The Brain of the Brain
The relationship between the brain and the gut have emerged as a fresh cornerstone of modern medical understanding. Western medicine defines the “gut-brain axis” as a “communication network” between the central nervous system (brain) and the enteric nervous system (gut). In particular, Western medicine describes the four main pathways of the gut-brain axis: neurologic, endocrine, metabolic, and immune.[1] The gut-brain axis is thus seen as a physiological pathway of sorts that encompasses a range of functional processes. The idea of physiological pathways of communication should remind us of the more long-standing conception of meridian pathways described in Chinese medical texts. Meridians are an interface that unite form and function––at once anatomically definable and functionally valuable. Modern scholars have described the linking between anatomical meridian pathways and organ function as “networks”. Seen in this context, the idea of the gut-brain axis is not entirely novel, but certainly a positive and important addition to Western anatomy and physiology.
My Ayurvedic teacher, Vaidya R.K. Mishra, was fond of saying that “the gut is the brain of the brain”, a dictum he learned from his father and teacher, Rameshwar Mishra.[2] The idea of the gut being the brain of the brain is another way of expressing the truth of the gut-brain axis. However, Vaidya’s statement also implies a hierarchy in which the gut is assigned a primary value. This understanding reflects the significant role of digestive health in Ayurvedic medicine, referred to in its totality as agni meaning “fire”. On a physical level, agni refers to the metabolic and enzymatic processes of digestion, but Ayurveda expands this understanding and describes thirteen types of “fire” in the body. The central fire is described as jatharagni, the digestive fire of the stomach. There are also secondary “fires” located in all of the tissues of the body that are responsible for the physiological transformation of food into bodily constituents (dhātu).
On a mental-emotional level, agni is seen as the “fire” of the intellect––the ability to process and digest information and emotions. Although subdivided, agni remains a singular process, and its impairment at any level will affect its function on another level. Therefore, indigestion of food can lead to mental-emotional stagnation or vice versa. In this way, the physiological paradigm of Ayurveda inherently unites the body and the mind, placing agni in the center as the prime mover of health and disease.
Returning to Vaidya Mishra’s remarkable statement, we have to appreciate that his father learned and taught Ayurveda in the context of a family lineage. Vaidya pursued formal education in India but learned the essence of Ayurveda from his father during a 7-year apprenticeship in his home village. Upon coming to the West, Vaidya opened his own practice and came to describe his approach as “sutra to science”. In other words, he sought to translate and affirm classical knowledge with the insights of modern science. However, we cannot attribute his intriguing statement about the gut-brain axis to a scientific understanding. This statement comes directly from his father who only practiced in a traditional village context in India, and who imparted this knowledge long before Western medicine discovered the gut-brain axis. Ayurvedic treatment always emphasizes the role of proper digestion, regardless of whether the patient’s complaint is mental-emotional or physical. In Ayurveda, healthy gut bacteria is referred to as krimi, but Vaidya used a term that was more common in his lineage, yoginis. The literal meaning of yogini is a female practitioner of yoga, and yoga means “to yoke or bind”. In referring to healthy microbiota as yoginis, Vaidya was illuminating how the gut bacteria links together so many aspects of the body and mind. With the modern paradigm of the “gut-brain axis” and the enumerating of bacteria strands, we can appreciate with more detail exactly why this is so.
The “gut-brain axis” is also well-understood in Chinese Medicine and has been the subject of much research by scholar and practitioner, Heiner Fruehauf. In an interview, Fruehauf describes the Chinese understanding of how gut health impacts mental-emotional health:
I found chronic parasitism reflected in a huge area of classical Chinese medicine that was called Gu zheng, or Gu syndrome, which essentially means “Possession Syndrome”. Gu is a character that is very old, perhaps one of the oldest characters in the Chinese textual record altogether, since it is a hexagram in the Yijing. It is literally the image of three worms in a vessel. This to me is one of those strokes of brilliance that you find in the symbolism of the ancient Chinese—that they recognized 3000 years ago that chronic parasitism can cause psychotic or psychological symptoms.[3]
Fruehauf’s recounting of classical knowledge is an interesting revelation of how the gut-brain axis has been understood by traditional physicians for thousands of years. Fruehauf describes pathologies of the gut-brain axis with the traditional Chinese classification of gu syndrome. Fruehauf further differentiates between two types of gu syndrome: digestive gu and brain gu. In other words, the pathodynamic can be seen with an emphasis on one side of the axis, either brain or gut. Fruehauf elaborates:
In modern terms, Brain Gu encompasses conditions like fibromyalgia, chronic fatigue syndrome, Lyme Disease, and certain types of mental diseases caused by pathogens infecting the nervous system, primarily spirochetes or certain types of viruses that can inflame the brain and other parts of the nervous system, causing symptoms such as body pain, compromised mental function, extreme emotional volatility, and traumatic fear responses to minor stimuli, i.e. hypersensitivity to smell and noise. This, in a nutshell, is the story of typical Brain Gu. Digestive Gu, in contrast, is caused by infectious agents that are primarily present in the gut, like certain types of worms, or protozoan parasites, or funguses, all of which happily coexist and promote each other. . .
. . . It is quite typical that someone with Brain Gu simultaneously also suffers from Digestive Gu, or the other way around. Either way, it is part of the definition of Gu Syndrome that proper mental functioning is affected in some way. In the case of Digestive Gu, the brain may not be directly inflamed, but becomes irritated via secondary metabolic pathways because the gut is inflamed. In cases like irritable bowel syndrome, for instance, or ulcerative colitis and Chron’s disease people’s brain chemistry is indirectly affected because the gut-brain barrier has become compromised and certain substances that have no business being in the body now can pass through the digestive membranes, often with the result that the body develops an autoimmune response to them, which then clouds people’s emotional and mental way of looking at the world. That is the reason why even the Digestive Gu patient will most likely exhibit some mental and emotional symptoms.[4]
Fruehauf’s observations accord with the Western medical description of the gut-brain axis, though his description strikes me with its detailing of pathodynamics and insights into the bi-directional nature of the axis. Fruehauf ultimately recommends an herbal approach to managing gut-brain pathologies and notes its significance as an increasingly common and recalcitrant clinical issue.
Traditional medical insights into the body-mind and gut-brain connection and its role in pathophysiology is now being validated by Western medical studies. Some studies state that research trends in the field remain unclear, but most studies posit a connection between gut-brain health and psychiatric disorders, even if they do not understand exactly how or why. Chemical connections between microbiota and the brain are the most mechanical explanations for gut-brain pathodynamics. However, we can see that traditional medicine has its own conceptual framework for explaining these mechanisms.
In Ayurveda, impairment of agni is the mechanism that leads to gut-brain imbalances. In Chiense medicine, the meridian network provides a physiological framework for understanding the mechanism of gut-brain imbalances. Prevention of such imbalances require proper dietary and lifestyle regimes In both systems, the prevention of gut-brain imbalances hinges upon proper dietary and lifestyle routines that maintain the balance of agni (or the free flow of qi) at all levels. Treatment options include a combination of dietary therapy, lifestyle adjustments, herbal formulas, and acupuncture.
In terms of etiology, Fruehauf identifies several modern factors resulting in gut-brain dysbiosis: inappropriate and casual use of antibiotics, overuse of medications, and environmental factors (such as pollution, GMO foods, and overpopulation in general). From this, we can see that gut-brain imbalances have an ecological root in the modern landscape of global warming and how the destruction of our Earthly terrain is having drastic consequences for our inner life. Therefore, it is imperative that we turn to sustainable and ecological lifestyle practices such as consuming locally-grown organic food, supporting biodynamic and permaculture farming practices, synchronizing our activities with the cycles of the Sun and Moon, and incorporating fermented foods into our diet (such as sauerkraut, kimchi, and yogurt).
References
[1] Appleton J. The Gut-Brain Axis: Influence of Microbiota on Mood and Mental Health. Integr Med (Encinitas). 2018 Aug;17(4):28-32. PMID: 31043907; PMCID: PMC6469458.
[2] https://www.svayurveda.com/happens-eat-mechanics-ayurvedic-digestion
[3] https://classicalchinesemedicine.org/gu-syndrome-interview-heiner-fruehauf
[4] https://classicalchinesemedicine.org/heiner-fruehauf-gu-syndrome-chronic-inflammation-autoimmune