Digest This

GUT HEALTH YOU ARE WHAT YOU EAT A s humans, we interact with our environment in many physical and emotional ways. Perhaps the most fundamental and life-sustaining physical interaction involves food, the source of the energy our body needs to stay alive. The connection between food and health is known since time immemorial but it is only recently that we are beginning to recognize the underlying biological mechanisms. These mechanisms involve not just the quantity (i.e. total calories), but also the precise nature and embodiment of the food. While much attention has been devoted to the relationship between excessive calories and the relationship to obesity and diabetes, very little is known about how other aspects of health including BY DR. PANKAJ JAY PASRICHA, M.B.B.S., MD OUR SENSITIVITY WITH FOOD IS A WORK IN PROGRESS AND STILL POSES MANY QUESTIONS THAT NEED TO BE ANSWERED both mental and physical dimensions are affected by not how much we eat, but what we eat. And this brings us to the central role that our digestive system plays as it is the first interface between the food and our bodies. The gut reacts to food directly through specialized cells in the lining (epithelium), immune cells (lymphocytes) near the lining, and nerve cells (enteric nervous system) within the gut. Together, or separately, these cells produce the response to specific components of the food. In addition, over time, what we eat influences the hundreds of millions of bacteria (what scientists call microbiota) in our gut which in turn interacts with all the above components. The role of the gut nerves (what we call enteric neurons) is worth emphasizing in this process. It is not widely known that the gut has as many if not more neurons, or nerve cells, as the spinal cord. We call this collection of cells the enteric nervous system- it lines the muscular walls of the intestines, but also the esophagus, stomach, and rectum and controls 20 DiGEST THIS

• Cover