At present, there is no evidence of the existence of the pathogenic microorganism “Smiling Pathogen”. According to the results of a search of Chinese and international authoritative databases (Pubmed, Zhi.com, Wanfang, etc.), there are no entries for the term “Smiling Bacteria”. There is no scientific evidence for the existence of the term “Smiling Bacteria”, which is only a random name on the Internet. In addition, there may be pathogenic microbial infections caused by facial muscle spasm, cognitive disorders and “smile” as a clinical symptom, for example, some viral infections can cause facial muscle spasm; prion infection affects the function of the central nervous system, so that the patient produces “demented smile” symptoms. Warm tips: medicine is constantly advancing, with the passage of time, may deepen the knowledge of the disease, perhaps in the future will find more new pathogenic microorganisms.