Can a small oral flora actually cause colorectal cancer?

The mouth is the first to come into contact with food and is the front line of communication between the human body and the outside world.

Here, there are nearly 700 species of microorganisms, which constitute the second largest flora in the human body after the intestinal flora.

Every day, a lot of bacteria from the mouth flow down with swallowing, break through the interception of gastric acid, successfully reach the intestines, and affect intestinal health.

Colorectal cancer is a common intestinal cancer and is closely related to intestinal flora. In my country alone, an average of more than 1,000 people are diagnosed with colorectal cancer and more than 500 people die from colorectal cancer every day.

So what is the relationship between oral bacteria and colorectal cancer?

Recently, an important study from the Affiliated Stomatological Hospital of Sun Yat-sen University found that Porphyromonas gingivalis, a pathogen that causes oral periodontitis, not only causes swollen gums, is also closely related to systemic diseases including cardiovascular, diabetes and Alzheimer's disease.

When this bacterium moves down from the mouth and colonizes in the colorectal tissue, it can recruit myeloid immune cells and activate the inflammasome NLRP3, thereby promoting the occurrence and development of colorectal cancer.

Animal experiments have shown that when mice are treated with Porphyromonas gingivalis, the experimental group has more and larger tumors than the control group. In the intestine, Porphyromonas gingivalis creates a pro-inflammatory tumor microenvironment for colorectal cells that is rich in myeloid cells.

The human body is a unified whole, and a small oral bacterium may have a great impact on the health of the whole body.

The human microbiome is a whole, and only by looking at it comprehensively can we respect objective laws.

After reading this article, will you brush your teeth better and pay more attention to the health of your oral flora?

Wang X, Jia Y, Wen L, et al. Porphyromonas gingivalis Promotes Colorectal Carcinoma by Activating the Hematopoietic NLRP3 Inflammasome. Cancer Res. 2021;81(10):2745-2759.

doi:10.1158/0008-5472.CAN-20-3827