It seems that gut bacteria play an important but poorly understand role in the development of colorectal cancer. Teasing apart the contributing factors could pave the way to cheaper, better and more effective treatments and maybe help even shed light on how to prevent it entirely.
“Five years ago, four women and two men donated samples of their gut bacteria to science. Three women had healthy guts, but the other donors had colorectal cancer. Researchers implanted the human gut microorganisms into ‘germ-free’ mice, which were delivered by Caesarean section and reared in sterile cages, and so lacked gut microbes of their own.This is a common technique for studying the health effects of the microbiome — the roughly 100-trillion bacteria that inhabit the gut. But the results were unexpected. When the scientists exposed the mice to a chemical mutagen that causes colorectal cancer, mice given microbes from colorectal-cancer patients developed fewer tumours than did mice that had received bacteria from healthy human donors1. “It was a very weird result,” says study leader Patrick Schloss, a microbial ecologist at the University of Michigan in Ann Arbor.”