Method of inhibiting harmful microorganisms and barrier-forming composition therefor

A method for prevention of infectious disease in a host, the method comprising:

• administering a therapeutically effective amount of a barrier-forming composition to a mucosa of the host for at least about consecutive two days and at least three times daily;
• the composition comprising:
• about 0.01%≦C≦about 0.4%;
• about 7%≦H≦about 65%;
• and
• 0.050%<A;
• wherein all percentages are by weight of the total composition;
• wherein C is a carbohydrate gum;
• H is a humectant;
• and A is an antimicrobial agent;
• wherein the infectious disease is caused by microorganisms selected from the group consisting of:
• Candida, pneumonia, MRSA, Streptococcus, Streptococcus, Porphyromonas Gingivalis, Acinetobacter baumannii, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Yersinia enterocolitica, microorganisms that cause upper respiratory infections, Epstein-Barr virus, cold viruses, and influenza viruses.