A new discovery has revealed that gut microbes play a key role in the formation of new nerve cells in the adult brain.
The international investigating team spanning Singapore, UK, Australia, Canada, US, and Sweden has discovered that the billions of microbes living in the gut could play a key role in supporting the formation of new nerve cells, with the potential to possibly prevent memory loss in old age and help to repair and renew nerve cells after injury. They found that gut microbes that metabolise an essential amino acid called tryptophan secrete small molecules called indoles, which stimulate the development of new brain cells in adults.
The study was led by Principal Investigator Professor Sven Pettersson, National Neuroscience Institute of Singapore, and Visiting Professor at Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore (NTU Singapore), and Sunway University, Malaysia.
Neurons in the hippocampus
In the study, published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS), Professor Pettersson and his team demonstrated that the indole-mediated signals elicit key regulatory factors known to be important for the formation of new adult neurons in the hippocampus – an area of the brain also associated with memory and learning.
Pettersson said: “This finding is exciting because it provides a mechanistic explanation of how gut-brain communication is translated into brain cell renewal, through gut microbe produced molecules stimulating the formation of new nerve cells in the adult brain.
“These findings bring us closer to the possibility of novel treatment options to slow down memory loss, which is a common problem with ageing and neurodegenerative diseases including but not limited to Alzheimer’s disease. These include drugs to mimic the action of indoles to stimulate the production of new neurons in the hippocampus or to replace neurons damaged by stroke and spinal injury, as well as designing dietary intervention using food products enriched with indoles as a preventive measure to slow down ageing.
“The work reported in this paper addresses the formation of neurons in the adult brain. We are currently assessing whether indoles can also stimulate early formation of neurons during brain development. Another area of potential intervention interest is in situations of stroke or spinal injury where there is an urgent need to generate new neurons. It is an interesting and exciting time ahead of us.”
Study co-author, Professor Paul Matthews, Centre Director at UK Dementia Research Institute at Imperial College London, Edmond and Lily Safra Chair, NIHR Senior Investigator, and Head of the Department of Brain Sciences, said: “There is increasing interest in our microbiomes and the connection between gut and brain health. This study is another intriguing piece of the puzzle highlighting the importance of lifestyle factors and diet. Importantly, it also points to new much-needed treatment opportunities for the diseases that cause dementia – now the leading cause of death in the UK.”
