Pooling samples for “top-down” molecular exposomics research: the methodology

Heqing Shen,Ambreen Alamdar,Jianwen She,Weipan Xu,Siyuan Peng,Kristina Voigt,Karl-Werner Schramm,Hagen Scherb

doi:10.1186/1476-069x-13-8

Abstract

BackgroundExposomics is the cutting-edge concept of screening the environmental risk factors for disease. In the novel “top-down” approach, we estimate the molecular exposome by measuring all body fluid analytes in a case-controlled study. However, to detect diverse pollutants, a sufficient sample size and multiple analytical methods are required. This may lead to dramatically increased costs and research workload.MethodsTo help reduce complexity, we suggest a sample pooling strategy along with a scheme for combining both general unknown or multi-targeted screening with targeted analysis. The sample pooling method was tested using computer simulations.ResultsBy comprehensively analysis of pooled samples, it is possible to identify environmental risk factors. Factors are initially screened in the pooled case and control population samples, then in the randomized grouped and pooled case and control subpopulation samples. In the sample grouping, five or more pools were suggested for groups having 30 individuals per pool.ConclusionsThis study suggests that sample pooling is a useful strategy for exposomics research, which provides a hypothesis-free method for pollutant risk screening.

Highlights

An estimated 70 to 90 percent of risk factors associated with chronic diseases are thought to arise from individuals’ exposure to environmental hazards [1,2,3]
The methodology discussed in this study majorly focuses on the broad analysis of environmental pollutants and their metabolites in case-control samples
Considered together, the requirement of large sample size and multiple analyses for each sample proves costly and labor intensive when working with human data. To help overcome these challenges, we propose a sample pooling strategy for molecular exposomics, in which fewer, but larger volume pooled samples are analyzed with the tradeoff losses of the signatures from individual observations in the case-control study

Summary

Results

By comprehensively analysis of pooled samples, it is possible to identify environmental risk factors. Factors are initially screened in the pooled case and control population samples, in the randomized grouped and pooled case and control subpopulation samples. Five or more pools were suggested for groups having 30 individuals per pool

Conclusions

Introduction

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