Study Gives New Meaning to ‘Gut Feeling’
18th September 2017
By Elliot Miller
New research published in the journal Microbiome, has found that gut bacteria may have an impact on brain development and anxiety-like behaviour. Whilst previous research has revealed a link between the gut microbiome – all of our microbes’ genes – and anxiety, the study is the first to show a link between gut bacteria and microRNAs (small biological molecules that regulate gene expression) in the brain.
Researchers at the APC Microbiome Institute at University College Cork, used next-generation sequencing (NGS) to compare miRNA levels in the amygdala and prefrontal cortex – areas of the brain associated with anxiety and depression – of mice grown in a germ-free environment (GF mice) with control mice.
They found different levels of 103 miRNAs in the amygdala and 31 miRNAs in the prefrontal cortex of GF mice compared to control mice with a normal gut microbiome. Furthermore, adding back gut microbes into the GF mice in later life normalised some of the changes to miRNAs. The findings suggest that a healthy microbiome is important for appropriate regulation of miRNAs in these brain regions.
The researchers also found adult rats whose gut microbiota – the community of microorganisms living in the intestine – had been depleted using antibiotics, affected brain miRNA levels in a similar way to GF mice. This suggests that although a healthy gut microbiota may be present in early development, certain changes in adulthood can impact miRNAs in brain regions which are implicated in anxiety and depression.
However, it is unclear how the gut microbiota affects miRNAs in the brain, and so further research is needed before the results can be applied to a clinical setting. Nevertheless, these findings could offer a potential treatment for anxiety, by targeting the gut microbiome to influence miRNAs in specific brain regions.
The full article can be read here: https://microbiomejournal.biomedcentral.com/articles/10.1186/s40168-017-0321-3