The bacterial kingdom contains an incredibly wide range of creatures that vary in size, shape, habitat, and metabolism despite having much smaller and simpler cells than eukaryotic cells. Studies of disease-causing bacteria have contributed significantly to our understanding of bacteria because they are easier to isolate in pure culture and study than many types of free-living bacteria. It should be emphasized that many free-living bacteria differ significantly from those that have evolved to exist as parasites or symbionts on animals. As a result, there are many exceptions to any generalization regarding the composition or structure of bacteria. In the current book, we have explored few Prevotella bacterial species with respect to its microbial characteristics.