227. Brain-Gut Axis

During evolution, cyanobacteria absorbed carbon dioxide and released oxygen making our existence possible. They evolved as chloroplasts which adapted to life inside plant cells enabling photosynthesis to give us food. The same is the case with the mitochondria, the powerhouse of the human cell, which adapted to life inside the cell. Both mitochondria and chloroplasts still possess their own DNA. Similarly, our intestine hosts hundreds of species of bacteria and fungi. They are responsible for the digestion of our food and providing us with nutrition. Current research indicates that they even control our behaviour through the brain-gut axis (vagus nerve) as 500 million neurons (half the percentage of the brain) are located in the intestine. This background helps us understand the following verses. Krishna says, "The food that people prefer is also threefold, as also sacrifice (yagna), austerity (tapa) and donation (danam) (17.7). Foods which increase longevity, purity, strength, health, happiness and cheer are dear to the satvik (17.8). Foods that are bitter, sour, salty, very hot and pungent are dear to Rajasic. Such foods produce pain, grief, and disease (17.9). Foods that are stale, putrid, polluted, and impure are dear to tamasic" (17.10). Firstly, Krishna is indicating about the brain-gut axis while mentioning about the foods using the language of those times. Secondly, though we possess all gunas, one guna is more prominent at any given point in time. Our choice of food varies depending on the guna that dominates. Conversely, we can identify the guna dominating us based on our liking for the type of food. Lastly, while describing guna-ateeth (one who transcends gunas) Krishna said that guna-ateeth hates not when present nor longs for gunas when absent (14.22). He remains unconcerned, firm and centred in the Self (14.23). Essentially, transcending attachment to food is guna-ateeth.