Abstract: The present invention relates to a method of prognosis and/or diagnosis of a pellicular condition of the scalp, based on the measurement of the quantity of the active form of transglutaminase 3. The present invention also relates to a cosmetic treatment method for the scalp, a method for identifying compounds for reducing and/or eliminating the pellicular condition. Finally, the present invention relates to a kit and the use thereof for identifying a compound for reducing and/or eliminating the pellicular condition.

Abstract: The present invention relates to a method for diagnosing esthetic degradations of skin, in particular linked to pollution, in a subject, comprising a step (a) of determining, in a skin sample of the subject, the level of at least one marker chosen from the group constituted of (i) bacteria of the species Propionibacterim acnes, bacteria of the family Micrococcaceae, bacteria of the genus Brachybacterium, bacteria of the genus Brevibacterium, bacteria of the order Burkholderiales, bacteria of the genus Parococcus, bacteria of the family Rhodobacteraceae and bacteria of the genus Fusobacterium, and (ii) metabolites of these bacteria chosen from 3-hydroxy-3-methylglutarate, 3-methylglutarate/2-methylglutarate, 4-guanidinobutanoate, 4-imidazoleacetate, 5-oxoproline, aconitrate, adipate, alanine, alpha-cetoglutarate, arabonate/xylonate, azelate, beta-citrylglutamate, choline, cis-urocanate, citraconate/glutaconate, fructose, fumarate, gamma-glutamylalanine, gamma-glutamylglutamine, gamma-glutamylglycine, gamma-glu