Diet and exercise are so important in today’s fast pasted world. It always seems like we are rushing to get everything in. Especially rushing to get out food in to get to our next work task or dealing with your little ones. This can put a damper on your digestion and cause issues in other areas of the body. Let us review what our GI tract does and how to make small improvements in your everyday routine to make sure everything is running as planned.
We have a muscular canal that runs 26 feet long, including the mouth and the anus the gastrointestinal tract is no small feet to say the least. GI tract aid in proper digestion, but it is also considered as a “second brain” which the enteric nervous system governing all of it. There are several other awesome benefits for having this long tube through out the body. The coolest thing is that the GI tract is also separate from the body, so could say it is on its own island of benefits.
Other benefits of the GI tract:
· Collects and processes nutrients.
· Gives us physical and chemical barriers against pathogens.
· Excretes wastes and detoxifies substances that could cause potential harm.
· Secretes some of our hormones & helps process them as well.
· It is a big regulator of our immune system.
Hunger activates our brain to get out of our seats and find food. Our brain overrides the instinct to stay put. When we think, see, and smell food our body starts pre prepping for digestion. Our mouth starts salivating to help break down the soon to be consumed nutrients. While the mouth is getting lubed up the stomach starts secreting digestive enzymes. The autonomic nervous system regulates the process of digestion and internal organs, unconsciously of course.The autonomic nervous system has two branches of its own control center, the sympathetic nervous system, and the parasympathetic nervous system. These sub-branches decide when and how to get the ball rolling for digestion and when to back of and shut it down. The sympathetic nervous system aka “fight or flight” shuts down digestion based on stressor placed on the body; things like stress, intense exercise, stimulation, or a big animal coming at you, the SNS has your back! On the other hand, the parasympathetic nervous system aka “rest, digest, & repair” is all for the easy going. Our relaxed friend helps regulate digestion and movement through the GI tract. These two systems can be affected by fear or extreme trauma; if SNS is fully exhausted, the relaxed buddy PNS will kick in and since they control motility you might lose bowl control. Both subbranches are affected by internal signals and environmental signals, intern effect the way we digest. Being overly stressed at the office or home or what we see, think, and feel also has effects on appetite, hunger, and fullness with meals.
Other processes that are involved in digestion are smell or known as retro-nasal olfaction. Retro-nasal olfaction is when the odors from food travel up the back of the throat and into our nasal passage when consuming and swallowing foods. By keeping food in our mouth longer contributes to satiety or fullness. This sends messages to the brain to tell it that we are getting enough nutrients. Helping with keeping use more satisfied, that is why eating slowly and chewing our food completely is important.Our mouth also contributes to digestions; the break down of food from chewing stimulates neurotransmitters. Did you know that our jaw muscle is considered among of the strongest muscle in the body!
The tongue helps move food around in the mouth using papillae which are tiny bumps on the tongue. These papillae contain taste buds which scout out receptors for flavor, texture, and the presence of fats and carbohydrates. We also absorb many different substrates in the mouth by the mucous membrane; a thin, porous lining in the mouth, these are rich in blood vessels and can be used to absorb medical drugs under the tongue. Did you know a lot of our preference to type, density, taste, texture of food is affected by our genes? If example if you have more fat receptors in the mouth, you may find many desserts or thick creamy sauces rich. Some people are unusually sensitive to certain chemicals, for instance vegetables are more likely to be bitter tasting. Our taste sensor does change with age that’s why it’s important to have a big variety of food in your diet!We make up 1.5 liters of saliva every day, 95% water with the remaining being mucus, glycoproteins, enzymes, and antimicrobial chemicals that fight off pathogens. The salivary glands keep our mouth moist, mucous membrane healthy, and gets ride of bacteria that tries to make its way into our system. A few digestive enzymes that play a role with our saliva are amylase and lipase. Amylase helps digest starches and lipase aids in fat digestion; fat is hard to break down, so lipase is more used when we begin life to help break down the fats in breast milk.
Once everything is chewed or known as “bolus”, this is passed through the pharynx which is a cone shaped passageway connecting the oral and nasal cavities to the esophagus and larynx. The salvia that aided in turning your food into bolus now helps transport food and water to the stomach. Gravity has a lot to do with our food travel, wavelike muscular contractions executed by the peristalsis finish guiding the bolus to the stomach. The Lower esophageal sphincter helps regulate food entering the stomach and prevents acidic juices from splashing backwards, if this unwanted situation occurs; this is known as gastroesophageal reflux disease.
The J – shaped stomach that evolution blessed us with sits around the base of the breastbone; slightly to the left to be precise. The stomach has stretch receptors that tell us when its filling up and does absorb some nutrients but most nutrients are absorbed in the small intestine. Chyme is a food broken down and mixed not a liquid substance. The pyloric sphincter is at the end of the stomach; this controls how much chyme enters the small intestine. The deeper layer of our stomach secretes a variety of substances called gastric juice with the help of gastric mucosa. Enzyme secretion begins with cells enzymes such as pepsin or gastric lipase to aid in the break down of proteins and fats. Several other functions happen as well while all this break down is happening. Gastric mucosal secretion of histamine to help with immunity & gastric acid production, hormone ghrelin which stimulates your appetite, and serotonin.
Finally, the stomach starts the empty; the small intestine starts taking on the terribly slow task, like a few milliliters at a time slow, turtle pace slow. The time frame is between 1 and 4 hours for the stomach to completely empty depending on the amount of food we consume. Carbohydrates are the easiest to digest so those empty first, then protein, and finally fats and fiber. Liquids always empty faster than solids and there is a separate chamber in the stomach where that liquid is separated, right where the “J” has its curve at the top.
When the chyme hits the small intestine takes another 4 to 8 hours or more, this lets the small intestine absorb most of the nutrients that we eat, oral drugs and alcohol too. The small intestine is lined with velvety finger like projections called Villi. These help us absorb our nutrients, if damaged we do not absorb proper nutrients. Some signs of your Villa not working the way they should are IBS (inflammatory bowel disease), celiac disease, food poisoning, some food tolerances as well. When we do have healthy villa ; these move molecules across the cell membranes of our intestinal cells into the bloodstream, then processed in the liver.
There are five processes that our body goes through for cell absorption and transporting nutrients, but we will not get too deep into that. That is a whole other ball game, just know that your body is amazing in what it does and efficient! Just think of it like this your cells are like mini-factories and every one of those functions have a job to help break down your macronutrients and get ride of access waste. The quality of your food effects your cells and overall become part of your DNA, so eating whole food filled with good nutrients will make your cells more efficient at what it does.
Getting off topic for a second and focus the incredible feet of our microbiome. We have some friendly oral microbiome, over 300 known species there is said to be as many as 700! Each of these friendly little helpers have their own oral community they stay in like the gumline or under the tongue.
You will hear your doctor talk about pre or probiotics and give you a generalized idea of what they are. The wide range of microorganisms that inhabit us, but most activity is in the large intestine. These little critters ferment dietary carbohydrates, fiber, complex carbohydrates, and sugars (lactose, sugar alcohol). The small intestine cannot absorb on its own. When fermented these carbohydrates converts these into short-chain fatty acids, the bacteria also ferment dead cells, enzymes, bacterial cells, elastin, and collagen in food.These little buddies also help with:
· Prevent bacteria and harmful yeast from colonizing the gut.
· Boost immune system & removes carcinogens.
· Allergy prevention.
· Regulates inflammation.
· Regulates our mood and our nervous system functions.
· Hormone regulation.
· Regulate body fat in the body.
· Prevents IBS.
Now that you have a generalized idea on how the GI tract functions, let us go over way to improve it!
Great way to make sure everything is working the way we want is taking pre or probiotics. Prebiotics give bacteria the food that they need, such as dietary fiber. Probiotics are fermented food that colonize with bacteria or supplements containing good bacteria. Keep these in mind if taking antibiotics as well; antibiotic clean out everything even the good bacteria. Always talk with your doctor first before trying to add in new supplementation to make sure this will not affect any medication or dietary requirements.
This might seem super simple way to regulate your GI tract but eating slowly and mindfully will help regulate and reduce discomfort as well. This technique also aids in weight loss when only eating to 80% full.Another easy way to regulate your GI tract is consuming fruits, vegetables, fiber, and protein.
Less processed more natural whole foods will improve your GI function. Many Gi problems come from eating a lot of processed food that may be higher in manufactured fats, sugar, and exceptionally low fiber. Correctly the balance of this will help gain back some control on your digestion. Experiment with your fibers, some people who deal with IBS (irritable bowel syndrome) might find higher fiber filled food cause more issues than expected. Try food that are soluble fibers, this may slow down occurring diarrhea.
Getting enough water and balancing out your electrolytes during the day is crucial for staying hydrated and a proper function GI tract. The recommended amount of water to consume daily based on a sedentary individual is 2 liters for women and 3 liters for men, or 8 – 8oz cup water daily.
If you work in a constant high stress environment, gastric emptying can be an issue. Planning out proper meals and knowing the amount of food to eat is important. For a quick energy boost that will not weigh you down try 1 or more meals as liquid that are lower in fats and higher in carbohydrates, with fast digestive proteins. For someone losing weight but wants to cut out the hunger pains, try meals higher in slow digesting proteins and fiber to slow down gastric emptying and to help feel fuller longer throughout the day. Taking proper small period of rest will also help reduce stress levels and help shut off your sympathetic nervous system.
Sleeping 7 – 8 hours daily and having a set sleep schedule and wake time will help regulate digestion and all the hormones that follow along with it. Not only that you will repair and replenish your body to perform better the next day!
Getting your GI under control can save you a ton of time in the doctor’s office, bathroom, and save you money on the gimmicky products to help with GI issues. Now that you have a basic understanding of what the GI tract does and how to improve it, you should have all the tools to go forward and improve your GI tract!
Refernece:
Scott- Dixon K., Berardi J. , St. Pierre B., Kollias H., Deputter C. The Essentials of Nutrition and Coaching: The Science of Nutrition. Precision Nutrition (2019).