Components of Gastrointestinal Tract • Mouth, Esophagus, Stomach, Small Intestine, Large Intestine and Rectum And Anus. Dental Carries, Gingivitis, And Periodontal Disease. Signs and symptoms ? Caries, appears as holes or pits in the teeth. ? Periodontal disease: gums that are swollen, tender, bright red, or bleeding Pathogen, Virulence Factors, And Pathogenesis ? Streptococcus mutans is a frequent cause of caries. Dextran and fimbriae allow biofilm formation on teeth. ? Porphyromonas gingivalis causes periodontal disease. Proteases break down gingival tissue.