Microbial Diseases of the Digestive System

1. Microbial Diseases of the Digestive System

2. Digestive System

3. Digestive System Gastrointestinal tract – mouth, pharynx, esophagus, stomach, small and large intestine Accessory structures – teeth, tongue, salivary glands, liver, gallbladder, pancreas

4. Bacterial Population of the GI Tract Mouth – large microbial population Stomach – relatively small due to high acid content Small intestine – small population Large intestine – VERY large. 100 billion bacteria per gram of feces

5. Bacterial Diseases of the Mouth Dental caries (tooth decay) So many bacteria in the mouth that it is difficult to say which bacteria is the most common cause of decay Streptococcus mutans is one of the more important cariogenic bacteria

6. Development of caries Bacteria accumulate on the teeth, this is called PLAQUE The bacteria in the plaque break down sucrose in our diet to produce glucose and fructose Glucose is converted to dextran, the fructose is metabolized and produces acids that attack the enamel of the tooth Over time the enamel can be destroyed and the softer tissue inside the tooth is attacked by bacteria causing decay which can lead to tooth loss!

7. Decay Prevention Removal of the plaque – visit the dentist and dental hygienist Regular brushing and flossing to remove and reduce the bacterial population of the teeth Consume less sucrose If you ignore decay it can lead to tooth loss, gum disease, periodontal disease, and visits to the dentist that you would rather avoid!

8. Dental caries!