Meditation has grown more common as a mental health intervention in recent years due to its myriad benefits to overall well-being. So far, the practice has been found to exert a positive impact on depression, anxiety, stress, smoking, addiction, subjective pain intensity, fatigue, and potentially, immune function.
Although the benefits of meditation are widely acknowledged, there has been little research on its direct impact on the gut microbiome, which plays a vital role in nearly all aspects of health and immunity.
That is until a recent study examined the intestinal microbiota of 56 Tibetan Buddhist monks, and compared their samples to neighboring residents to see if long-term meditation can alter the gut microbiome.
The monks had all practiced Samatha and Vipassana for at least 2 hours daily over 3-30 years. Samatha is the practice of cultivating internal tranquility to steady and focus the mind. Vipassana involves cultivating ‘insight’ into the true nature of reality and clear awareness of the present moment.
Although the study did not exactly provide insight into the true nature of all phenomena, it did offer insight into the true nature of the microbiome – which some researchers have gone so far as to liken to “the force”.
What is the gut microbiome, anyway?
The gut microbiome refers to the trillions of bacteria, fungi, and viruses residing in the digestive tract. Certain gut bacteria are vital for nutrition, heart health, digestive health, mental health, and the regulation of our immune system.
In fact, some 70-80% of immune cells reside in the gut, communicating with the intestinal microbiota, the intestinal epithelial layer, and the mucosal immune system. This is why gut bacteria play such a large role in immune-mediated inflammatory diseases like Crohn’s disease and ulcerative colitis.
Gut microbiota also considerably influence the brain, mood, and behavior through the ‘gut-brain axis’. The gut-brain axis refers to the bi-directional superhighway of communication within the body, with signals passing via microbial byproducts, immune and inflammatory pathways, neuroendocrine and enteroendocrine signaling, stress responses, and the vagus nerve.
It is through the gut-brain axis that stress can impact the gut and worsen inflammation – especially in cases of IBD.
How Meditation Influences Gut Bacteria
The study on Tibetan Buddhist monks found the effects of long-term meditation did indeed result in a different microbial composition to their non-meditating neighbors. For instance, the monks had “enriched” Prevotella, Faecalibacterium, and Bacteroides compared to the control group.
Prevotella is a bacteria found to be greatly reduced in patients suffering from major depressive disorder. Bacteroides have been found to help with binge eating and anxiety-like behavior. Faecalibacterium was reduced in patients suffering from anxiety disorders, and a greater abundance is linked with a higher quality of life.
Collectively, the enriched bacteria found in the meditation group have been associated with the improvement of mental illness, suggesting the practice of meditation can positively impact levels of bacteria that play a role in mental health.
Meditation: The Path to Better Pathways
Researchers also found significant differences in certain biological pathways. The monks showed enriched glycan and lipopolysaccharide (LPS) biosynthesis, which both play a role in mitigating intestinal inflammation.
Glycans not only alleviate gut inflammation but also improve barrier function and reduce infection-induced colitis. And LPS-stimulated T-cells have been found to limit the “self-reactivity” of immune cells and excessive inflammation.
The monks had enriched toluene degradation and adipocytokine pathways, which were found to be dysregulated in a depressed mouse model. As chronic toluene is reported to increase anxiety and can reduce neurogenesis, this may indicate the further benefits of meditation for mental health.
The control group also showed higher levels of cholesterol, which decreases immune function and raises the risk of cardiovascular disease. So, not only is meditation beneficial for the mind and gut, but it may also reduce the risk of stress-induced heart conditions.
Takeaway
Overall, it appears long-term meditation can improve anxiety and depression by exerting a beneficial effect on gut microbiota. The practice also has a positive effect on immune function, alleviates intestinal inflammation, and promotes an overall state of health and well-being.
And if Samatha-vipassana sounds a bit intimidating, don’t worry – much of the research on meditation has been conducted on Mindfulness practices, which show similar results and health benefits.
Tessa Eskin
