how bacteria hijack our brain: what you should know

The number of bacteria cells in our guts exceeds the number of cells in our body. For the bacteria, our guts must feel like a planet. Same as humans shape global processes on Earth, bacteria change their environment — us. 

INTRODUCING BACTERIA: We are not under our own control

It turns out that bacteria can communicate to the brain directly by hijacking vagus nerve signaling. An  article published in Neuron yesterday explains how it works. The vagus nerve delivers information from the guts to the brain, and back. Its sensory branches end in the epithelium (the inside layer) of the intestines. The microbiota can alter vagus signaling by changing the concentration of nutrients, peptides, and hormones inside the guts. Within seconds, information about these chemical changes is transmitted to the brain. 

Why is this important? We know that information from the vagus affects our emotions, decisions, and even memory processes. Vagus nerve activity may also influence our social connection and bonding (read here).

Bacteria make physical changes to the brain and who we are

Experiments in mice demonstrate that certain gut bacteria species alter social behavior. By activating the vagus nerve, the bacteria increased oxytocin levels in the brain and made the mice more social. To make the story even more mind-blowing,  studies show that gut microbiota influence gene expression in the cortex and may change the brain structure and function. 

Studies on humans have shown that changes in microbiota affect psychological processes and may contribute to psychiatric disorders. This includes mood and anxiety disorders, autism and schizophrenia, and even neurodegenerative disorders such as Alzheimer’s and Parkinson’s diseases.

While science is only starting to understand the complexity of mind-body-microbiota relationships, it seems like the vagus nerve plays an important role. Prof. Stephen Porges, a pioneer of the research of vagus and mind-body connections, and Prof. Sue Carter, an oxytocin expert, will come to Amsterdam in May this year for our conference “The Science of Human Connection in Yoga Therapy”. They will be ready to answer all of our questions about the vagus nerve.

WE KEEP BACTERIAS HAPPY AND THEY KEEP US HEALTHY

The vagus nerve communicates information from, but also to the gut. We know that exercise and slow breathing practices may increase vagus activity and influence the composition of microbiota. Together with a healthy diet and stress management, exercise or yoga helps to keep our microbiota balanced. And it seems like balanced microbiota in turn keeps our moods and behaviour balanced. 

So:

Namaste. The bacteria in my gut send light to the bacteria in your gut.