Bacteria Bonanza: How Many Germs Are In My Mouth?

December 8, 2025

Illustration of green bacteria

Many people assume that their mouths must be healthy if they haven’t noticed any immediate or visible concerns, such as tooth decay or dark, swollen, or bleeding gums. However, just because you don’t see problems doesn’t mean they aren’t developing.

This is because your mouth is full of bacteria, which can sometimes cause oral issues if you don’t take proper preventive measures. Continue reading to learn more about how many bacteria live in your mouth, what they do, and how to avoid common dental concerns!

How Many Bacteria Do Human Mouths Have?

Would you be surprised to learn that human mouths have their own microbiome? Your mouth contains an entire ecosystem made up of billions of bacteria representing over 700 different species, though the average mouth typically contains 100 to 200 types. They can be found in various places throughout your mouth, such as on your teeth, gums, tongue, and the insides of your cheeks and lips.

It’s normal to feel somewhat alarmed to learn there are so many germs living in your mouth, but many of these microbes are beneficial. For example, certain species are responsible for fighting disease, clearing plaque, and aiding with digestion.

What are the Risks of Unhealthy Bacteria?

Although many of the bacteria in your mouth are helpful, others are decidedly more harmful. For example, Streptococcus mutans causes tooth decay, and Porphyromonas gingivalis is known to contribute to periodontal problems.

Under normal circumstances, the various germs in your mouth create a matrix that includes both helpful and disease-causing bacteria. Under normal circumstances, beneficial microbes help keep the others in check, maintaining a healthy mouth. Unfortunately, if the balance shifts and toxic bacteria are allowed to thrive, you could develop cavities, gum disease, or other concerns.

How Can I Prevent Oral Issues Caused by Bacteria?

If you’re worried that the unhealthy germs in your mouth will inevitably overpower the ‘good’ ones, you can set your concerns aside. Thankfully, there are several things you can do to proactively protect your teeth and gums, including:

  • Implementing an at-home dental hygiene routine. Brushing and flossing twice daily helps remove plaque and bacteria to prevent cavities and periodontal disease.
  • Eating wholesome foods. Minimizing consumption of sugary or acidic foods and eating healthier options can support your oral and overall well-being.
  • Scheduling routine dental checkups. Having a standard exam and cleaning every six months allows your dentist to catch and treat any areas of concern before they can progress.

If you suspect that you might have developed a dental problem, contacting your provider can give you some much-needed peace of mind regarding the condition of your smile!

Meet the Author

Dr. Britta Lundgren is passionate about helping people improve their quality of life by enhancing their oral health. She earned her dental degree from the prestigious Tufts University School of Dental Medicine, and has since completed continuing educational courses in a variety of topics to offer the most contemporary services. Her caring approach is combined with advanced technology to help you feel comfortable while she delivers accurate treatment results tailored to meet your unique needs. You can request an appointment on the website or call (910) 777-5023.