Our intestines harbour trillions of bacteria which are living in harmony with our body. These bacteria form part of a huge ecological community in our digestive tract known as the gut microbiota. Many of the colonies are commensal in nature and some even help to produce vitamin K which is essential to the body. Overall, we need these bacteria to maintain normal gut digestive and absorption functions.
Probiotics belong to the group of bacteria we classified as "non-pathogenic" and they can help our microbiota in maintaining gut health in many situations. These include the following conditions:
- acute diarrhoea
- patients with inflammatory bowel disease (IBD)
- possibly patients suffering from chronic liver disease.
It is believed that a healthy gut micrbiota can help to limit the growth of gut pathogens through competition and through inducing healthy defence put up by the intestinal cells. This phenomenon is known as colonisation resistance. A healthy gut microbiota is also believed to be important in conditioning and regulating our body immune system.
There is data to suggest that the risk of colorectal cancer goes up with active inflammation in the colon. Some strains of bacteria are believed to induce more inflammation than others. By maintaining a balance of good gut bacteria through proper diet, and perhaps the use of probiotics in the right situations, we hope to lower the risk of colorectal cancer in the long run.