SAMPLING BODY ODOR FOR HEALTHCARE MONITORING

Importance of the topic

Body odor is a complex matrix of volatile organic compounds (VOCs) influenced by metabolic activity, lifestyle, and environmental factors. Monitoring these compounds non-invasively offers potential for early detection of diseases such as diabetes, epilepsy, COVID-19 and for understanding skin microbiota dynamics.

Objectives and study overview

The study aims to develop a robust sampling and analysis workflow to minimise intra‐individual variability and environmental contamination when profiling human body odor. Key goals include:

• Designing a sampling system suitable for different body regions
• Applying comprehensive GC×GC-TOF/MS analysis
• Evaluating the impact of cosmetics, environment and exposure on VOC profiles
• Exploring VOC biomarkers for COVID-19 detection alone and in combination with canine olfaction

Methodology and experimental design

Sampling was performed on four body areas (armpit, forearm, upper back, groin) under controlled cosmetic habits. Two conditions were compared: constant cosmetic use vs 24 h cosmetics removal. Samples were collected thrice daily for one week to assess temporal variability.

Instrumentation

The analysis employed:

• Sampling device with optimized sorbent phase cartridge
• Thermal desorption unit (Markes TD-100xr): 220 °C for 20 min, helium flow 50 mL/min, split ratio 3
• Two-dimensional gas chromatography (GC×GC): 1D Rxi-5ms (30 m×0.5 mm×0.25 µm), 2D DB-1701 (50 cm×0.18 mm×0.18 µm), modulation period 3 s
• Time-of-flight mass spectrometer (LECO Pegasus BT 4D): acquisition rate 200 Hz, mass range 45–300 m/z
• Data processing via LECO ChromaToF Tile software and manual validation

Main results and discussion

• Over 1 000 peaks detected per sample; 85 VOCs confirmed after manual curation.
• Classification revealed 70 compounds linked to cosmetic ingredients and 15 associated with skin bacteria.
• Armpit samples exhibited the highest diversity, with ~200 additional compounds compared to other regions.
• A stable core odor profile was identified alongside variable components influenced by environment, cosmetics and exposure.
• Exposure to chlorinated pool water resulted in appearance of chlorinated derivatives of acetophenone and benzaldehyde.
• COVID-19 study (34 positive, 12 negative): canine detection achieved ~100% accuracy but may reflect hospital environment.
• Analytical chemometrics highlighted 7 potential VOC biomarkers for COVID-19, though 12 were attributed to cosmetics and 7 to environmental factors.

Benefits and practical applications

The developed workflow enables reproducible body odor profiling for:

• Non-invasive disease monitoring and early diagnostics
• Quality control in clinical and forensic settings
• Complementary use of canine detection and analytical methods for enhanced specificity

Future trends and applications

• Clinical trials on skin cancer incorporating standardized sampling and environmental controls
• Development of advanced sampling devices for improved reproducibility
• Use of synthetic odor mixtures to calibrate canine detection against defined VOC panels
• Integration of machine learning and chemometrics to refine biomarker selection
• Expanded studies on other pathologies and personalized odoromics

Conclusion

A systematic sampling and GC×GC-TOF/MS workflow was established to characterize body odor VOCs while minimising variability and contamination. The approach revealed key compounds from cosmetics, bacteria and environmental exposure, and identified candidate biomarkers for COVID-19 pending further validation. Combining canine olfaction with analytical chemistry holds promise for non-invasive health monitoring.

Reference

• Hara T, et al. Suppression of Microbial Metabolic Pathways Inhibits the Generation of the Human Body Odor Component Diacetyl by Staphylococcus spp.