Anthropometry before Day 46 and Growth Velocity before 6 Months of Guatemalan Breastfed Infants Are Associated with Subclinical Mastitis and Milk Cytokines, Minerals, and Trace Elements.

BACKGROUND: Subclinical mastitis (SCM) is an inflammatory condition of the mammary gland, but its association with human milk composition and infant growth is not well described. OBJECTIVES: We investigated whether SCM, milk cytokines, and/or estimated intakes of milk minerals and trace elements were associated with infant anthropometry or growth velocity before 6 mo. METHODS: Breast milk was collected from Mam-Mayan mothers (n = 114) at both early (2-46 d) and established (4-6 mo) lactation. Concentrations of 9 elements (sodium, potassium, calcium, magnesium, copper, iron, manganese, selenium, zinc) analyzed by inductively-coupled plasma mass spectrometry were used to estimate infants' daily intakes. Concentrations of 4 cytokines were measured. Milk concentrations and infants' estimated elemental intakes and anthropometric measurements during early and established lactation were compared by SCM status. Multiple regression was used to identify factors associated with infant growth attainment (<46 d) for infant weight- (WAZ), length- (LAZ), and head circumference-for-age (HCAZ) and weight-for-length (WLZ) z scores and with growth velocity (expressed as Δ/d) from early to established lactation. RESULTS: SCM prevalence was higher in early (30%) than established (10%) lactation. Breast milk of SCM mothers had higher cytokine concentrations and higher magnesium in early and higher selenium concentrations in both early and established lactation (Padj < 0.0121). At day 46, regression models showed inverse associations of SCM with WLZ and IL-1ß with LAZ (Padj < 0.0150). In contrast, linear growth velocity was positively associated with IL-1ß measured in early lactation (Padj < 0.0124), whereas cranial growth velocity was positively associated with IL-8 measured during established lactation ( Padj < 0.0124). CONCLUSIONS: Despite a high prevalence of inadequate intakes, only infants' intake of milk magnesium during early lactation was associated with linear growth velocity in breastfed infants <6 mo. Evidence shows that SCM, breast-milk cytokines, and infants' estimated intakes of select elements are independently associated with growth attainment and growth velocity during lactation.

Infant growth faltering linked to subclinical mastitis, maternal faecal-oral contamination, and breastfeeding.

Infant growth faltering occurs in breastfed infants <6 months of age. The possibility that maternal health status contributes to this growth faltering is underexplored. We investigated whether (a) subclinical mastitis (SCM), an asymptomatic inflammation of the breast, (b) maternal intestinal nematode and protozoan infections, indicators of faecal-oral contamination, or (c) poor breastfeeding practices increased the odds of stunting (length-for-age z-score < -2SD), underweight (weight-for-age z-score < -2SD), or low head circumference (head circumference-for-age z-score < -2SD) in breastfed infants in rural indigenous communities in Guatemala. Mother-infant dyads (n = 105) were subdivided into those with and without SCM (milk Na:K ratio > 0.6). Maternal and infant anthropometry were measured at the time of breast milk collection. Maternal stool samples were examined for the presence of intestinal nematodes and protozoa. Questionnaires were used to characterize breastfeeding practices (exclusivity and frequency) and support, hygiene (latrine use and household faucet), and infant diarrhoea. SCM occurred in 14% of women and was associated with increased odds of infant stunting (odds ratio [OR] = 4.3; confidence interval [CI] [1.1, 15.8]), underweight (OR = 9.2; CI [1.8, 48.0]), and low head circumference (OR = 15.9; CI [2.6, 96.9]). Maternal pathogenic protozoa and nematodes were uncommon (<4%), but nonpathogenic protozoa were common (e.g., Entamoeba coli [39%]). Entamoeba coli increased the likelihood (OR = 3.3; CI [1.02, 10.6]) of low head circumference, whereas higher breastfeeding frequency lowered its odds (OR = 0.74, CI [0.56, 0.97]). Prevention of SCM may improve early infant growth, but public health measures that increase breastfeeding frequency and reduce faecal-oral contamination may be required to minimize low head circumference.

Upregulation of Zinc Absorption Matches Increases in Physiologic Requirements for Zinc in Women Consuming High- or Moderate-Phytate Diets during Late Pregnancy and Early Lactation.

Background: Estimated physiologic requirements (PRs) for zinc increase in late pregnancy and early lactation, but the effect on dietary zinc requirements is uncertain.Objective: The aim of this study was to determine changes in daily fractional absorbed zinc and total absorbed zinc (TAZ) from ad libitum diets of differing phytate contents in relation to physiologic zinc requirements during pregnancy and lactation.Methods: This was a prospective observational study of zinc absorption at 8 (phase 1) and 34 (phase 2) wk of gestation and 2 (phase 3) and 6 (phase 4) mo of lactation. Participants were indigenous Guatemalan women of childbearing age whose major food staple was maize and who had been randomly assigned in a larger study to either of 2 ad libitum feeding groups: low-phytate maize (LP; 1.6 mg/g; n = 14) or control maize (C; 7.1 mg/g; n = 8). Total dietary zinc (milligrams per day, TDZ) and phytate (milligrams per day) were determined from duplicate diets and fractional absorption (FAZ) by dual isotope ratio technique (TAZ = TDZ × FAZ). All variables were examined longitudinally and by group and compared with PRs. TAZ values at later phases were compared with phase 1. Measured TAZ was compared with predicted TAZ for nonpregnant, nonlactating (NPNL) women.Results: TAZ was greater in the LP group than in the C group at all phases. All variables increased from phase 1 to phases 2 and 3 and declined at phase 4. TAZ increased by 1.25 mg/d (P = 0.045) in the C group and by 0.81 mg/d (P = 0.058) in the LP group at phase 2. At phase 3, the increases were 2.66 mg/d (P = 0.002) in the C group and 2.28 mg/d (P = 0.0004) in the LP group, compared with a 1.37-mg/d increase in PR. Measured TAZ was greater than predicted values in phases 2-4.Conclusions: Upregulation of zinc absorption in late pregnancy and early lactation matches increases in PRs of pregnant and lactating women, regardless of dietary phytate, which has implications for dietary zinc requirements of pregnant and lactating women.

Normative Fecal Calprotectin Concentrations in Guatemalan Preschoolers Are High Relative to Children Reported Elsewhere.

BACKGROUND: Calprotectin is a fecal marker of intraintestinal inflammation derived from activated enteric neutrophils and macrophages. It is useful as a clinical marker in inflammatory bowel diseases; furthermore, it may have a role in public health epidemiology. OBJECTIVES: The aim of the study was to describe the distribution of fecal calprotectin in Guatemalan preschool children sharing a common institutional diet; to relate it collectively to pediatric distributions in other geographic settings, and individually to concomitant indicators of intestinal infection or colonization and other descriptive features of the child. METHODS: Fecal samples were collected in 87 subjects, ages 2 to 7 years across 3 daycare centers sharing a common institutional menu, but from different ecological settings. Stools were examined, variously by routine light microscopy, quantitative egg counts, and a Giardia antigen test, for microbiological diagnosis, and an ELISA assay for fecal calprotectin (CalproLab). RESULTS: The median fecal calprotectin value was 58 mg/kg, with a mean of 98 ±â€Š136 mg/kg and a range from 10 to 950 mg/kg; 61% of values were above the manufacturer's cut-off for elevated concentration and 51% exceeded an age-adjusted criterion. There were no associations between sex, age, growth indicators, or fecal microbiological findings by microscopy or ELISA assays, alone or in combination. The central tendency (mean or median) and distribution were generally shifted to the right in relation to comparable reports from children across the world literature. CONCLUSIONS: Although specific, low-grade intestinal infections do not define calprotectin subgroups, right-shifted fecal calprotectin status in this population may reflect a general and diffuse stress of adverse environmental sanitation.

Vitamin D status among indigenous Mayan (Kekchi) and Afro-Caribe (Garifuna) adolescents from Guatemala: a comparative description between two ethnic groups residing on the Rio Dulce at the Caribbean coast in Izabal Province, Guatemala.

OBJECTIVE: To assess vitamin D status and the influence of risk factors such as skin pigmentation and time spent outdoors on hypovitaminosis D among Guatemalan Kekchi and Garifuna adolescents. DESIGN: Cross-sectional study, with convenient sampling design. Blood samples, anthropometric and behavioural data were all collected during the dry season. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured by RIA. SETTING: Communities of Rio Dulce and Livingston, Izabal Province, Caribbean coast of Guatemala, with latitude and longitude of 15°49'N and 88°45'W for Livingston and 15°46'N and 88°49'W for Rio Dulce, respectively. SUBJECTS: Eighty-six adolescents, divided evenly by sex and ethnicity, with mean age of 14 years. RESULTS: Mean (sd) 25(OH)D value was 27·8 (7·2) ng/ml for the total group, with 25·8 (5·9) and 29·8 (7·9) ng/ml, respectively, in Kekchis and Garifunas (P=0·01). Use of vitamin D supplementation, clothing practices and sun protection were not statistically different between groups. Skin area exposed on the day of data collection ranged from 20·0 % minimum to 49·4 % maximum, with mean (sd) exposure of 32·0 (8.5) %. With univariate regression analysis, age (P=0·034), sex (P=0·044), ethnicity (P=0·010), time spent outdoors (P=0·006) and percentage skin area exposed (P=0·001) were predictive. However, multivariate analysis indicated that only sex (P=0·034) and percentage skin area exposed (P=0·044) remained as predictors of 25(OH)D. CONCLUSIONS: Despite residing in an optimal geographic location for sunlight exposure, nearly 65 % of study adolescents were either insufficient or deficient in vitamin D. Correction and long-term prevention of this nutritional problem may be instrumental in avoiding adverse effects in adulthood attributed to low 25(OH)D during adolescence.

Minerals and Trace Elements in Human Breast Milk Are Associated with Guatemalan Infant Anthropometric Outcomes within the First 6 Months.

BACKGROUND: Breast milk is the recommended source of nutrients for infant growth, but its adequacy to meet infants' mineral and trace element needs is unknown. OBJECTIVES: We used breast-milk mineral and trace element concentrations of Guatemalan mothers at 3 lactation stages to estimate total daily intakes and to determine whether intakes were associated with early infant growth. METHODS: In this cross-sectional study, breast-milk samples were collected from Mam-Mayan mothers during transitional (5-17 d, n = 56), early (18-46 d, n = 75), and established (4-6 mo, n = 103) lactation; z scores for weight (WAZ), length (LAZ), and head circumference (HCAZ) were measured. Concentrations of 11 minerals (calcium, potassium, magnesium, sodium, copper, iron, manganese, rubidium, selenium, strontium, and zinc) were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). WHO equations were used to calculate the estimated energy requirement, which was divided by the energy density of breast milk to estimate daily milk volume, and this number was multiplied by breast-milk mineral concentrations to estimate intakes. Principal component analyses identified clusters of minerals; principal components (PCs) were used in regression analyses for anthropometric outcomes. RESULTS: Estimated breast-milk intakes during established lactation were insufficient to compensate for the lower milk sodium, copper, manganese, and zinc concentrations in male infants and the lower sodium, iron and manganese concentrations in female infants. Estimated intakes of calcium, magnesium, potassium, sodium, and selenium were below the Institute of Medicine Adequate Intake for both sexes at all 3 stages of lactation. In early lactation, multiple linear regressions showed that PC1 (calcium, magnesium, potassium, rubidium, and strontium intakes) was positively associated with WAZ, LAZ, and HCAZ. In established lactation, the same PC with sodium added was positively associated with all 3 anthropometric outcomes; a second PC (PC2: zinc, copper, and selenium intakes) was associated with WAZ and LAZ but not HCAZ. CONCLUSIONS: Breast milk may be inadequate in selected minerals and trace elements where higher estimated intakes were associated with greater infant growth.

Interaction of Giardia intestinalis and Systemic Oxidation in Preschool Children in the Western Highlands of Guatemala.

BACKGROUND: Guatemala is a country with the highest prevalence of stunting in under-5 children in the Americas, with a national average of 49.8%. Asymptomatic intestinal colonization with Giardia intestinalis is common in Guatemalan preschoolers and has been implicated as a factor in linear growth retardation. The potential mechanisms of any giardiasis-growth interaction have not been exhaustively explored. OBJECTIVES: The aim of the present study was to describe urine oxidative stress biomarkers and erythrocyte antioxidant enzyme activity, and to explore any association with prevalence or intensity of G intestinalis infection in preschoolers attending 3 government-subsidized day care centers in the Guatemalan Western Highlands. METHODS: Samples of feces, urine, and red blood cell (RBC) hemolysate were collected in a total of 74 preschoolers enrolled in 3 day care centers. Giardia prevalence and a proxy index for intensity were assessed by enzyme-linked immunosorbent assay (ELISA). Urinary biomarkers of oxidative damage to DNA (8-hydroxydeoxyguanosine [8-OHdG]) and to lipid (F2t 15-Isoprostane [F2-Iso]) were measured by ELISA. The erythrocyte activity of catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GSR), and glutathione peroxidase (GPX) were measured by respective spectroscopic substrate-based reaction assays. RESULTS: Median values of RBC CAT activity (P = 0.016) and urine F2-Iso (P = 0.023) differed between children who were positive (n = 39) and negative (n = 35) for Giardia. Similarly, G intestinalis intensity was significantly and positively associated with urinary F2-Iso (r = 0.446, P < 0.001), RBC SOD (r = 283, P = 0.014), and RBC CAT (r = 0.260, P = 0.025). CONCLUSION: The optical density reading of the fecal ELISA assay for G intestinalis has potential as a proxy for the intensity of infestation. In this respect, there exists an association of this intensity with indicators of the systemic oxidation.

The stunted child with an overweight mother as a growing public health concern in resource-poor environments: a case study from Guatemala.

BACKGROUND: Overweight and obesity are emerging at alarming rates in low income women in many countries. Guatemala has the additional burden of a high prevalence of chronic under-nutrition (stunting) in children. AIM: The purpose of this paper is to explore the dual burden of infant and child (5-23 months) under-nutrition and maternal over-weight and obesity in the Western Highlands of Guatemala. SUBJECTS AND METHODS: Anthropometric measures were collected in 446 mother-infant dyads in a metropolitan population of mixed indigenous (Maya) and non-indigenous descent in the Western Highlands of Guatemala. Children were identified as stunted based on a height for age <-2 below the WHO reference median and maternal overweight/obesity defined as a BMI ≥25. Stunted children with an overweight/obese mother were compared to other children who were not stunted and/or who did not have an overweight/obese mother. RESULTS: The prevalences of stunting (38%) and maternal overweight/obesity (45%) were high, but just 17% of the mother and child pairs were dual burden. The socio-demographic characteristics of stunted children were not influenced by maternal overweight or obesity. CONCLUSION: Policies are needed to address under-nutrition as well as preventing obesity and obesity-related chronic disease risks of stunted children and their mothers.

Stunting at birth: recognition of early-life linear growth failure in the western highlands of Guatemala.

OBJECTIVE: Measurements of length at birth, or in the neonatal period, are challenging to obtain and often discounted for lack of validity. Hence, classical 'under-5' stunting rates have been derived from surveys on children from 6 to 59 months of age. Guatemala has a high prevalence of stunting (49.8%), but the age of onset of growth failure is not clearly defined. The objective of the study was to assess length-for-age within the first 1.5 months of life among Guatemalan infants. DESIGN: As part of a cross-sectional observational study, supine length was measured in young infants. Mothers' height was measured. Length-for-age Z-scores (HAZ) were generated and stunting was defined as HAZ <-2 using WHO growth standards. SETTING: Eight rural, indigenous Mam-Mayan villages (n 200, 100% of Mayan indigenous origin) and an urban clinic of Quetzaltenango (n 106, 27% of Mayan indigenous origin), Guatemala. SUBJECTS: Three hundred and six newborns with a median age of 19 d. RESULTS: The median rural HAZ was -1.56 and prevalence of stunting was 38%; the respective urban values were -1.41 and 25%. Linear regression revealed no relationship between infant age and HAZ (r = 0.101, r(2) = 0.010, P = 0.077). Maternal height explained 3% of the variability in HAZ (r = 0.171, r(2) = 0.029, P = 0.003). CONCLUSIONS: Stunting must be carried over from in utero growth retardation in short-stature Guatemalan mothers. As linear growth failure in this setting begins in utero, its prevention must be linked to maternal care strategies during gestation, or even before. A focus on maternal nutrition and health in an intergenerational dimension is needed to reduce its prevalence.

Energy contribution from non-breastmilk items in low-income Guatemalan infants in their sixth month of life.

OBJECTIVE: To examine the nature and energy contribution of complementary feeding in breastfed infants in their sixth month of life, and the prevalence of the use of bottles as a delivery method. MATERIALS AND METHODS: We recruited 156 breastfeeding infants at a health clinic in metropolitan Quetzaltenango, Guatemala. A previous-day recall was performed. RESULTS: Sixty nine mothers (44%) reported offering items other than breastmilk. The median contribution of energy from complementary foods among infants with mixed feeding (n=66) was 197 kcal/day (interquartile range [IQR] 49-353). The median energy contribution of formula or cow's milk among consumers (n=39) was 212 kcal/day (IQR 84-394). Bottles were used on the previous day by 55 (80%) of the 69 mothers not offering exclusive breastfeeding. CONCLUSIONS: Premature introduction of non-breastmilk items is commonly practiced in feeding Guatemalan infants. Adherence to the internationally recognized guidelines for early infant feeding should be an intervention priority for this population.

Quantitative Methodologies Reveal a Diversity of Nutrition, Infection/Illness, and Psychosocial Stressors During Pregnancy and Lactation in Rural Mam-Mayan Mother-Infant Dyads From the Western Highlands of Guatemala.

BACKGROUND: The nature and severity of 3 categories of maternal stressors (nutritional, infectious, and psychosocial) that may impact maternal health and early infant growth are not often considered together. OBJECTIVES: To describe quantitative methodologies; assess construct validity of questionnaires; report variability in sociodemographic, obstetric, nutritional, infectious, and psychosocial characteristics; and compare characteristics between pregnancy and lactation and between study cohorts of Mam-Mayan mother-infant dyads. METHODS: Grounded in participatory action research and a socioecological framework, this observational study enrolled a longitudinal cohort of 155 women, followed during pregnancy (6-9 months), early (0-6 weeks), and later (4-6 months) postpartum, and 2 cross-sectional cohorts (60 early and 56 later postpartum). Household and social factors; obstetric history; nutritional, infectious, and psychosocial stressors; and infant characteristics were explored. RESULTS: Diet diversity (3.4 ± 1.3) and adult food security (38%) were low. Urinary and gastrointestinal infections were rare (<5%), whereas experience of local idioms of distress was frequent (20%-50%). Participants reported low maternal autonomy (81%), high paternal support (70%), small social support networks (2.7 ± 1.3 individuals), and high trust in family (88%) and community-based institutions (61%-65%) but low trust in government services (6%). Domestic violence was commonly reported (22%). Infant stunting was common (36% early postpartum and 43% later postpartum) despite frequent antenatal care visits (7.5 ± 3.8). Participant engagement with the research team did not influence study outcomes based on comparisons between longitudinal and cross-sectional cohorts. CONCLUSIONS: The variability in sociodemographic, nutritional, and psychosocial variables, will allow exploration of factors that promote resilience or increase vulnerability of the mother-infant dyad.

The Nutritional Contribution of Foods and Beverages Provided by Government-Sponsored Day Care Centers in Guatemala.

BACKGROUND: Meals served at government-run day care centers must be nutritionally adequate to ensure good health and proper development of preschool-aged children. They can provide a controlled opportunity to complement the daily diet of children in vulnerable populations. OBJECTIVE: To determine the nutrient adequacy and leading food sources of nutrients provided by the diet served in government-sponsored day care centers. METHODS: Estimated daily energy and nutrient intakes of a theoretical 40-day day care center menu were calculated, and the nutrient adequacy was assessed. Nutrient densities and critical nutrient densities of the menu were computed to identify nutrient inadequacies. Furthermore, main sources of nutrients were identified, and energy and nutrient distributions were examined by meal time. RESULTS: The menu provides approximately 90% of daily energy requirement and more than 100% of Recommended Nutrient Intakes (RNIs), with the exception of vitamin D and calcium. Sugar was the first leading source of energy, whereas milk was the first leading contributor of vitamin D. CONCLUSION: Within an environment of budgetary constraints, the Guatemalan government developed and advocated an exemplary menu offering for children in the vulnerable preschool period. We have demonstrated that, if prepared and served as planned, the items from the official, standard menu would supply most of the nutrients needed. High vitamin A intake related to the mandated national fortification program is a potential problem. From the analysis, it was found that vitamin D emerges as the most prominent candidate for a problem nutrient of deficient intake.

Challenges in the elaboration of a field interview instrument to capture information for the evaluation of adherence to the WHO/PAHO Guiding Principles for Complementary Feeding of the Breastfed Child.

BACKGROUND: In 2003, the World Health Organization (WHO) and the Pan American Health Organization (PAHO) published "Guiding principles for complementary feeding of the breastfed child," which includes a series of 10 recommendations. OBJECTIVE: To illustrate the challenges in creating operative criteria for the evaluation of concordance with the tenets of the WHO/PAHO Guiding Principles recommendations. METHODS: We set out to define operative criteria for the evaluation of adherence to the tenets of the WHO/PAHO Guiding Principles. The 10 Guiding Principles were divided into subcomponents and examined carefully. Our indicators were based on evaluation variables collected by means of our prospectively designed data collection tool. The 2008 WHO-validated infant and young child feeding (IYCF) indicators were taken as a reference for evaluation. RESULTS: After careful examination of the 10 WHO/PAHO Guiding Principles, we were able to identify 28 specific subcomponents for evaluation. With our prospectively designed data collection tool, we were able to set evaluations for 17 of these 28 subcomponents. CONCLUSIONS: The considerations for devising the criteria involved in evaluation instruments must be transparently available to clarify the interpretations and conclusions derived from their application. Evaluation criteria can be set for most, but not all, IYCF practices of the WHO/PAHO Guiding Principles. Indicators that focus on selected, food-related dimensions of childfeeding can be measured in large surveys, whereas other dimensions of optimal feeding, such as hygienic food handling and adequate texture of food, are likely to require more complex measurement and evaluation approaches.

Maternal health and health-seeking behaviors among indigenous Mam mothers from Quetzaltenango, Guatemala.

OBJECTIVE: To obtain background information about maternal health and health-seeking behaviors among indigenous mothers living in rural Mam-Mayan communities of Quetzaltenango, Guatemala. METHODS: A cross-sectional analysis of 100 pregnant and breastfeeding women in four communities was performed to determine prevalence and determinants of service utilization. RESULTS: Extreme poverty, poor education, and poor access to basic resources were prevalent. Out of 100 women 14-41 years old, 33% did not use the formal health care sector for antenatal care; the majority consulted a traditional birth attendant. Only 13% delivered in a hospital. Lower socioeconomic status, lack of fluency in Spanish, and no ownership of a motorized vehicle were associated with the highest likelihood of poor utilization of services. CONCLUSIONS: A variety of factors affect utilization of maternal health services by indigenous women in rural Quetzaltenango. These include socioeconomic disparities, ethnic and linguistic differences, and poor access to basic resources. The current reproductive needs of women should be addressed to improve their health and increase their chance of having healthy children.

Perspective on Emerging Micronutrient Deficiencies in Latin America and the Caribbean.

The moral imperative of public health systems is to maximize the health and welfare of the population to the extent possible. Constraints often include a lack of resources, political will, popular acceptance, or an acceptable safety margin. Major agencies have established iron, iodine, and vitamin A as the principal elements for micronutrients, with folate and zinc on the second plane. As the armamentarium of interventions to favor micronutrient nutrition, for example, preventive health measures, dietary improvement, forms of fortification, and nutrient supplements, is offered in public health policy. The utility of their merger with other nutrients, emergent nutrients, has been considered. The Latin America and Caribbean Region has unique characteristics. The scientific and epidemiology considerations for action in the Region's health concern on 4 emergent nutrient deficiencies of public health-vitamins D and E, essential fatty acids, and choline-are reviewed.

Plain language titleMicronutrient Deficiencies of Interest in Latin America and the CaribbeanPlain language summaryThe diets consumed in the diverse corners and societies in the nations of Latin America and the Caribbean area do not fully supply the vitamins and minerals needed by people of all ages and conditions. Some public health actions are being taken, but only against a limited selection of such nutrients as iron, vitamin A, iodine, and folic acid. The composition of diets and environmental conditions across the region suggests that 4 additional nutrients might be candidates for public health efforts. These include vitamin D, vitamin E, certain large fatty acid molecules, and choline.

Human milk microbiome: associations with maternal diet and infant growth.

Introduction: Ingestion of human milk (HM) is identified as a significant factor associated with early infant gut microbial colonization, which has been associated with infant health and development. Maternal diet has been associated with the HM microbiome (HMM). However, a few studies have explored the associations among maternal diet, HMM, and infant growth during the first 6 months of lactation. Methods: For this cross-sectional study, Mam-Mayan mother-infant dyads (n = 64) were recruited from 8 rural communities in the Western Highlands of Guatemala at two stages of lactation: early (6-46 days postpartum, n = 29) or late (109-184 days postpartum, n = 35). Recruited mothers had vaginally delivered singleton births, had no subclinical mastitis or antibiotic treatments, and breastfed their infants. Data collected at both stages of lactation included two 24-h recalls, milk samples, and infant growth status indicators: head-circumference-for-age-z-score (HCAZ), length-for-age-z-score (LAZ), and weight-for-age-z-score (WAZ). Infants were divided into subgroups: normal weight (WAZ ≥ -1SD) and mildly underweight (WAZ < -1SD), non-stunted (LAZ ≥ -1.5SD) and mildly stunted (LAZ < -1.5SD), and normal head-circumference (HCAZ ≥ -1SD) and smaller head-circumference (HCAZ < -1SD). HMM was identified using 16S rRNA gene sequencing; amplicon analysis was performed with the high-resolution ANCHOR pipeline, and DESeq2 identified the differentially abundant (DA) HMM at the species-level between infant growth groups (FDR < 0.05) in both early and late lactation. Results: Using both cluster and univariate analyses, we identified (a) positive correlations between infant growth clusters and maternal dietary clusters, (b) both positive and negative associations among maternal macronutrient and micronutrient intakes with the HMM at the species level and (c) distinct correlations between HMM DA taxa with maternal nutrient intakes and infant z-scores that differed between breast-fed infants experiencing growth faltering and normal growth in early and late lactation. Conclusion: Collectively, these findings provide important evidence of the potential influence of maternal diet on the early-life growth of breastfed infants via modulation of the HMM.

Update on zinc biology.

Zinc has become a prominent nutrient of clinical and public health interest in the new millennium. Functions and actions for zinc emerge as increasingly ubiquitous in mammalian anatomy, physiology and metabolism. There is undoubtedly an underpinning in fundamental biology for all of the aspects of zinc in human health (clinical and epidemiological) in pediatric and public health practice. Unfortunately, basic science research may not have achieved a full understanding as yet. As a complement to the applied themes in the companion articles, a selection of recent advances in the domains homeostatic regulation and transport of zinc is presented; they are integrated, in turn, with findings on genetic expression, intracellular signaling, immunity and host defense, and bone growth. The elements include ionic zinc, zinc transporters, metallothioneins, zinc metalloenzymes and zinc finger proteins. In emerging basic research, we find some plausible mechanistic explanations for delayed linear growth with zinc deficiency and increased infectious disease resistance with zinc supplementation.

Prevalence of giardiasis in children attending semi-urban daycare centres in Guatemala and comparison of 3 giardia detection tests.

Giardia intestinalis is an intestinal parasite widely prevalent in children attending daycare centres worldwide and has been associated with undernutrition. Stool samples from 48 Guatemalan children (aged 1.5-7 years) attending participating daycare centres were analyzed over five weeks for presence of Giardia intestinalis using light microscopy, ELISA, and rapid dipstick test. Giardia prevalence rates were 43.7% at Week 0 and 44.7% at Week 4, based on ELISA. Intensity, but not prevalence, of infection showed a trend toward decreased weight-for-age (1-tailed p = 0.08). We believe that ELISA analysis of stool samples may be further adapted for measuring the intensity of infection in humans.