Among its many functions in the body, water is critical to healthy digestion and supports the process from start to finish.

If you’re like many people, healthy digestion might be more top of mind than it used to be. Part of this renewed interest in digestive health may have to do with an abundance of emerging science on the importance of maintaining a healthy “gut microbiome” – the collection of bacteria that inhabits the digestive tract and which affects the health of many systems in the body.

And so, to keep your digestive system healthy and happy, you may be aware of the importance of taking in probiotics (the ‘good’ bacteria) as well as prebiotics (such as certain forms of fiber that serve as “food” for the probiotics) and adequate fiber, which helps move waste through your system and promotes regularity.

But there’s something much more simple and basic to keeping your digestive system running smoothly: water. Water is involved in literally every step of the digestive process, which is just another reason why staying adequately hydrated is so critically important to your health.

How Water Supports Healthy Digestion

Starting at the very beginning of the digestive process, water is a major component of your saliva. Saliva serves several functions: it helps to moisten your food, which makes it easier to chew and swallow, and it is also a vehicle for enzymes that begin the process of chemically breaking down the fats and carbohydrates as you chew.

As the food passes into your stomach, watery gastric juices are released. These juices also contain enzymes, which begin to break the proteins and carbohydrates in the foods that you eat into smaller parts, preparing them for their trip to the small intestine, where much of the digestion of your food takes place. (And, by the way, there’s no truth to the myth that drinking water with meals will dilute the digestive juices so much that they can’t do their job. Adequate fluid with meals helps promote the process.) Water is also needed to produce the mucus that coats the inside of your stomach, which protects it from the highly acidic digestive juices.

As the food moves through the small intestine, there’s a lot of digestive activity that is facilitated by water. More watery secretions are shot into the small intestine from the intestinal lining itself as well as from the pancreas and liver. Enzymes work to speed up chemical processes and help prepare for the absorption of the end products of digestion: amino acids from proteins, fatty acids from fats and individual sugar molecules from the carbohydrates that you eat. Most nutrient absorption takes place here in the small bowel, and then digested nutrients pass to the watery environment of your bloodstream.

As the digestive process continues in the large bowel, water is critically important, too. The soluble fibers that you eat (from foods like oats, beans and barley) dissolve in water, allowing them to swell and add bulk. And the insoluble fiber that you eat (from foods like whole grains and most vegetables) tends to trap and attract water rather than absorb it, which helps promote regular bowel movements. The lower bowel is also where your body takes up most of the minerals that you eat, and the watery environment there facilitates their absorption.

There’s no question that healthy digestion relies on adequate fiber (and probiotics are a good idea, too). Exercise is also important – when you move your skeletal muscles during exercise, you’re stimulating the smooth muscles of your digestive tract at the same time, which helps promote regularity. But don’t forget the simplest and most basic thing of all – make sure to take in plenty of fluids every day to keep your system running smoothly.