Household environment and animal fecal contamination are critical modifiers of the gut microbiome and resistome in young children from rural Nicaragua.

BACKGROUND: Early life plays a vital role in the development of the gut microbiome and subsequent health. While many factors that shape the gut microbiome have been described, including delivery mode, breastfeeding, and antibiotic use, the role of household environments is still unclear. Furthermore, the development of the gut antimicrobial resistome and its role in health and disease is not well characterized, particularly in settings with water insecurity and less sanitation infrastructure. RESULTS: This study investigated the gut microbiome and resistome of infants and young children (ages 4 days-6 years) in rural Nicaragua using Oxford Nanopore Technology's MinION long-read sequencing. Differences in gut microbiome diversity and antibiotic resistance gene (ARG) abundance were examined for associations with host factors (age, sex, height for age z-score, weight for height z-score, delivery mode, breastfeeding habits) and household environmental factors (animals inside the home, coliforms in drinking water, enteric pathogens in household floors, fecal microbial source tracking markers in household floors). We identified anticipated associations of higher gut microbiome diversity with participant age and vaginal delivery. However, novel to this study were the significant, positive associations between ruminant and dog fecal contamination of household floors and gut microbiome diversity. We also identified greater abundance of potential pathogens in the gut microbiomes of participants with higher fecal contamination on their household floors. Path analysis revealed that water quality and household floor contamination independently and significantly influenced gut microbiome diversity when controlling for age. These gut microbiome contained diverse resistome, dominated by multidrug, tetracycline, macrolide/lincosamide/streptogramin, and beta-lactam resistance. We found that the abundance of ARGs in the gut decreased with age. The bacterial hosts of ARGs were mainly from the family Enterobacteriaceae, particularly Escherichia coli. CONCLUSIONS: This study identified the role of household environmental contamination in the developing gut microbiome and resistome of young children and infants with a One Health perspective. We found significant relationships between host age, gut microbiome diversity, and the resistome. Understanding the impact of the household environment on the development of the resistome and microbiome in early life is essential to optimize the relationship between environmental exposure and human health. Video Abstract.

The complementary feeding practices of low-income Black mothers with infants between 6 and 24 months of age: A qualitative study.

BACKGROUND: The period from 6 to 24 months in an infant's life presents a critical window for understanding feeding practices and for designing culturally appropriate interventions. However, little is known about the complementary feeding practices of Black mothers and how this period can be used to optimise the long-term health of their children. The present study aimed to identify factors that influence the complementary feeding practices of low-income Black mothers with children aged 6-24 months. METHODS: Participants were recruited through Research Match, Facebook advertising, flyers, and snowballing techniques. Low-income, Black mothers, with a 6-24-month-old infant, and who lived in Franklin County, Ohio, USA, were eligible for the study. A cross-sectional design using in-depth interviews was used. Reflexive thematic analysis was utilised to analyse and interpret the feeding practices of Black mothers. RESULTS: Mothers (n = 8) were aged between 18 and 30 years old and most completed college or had some college education (n = 6). Half (n = 4) were married, employed, and rated their diet quality and their children's as very good. Three themes emerged: (a) complementary feeding at ≥ 6 months of age; (b) involvement of health care providers and service organisations in feeding decisions; and (c) use of responsive feeding cues. CONCLUSIONS: All mothers breastfed exclusively and most (n = 6) initiated complementary feeding at 6 months. Paediatricians, other health providers and service organisations were instrumental in helping Black mothers adopt complementary feeding practices. Mothers also engaged in responsive feeding practices. These findings point to the critical nature of access and education in helping Black mothers in the study achieve feeding recommendations for their infants.

Measuring food insecurity: An introduction to tools for human biologists and ecologists.

OBJECTIVE: Food insecurity is a significant and growing concern undermining the wellbeing of 30% of the global population. Food in/security is a complex construct consisting of four dimensions: availability, access, utilization, and stability, making it challenging to measure. We provide a toolkit human biologists/ecologists can use to advance research on this topic. METHODS: We review the strengths and limitations of common tools used to measure food access and utilization, the two dimensions most proximate to people's lived experience, and emphasize tools that provide data needed to best link food security with human biological outcomes. We also discuss methods that provide contextual data human biologists/ecologists will find useful for study design, ensuring instrument validity, and improving data quality. RESULTS: Food access is principally measured using experience-based instruments that emphasize economic access. Social access, such as food sharing, is under-studied and we recommend using social network analysis to explore this dimension. In terms of utilization, emphasis has been on food choice measured as dietary diversity. Food preparation and intrahousehold distribution, also part of the utilization dimension, are less studied and standardized instruments for measuring both are lacking. The embodiment of food insecurity has focused on child growth, although a growing literature addresses adult mental wellbeing and chronic and infectious disease risk. CONCLUSIONS: We see the potential to expand outcomes to include reproductive and immune function, physical activity, and the gut microbiome. Human biologists/ecologists are well-positioned to advance understanding of the human health impacts of food insecurity and provide data to support intervention efforts.

"Hey child, why were you born when the world is almost over?": An analysis of first-time mothers' postpartum experiences during the early stages of the COVID-19 pandemic in Coatepec, Veracruz, Mexico.

INTRODUCTION: In Coatepec, Mexico, the immediate postpartum is considered a special time, called the cuarentena, when postpartum women receive critical social support and observe diet and activity pre- and proscriptions-all intended to enhance maternal-child health. This study examined how public health mandates aimed at containing COVID-19, which instructed people to socially isolate, affected women's postpartum experiences, including observing the cuarentena. METHODS: We recruited first-time mothers from the local public health clinic and collected qualitative data via a verbally administered survey that covered knowledge/perceived threat of COVID-19 and its effect on the cuarentena and maternal mood. We used content analysis to analyze the data. RESULTS: We conducted 33 telephonic interviews from March to December 2020. Overall, women were knowledgeable about and receptive to public health messaging regarding COVID-19 risks and safety measures. Despite knowledge and receptivity, most followed their original cuarentena plans to observe culturally prescribed postpartum practices, even when doing so contradicted public health mandates. However, the mandates that limited socialization with friends and extended family during the cuarentena negatively affected maternal mood. DISCUSSION: Postpartum women, especially in under-studied low- and middle-income countries, merit research attention. Emergent from this study is that public health messaging should speak to its target audience in a way that makes sense within local contexts, which includes consideration of highly valued health practices. Future studies aimed at understanding how to achieve this goal will facilitate development of stronger programs that address public health needs and protect individual well-being.

Tranquility is a child with a full belly: Pathways linking food insecurity and maternal mental distress in Nicaragua.

A growing body of literature identifies food insecurity (FI) as a critical social determinant of mental health. Across settings, quantitative studies report positive correlations between FI and mental distress, especially among women. Less understood are the pathways by which FI undermines women's mental well-being. To address this gap, we conducted six focus group discussions with 45 Nicaraguan mothers. Thematic analysis identified three themes linking the management of FI and maternal mental well-being in this setting. The theme, la lucha, underscored how the chronicity of FI served as a constant mental strain by demanding mothers strategize on a daily basis to resolve it. The themes "tranquility is a child with a full belly" and "the despairing and frustrated mother" emphasized how FI challenged women's abilities to fulfill the responsibilities of motherhood and served as a reminder of social status. Our findings advance earlier quantitative work by identifying how the management of food insecurity undermines maternal mental well-being in a low-middle income setting and indicate that policies aimed at combating food insecurity can concomitantly improve maternal mental well-being if they bolster women's agency and work to reduce the stigma associated with being food insecure.

Characterization of the gut microbiota of Nicaraguan children in a water insecure context.

OBJECTIVES: The gut microbiota varies across human populations. The first years of life are a critical period in its development. While delivery mode and diet contribute to observed variation, the additional contribution of specific environmental factors remains poorly understood. One factor is waterborne enteric pathogen exposure. In this pilot study, we explore the relationship between household water security and the gut microbiota of children. METHODS: From Nicaraguan households (n = 39), we collected drinking water samples, as well as fecal samples from children aged one month to 5.99 years (n = 53). We tested water samples for total coliforms (CFU/mL) and the presence of common enteric pathogens. Composition and diversity of the gut microbiota were characterized by 16S rRNA sequencing. Households were classified as having drinking water that was "low" (<29 CFU/mL) or "high" (≥29 CFU/mL) in coliforms. We used permutational analyses of variance and Mann-Whitney U-tests to identify differences in the composition and diversity of the gut microbiota of children living in these two home types. RESULTS: Insecure access led households to store drinking water and 85% tested positive for coliforms. High concentrations of Salmonella and Campylobacter were found in water and fecal samples. Controlling for age, the gut microbiota of children from high coliform homes were compositionally different and less diverse than those from low coliform homes. CONCLUSIONS: Results indicate that research exploring the ways water insecurity affects human biology should consider the gut microbiome and that investigations of inter-population variation in the gut microbial community of children should consider pathogen exposure and infection.

Secular trends in adult stature among the Makushi of Guyana in the 20th Century.

OBJECTIVE: This study describes secular trends in physical stature, Cormic Index (CI), and body mass index (BMI) of adult Makushi Amerindians born between 1910 and 1980, compares the stature of these Makushi adults to Makushi adults measured in 1921, and provides contextual data to inform the findings. METHODS: Pearson's correlation was used to assess the relationship between year of birth and physical stature, BMI, and CI for 231 females and 113 males, 20 to 90 years of age measured in 2000 to 2001. Wilcoxon's test was used to compare physical stature of Makushi adults measured in 2000 to 2001 with that of 40 Makushi adults measured in 1921. RESULTS: Among Makushi measured in 2000 to 2001, females and males born more recently were taller and had a lower CI but did not differ in BMI relative to their elders. Makushi measured in 2000 to 2001 are significantly taller than those Maksuhi measured in 1921. CONCLUSION: The increased physical stature of and decreased CI in more recently born Makushi may be explained by a more favorable early life environment possibly due to public health measures and dietary changes. As well, trends in stature may be linked to genetic admixture with African-Guyanese migrating into the region during this time.

Household food insecurity and child health.

Food insecurity, the lack of consistent access to sufficient quality and quantity of food, affects an estimated 800 million people around the world. Although household food insecurity is generally associated with poor child nutrition and health in the USA, we know less about household food insecurity and child health in developing countries. Particularly lacking is research assessing how associations between household food insecurity and children's health outcomes may differ by child age and among children beyond age 5 years in low-income settings. We use data from a population-based sample of households with children ages 3-11 years (N = 431) in León, Nicaragua to consider how household food insecurity is associated with three measures of child health: illness, anaemia and low height-for-age. Our results provide new evidence that even mild household food insecurity is detrimental to children's health; and that child age conditions the associations between household food insecurity and child health. We find that food insecurity is especially harmful to health during early childhood, but continues to have significant associations with health into middle childhood (up to ages 7-8 years). We discuss the potential implications of these results for future child health research and policies in low-income countries. © 2016 John Wiley & Sons Ltd.

Food insecurity and maternal mental health in León, Nicaragua: Potential limitations on the moderating role of social support.

Poor mental health among those living in poverty is a serious global public health concern. Food insecurity (FI) is recognized as an important, yet critically understudied social determinant of mental health. The relationship between FI and mothers' mental health in low- and middle-income countries (LMIC) is especially important to understand considering the high rates of poverty and associated FI in these settings. For these mothers, social support may serve as a buffer in ameliorating the impact of FI on mental distress. However, data required to understand these relationships in LMIC remain sparse. To address this gap we used quantitative and qualitative data and convergence parallel analysis to assess: the association between FI and maternal mental distress; and, whether three forms of social support - mother's general social network support and family support (spouse/partner living in the home, parents/in-laws living in the home) - moderated the association. A survey that included data on FI (ELCSA) and mental distress (SRQ-20) was administered to a population-based sample of mothers in León, Nicaragua (n = 434) in 2012. The survey was complemented by data from 6 focus groups. Regression models identified a strong positive relationship between household-level FI and maternal distress. Evidence of social support moderation was mixed: while maternal social network and spousal/partner support did not moderate this relationship, parental support did. Our ethnographic data revealed three themes that help explain these findings: FI is embarrassing/shameful, close family is the most appropriate source of social support and, fear of gossip and ridicule limit the buffering capacity of the social support network. Our findings contribute to a growing literature demonstrating that FI is an important social determinant of maternal mental distress in LMIC; and that some forms of social support may reduce (but not eliminate) the impact of FI on mental distress.

Amazonian foods and implications for human biology.

CONTEXT: Diets of subsistence-based Amazonian populations have been linked to local resources, but are changing with market penetration. OBJECTIVE: To review the available data on traditional Amazonian foods and diets and evaluate their implications for human biology as a step toward understanding nutrition transitions in the region. METHODS: This study used the Human Relations Area Files for information on the diets of Amerindian groups in the Amazon Basin from 1950 to the present, and used other published sources and the authors' own data. RESULTS: Data on food use was identified for only nine groups and dietary intake data for individuals in only three of the groups. A diet based on starchy staples (manioc and plantains) and fish, supplemented with a limited variety of other plant and animal foods, was found. Bitter manioc-based foods were associated with the consumption of cyanogens and fish with the consumption of mercury. Diets of adults appear to be adequate in energy and protein and low in fats. Children's diets were not well documented. CONCLUSION: Based on the limited available data, Amazonian diets are restricted in variety, but appear to be adequate in energy and protein for adults, but likely insufficiently nutrient-dense for children.

Maternal resources and household food security: evidence from Nicaragua.

OBJECTIVE: Women (especially mothers) are theorized as critical to reducing household food insecurity through their work and caregiver roles. The present study tests these assumptions, assessing how maternal economic and social resources are associated with food insecurity in households with young children. DESIGN: Data from a population-based sample of households was collected in León, Nicaragua (n 443). Data include a newly validated measure of household food insecurity (ELCSA), maternal resource measures, and household economic status and demographics. Regression analysis tests the statistical associations (P<0·05) of maternal resources with household, adult-specific and child-specific food insecurity. SETTING: Municipality of León, Nicaragua. SUBJECTS: Households with children aged 3-11 years in rural and urban León. RESULTS: Only 25% of households with young children were food secure, with 50% mildly food insecure and 25% moderately/severely food insecure. When mothers contributed substantially to household income, the odds of moderate/severe household food insecurity were 34% lower than when their spouse/partner was the main provider. The odds of food insecurity were 60% lower when mothers managed household money, 48% lower when mothers had a secondary (v. primary) education, 65% higher among single mothers and 16% lower with each indicator of social support. Results were similar for adult- and child-specific food insecurity. CONCLUSIONS: This research provides new evidence that maternal economic and social resources are important for reducing household food insecurity and adult- and child-specific food insecurity. Women's social status, social support and access to economic resources need to be enhanced as a part of policies aimed to reduce food insecurity in high-poverty settings.

Exploring the multidimensionality of stature variation in the past through comparisons of archaeological and living populations.

Adult stature variation is commonly attributed to differential stress-levels during development. However, due to selective mortality and heterogeneous frailty, a population's tall stature may be more indicative of high selective pressures than of positive life conditions. This article examines stature in a biocultural context and draws parallels between bioarchaeological and living populations to explore the multidimensionality of stature variation in the past. This study investigates: 1) stature differences between archaeological populations exposed to low or high stress (inferred from skeletal indicators); 2) similarities in growth retardation patterns between archaeological and living groups; and 3) the apportionment of variance in growth outcomes at the regional level in archaeological and living populations. Anatomical stature estimates were examined in relation to skeletal stress indicators (cribra orbitalia, porotic hyperostosis, linear enamel hypoplasia) in two medieval bioarchaeological populations. Stature and biocultural information were gathered for comparative living samples from South America. Results indicate 1) significant (P < 0.01) differences in stature between groups exposed to different levels of skeletal stress; 2) greater prevalence of stunting among living groups, with similar patterns in socially stratified archaeological and modern groups; and 3) a degree of regional variance in growth outcomes consistent with that observed for highly selected traits. The relationship between early stress and growth is confounded by several factors-including catch-up growth, cultural buffering, and social inequality. The interpretations of early life conditions based on the relationship between stress and stature should be advanced with caution.

Intra-population variation in anemia status and its relationship to economic status and self-perceived health in the Mexican Family Life Survey: implications for bioarchaeology.

Recently scholars have advocated for the use of a critical biocultural approach in bioarchaeology, where osteological and dental markers of stress are used to understand the broader biosocial context of past populations. However, the ability to accomplish this task rests on the assumption that ultimate-level environmental stressors and well-being in the past can be reconstructed from the prevalence of pathologies in skeletal collections. Here we test this assumption using anemia prevalence in the Mexican Family Life Survey. Specifically we test three hypotheses: (1) that individuals sharing the same household are more likely to share anemia status; (2) anemia status is a predictor of economic status (a common proxy for broader environmental context); and (3) anemia status is related to self-rated health. Results demonstrate that: anemia status was not commonly shared between household members; there was a significant overlap in economic status between anemic and nonanemic individuals (i.e., anemia poorly predicted economic status) and; while anemia status was associated with self-perceived health, the majority of those who reported poor health were nonanemic while a significant number of those who reported very good health were anemic. We argue that these findings are likely related to variation in individual frailty, which is shaped by biological and cultural risk factors. Therefore, we advocate for greater incorporation of individual frailty into bioarchaeological investigations, and, in effort to overcome some of the difficulties associated with this task, increased use of data from living populations and greater collaboration between bioarchaeologists and human biologists.

Dietary inequalities of mother-child pairs in the rural Amazon: evidence of maternal-child buffering?

This paper explores the expected outcome of maternal nutritional "buffering," namely that children's diets will be more adequate than mothers' diets under conditions of food scarcity. Data on Amazonian mothers and their children, household demography and economics and direct, weighed measures of household food availability and dietary intakes of mother-child pairs were collected from 51 households to address the following research questions: (1) is there evidence of food scarcity in this setting?; (2) are there differences in energy and protein adequacy between children and their mothers?; and, (3) which individual and household-level factors are associated with these mother-child differences in energy and protein adequacy? In this context of food scarcity, we found that the majority of children had more adequate energy (p < 0.001) and protein (p < 0.001) intakes than their mothers. Multivariate OLS regression models showed that of the individual-level factors, child age and height-for-age were negatively associated with maternal-child energy and protein inequalities while maternal reproductive status (lactation) was positively associated with energy inequality. While there were no gender differences in dietary adequacy among children, boys had a larger advantage over their mothers in terms of protein adequacy than girls. Household food availability was related to maternal-child energy and protein inequalities in a curvilinear fashion with the lowest inequalities found in households with extremely low food availability and those with adequate food resources. This is the first study to quantify maternal-child dietary inequalities in a setting of food scarcity and demonstrates the importance of the household context and individual characteristics in understanding the degree to which mothers protect their children from resource scarcity.

The use of biocultural data in interpreting sex differences in body proportions among rural Amazonians.

Variation in height and body proportions is relatively well-understood at the inter-population level, but less is known about intra-population variation. This study explores intra-population variation in body proportions among 172 (88 female; 84 male) adult rural Amazonians. We test the hypotheses that: (1) stunting is associated with changes in proportions and fatness; (2) the sexes express different proportions in response to similar environmental stress; and (3) female growth is negatively affected by the costs of reproduction. We examined height, sitting height, and total leg length in subsamples based on sex and nutritional status (stunted/nonstunted) in relation to biocultural factors including access to food and healthcare and female reproductive history parameters. Differences in proportions were examined using the Quick-Test (Tsutakawa and Hewett: Biometrics 33 (1977) 215-219); correlation analyses were used to detect associations between anthropometric data and body fatness, and female reproductive history parameters. We found significantly higher rates of stunting among females (X(2) = 5.31; P = 0.02; RR = 1.4). Stunted individuals exhibited relatively shorter legs than nonstunted individuals (P = 0.02), although this was not found in within-sex analyses. A significant negative correlation was found between leg length index and fatness (P < 0.01). Lastly, females exhibited relatively shorter legs than males (P = 0.0003) and, among females, height and leg length were significantly positively correlated with age-at-first-birth (P < 0.02) suggesting that adolescent pregnancy may negatively affect growth in this population. Our findings provide insights for the study of intra-population variation in body proportions and highlight the importance of biocultural data in interpreting the pattern of variation observed in living and past populations.

Nutritional status of Makushi Amerindian children and adolescents of Guyana.

BACKGROUND: Amazonian Indians are in the midst of a rapid cultural transition. The developments affecting Amazonian Indians present an opportunity to address important public health problems through public and private initiatives, but to do so it is imperative to begin with information on the health status of these peoples and the underlying factors affecting it. However, relatively few such data are available for this vast region. AIM: This study describes the nutritional status of Makushi Amerindians of Guyana and considers several variables which might help to explain it. SUBJECTS AND METHODS: Data for 792 Makushi, 0-20 years of age from 11 villages are considered. Outcome variables considered are anthropometric markers of growth and nutritional status; specifically height-for-age, weight-for-height and body-mass index. Predictor variables explored are age, sex, relative isolation, number of siblings, season of birth, diet and morbidity. Fisher's exact test, chi-square, Pearson's correlation and multiple regression were used to assess possible relationships between these variables. RESULTS: Relative to other Amazonian Indians, the Makushi have a lower rate of linear-growth faltering and a higher rate of linear-growth faltering relative to non-Amerindian Guyanese. Males, older cohorts, those living in isolated villages or born in the wet season showed higher rates of growth faltering. CONCLUSION: Makushi nutritional status may be explained by sex, age, relative isolation, family size, season of birth, dietary intake and infectious disease.

The nutrition transition in amazonia: rapid economic change and its impact on growth and development in Ribeirinhos.

The goal of this longitudinal study was to assess the impact of economic change and increased market integration on subsistence strategies, living conditions, growth, and nutritional status of Ribeirinhos living in the rural Amazon, Brazil. Data on weight, height, skinfolds, and circumferences, as well as data on economic strategies and living conditions were collected from 469 individuals in 2002 and 429 in 2009. Of these, 204 individuals were measured on both occasions. Independent and paired t-tests were used to identify changes in nutritional status over time in the larger sample and smaller, longitudinal subsample, respectively. Multiple linear regressions were used to examine the relationship between changes in economic/living conditions and nutritional status in the longitudinal subsample. Results indicate modest improvements in linear growth (HAZ) and among male children the observed increase was related to enrollment in the Brazilian conditional cash transfer program, Bolsa Família (P = 0.03). In terms of short-term measures of nutritional status, we found a significant increase in ZTSF and a reduction in ZUMA in most age/sex groups. Among subadults, there was a negative relationship between ZUMA and access to electricity (P = 0.01) and positive relationship between ZUMA and the sale of the açaí fruit (P = 0.04). Significant changes in weight and BMI (P < 0.01) were found among adult females and both were negatively related to household cash income (P = 0.02 and P = 0.03, respectively). Despite significant changes in economic strategies and lifestyle, changes in nutritional status were modest which may be explained by increased food insecurity documented during this early stage of transition.

Nutrition in transition: dietary patterns of rural Amazonian women during a period of economic change.

OBJECTIVES: The goal of this study was to understand the relationship between economic change (wage labor, retirement, and the Bolsa Família program) and dietary patterns in the rural Amazon and to determine the extent to which these changes followed the pattern of the nutrition transition. METHODS: The study was longitudinal. The weighed-inventory method and economic interviews were used to collect data on dietary intake and household economics in a sample of 30 and 52 women in 2002 and 2009, respectively. Twenty of the women participated in both years and make-up the longitudinal sub-sample. Comparative statistics were used to identify changes in dietary patterns over time and multiple linear regressions were used to explore the relationship between economics, subsistence strategies, and diet. RESULTS: There was a significant decline in kcal (P < 0.01) and carbohydrate (P < 0.01) but no change in protein intake over time in both the larger and smaller, longitudinal subsample. The percent of energy, carbohydrate, protein, and fat purchased increased in the larger and longitudinal samples (P ≤ 0.02) and there was an increase in refined carbohydrate and processed, fatty-meat consumption over time. The abandonment of manioc gardens was associated with increased dependence on purchased food (P = 0.03) while receipt of the Bolsa Família was associated with increased protein intake and adequacy (P = 0.02). CONCLUSIONS: The dietary changes observed are only in partial agreement with predictions of the nutrition transition literature. The relationship between the economic and diet changes was shaped by the local context which should be considered when implementing CCT programs, like the Bolsa Família.