The present invention relates to vesicles derived from bacteria of the genus Propionibacterium and a use thereof. It was experimentally confirmed that the production of vesicles derived from bacteria of the genus Propionibacterium was increased in the body by a high-fat diet rather than a high-carbohydrate diet； the vesicles were significantly reduced in the blood of patients with cancers, such as breast cancer and liver cancer, inflammation diseases, such as asthma and atopic dermatitis, and metabolic diseases, such as diabetes and liver cirrhosis, compared with normal persons； and the vesicles inhibited the secretion of inflammatory mediators by pathogenic vesicles, inhibited the apoptosis of keratinocytes, and increased the expression of an androgen receptor in the body. The vesicles derived from bacteria of the genus Propionibacterium according to the present invention are expected to be advantageously used in a method for diagnosis or prediction of cancers, inflammatory diseases, endocrine diseases, or metabolic diseases, a pharmaceutical composition, a food, a cosmetic product, and the like.
