Respiratory Colonization and Short-Term Temporal Changes in the Urinary Metabolome of Children.

Lilliam Ambroggio,Todd A Florin,Brandie D Wagner,Kathleen A Stringer,Larisa Yeomans,Kayla Williamson,Cory Pfefferman,Jae Hyun Kim,Samir S Shah,Heidi Sucharew,Richard M Ruddy,Maurizio Macaluso

doi:10.3390/metabo11080500

Abstract

The human metabolome may vary based on age, over time, and in the presence of viral carriage and bacterial colonization—a common scenario in children. We used nuclear magnetic resonance spectroscopy to identify and quantify urinary metabolites of children without signs or symptoms of respiratory illness. A urine sample and two nasopharyngeal swabs were collected to test for respiratory viral pathogens and colonization by Streptococcus pneumoniae (Sp). Urine samples were collected at the initial visit, 24 h post-enrollment, and 10–14 days post-enrollment. Of the 122 children enrolled, 24% had a virus detected and 19.7% had Sp detected. Intraclass correlation coefficients demonstrated greater within-subject versus between-subject variability for all metabolites detected. In linear mixed models adjusted for age, time, history of asthma, Sp, and viruses, 1-methylnicotinamide was increased by 50% in children with Sp and decreased by 35% in children with rhinovirus/enterovirus. Children with Sp had 83% higher levels of trimethylamine-N-oxide compared with those without Sp. However, when adjusting for multiple comparisons, the association was no longer statistically significant. In conclusion, there appear to be short-term changes within the urinary metabolome of healthy children, but levels of metabolites did not statistically differ in children with viral carriage or Sp detected.

Highlights

The human metabolome can be affected by environmental and biological factors
We found that among a cohort of healthy children with no signs or symptoms of respiratory illness, 24% had a virus detected and 19.7% had Streptococcus pneumoniae (Sp) detected
Metabolite levels did not change over time when accounting for multiple comparison testing

Summary

Introduction

The human metabolome can be affected by environmental (e.g., diet, medications) and biological (e.g., age, sex) factors. Non-neonate children, the difference in muscle mass is much less pronounced, making the impact of sex less than the impact of age alone [3]. Studies assessing the impact of diet on the metabolome in adults have shown greater variability in the metabolome between subjects than within subjects [4,5], but such variability did not distinguish healthy and non-healthy subjects [5]. Age may be an important predictor of metabolite changes over time in adults [1,4]. The metabolome varies with age [6]; acute changes over time in the metabolome of children remain of interest

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