A Brief Introduction To Digestive System.

“If you care about your digestion, my advice is – don’t talk about bolshevism or medicine at table. And, God forbid – never read Soviet newspapers before dinner.” (c) M. A. Bulgakov, Heart of a Dog.

Digestive system is the largest and extremely complex system of organs in our body. It is responsible for many crucial to life processes, such as detoxification and nutrient absorption, and is a big part of immune system. Absorption of the nutrients from diet depends on efficient digestion. Our body produces enzymes (substances that speed up chemical reactions) to digest fats, proteins, carbohydrates and dairy foods. When something goes wrong and certain enzymes are not produced, the digestion is compromised, leading to a whole array of side effects, ranging from mild discomfort to allergies, pain and chronic inflammation conditions. Friendly bacteria in our gut is largely responsible for a healthy immune system, lack of inflammation, good nutrient absorption and protection of the intestine walls. Therefore it is crucial to also maintain healthy gut flora.

Digestion begins when we smell, see or just think about food, as saliva begins to form in the mouth. During eating, the food passes through oesophagus to the stomach with a help of muscle contraction known as peristalsis. In the stomach hydrochloric acid (HCI) is secreted from its lining and the main digestion occurs. HCI lowers the pH of the stomach, activating pepsin and rennin that break up proteins in food. The mix of acid and food in the stomach is called chyme and once formed, it enters the small intestine. Food spends between 3-5 hours in the stomach, with carbohydrates taking the least amount of time to digest, proteins (depending on its kind) longer and fats the longest.

In the small intestine, the juices of two other organs mix with the food. First, liver produces bile, which is stored in the gallbladder and released as needed through the bile duct into the small intestine, to emulsify fat to assist its digestion and absorption. Then, the pancreas secretes a variety of enzymes to further break down carbohydrates, fat and protein in food. These are amylases, lipases and proteases. Once everything is braked down, nutrients are absorbed through the intestinal villi and transported throughout the body by the circulatory system. The small intestine is about 6 meters long and consist of three parts: duodenum, jejunum and ileum.

The waste products of the digestive process, that include undigested parts of food, such as fibre, are then enter the large intestine, where faeces are formed with the aid of water and bacteria. Water is then absorbed back into the body, so the waste material becomes solid enough on its way out of the large intestine. It can take up to 30 hours for food to pass completely through the large intestine.

Digestive Problems.

At the beginning of the meal, the saliva production is increased, sending signal to the stomach that the food is on its way. This is a cue for the stomach to release HCI and digestive enzymes. If we eat too quickly, not allowing enough time to chew, the food enters the stomach before the amount of HCI and enzymes can be sufficient enough to break it down. The problem is two-fold. First,  only partially digested proteins enter the digestive tract, causing a lot of problems as they move along. It also cause the “heavy” feeling in the stomach. Second, HCI arrives late and might damage the stomach wall, causing pain and creating an ideal environment for ulcers. Poor digestion process in the stomach might lead to late production of pancreatic juices and enzymes in the small intestine, which results in poor nutrient absorption.

On the later stage, the production of bile starts the process of “waste removal” through large intestine before too much water is absorbed. If it doesn’t happen in time, it results in constipation. If this happens often, the waste matter accumulates and ferments in large intestine, causing bloating. Eventually, it can also lead to intestinal permeability or “leaky gut syndrome”, where the mucosal membrane of the intestinal wall becomes damaged and cause unprocessed proteins and toxins to enter the circulation. This triggers adverse reactions like allergies, skin rashes, inflammation, fatigue, etc.

The use of antacids to decrease the hyper-acidity also cause problems described above, as it inhibits digestion of proteins. Those who have been prescribed to take antacids should make sure that they take it away from meals. Stomach acid also decreases with age. Low stomach acid can also lead to increased levels of H. Pylori – the bacteria that causes ulcers, bacterial overgrowth in small intestine,  and poor absorption of vitamin B12.

The opposite problem is too much acidity, which is so common now. Too much processed, spicy or fatty food, caffeine and sugar consumption, alcohol, prescription drugs and painkillers and even stress cause too much acid production in the stomach, which damages the stomach lining. Also, remember that digestion starts with the production of saliva and we do produce more of it while thinking about food. So browsing through so popular now cooking websites or watching cooking programmes on TV triggers the digesting process and the production of HCI – good news if you are eating – bad on empty stomach.

Common Digestive Disorders.

Candidiasis is an overgrowth of the normally benign yeast – Candida Albicans – that lives in the intestines. It is associated with prolonged antibiotic use or diet rich in sugar, processed carbohydrates and yeast. Candidiasis may manifest itself in thrush, poor digestion, malabsorption, that result in allergies, skin problems, fatigue, irritability, poor sleep, etc. Candidiasis is completely reversible through the appropriate diet and supplementation, but depending on its severity, can take up to a year.

Coeliac Disease is an allergy (or severe immune response) to gluten – a protein found in wheat, barley, rye, oats and some types of rice. It manifests itself in lower abdomen pain and diarrhoea, resulting in dehydration, weight loss and fatigue. The inflammation of the intestine also makes villi shrink, which interferes with nutrient absorption. Because Coeliac Disease is triggered by immune response, there are no enzymes or other supplements that can help this condition. The only treatment is a complete exclusion of gluten from diet.

Crohn’s disease is an inflammatory condition that occurs when immune system attacks the gastrointestinal tract. Symptoms include mild to severe abdominal cramps and pain, diarrhoea and frequent bowel movements, fatigue, etc. This is an autoimmune inflammatory disorder, which is chronic and manageable, but mostly untreatable by conventional medicines. However, it is possible to reverse it by following a diet and lifestyle that helps to reduce inflammation.

Heartburn or acid indigestion occurs when the ring of muscle designed to keep the lower oesophagus closed, fails to do so, resulting stomach acid spill into the oesophagus, causing pain, i. e. heartburn. Overeating is a common cause of heartburn, but if it occurs often, it may be a symptom of GERD – gastric reflux disease. Treatment often include antacids and proton-pump inhibitors. Alkaline diet helps to control this condition, as well as moderate food intake.

Irritable Bowel Syndrome is a digestive disorder, that most commonly manifests itself in alternating constipation and diarrhoea, mild to severe stomach and abdomen pain and severe bloatiness and gas. It is still not recognised as a “medical” condition, despite large and seemingly increasing number of sufferers. This is because it is not well understood yet, and the most common theory behind it is that it  is caused by stress. Stomach ulcers also thought to be appear due to stress, but it was later discovered that it is in fact bacteria that causes it (see below). So, to this day, the exact cause of Irritable Bowel Syndrome is unknown. Because of this, only nutritional advise can be applied to this condition, as there are no drugs that can treat it. Nutritional therapists would generally recommend a suitable dietary changes and supplements to assist digestion and reduce stress.

Food intolerances are on the rise also, most common being dairy, wheat and gluten intolerance. Just as with Irritable Bowel Syndrome, it is not generally recognised as a medical condition. The common approach is: either you are allergic or you are not. However, it is never this simple when it comes to a system as large as digestive and so many people might be fine drinking milk during childhood, but can not tolerate it anymore in their adult years. It can simply be the lack of enzymes produced, or the different quality of food produced. Regardless of the reason, the best way to “treat” it is to either eliminate the trouble-causing food from the diet, or to take digestive enzymes.

Ulcers are now known to be caused by Helicobacter Pylori (H. Pylori) bacteria that lives in the stomach. It manifests itself in mild to severe stomach pains, that tent to be more severe when the stomach is empty or after too fatty or acidic meal. Some specialists say that H. Plylori originally belongs to the stomach and should not be eliminated completely with commonly used “eradication treatment”, but rather should be controlled with diet. Others prefer to use antibiotics to get rid of it. However, there are also ulcers that are caused by damage to the stomach lining due to too much HCI or taking too many NSAIDS. Either way, it is recommended to eat smaller meals more often to prevent stomach acid build up, and to avoid food irritants, such as coffee, dark chocolate, alcohol, too fatty food and too spicy food.

Of course, there is much more to each one of the conditions above then just a few sentences and children have different digestive issues then adults and elderly. I plan on expanding on each one as soon as I gather enough resources, but for now, I hope this introduction would be of help for better understanding of how things work and how to recognise when something is going wrong. In this post, I have described what kind of supplements are available in stores for better digestion and treatment of certain disorders.

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