“If bacteria in the mouth are thriving and have an increased ability to invade the body, isn’t that terrible? A recent study found that the smoke from smoking “feeds” oral bacteria and promotes the formation of biofilms. Biofilms are complex membranes produced by microorganisms colonizing solid surfaces, which not only make bacteria more resistant to attack by the body’s immune system, but also make them resistant to a variety of antibiotics. In addition, biofilms can also transmit the genetic material of different bacterial groups to interact with each other, making them more capable of spreading and more virulent. Moreover, once biofilms are formed, bacteria are densely arranged and metabolically active. Plaque is the most common biofilm, and plaque-induced gingivitis is more common in the population. The smoke released from tobacco is more complex, and it is known that secondhand smoke alone contains 4,000 chemicals. The study found that smoke from smoking promotes the formation of a variety of bacterial biofilms in the mouth, such as Staphylococcus aureus, Streptococcus pyogenes, Klebsiella pneumoniae, Porphyromonas gingivalis, and Pseudomonas aeruginosa. It is important to know that in addition to increasing the chances of human infection, these bacteria also have “tough moves”. A study published by Gao Shegan and others at the First Affiliated Hospital of Henan University of Science and Technology confirmed that Porphyromonas gingivalis may be a risk factor for esophageal squamous cell carcinoma. A study conducted by scholars in the United States and Japan found that brain hemorrhage is closely related to a type of Streptococcus pyogenes that carries a gene called “CNM” in the oral cavity.