Meditation May Change the Gut Microbiome, Study of Buddhist Monks Suggests

A study of 37 Tibetan Buddhist monks suggests that long-term, deep meditation could positively affect the gut microbiome. The research is published in General Psychiatry.

How does meditation affect the body?

In the era of “wellness”, an increasing number of people are taking up a regular meditation practice. In parallel, diagnostic and imaging techniques – such as functional magnetic resonance imaging (MRI) and electroencephalography (EEG) – have evolved to new levels of sophistication, enabling scientists to study the effects of meditation on the human body. Growing evidence supports the notion that meditation can improve attention, memory, mood, emotional regulation and even offset the symptoms of some health conditions.

A new study led by Dr Jinghong Chen at the Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, suggests meditation might alter the gut microbiome – the collection of microorganisms that inhabit the intestinal tract. In recent years, the term “microbiota–gut–brain axis” was coined to reflect the influence of the brain on mood and behavior through its relationship with the microbes living in the gut.

“In this study, we aimed to investigate the association between traditional long-term Tibetan Buddhist meditation and fecal microbiota and to explore further whether meditation can impact human health by manipulating gut bacteria as a novel target,” the authors write.

Meditation can influence certain bacteria that may have a role in mental health

While its scientific study may be a novel field, meditation as a practice is thousands of years old, with roots in many ancient philosophies and world religions, such as Buddhism. Tibetan Buddhist meditation is derived from Ayurveda, an ancient Indian medical system often referred to as “the sister science” of yoga.

Chen and colleagues recruited a sample of 37 Buddhist monks across three temples in Tibet and 19 control subjects living locally to the temples. The Tibetan Buddhist monks had practiced Samatha and Vipassana for a minimum of 2 hours per day for 3–30 years (with an average of 7.56 years). “Samatha is the Buddhist practice of calm abiding, which steadies and concentrates the mind by resting the individual’s attention on a single object or mantra. Vipassana is an insightful meditation practice that enables one to enquire into the true nature of all phenomena,” the authors write.

The participants were matched for variables such as age, blood pressure, heart rate and diet. A prerequisite for participating in the study was that the individuals had not used agents that could alter the gut microbe diversity over the last three months, such as probiotics, antibiotics, prebiotics or antifungal drugs. Chen and team collected stool and blood samples from the entire cohort, which were sequenced and analyzed.

There were significant differences in both the diversity and number of microbes present in the samples from both groups. Bacteroidetes and Firmicutes species were dominant in both groups, which the researchers say is “to be expected”. However, Bacteroidetes were significantly enriched in the Tibetan Buddhist monks’ samples. In addition, their samples were abundant with Prevotella, Megamoonas and Faecalibacterium. “Collectively, several bacteria enriched in the meditation group [have been] associated with the alleviation of mental illness, suggesting that meditation can influence certain bacteria that may have a role in mental health,” the research team says.

Chen and colleagues dug deeper into the samples, using an analysis tool called PICRUSt to explore the chemical processes and pathways that might be influenced by the diversity of microbes present across the samples. They identified specific protective anti-inflammatory and metabolic pathways that were enhanced in the meditators. “Glycan biosynthesis, metabolism and lipopolysaccharide biosynthesis pathways were enriched in the meditation group. Glycans can reportedly alleviate intestinal inflammation, improve barrier function and reduce infection-induced colitis,” they write.

Analysis of the blood samples also demonstrated a significantly lower level of molecules associated with increased risk of cardiovascular disease – such as total cholesterol and apolipoprotein B – in the monks, compared to controls.

A key research avenue

There are limitations to the work, which the researchers address in the paper. Due to logistical challenges in recruiting participants from such a specific location, the cohort is uneven, with more meditators analyzed than controls. Furthermore, the sequencing method adopted – 16S rRNA sequencing – does not allow for “direct data on functionally important changes in the microbiota,” according to the researchers. To overcome the latter limitation, Chen and colleagues propose a study adopting metagenomic sequencing in the future.

“Long-term deep meditation could profoundly impact psychosomatic disorders by altering the structure of the human gut flora,” the researchers conclude, adding that their data supports the effectiveness of meditation in psychosomatic diseases as a “key research avenue in coming years.”

Reference: Sun Y, Ju P, Xue T et al. Alteration of fecal microbiota balance related to long-term deep meditation. General Psychiatry. 2023. doi: 10.1136/gpsych-2022-100893.