Are most bacteria beneficial pathogenic or anaerobic?

Most bacteria are beneficial. In fact, only about 1% of all bacteria are pathogenic, or disease-causing. The vast majority of bacteria are actually beneficial, playing important roles in the environment and in our bodies. For example, bacteria help to decompose organic matter, recycle nutrients, and produce oxygen. They also help us to digest food, fight off infections, and produce vitamins. Anaerobic bacteria are those that do not require oxygen to survive. Some anaerobic bacteria are beneficial, such as those that help us to digest food, while others are pathogenic, such as those that cause tetanus and botulism.