Consuming high amounts of saturated fat may increase the risk of developing colorectal cancer by modifying the gut microflora, the researchers say in the journal Nature.
Scientists from the Institute of Molecular Immunology of the Technical University in Munich used mice with a genetic predisposition to develop this tumor (with a mutation in the K-RAS gene) in their research. Some of the rodents were fed high-fat foods, while others were fed normal chow. From time to time, researchers compared the bacterial composition in samples of mouse faeces.
It turned out that the change to a high-fat diet went hand in hand with the change in the composition of the bacterial flora in the intestines. As a result, these rodents had fewer immune barriers to cancer and became ill more often. After the antibiotic was applied and some mice were eliminated all the gut flora, it was observed that the cancer incidence was reduced.
The researchers then transplanted a sample of the bacterial microflora from the intestines of tumor bearing mice into healthy mice (with a genetic predisposition to develop cancer). In this group, a significantly higher incidence was then observed than in mice from the control group (with predisposition, but without bacterial transplantation).
These studies suggest that a high-fat diet plays a greater role in the development of colorectal cancer than obesity. In order to reduce the risk, apart from changing the diet, it would also be necessary to consider methods to restore the proper bacterial flora in the intestines, emphasize the authors of the study. (PAP)