The New Application of the Gut Microbiota for the Early Diagnosis of Colorectal Cancer

Post date:2019.07.19

Our intestinal tract is inhabited by trillions of bacteria, with a total weight of between 1 kg and 1.5kg. Most of them are good bacteria that play a vital role in our health. These microorganisms, referred to as “gut flora” and also known as “microbiome”, perform essential functions in our digestive system. They are from 100 to 300 species, but most of them are anaerobic bacteria.

Gut flora assist in proper digestion and absorption. They help in the synthesis of vitamins, and control the growth of intestinal harmful bacteria. They also promote immunostimulation and protect our bodies from pathogenic microorganisms. Disrupted gut flora causes constipation, diarrhea and a number of lifestyle diseases which may lead to complications.

To avoid these illnesses, there is a need to take care of our gut health and maintain the right balance of microorganisms in our digestive system. The growth of harmful bacteria such as the Welsh bacteria should be controlled, while good bacteria such as Bifibacterium and Lactic acid bacteria should be increased.

A protein-based diet, an irregular life, various stress, and constipation are known to induce the increase of negative bacteria. On the other hand, probiotics prevent the increase of negative bacteria and promote intestinal movement by acidifying the intestinal tract through the production of lactic acid and acetic acid. They also produce some vitamins, enhance our body’s immunity, and reduce cholesterol concentration in our blood.

To boost the good bacteria in our digestive tract, it is recommended that we have a daily intake of food rich in probiotics, such as yogurt, probiotic drink and Natto. Including dietary fiber in our diet also helps to activate them.

Recently, it was discovered that the intestine associates with the brain through the autonomic nervous system. This process is called gut-brain interaction or gut-brain axis, in which the intestine transmits information to the brain through the nervous system. When there is abdominal discomfort, depression and anxiety are triggered. Such changes of emotions transmit to the gut, leading to intestinal dyskinesia.

Lately, the relevance between the central nerve and gut flora became the subject of a new study.  A group of researchers from Osaka University released a study on the connection between gut microbiota and colorectal cancer.

According to the report published in Nature Medicine, fecal samples from 616 patients who underwent colonoscopy showed specific changes in their gut microbiota between the different stages of the disease.
http://www.med.osaka-u.ac.jp/eng/activities/results/2019year/yachida201906

This may lead to the discovery of new methods in the early detection of colorectal cancer. It will also help in determining why specific bacteria increase and why intestinal metabolites change as the cancer progresses.

To examine in detail the relevance between gut microbiota and eating habits also has potential for new prevention and treatment.