title: Spatial variations in the microbial community structure and diversity of the human foot is associated with the production of odorous volatiles.
abstract: The human foot provides an ideal environment for the colonization and growth of bacteria and subsequently is a body site associated with the liberation of odour. This study aimed to enumerate and spatially map bacterial populations' resident across the foot to understand any association with odour production. Culture-based analysis confirmed that Staphylococci were present in higher numbers than aerobic corynebacteria and Gram-positive aerobic cocci, with all species being present at much higher levels on the plantar sites compared to dorsal sites. Microbiomic analysis supported these findings demonstrating that Staphylococcus spp. were dominant across different foot sites and comprised almost the entire bacterial population on the plantar surface. The levels of volatile fatty acids, including the key foot odour compound isovaleric acid, that contribute to foot odour were significantly increased at the plantar skin site compared to the dorsal surface. The fact that isovaleric acid was not detected on the dorsal surface but was present on the plantar surface is probably attributable to the high numbers of Staphylococcus spp. residing at this site. Variations in the spatial distribution of these microbes appear to be responsible for the localized production of odour across the foot.
authors.affiliation: Unilever R&D, Quarry Road East, Port Sunlight, Bebington, Wirral, CH63 3JW, UK.
authors.forename: Deborah
authors.initials: D
authors.lastname: Stevens
authors.affiliation: Unilever R&D, Quarry Road East, Port Sunlight, Bebington, Wirral, CH63 3JW, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: Cornmell
authors.affiliation: Unilever R&D, Quarry Road East, Port Sunlight, Bebington, Wirral, CH63 3JW, UK.
authors.forename: David
authors.initials: D
authors.lastname: Taylor
authors.affiliation: Unilever R&D, Quarry Road East, Port Sunlight, Bebington, Wirral, CH63 3JW, UK.
authors.forename: Sally G
authors.initials: SG
authors.lastname: Grimshaw
authors.affiliation: Unilever R&D, Quarry Road East, Port Sunlight, Bebington, Wirral, CH63 3JW, UK.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Riazanskaia
authors.affiliation: Unilever R&D, Quarry Road East, Port Sunlight, Bebington, Wirral, CH63 3JW, UK.
authors.forename: David S
authors.initials: DS
authors.lastname: Arnold
authors.affiliation: Unilever R&D, Quarry Road East, Port Sunlight, Bebington, Wirral, CH63 3JW, UK.
authors.forename: Sara Johansson
authors.initials: SJ
authors.lastname: Fernstad
authors.affiliation: Unilever R&D, Colworth Science Park, Sharnbrook, Bedfordshire, MK44 1LQ, UK.
authors.forename: Adrian M
authors.initials: AM
authors.lastname: Smith
authors.affiliation: School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, Leics, LE11 3TU, UK.
authors.forename: Liam M
authors.initials: LM
authors.lastname: Heaney
authors.affiliation: Centre for Analytical Science, Department of Chemistry, Loughborough University, Loughborough, Leics LE11 3TU, UK.
authors.forename: James C
authors.initials: JC
authors.lastname: Reynolds
authors.affiliation: Centre for Analytical Science, Department of Chemistry, Loughborough University, Loughborough, Leics LE11 3TU, UK.
authors.forename: C L Paul
authors.initials: CL
authors.lastname: Thomas
authors.affiliation: Unilever R&D, Quarry Road East, Port Sunlight, Bebington, Wirral, CH63 3JW, UK mark.harker@unilever.com.
authors.forename: Mark
authors.initials: M
authors.lastname: Harker
mesh_terms: D003352:Corynebacterium; D005232:Fatty Acids, Volatile / Q000096:biosynthesis*; D005528:Foot / Q000382:microbiology*; D045782:Hemiterpenes; D006801:Humans; D009812:Odorants; D010421:Pentanoic Acids; D012867:Skin / Q000382:microbiology*; D013210:Staphylococcus / Q000378:metabolism
chemical_list: D005232:Fatty Acids, Volatile; D045782:Hemiterpenes; D010421:Pentanoic Acids; C008216:isovaleric acid
keywords: GC/MS; isovaleric acid; microbiomics; odour