# Metabolomic breath landscape analysis unravels lipid biomarker candidates in patients with genetic and idiopathic Parkinson’s disease

## TL;DR

This study uses breath analysis to identify lipid biomarkers in Parkinson's disease patients, offering a non-invasive way to detect the condition.

## Contribution

The study introduces a novel untargeted metabolomics approach using exhaled breath to identify lipid biomarkers in Parkinson's disease.

## Key findings

- Breath analysis identified seven significant metabolites in PD patients, including fatty acid intermediates.
- Five of these metabolites were also found in unaffected carriers of PD-related genetic variants.
- Breath profiling can distinguish PD patients from healthy controls with high accuracy.

## Abstract

Parkinson’s disease (PD) is the fastest growing neurodegenerative disorder. The current lack of efficient early diagnostic tools necessitates novel approaches to biomarker discovery. We propose an untargeted metabolomics approach using non-invasive exhaled breath analysis. Breath samples, collected from 73 PD patients, encompassing both genetic (LRRK2: n = 12, GBA1: n = 35, PRKN: n = 6) and idiopathic PD (n = 20), 4 unaffected LRRK2 pathogenic variant carriers, and 90 controls underwent extreme-resolution FT-ICR-MS analysis. Findings were compared with metabolomics data from blood plasma. Biostatistical analyses identified discernible metabolic patterns in both biofluids, enabling differentiation of PD patients from healthy controls (OOB error < 1%). Metabolomic breath profiling of PD patients yielded 7 significant metabolites putatively identified as tricosanoic acid, docosanamide, eicosanoic acid, homophytanic acid, nonadecyl-MG, stearic acid, and palmitic acid in PD patients, irrespective of the genetic status. Five of these metabolites were also found in unaffected carriers of pathogenic variants in LRRK2 when compared to controls. Most of the proposed structures are intermediates in fatty acid metabolism, introducing new candidate biomarkers for breath analysis in PD, although their identities require MS/MS confirmation. Breath analysis effectively distinguishes between PD patients and healthy controls and can identify metabolites that could serve as noninvasive biomarkers for PD, potentially including its presymptomatic stage.