1/26/2016 Relationships between the Normal If the balance between the normal microbiota and pathogens is disturbed.disease can occur Microbiota and the Host An example,Clostridium difficile infection,a mild diarrhea Microbial antagonism (competitive to severe to fatal inflammation of the colon.Responsible for exclusion)is a competition between most gastrointestinal infections after antibiotic therapy microbes Normal microbiota protect the host by: -Competing for nutrients -Producing substances harmful to invading microbes -Fecal transplants 。。 -Affecting pH and available oxyger Pills containing fecal bacteric When the balance between the normal mic robiota and pathogens is disturbed,disease can occur.1/26/2016 4 Relationships between the Normal Microbiota and the Host • Microbial antagonism (competitive exclusion) is a competition between mi b s cro e • Normal microbiota protect the host by: – Competing for nutrients – Producing substances harmful to invading microbes – Affecting pH and available oxygen • When the balance between the normal microbiota and pathogens is disturbed, disease can occur. If the balance between the normal microbiota and pathogens is disturbed, disease can occur. • An example, Clostridium difficile infection, a mild diarrhea to severe to fatal inflammation of the colon. Responsible for most gastrointestinal infections after antibiotic therapy -F p ecal transplants - Pills containing fecal bacteria