Oral bacteria are microorganisms that naturally inhabit the mouth. They play a crucial role in maintaining oral health by helping to break down food particles and prevent the growth of harmful pathogens. However, an imbalance in these bacteria can lead to dental issues such as cavities and gum disease. The most common types of oral bacteria include Streptococcus mutans, which is primarily responsible for tooth decay, and Porphyromonas gingivalis, associated with gum disease. Good oral hygiene practices, such as regular brushing and flossing, help manage these bacteria and promote a healthy mouth.