Georgia State University researchers found out that colon cancer inhibition can happen if a person is exposed to microbiota in the early stages of life.
Dr. Tim Denning, the lead researcher, showed that development of cancer associated with colitis is related to microbiota exposure in utero and in the weeks after birth. Literature about the effects of prenatal and early prenatal microbiotic exposure on disease and health outcomes have been limited. The team published their findings in the journal Cancer Immunology Research.
"Our conclusions are that early-life microbiota is instrumental in regulating proper immune responses that are effective at limiting the development of colon cancer in mice," said Dr. Tim Denning, professor in the Institute for Biomedical Sciences at Georgia State. "When you have altered microbiota early in life or the absence of microbiota in early life, in this case, that may predispose you to the development of colon cancer and perhaps other cancers.
"It's been appreciated for quite some time that the microbiota can play an important role in the development of cancer and other diseases. However, the majority of these studies have been in adults. Our findings show that a key timing of exposure to the microbiota and microbiota metabolites may actually be very early in life. We think this makes sense because during development, whether it's in utero or early postnatal, there are so many changes going on that the contribution of the microbiota can be very impactful. That is the novelty of this finding," according to Denning in his statement with Medical Express.
A stable immune system and normal body function result from the presence of gut microorganisms. However, adult mice and humans have been studied instead of in utero or in newborns as the latter is difficult to perform. Microbiota exposure occurs when humans and mice are delivered through Caesarean section or through the birth canal. Development of the fetus is influenced by the metabolites produced by microbiota in mothers. The aim of their study was to investigate whether disease in adulthood can be influenced by early-period microbiota.
Two groups of mice were compared. Mice of the first group were born to mothers who are free from germs and raised in conditions with no germs until weaning. These mice were exposed to normal conditions and normal microbiota. The second group had mice who were born to normal mothers and were raised under regular conditions with microbiota. There was an induced colon cancer of all of the mice at six weeks old.
"We found remarkable differences," Denning said. "The ex-germ-free mice had much larger and many more tumors in the colon."
It was found out that an accumulation of immune cells and an enhanced pro-inflammatory gene expression resulted from the absence of microorganisms in early life. These accumulated immune cells called myeloid-derived suppressor cells limited other immune cells in killing tumors.
