# Dried Blood Spots Capture a Wide Range of Metabolic Pathways and Biological Characteristics Associated with Fish Oil Supplementation, Fasting, and the Postprandial State

## TL;DR

Dried blood spots can capture metabolic changes related to fasting, eating, and fish oil, making them useful for diagnostic testing.

## Contribution

This study demonstrates that dried blood spots can capture a wide range of metabolic pathways and biological changes associated with dietary and physiological states.

## Key findings

- DBSs captured metabolic changes related to fasting, postprandial states, and fish oil supplementation.
- The findings align with previously reported changes in plasma and serum.
- DBSs are a viable sample type for metabolomics-based diagnostics.

## Abstract

Background: Metabolomics is recognized as crucial technology for advancing our ability to diagnose, characterize, and monitor treatment of disease. Yet, metabolomics-based diagnostic testing has not been widely adapted into clinical practice because its technical requirements make it generally incompatible with operation at the point of care. One way to expand the reach of metabolomics-based testing, and its clinical benefits, is to utilize dried blood spots (DBS) as a testing sample type. Their easy collection, ambient storage capability, and cost-effective shipment make DBSs ideal for diagnostic tests that require the use of a centralized technology. Methods: To date, relatively few studies have investigated the performance of DBSs at capturing the global metabolome and reporting changes associated with physiological processes. In this study, we investigated those factors by performing global metabolomic profiling on DBSs collected from study volunteers under fasted and postprandial states, with and without dietary fish oil supplementation. Results: DBSs demonstrated broad coverage of metabolic pathways and captured numerous metabolic changes associated with feeding, fasting, and fish oil supplementation that have been reported in plasma and serum. Conclusions: Our findings support the hypothesis that DBSs are a viable sample type for metabolomics-based diagnostic testing and justify follow-up validation studies.