Daily battle against body odor: towards the activity of the axillary microbiota.

The microbial community of the human axilla plays a key role in the formation of axillary odor by biotransformation of odorless natural secretions into volatile odorous molecules. Culture-based microbiological and biochemical studies have allowed the characterization of the axillary microbiota, but the advent of next-generation culture-independent DNA sequencing approaches has provided an unprecedented depth of data regarding the taxonomic composition of the axillary microbiota and intra- and interindividual variation. However, the physiological activity of the microbiota of an individual and its variation under different environmental conditions remains largely unknown. Thus, metatranscriptomics represents a promising technique to identify specific metabolic activities in the axillary microbiota linked to individual differences in body odor.