TOWARDS A BETTER UNDERSTANDING OF THE BODY VOLATOLOME: FOCUS ON ENDOGENOUS PARAMETERS INFLUENCING BODY VOLATOLOME COMPOSITION

Significance of the Topic

The human body volatolome reflects metabolic and microbial processes on the skin. Characterizing these volatile organic compounds (VOCs) is crucial for disease biomarker discovery, personalized health monitoring, and non-invasive diagnostics. Understanding endogenous factors that shape the skin VOC profile is fundamental to standardize sampling methods and interpret results accurately.

Study Objectives and Overview

This study aimed to dissect how intrinsic parameters—body area, lateral symmetry, age, and gender—influence the composition of the skin volatolome. By comparing healthy and skin cancer cohorts and focusing on healthy volunteers, the research sought to establish baseline variability. A mixed targeted and non-targeted approach was applied to highlight both known and novel compounds.

Methodology and Instrumentation

Sampling: Skin VOCs were collected over one hour from three body sites (armpits, forearm, back) using SkinVOCs® adsorbent patches. Subjects refrained from deodorants or perfumes for 24 hours prior.

• Two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC‐TOFMS) with ChromaTOF Tile software for data processing
• Statistical analyses including PERMANOVA for variance testing, Principal Component Analysis (PCA), and Partial Least Squares Discriminant Analysis (PLS‐DA) for group differentiation

Main Results and Discussion

Body Area Variation

• Distinct VOC profiles were observed among the armpits, forearm, and back (PERMANOVA p < 0.001)
• Some compounds (e.g., benzenemethanethiol) were specific to the armpits, while others (e.g., benzyl alcohol) were ubiquitous across sites

Lateral Symmetry

• Left/right sample pairs from the same individual showed higher similarity than between different individuals, supporting the use of bilateral sampling as technical replicates

Age Influence

• PCA and PLS‐DA revealed separation between subjects below and above 40 years, largely driven by steroid VOCs more abundant in younger individuals
• ANOVA highlighted molecules such as 3-methyl-2-hexenoic acid and nonanal contributing to age differentiation

Gender Influence

• Specific VOC patterns differed between male and female subjects, indicating a need for gender-matched cohorts in clinical studies

Benefits and Practical Applications

• Establishes baseline variability of skin VOCs across intrinsic factors, improving biomarker identification
• Supports standardized sampling by demonstrating body-site and lateral consistency
• Facilitates design of non-invasive diagnostics with controlled cohort matching for age and gender

Future Trends and Opportunities

Expanding cohort size and diversity will refine endogenous VOC signatures. Integration with microbial and metabolomic data can unravel the biological origins of key volatiles. Advanced machine learning models on comprehensive GC×GC datasets may enable real-time VOC-based health monitoring and early disease detection.

Conclusion

Endogenous factors significantly shape the skin volatolome. Body site and laterality present consistent sampling features, while age and gender introduce systematic variability. Clinical studies should employ age- and gender-matched designs to ensure robust VOC biomarker discovery.

Reference

• Gallagher M et al. The British Journal of Dermatology (2008)
• Haze S et al. The Journal of Investigative Dermatology (2001)