Scientists at the APC Microbiome Institute at University College Cork (UCC) who investigated whether gut bacteria influence the area of the brain that governs our higher cognitive functions (prefrontal cortex) found, to their surprise, that it does.
Specifically, the scientists found that gut microbiome (bacteria, fungi, viruses that live in the gut) have a potential role in regulating myelination in the brain. Myelin is the insulation around nerve cells that allows appropriate and efficient communications between the nerve cells and is essential for the proper functioning of the nervous system.
Lead scientist Professor John Cryan said understanding the mechanisms regulating myelination is important for developing strategies for disorders such as Multiple Sclerosis, which is characterised by a loss of myelin. Germ-free mice reared in a sterile environment were used in the research. When scientists examined their prefrontal cortex, they found a lot of the genes that had changed were involved in the myelination process.
“Myelination is a very important process during early development and during adolescence and it keeps the brain healthy,” Prof Cryan said.
Further study of the gene changes indicated the processes underlying myelination were under the control of gut bacteria.
As part of the research, some of the mice used were exposed to bacteria for the first time, and the scientists were able to reverse many of the gene changes observed in the mice who had remained germ-free.
“Our finding, which is a first, reinforces how important having bacteria in the gut is for normal brain processes,” Prof Cryan said.
“It also shows that gut bacteria probably has implications for neurodevelopmental disorders and it means perhaps in the future, we can target the myelination process through targeting gut microbiomes.”
This could potentially be done through use of probiotics, antibiotics and prebiotics, Prof Cryan said.
“Anything that will change the microbiota in the gut now has the potential to change the myelination process,” he said. “That’s why we are excited about it — it’s kind of a paradigm shift in understanding fundamental brain processes.” The research is being published in the journal Translational Psychiatry.