The present invention relates to a vesicle derived from Proteus genus bacteria, and a use thereof. The inventors experimentally confirmed that, compared to normal people, the vesicle is significantly reduced in samples from cancer patients suffering from stomach cancer, colorectal cancer, liver cancer, biliary duct cancer, pancreatic cancer, lung cancer, breast cancer, or ovarian cancer and the like, and patients with allergic respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), or atopic dermatitis and the like, cardiovascular diseases such as myocardial infarction, cardiomyopathy, variant angina pectoris, or atrial fibrillation and the like, metabolic diseases such as diabetes and the like and neuropsychiatric diseases such as Parkinson's disease or depression and the like, and the vesicle inhibits the secretion of inflammatory mediators by pathogenic vesicles, while also exhibiting an anticancer effect. It is anticipated that the vesicle derived from Proteus genus bacteria can be usefully utilized to develop diagnostic methods and compositions for preventing, treating, and/or improving cancer, cardiovascular diseases, metabolic diseases, neuropsychiatric diseases, allergic respiratory diseases, and inflammatory intestinal diseases.
