Humans are not designed to be stressed all the time, and when we learn to calm our nervous system, our health improves dramatically. Our nervous system and the gut are inextricably linked.
When stressed, an altered microbial population in the gut affects the regulation of neurotransmitters mediated by the microbiome and the barrier function of the gut. Meditation helps regulate the stress response, suppressing chronic inflammatory conditions and maintaining healthy gut barrier function.
Mental health and its impact on overall well-being is an issue that is prominent in most developed countries. Ironically, in the vast world of the microbiome, the gut microbiota is most impacted by the modern, fast-paced, Westernized lifestyle, suggesting a significant correlation between geographic location and physical and mental habits. The gut-brain axis is an established axis that demonstrates the effects of the gut microbiota on biochemical processes in the brain. Given the effort of mindfulness initiatives such as the adoption of a “yogic lifestyle” which aims to create a sense of harmony and balance in the individual - this special report examines the available evidence base and questions whether the harmony created by the adoption of this lifestyle can be linked to the establishment of harmony on the gut-brain axis.
Stress and the link to the microbiome
Microbiome research has exploded in recent years as scientists seek to understand this microscopic ecosystem in our bodies better. "The Mind-Gut Connection," Mayer's recent book on the subject, explores the ongoing dialogue between our brain, gut, and gut microbiota. He explores what can go wrong when communication breaks down between the three areas and how to reverse the adverse effects. The necessary communication begins in the brain. There, stress stimulates the release of a hormone called corticotropin-releasing factor (CRF), which triggers two messages to the body: one is an increase in the stress hormone cortisol. The other is a signal that travels through our autonomic nervous system to the gut, where it can affect digestion and cause symptoms such as abdominal pain, bloating, and irregular bowel movements. Nerve signals can also alter the composition of gut microbes, affecting their behavior and making the gut lining more permeable, eventually leading to a "leaky gut." When this happens, gut microbes and food particles gain access to the gut's immune system, leading to low-grade inflammation that can spread throughout the body. A leaky gut can increase the risk of developing several other health problems, including food allergies, autoimmune diseases, and possibly depression.
"Every emotion that starts in the brain is reflected in the gut, and everything that happens in the gut is reflected in the brain in some way," Mayer says. Our gut houses 60 to 80 percent of our immune system and 90 percent of our neurotransmitters, chemical messengers that help control mood. That's one reason it's so important to make sure our gut is healthy, Mayer says. "We're fascinated with healthy eating," he adds, "but people forget that if you're not in the right frame of mind, the benefits of a healthy diet are greatly reduced. Chronic stress can reshape our gut cells. Negative emotions aren't just psychological," he adds, "they can have real effects on the entire body. Mayer and his colleagues recently published a study in the journal Microbiome demonstrating a link between gut microbiota and sensory areas of the brain in patients with irritable bowel syndrome (IBS). IBS patients with altered microbiomes showed differences in the thalamus, basal ganglia, and sensory-motor cortex.