Biomarkers of Infant Health and Growth Outcomes in Low-Resource Settings Restricted; Files & ToC
Das, Rina (Spring 2026)
Abstract
The microbiome shapes early-life immunity and susceptibility to infection, but its contribution to key childhood burdens in low-income settings, such as undernutrition, diarrhea, and pneumonia, remains unclear. This dissertation examines how infant gut and oro/nasopharyngeal microbiomes develop and relate to common infections that can impair growth in resource-limited environments. Although higher gut microbial diversity, particularly anaerobic taxa, has been linked to lower diarrhea risk, protective profiles and their implications for growth are not well defined in high-pathogen, low-resource populations.
We addressed the knowledge gaps through two specific objectives from the PAASIM study in Mozambique and another specific objective from a sub-study of the HAPIN trial in Guatemala. We hypothesized that: (1) there is an association between a. the cumulative period prevalence of diarrhea reported since birth and gut microbiome characteristics at 12 months of age; and b. the gut microbiome characteristics at 3, 6, and 9 months of age are associated with child growth outcomes at subsequent time points as measured by LAZ, and WLZ; (2) Whether early life exposures: socioeconomic status, nutrition, WASH, animal exposure, and other environmental factors measured at 3/6/9 months are associated with microbiome features at 6/9/12 months (lagged by ~3 months); (3) child oropharyngeal or nasopharyngeal microbiome characteristics at birth and 6 months of age are associated with a. infant pneumonia, measured by incidence of pneumonia from birth to 12 months of age; and b. Symptoms of respiratory tract infections from birth to age 12 months. I accomplished these through the following aims:
Research Aim 1: Investigate the effect of diarrhea on early-life gut microbiome composition and subsequent infant growth in Beira, Mozambique. These findings suggest that early microbial trajectories, independent of cumulative diarrheal burden, may be linked to growth outcomes, warranting further research to identify potential microbiome-targeted interventions in the first year of life, a pivotal window for promotion of healthy growth in resource-limited settings.
Research Aim 2: Investigate the early-life exposures and infant microbiome development across the first year of life in low-resource settings, Beira, Mozambique. These results reinforce that early infancy contains discrete, time-sensitive opportunities when modifiable caregiving and household conditions can shape foundational gut microbiome development with potential downstream consequences for immune maturation and enteric infection risk.
Research Aim 3: Investigate the Upper respiratory microbiome composition and associations with air pollution and infant respiratory health: a longitudinal study in Guatemala. These findings reveal coordinated but site-specific patterns of microbial maturation in early infancy and suggest that both ecological dynamics and environmental exposures shape upper airway communities with implications for respiratory health.
Table of Contents
This table of contents is under embargo until 27 May 2028
About this Dissertation
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File download under embargo until 27 May 2028 | 2026-03-11 13:04:36 -0400 | File download under embargo until 27 May 2028 |
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