Functional characterisation of a SNP in the ABCC11 allele—Effects on axillary skin metabolism, odour generation and associated behaviours
Article InfoFig. 1
Concentrations of axillary malodour precursors in axillary wash samples of subjects with different ABCC11 genotypes. (a) Average HMHA-Gln levels across the different genotype groups. (b) Average 3M2H-Gln levels across the different genotype groups. (c) Average 3M3SH-Cys-Gly levels across the different genotype groups.
Fig. 2
(a) PCA scores plot of the metabolite profiles of the three different genotypes, 
G/G, 
G/A, ■ A/A and 
pooled sample. (b) Corresponding loadings plot from PCA analysis of the three genotypes. (c) PLS-DA scores plot of the metabolite profiles, G/G, G/A and ■ A/A. (d) Corresponding loadings plot from OPLS-DA analysis of the AA, GA and GG genotypes.
Fig. 3
Two-dimensional gas chromatography coupled with time-of-flight mass spectrometry analysis of axillary skin volatile organic compounds sampled on PDMS patches. (a) Frequency of detection of sulfanylalkanols from subjects with different ABCC11 genotypes, 3-mercapto-3-methylhexan-1-ol, ■ 2-methyl-3-mercaptobutan-1-ol, 3-mercapto-2-methyl-pentan-1-ol and 
3-mercapto-hexan-1-ol. (b) Frequency of detection of 3M2H from subjects with different ABCC11 genotypes. (c) Frequency of detection of various short chain fatty acids derived from presumed non-conjugated sources, from subjects with different ABCC11 genotypes, 
butyric acid, 
isovaleric acid, 
valeric acid and 
caproic acid.
Fig. 4
(a) Mean relative abundance of the 9 most predominant bacterial genera observed across all three genotypes. (b) Phylum-level (OTU's) and human subjects were designated as nodes in a bipartite network, in which OTU's are connected to their subjects in which their sequences were found. Squares are samples coloured by genotype, A/A (orange), G/G (purple) and G/A (green). Lines indicate that an OTU was found in a given sample. Diamonds indicate OTU's present in a sample and are coloured by phylum (OTU's are not sized in proportion to their counts). All genotypes cluster centrally and demonstrate little or no differentiation, indicating no major differences in their microbiota. (c) Left hand side, A/A samples and connected OTU's that occurs uniquely in the A/A genotype. Right hand side, G/A, G/G samples and connected OTU's that occur uniquely in G/A and G/G genotypes. Centre, OTU's that occur in both groups/all three genotypes.
Fig. S1
Interpersonal variation in bacterial community composition for the 18 most predominant genera observed across all three genotypes. Interpersonal variation in community composition was observed within and between genotypes, with 73/75 individuals found to be dominated by either Staphylococcus or Corynebacterium. Staphylococcus was the dominant genus for 68%, 88% and 96% of all individuals for AA, GG and GA genotypes, respectively.
Abstract
Background
A single nucleotide polymorphism (SNP), 538G→A, leading to a G180R substitution in the ABCC11 gene results in reduced concentrations of apocrine derived axillary odour precursors.
Objective
Determine the axillary odour levels in the SNP ABCC11 genotype variants and to investigate if other parameters associated with odour production are affected.
Methods
Axillary odour was assessed by subjective quantification and gas chromatography headspace analysis. Metabolite profiles, microbiome diversity and personal hygiene habits were also assessed.
Results
Axillary odour in the A/A homozygotes was significantly lower compared to the G/A and G/G genotypes. However, the perception-based measures still detected appreciable levels of axillary odour in the A/A subjects. Metabolomic analysis highlighted significant differences in axillary skin metabolites between A/A subjects compared to those carrying the G allele. These differences resulted in A/A subjects lacking specific volatile odourants in the axillary headspace, but all genotypes produced odoriferous short chain fatty acids. Microbiomic analysis revealed differences in the relative abundance of key bacterial genera associated with odour generation between the different genotypes. Deodorant usage indicated a high level of self awareness of axillary odour levels with A/A individuals less likely to adopt personal hygiene habits designed to eradicate/mask its presence.
Conclusions
The SNP in the ABCC11 gene results in lower levels of axillary odour in the A/A homozygotes compared to those carrying the G allele, but A/A subjects still produce noticeable amounts of axillary odour. Differences in axillary skin metabolites, bacterial genera and personal hygiene behaviours also appear to be influenced by this SNP.
