There's a party going on in your mouth, to which you might not have been invited. The human mouth can be home to more than 700 species of bacteria, some of which might be more harmful than others. While many types of bacteria will help break down food and actually protect your teeth, some, such as Streptococcus mutans, play a part in tooth decay, and others, such as Porphyromonas gingivalis, can lead to gum disease. If you've ever dealt with bad breath, you can blame bacteria for that, too.
Luckily, figuring out how to kill mouth bacteria isn't that tricky. It comes down to developing a great at-home oral care routine and doing what you can to minimize the presence of the bad bacteria.