title: Foot odor due to microbial metabolism and its control.
abstract: To characterize foot odor, we analyzed its components by sensory tests, isolated microorganisms that produce it, and evaluated the mechanism of the occurrence of foot odor. As a result, foot odor was found to be derived from isovaleric acid, which is produced when Staphylococcus epidermidis, a resident species of the normal cutaneous microbial flora, degrades leucine present in sweat. In addition, Bacillus subtilis was detected in the plantar skin of subjects with strong foot odor, and this species was shown to be closely associated with increased foot odor. Therefore, we screened various naturally occurring substances and fragrant agents that inhibit microbial production of foot odor without disturbing the normal microbial flora of the human skin. As a result, we identified citral, citronellal, and geraniol as fragrant agents that inhibit the generation of isovaleric acid at low concentrations.
authors.affiliation: Biological Science Laboratories, Kao Co., Ltd., Tochigi 321-3497, Japan. ara.katsutoshi@kao.co.jp
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Ara
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Hama
authors.forename: Syunichi
authors.initials: S
authors.lastname: Akiba
authors.forename: Kenzo
authors.initials: K
authors.lastname: Koike
authors.forename: Koichi
authors.initials: K
authors.lastname: Okisaka
authors.forename: Toyoki
authors.initials: T
authors.lastname: Hagura
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Kamiya
authors.forename: Fusao
authors.initials: F
authors.lastname: Tomita
mesh_terms: D000080462:Acyclic Monoterpenes; D000328:Adult; D000447:Aldehydes / Q000494:pharmacology; D000596:Amino Acids / Q000032:analysis; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015169:Colony Count, Microbial; D004305:Dose-Response Relationship, Drug; D005260:Female; D005528:Foot / Q000382:microbiology*; D006801:Humans; D050803:Leucine Dehydrogenase / Q000037:antagonists & inhibitors / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects; D008055:Lipids / Q000032:analysis; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D039821:Monoterpenes / Q000494:pharmacology; D009812:Odorants; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D012867:Skin / Q000382:microbiology; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D013546:Sweating / Q000502:physiology
chemical_list: D000080462:Acyclic Monoterpenes; D000447:Aldehydes; D000596:Amino Acids; D000900:Anti-Bacterial Agents; D008055:Lipids; D039821:Monoterpenes; D010936:Plant Extracts; D050803:Leucine Dehydrogenase; C108217:citronellal; C007076:citral