The immune globulin A contained in saliva originally played an antibacterial effect. Researchers at Loughborough University in the UK found that the amount of this protein in saliva was inversely related to human immunity. They spent more than three years on 38 Racers who participated in America's Cup sailing plugs were tested and observed that about two-quarters of the racers had a sharp drop in the level of immunoglobulin A in their saliva, although they felt good at the time, two weeks before the cold. The significance of this study of saliva by British researchers is that. ['Revealed that by detecting the amount of immunoglobulin A. contained in saliva, people can judge their immune status and take timely measures to prevent disease infestation.', 'It is clear that the higher the amount of immunoglobulin A in saliva, the stronger the body is immune, because immunoglobulin A. plays a role.', 'The incubation period for dry flu was found to be two weeks, during which the level of immune globulin A in saliva has dropped sharply, and two people will not feel the decline in immunity.', "Subverts people's understanding of the antibacterial effects of immunoglobulin A contained in saliva."]