Assessment of aflatoxin exposure, growth faltering and the gut microbiome among children in rural Guatemala: protocol for an observational prospective cohort and bioreactor simulations.

INTRODUCTION: Aflatoxin B1 (AFB1) is a carcinogen produced by Aspergillus flavus and Aspergillus parasiticus which grow on maize. Given the high prevalence of child stunting (ie, impaired growth) and other nutritional disorders in low-income and middle-income countries, where maize is consumed, the role of aflatoxin exposure may be significant. Observational reports have demonstrated associations between aflatoxin exposure and impaired child growth; however, most have been cross-sectional and have not assessed seasonal variations in aflatoxin, food preparation and dynamic changes in growth. Biological mechanistic data on how aflatoxin may exert an impact on child growth is missing. This study incorporates a prospective cohort of children from rural Guatemala to assess (1) temporal associations between aflatoxin exposure and child growth and (2) possible mediation of the gut microbiome among aflatoxin exposure, inflammation and child growth. METHODS AND ANALYSIS: We will prospectively evaluate aflatoxin exposure and height-for-age difference trajectories for 18 months in a cohort of 185 children aged 6-9 months at enrolment. We will assess aflatoxin exposure levels and biomarkers of gut and systemic inflammation. We will examine the faecal microbiome of each child and identify key species and metabolic pathways for differing AFB1 exposure levels and child growth trajectories. In parallel, we will use bioreactors, inoculated with faeces, to investigate the response of the gut microbiome to varying levels of AFB1 exposure. We will monitor key microbial metabolites and AFB1 biotransformation products to study nutrient metabolism and the impact of the gut microbiome on aflatoxin detoxification/metabolism. Finally, we will use path analysis to summarise the effect of aflatoxin exposure and the gut microbiome on child growth. ETHICS AND DISSEMINATION: Ethics approval was obtained from Arizona State University Institutional Review Board (IRB; STUDY00016799) and Wuqu' Kawoq/Maya Health Alliance IRB (WK-2022-003). Findings will be disseminated in scientific presentations and peer-reviewed publications.

Outcome predictors of pneumonia in elderly patients: importance of functional assessment.

OBJECTIVES: To evaluate the outcome of elderly patients with community-acquired pneumonia (CAP) seen at an acute-care hospital, analyzing the importance of CAP severity, functional status, comorbidity, and frailty. DESIGN: Prospective observational study. SETTING: Emergency department and geriatric medical day hospital of a university teaching hospital. PARTICIPANTS: Ninety-nine patients aged 65 and older seen for CAP over a 6-month recruitment period. MEASUREMENTS: Clinical data were used to calculate Pneumonia Severity Index (PSI), Barthel Index (BI), Charlson Comorbidity Index, and Hospital Admission Risk Profile (HARP). Patients were then assessed 15 days later to determine functional decline and 30 days and 18 months later for mortality and readmission. Multiple logistic regression was used to analyze outcomes. RESULTS: Functional decline was observed in 23% of the 93 survivors. Within the 30-day period, case-fatality rate was 6% and readmission rate 11%; 18-month rates were 24% and 59%, respectively. Higher BI was a protective factor for 30-day and 18-month mortality (odds ratio (OR)=0.96, 95% confidence interval (CI)=0.94-0.98 and OR=0.97, 95% CI=0.95-0.99, respectively; P<.01), and PSI was the only predictor for functional decline (OR=1.03, 95% CI=1.01-1.05; P=.01). Indices did not predict readmission. Analyses were repeated for the 74 inpatients and indicated similar results except for 18-month mortality, which HARP predicted (OR=1.73; 95% CI=1.16-2.57; P<.01). CONCLUSION: Functional status was an independent predictor for short- and long-term mortality in hospitalized patients whereas CAP severity predicted functional decline. Severity indices for CAP should possibly thus be adjusted in the elderly population, taking functional status assessment into account.