Oral Microbiome
Oral Microbiome is the full group of tiny living things, like germs, that live in your mouth.
Your mouth is like a kitchen counter with many small bowls, each holding a different type of tiny germ. Some bowls hold helpful germs that break down food and keep bad germs in check. Other bowls hold less helpful germs that can cause problems if they grow too large. The balance between all these bowls is what keeps your mouth healthy.
Explaining oral microbiome by grade level
Your mouth has tiny living things in it. You can not see them, but they are there. Some help keep your mouth clean. When you brush your teeth, you wash many of them away, but new ones grow back.
Projects that explore oral microbiome
Your mouth holds a whole community of tiny living things — and so does a dog's. When you swab both mouths and grow what you collect on agar, you can compare the two communities side by side. The results show whether the old claim about clean dog mouths actually holds up.
Mouthwash fights the tiny living things in your mouth, but not all formulas work equally well. Four mouthwashes with different active ingredients go head to head in this test. You swab the back of someone's tongue, count what grows on a petri dish, and compare results across formulas.
Alpha streptococcus is one of the most common bacteria found in the mouth. Mouthwash targets these germs, but different brands use different ingredients — and that matters. You isolate alpha streptococcus from a mouth swab, grow it on Mueller Hinton plates, and apply measured doses of each mouthwash. After overnight incubation, you measure the death zone, the clear ring where bacteria could not survive. The larger the death zone, the more effective that formula is at killing this part of the mouth's bacterial community.
Germs cling to your teeth, and brushing with toothpaste removes some of them. To measure how much, you swab your teeth before and after brushing and spread each sample on an agar dish. Over four days you repeat the process with a different brand each day. After five days of growth, you measure the diameter of each bacteria colony. Every brand reduces bacteria compared to the before-brushing sample — but the results show which one leaves the smallest colony behind.
The tiny living things in your mouth move onto objects you use every day. When you brush your teeth, bacteria collect on the bristles. How you store the brush afterward affects the microbiome that transfers. You can test this by preparing three toothbrushes with different five-day routines. One uses water only, one uses toothpaste, and one is stored in Listerine after brushing. After five days, swab each brush onto an agar dish and measure the bacteria colonies. The brush stored in Listerine grows far less bacteria than the others.