Researchers Find Link Between Nervous System and Gut Microbiome

Researchers from the Immanuel Kant Baltic Federal University and the Pavlov Institute of Physiology have discovered that animals with a more excitable nervous system have a less diverse microbiome. The findings will be used to develop new treatments for humans — for example, scientists plan to test the effectiveness of probiotics in reducing stress symptoms.

Biologists evaluated the intestinal microflora composition in rats with different nervous system excitability. To do this, they sequenced the 16S rRNA gene, which made it possible to understand what bacteria inhabit the gut, their quantity and what role they play.

Even before stress exposure, highly anxious animals were shown to have a poorer intestinal microbiome diversity. It is possible that the deficiency in some important bacteria is one of the reasons for more pronounced depression- and anxiety-like symptoms in rats.
Irina Shalaginova, Researcher and Assistant Professor at the IKBFU Institute of Medicine and Life Sciences.

The researchers also found that prolonged stress exposure in rats previously not displaying anxious behaviour increased the number of Faecalibacterium and Prevotella bacteria in the gut. The results suggest potential for developing new therapies for stress-induced disorders.

There is a body of evidence that stress is able to induce changes in the intestinal microbiota, and rectifying these changes can help in treating stress-related conditions. Our research is distinct in that it focuses on rat lineages with differing nervous system excitability. By investigating the impact of inherited individual variations on psychiatric disorder development we can explore more personalised treatments.

added Irina Shalaginova.

The scientists now intend to verify the hypothesis that high nervous system excitability in humans is also associated with a greater predisposition to stress-related disorders. The scientists are currently working on a methodology to assess the excitability threshold in humans using electrostimulation and myography. The researchers will also evaluate the effectiveness of probiotics in correcting neuroinflammation and behavioural stress symptoms.

Earlier, IKBFU and Pavlov Institute of Physiology scientists established that rats with genetically determined high nervous system excitability were more prone to develop neuroinflammation in response to stress and form more pronounced behavioural disorders compared to low-excitable rats.