genotype had two times larger areas of fatty streaks compared to the CC carriers (8·8% vs. 4·3%, P = 0·009). However, this association disappeared in men over 53 years. The areas of more advanced atherosclerotic lesions did not vary significantly among the genotype groups. Conclusions Our results suggest that the HL C-480T polymorphism affects the formation of early coronary atherosclerotic lesions in men in their early middle age.

We investigated the association between hepatic lipase (HL) C-480T polymorphism and the risk of acute myocardial infarction (AMI) as well as pre-hospital sudden cardiac death (SCD).Seven hundred sudden or unnatural pre-hospital deaths of middle-aged (33-70 years, mean 53 years) Caucasian Finnish men were subjected to detailed autopsy (Helsinki Sudden Death Study). Genotype data were obtained for 682 men.In logistic regression analysis with age, body mass index, hypertension, diabetes, smoking and alcohol consumption as covariates, men with the TT genotype had an increased risk for SCD and AMI compared to CC carriers (OR=3.0, P=0.011; and OR=3.7, P=0.003). There was a significant age-by-genotype interaction (P0.05) on the risk of SCD. Compared to CC genotype carriers, the association between the TT genotype and SCD was particularly strong (P=0.001) among men53 years of age, but this association was non-significant among older men. This was mainly due to a strong association between the TT genotype and AMI due to severe coronary disease in the absence of thrombosis. Carriers of the TT genotype were more likely to have severe coronary stenoses (or =50%) than men with the CT or CC genotype (P=0.019).The results suggest that HL C-480T polymorphism is a strong age-dependent risk factor of SCD in early middle-aged men.

Hepatic lipase (HL) is a lipolytic enzyme that hydrolyzes triglycerides and phospholipids in almost all major classes of lipoproteins. The HL gene has a functional promoter polymorphism at position 480, which affects transcription and leads to CC, CT, and TT genotypes. We investigated the effect of long-term hormone replacement therapy (HRT) on the progression of atherosclerosis in a 5-yr follow-up observational study of 88 postmenopausal women with different HL genotypes (CC, n 49; CT, n 34; TT, n 5). These women, aged 45–71 yr, were divided into three groups based on the use of HRT. The HRT-EVP group (n 26) used sequential estradiol valerate (EV) plus progestin (levonorgestrel), the HRT-EV group used EV alone (n32), and the control group (n 30) used no HRT. The HRT-EV and HRT-EVP groups started estrogen at menopause for estrogendeficiency symptoms, whereas the control group took no estrogen due to either the absence of such symptoms or a dislike of estrogen therapy. In addition to serum lipid concentration and HL genotype, the atherosclerosis severity score (ASC) for the abdominal aorta and carotid arteries was determined by ultrasonography. There was a significant interaction between HRT therapy and HL genotypes on the increaseinASC(P0.046)afteradjustmentforage,bodymassindex, changes in high-density lipoprotein cholesterol and baseline ASC. In subjects with the T allele, the progression of ASC was significantly faster in the control group than the HRT group (P 0.0006), whereas in the CC genotype, there were no significant differences in ASC progression between the control and HRT groups. Our results suggest that the beneficial effect of HRT on atherosclerosis progression was restricted to women with the T allele, in whom the progression of ASC was slower by half. These results may help us understand in greater detail the benefits and possible risks associated with HRT in atherosclerotic diseases. (J Clin Endocrinol Metab 90: 3786–3792, 2005)

Mannan-binding lectin (MBL) is a serum acute-phase protein and a complement component secreted by the liver. Its deficiency caused by point mutations in the MBL gene has recently been associated with severe atherosclerosis. In this study, we investigated the effect of MBL variant alleles on coronary artery reactivity, which is an early marker of coronary dysfunction and predicts the development of atherosclerosis and coronary artery disease. The study population consisted of 51 apparently healthy, normo- or mildly hypercholesterolemic young men. Myocardial blood flow was measured at baseline and during adenosine-induced hyperemia with positron emission tomography (PET), and MBL genotyping was performed using restriction fragment-length polymorphism. As a result, MBL variant alleles had no effect on coronary artery reactivity. This finding suggests that MBL deficiency is not an independent risk factor for coronary dysfunction and early atherogenic changes but rather a co-factor in the development of atherosclerosis. Thus, the connection of MBL variant alleles with environmental risk factors in atherosclerosis should further be assessed.