Intestinal microbes associated with a fatty diet contribute to the growth of the tumor!

Scientists know that there is a connection between obesity and some types of cancer. Research on mice and humans suggests why this may be the case.

Researchers have found a link between diet, type of intestinal bacteria and breast cancer. A study published on May 6 in the journal Proceedings of the National Academy of Science1 showed that a high-fat diet increases the number of bacteria in the intestines of mice, suppressing their immune system and accelerating the growth of tumors.

Researchers say that this discovery may be an impetus for new ideas in the treatment of breast cancer, the most common malignant neoplasm affecting women around the world.

Ervey Song, a breast cancer surgeon at Sunyat Sena Memorial Hospital in Guangzhou, China, and his colleagues studied the intestinal bacteria of people with breast cancer after collecting data showing that people with a high body mass index have a lower chance of survival.

"A high-fat diet can contribute to the progression of tumors or cause their recurrence," Song notes.

The researchers took tissue and fecal samples from 61 people with breast cancer at Sunyat Sena Memorial Hospital before the participants began treatment.

Then the researchers turned to mice to further study this connection. Mice fed high-fat foods often serve as an indicator of obesity in humans in animal studies. The team found that mice consuming a high-fat diet had more bacteria and increased levels of cells that suppress the immune system - myeloid suppressor cells (MDSC) that occur in the bone marrow. This allowed the researchers to assume that more Desulfovibrio bacteria and a suppressed immune system were related; they just needed to figure out how to do it.