After analysing 4,000 plus genomes of bacterial strains of E. coli, the common bacteria found in the lower intestine, researchers said the genotoxic strains of the bacteria is a huge risk factor in colorectal cancer.
Researchers say good hygiene and sanitation habits could keep the E. coli populations at bay.
Colorectal cancer affects the colon and the rectum at the digestive tract’s lower end. It is commonly known as bowel cancer, colon cancer or rectal cancer.
The MNJ Institute of Oncology Regional Cancer Centre and several other institutes received double the number of colon cancer cases in 2020, compared to previous years.
Doctors said unhealthy food habits, more consumption of animal fat and untimely eating can trigger colon cancer.
Niyaz Ahmed, department of biotechnology and bioinformatics, school of life sciences, UoH, said the study would help understand bacterial toxins that are associated with colorectal cancer.
Researchers said that while they know that bacterial toxins result in cancer progression, the study was to find out the proportion, risk, transmission and possible prevention of such bacteria.
“The idea was to determine the exact nature of the risk. How they are carried, where are they acquired in the body, probability of acquisition and domination of such bacteria and their evolution, etc,” said Prof Ahmed.
Bacterial strains of E. coli that produces colibactin, a toxin that breaks the DNA leading to cancer, was studied by the team of researchers.
“We found that such genotoxic strains occur at about 12% among all the E. coli populations world over and up to 7% in India,” he said.
The findings of the study were published in the March 2, 2021, issue of an international journal, mBio published by the American Society for Microbiology.
“Colibactin encoded by the family of E. coli has a character that causes a chemical change in the DNA. The DNA codes are modified by this bacterial protein and some of them get selected for cancer,” added Prof Ahmed.
According to an estimate, there are close to 14 trillion different bacterial cells of about 2,000 different species types in a human gut.