Laura E. Smith

Dr. Laura E. Smith


Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2019 in The Lancet Global Health
Verified
Journal Article
Open access
JHJean H Humphrey
Jean H Humphrey
MMMduduzi N N Mbuya
Mduduzi N N Mbuya
RNRobert Ntozini
Robert Ntozini
LMLawrence H Moulton
Lawrence H Moulton
RSRebecca J Stoltzfus
Rebecca J Stoltzfus
TMTalent Makoni
Talent Makoni
Child stunting reduces survival and impairs neurodevelopment. We tested the independent and combined effects of improved water, sanitation, and hygiene (WASH), and improved infant and young child feeding (IYCF) on stunting and anaemia in in Zimbabwe. We did a cluster-randomised, community-based, 2 × 2 factorial trial in two rural districts in Zimbabwe. Clusters were defined as the catchment area of between one and four village health workers employed by the Zimbabwe Ministry of Health and Child Care. Women were eligible for inclusion if they permanently lived in clusters and were confirmed pregnant. Clusters were randomly assigned (1:1:1:1) to standard of care (52 clusters), IYCF (20 g of a small-quantity lipid-based nutrient supplement per day from age 6 to 18 months plus complementary feeding counselling; 53 clusters), WASH (construction of a ventilated improved pit latrine, provision of two handwashing stations, liquid soap, chlorine, and play space plus hygiene counselling; 53 clusters), or IYCF plus WASH (53 clusters). A constrained randomisation technique was used to achieve balance across the groups for 14 variables related to geography, demography, water access, and community-level sanitation coverage. Masking of participants and fieldworkers was not possible. The primary outcomes were infant length-for-age Z score and haemoglobin concentrations at 18 months of age among children born to mothers who were HIV negative during pregnancy. These outcomes were analysed in the intention-to-treat population. We estimated the effects of the interventions by comparing the two IYCF groups with the two non-IYCF groups and the two WASH groups with the two non-WASH groups, except for outcomes that had an important statistical interaction between the interventions. This trial is registered with ClinicalTrials.gov, number NCT01824940. Between Nov 22, 2012, and March 27, 2015, 5280 pregnant women were enrolled from 211 clusters. 3686 children born to HIV-negative mothers were assessed at age 18 months (884 in the standard of care group from 52 clusters, 893 in the IYCF group from 53 clusters, 918 in the WASH group from 53 clusters, and 991 in the IYCF plus WASH group from 51 clusters). In the IYCF intervention groups, the mean length-for-age Z score was 0·16 (95% CI 0·08-0·23) higher and the mean haemoglobin concentration was 2·03 g/L (1·28-2·79) higher than those in the non-IYCF intervention groups. The IYCF intervention reduced the number of stunted children from 620 (35%) of 1792 to 514 (27%) of 1879, and the number of children with anaemia from 245 (13·9%) of 1759 to 193 (10·5%) of 1845. The WASH intervention had no effect on either primary outcome. Neither intervention reduced the prevalence of diarrhoea at 12 or 18 months. No trial-related serious adverse events, and only three trial-related adverse events, were reported. Household-level elementary WASH interventions implemented in rural areas in low-income countries are unlikely to reduce stunting or anaemia and might not reduce diarrhoea. Implementation of these WASH interventions in combination with IYCF interventions is unlikely to reduce stunting or anaemia more than implementation of IYCF alone. Bill & Melinda Gates Foundation, UK Department for International Development, Wellcome Trust, Swiss Development Cooperation, UNICEF, and US National Institutes of Health.

15 August 2013 in Maternal & Child Nutrition
Verified
Journal Article
Closed access
PDF file
AJAndrew D. Jones
Andrew D. Jones
SIScott B. Ickes
Scott B. Ickes
LSLaura E. Smith
Laura E. Smith
MMMduduzi N.N. Mbuya
Mduduzi N.N. Mbuya
BCBernard Chasekwa
Bernard Chasekwa
RSRebecca J. Stoltzfus
Rebecca J. Stoltzfus

31 January 2012 in Journal of Public Health
Verified
Journal Article
Open access
PDF file
AHAndrew S Hanks
Andrew S Hanks
DJDavid R. Just
David R. Just
LSLaura E. Smith
Laura E. Smith
BWBrian Wansink
Brian Wansink
In the context of food, convenience is generally associated with less healthy foods. Given the reality of present-biased preferences, if convenience was associated with healthier foods and less healthy foods were less convenient, people would likely consume healthier foods. This study examines the application of this principle in a school lunchroom where healthier foods were made more convenient relative to less healthy foods. One of two lunch lines in a cafeteria was arranged so as to display only healthier foods and flavored milk. Trained field researchers collected purchase and consumption data before and after the conversion. Mean comparisons were used to identify differences in selection and consumption of healthier foods, less healthy foods and chocolate milk. Sales of healthier foods increased by 18% and grams of less healthy foods consumed decreased by nearly 28%. Also, healthier foods' share of total consumption increased from 33 to 36%. Lastly, we find that students increased their consumption of flavored milk, but flavored milk's share of total consumption did not increase. In a school lunchroom, a convenience line that offered only healthier food options nudged students to consume fewer unhealthy foods. This result has key implications for encouraging healthy behavior in public schools nation wide, cafeterias and other food establishments.

1 July 2012 in Advances in Nutrition
Verified
Journal Article
Open access
PDF file
LSLaura E. Smith
Laura E. Smith
RSRebecca J. Stoltzfus
Rebecca J. Stoltzfus
APAndrew Prendergast
Andrew Prendergast
Childhood stunting is an important and intractable public health problem that underlies ∼20% of deaths among children aged <5 y in developing countries. Environmental enteropathy (EE), a subclinical condition of the small intestine characterized by reduced absorptive capacity and increased intestinal permeability, is almost universal among children in developing countries and may mediate stunting. However, the etiology of EE is poorly understood. Mycotoxins are metabolites of fungi that frequently contaminate the staple foods of children living in developing countries. We review evidence from human and animal studies that exposure to mycotoxins, particularly aflatoxin (AF), fumonisin (FUM), and deoxynivaenol (DON), may impair child growth. Although these toxins have distinct actions, they all mediate intestinal damage through: 1) inhibition of protein synthesis (AF, DON); 2) an increase in systemic proinflammatory cytokines (DON); and 3) inhibition of ceramide synthase (FUM). The intestinal pathology that arises from mycotoxin exposure is very similar to that of EE. We propose that future studies should address the role of mycotoxins in the pathogenesis of EE and evaluate interventions to limit mycotoxin exposure and reduce childhood stunting.

11 November 2015 in Clinical Infectious Diseases
Verified
Journal Article
Open access
PDF file
TTThe Sanitation Hygiene Infant Nutrition Efficacy (SHINE) Trial Team
The Sanitation Hygiene Infant Nutrition Efficacy (SHINE) Trial Team
JHJean H. Humphrey
Jean H. Humphrey
AJAndrew D. Jones
Andrew D. Jones
AMAmee Manges
Amee Manges
GMGoldberg Mangwadu
Goldberg Mangwadu
HMHilda A. Mujuru
Hilda A. Mujuru
Child stunting and anemia are intractable public health problems in developing countries and have profound short- and long-term consequences. The Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial is motivated by the premise that environmental enteric dysfunction (EED) is a major underlying cause of both stunting and anemia, that chronic inflammation is the central characteristic of EED mediating these adverse effects, and that EED is primarily caused by high fecal ingestion due to living in conditions of poor water, sanitation, and hygiene (WASH). SHINE is a proof-of-concept, 2 × 2 factorial, cluster-randomized, community-based trial in 2 rural districts of Zimbabwe that will test the independent and combined effects of protecting babies from fecal ingestion (factor 1, operationalized through a WASH intervention) and optimizing nutritional adequacy of infant diet (factor 2, operationalized through an infant and young child feeding [IYCF] intervention) on length and hemoglobin at 18 months of age. Within SHINE we will measure 2 causal pathways. The program impact pathway comprises the series of processes and behaviors linking implementation of the interventions with the 2 child health primary outcomes; it will be modeled using measures of fidelity of intervention delivery and household uptake of promoted behaviors and practices. We will also measure a range of household and individual characteristics, social interactions, and maternal capabilities for childcare, which we hypothesize will explain heterogeneity along these pathways. The biomedical pathway comprises the infant biologic responses to the WASH and IYCF interventions that ultimately result in attained stature and hemoglobin concentration at 18 months of age; it will be elucidated by measuring biomarkers of intestinal structure and function (inflammation, regeneration, absorption, and permeability); microbial translocation; systemic inflammation; and hormonal determinants of growth and anemia among a subgroup of infants enrolled in an EED substudy. This article describes the rationale, design, and methods underlying the SHINE trial. Clinical Trials Registration. NCT01824940.

5 April 2017 in The American Journal of Tropical Medicine and Hygiene
Verified
Journal Article
Open access
LSLaura E. Smith
Laura E. Smith
APAndrew J. Prendergast
Andrew J. Prendergast
Paul C. TurnerPaul C. Turner
Paul C. Turner
JHJean H. Humphrey
Jean H. Humphrey
RSRebecca J. Stoltzfus
Rebecca J. Stoltzfus
Pregnant women and their developing fetuses are vulnerable to multiple environmental insults, including exposure to aflatoxin, a mycotoxin that may contaminate as much as 25% of the world food supply. We reviewed and integrated findings from studies of aflatoxin exposure during pregnancy and evaluated potential links to adverse pregnancy outcomes. We identified 27 studies (10 human cross-sectional studies and 17 animal studies) assessing the relationship between aflatoxin exposure and adverse birth outcomes or anemia. Findings suggest that aflatoxin exposure during pregnancy may impair fetal growth. Only one human study investigated aflatoxin exposure and prematurity, and no studies investigated its relationship with pregnancy loss, but animal studies suggest aflatoxin exposure may increase risk for prematurity and pregnancy loss. The fetus could be affected by maternal aflatoxin exposure through direct toxicity as well as indirect toxicity, via maternal systemic inflammation, impaired placental growth, or elevation of placental cytokines. The cytotoxic and systemic effects of aflatoxin could plausibly mediate maternal anemia, intrauterine growth restriction, fetal loss, and preterm birth. Given the widespread exposure to this toxin in developing countries, longitudinal studies in pregnant women are needed to provide stronger evidence for the role of aflatoxin in adverse pregnancy outcomes, and to explore biological mechanisms. Potential pathways for intervention to reduce aflatoxin exposure are urgently needed, and this might reduce the global burden of stillbirth, preterm birth, and low birthweight.