What evidence is there to suggest that the gut is our body’s most under-rated organ?
“The Gut- by Giulia Enders” reveals the fascinating concept of our gut that is usually overlook by most due to its complex mechanism and wide range of microbiome that resides in it. In modern times, we often use the term “going with our gut” as a way of expressing an important decision-making situation where we unconsciously follow our intuition to make the final decision, this ability to know things without consciously reasoning has actually been scientifically proven that our gut is, in fact linked to our brain. The gut, is the body’s largest sensory organ, this clever structure not only has a huge surface area but a remarkable system of nerves to gather information about our body. The ‘gut-brain’ often sends signals to the brain and this information they gather is received by our conscious mind to formulate a response to our environment. Needlessly, our gut serves as an important aspect in our lives that enables us to carry out day-to-day functions with ease.
The gut is often mistaken for one whole organ when in fact it consists of a series of organs that work together to allow the body to carry out its daily necessities, such as excretion and digestion. This group of organs each have specific roles to play in, but they all work collectively towards the same goal which is to convert food into energy and basic nutrients to feed the entire body, this is known as the digestive system. This system works its way from our mouth cavity, forming a long tube across our body, to our anus where excretion happens. When we food enters our body through our mouth cavity, it undergoes mechanical digestion, a process whereby food is broken down by force into smaller elements, this includes the grinding and churning of food then these small particles are mixed with saliva from the mouth to form a bolus. After swallowing, the bolus then travels down the oesophagus with the help of involuntary muscle contractions that prevents the food from going back up, this process is known as peristaltic movement where the bolus moves down the oesophagus and through the intestine. When food particles enter the stomach, they are mixed with the gastric juices of the stomach. This digested food is broken down in the acids of the stomach with the help of enzymes, they become ‘chyme’, a mixture of partially digested food with bile from the liver and pancreatic juice from the pancreas, this mixture then works its way into the small intestine where the magic happens.
The small intestine is by far the most important piece to the puzzle, it has many special features that allows it to maximise the absorption of nutrients from ingested food particles, these nutrients enter the bloodstream and makes it way to parts of the body as energy. 90% of these nutrients are absorbed in three different sections of our small intestine, the duodenum, jejunum and ileum. The wall lining of the small intestine is also designed to have special adaptations in each layer to allow nutrients intake to happen more efficiently. The wall linings of the small intestine are made up of 4 layers, the mucosa, submucosa, muscularis layer and serosa. The innermost layer: the mucosa contains a layer of epithelium, made of epithelial cells, which have billions of finger-like projections called villi with even smaller folded structures called microvilli. These tiny but important structures increase the internal surface of the intestinal wall providing a greater surface area for absorption, at the same time also increasing the amount of contact between the cells of the mucosa and the chime. By the time food particles reaches the villi, it is already digested into small nutrients. These nutrients can then be readily absorbed into the bloodstream through the villi. The villi have a rich blood supply which allows nutrients to quickly diffuse into the low-solute concentration blood stream found in the submucosa layer to be taken to the rest of the body. Several layers of smooth muscle tissue form the muscularis layer that contracts and moves the bolus within the small intestines. Finally, the outermost layer of the intestine known as the serosa consists of epithelial tissue that is continuous with the mesentery and surrounds the intestines.
Besides that, the small intestine is also filled with hundreds and thousands of bacteria that protect the lining of the intestines to provide a strong barrier against toxins and “bad” bacteria that causes inflammation and disrupts the process of digestion. Anything that causes an inflammation reaction in the small bowel can cause major problems to the body, coeliac disease being one of the known causes. This autoimmune disorder affects one in every hundred UK citizens, it is caused by an adverse reaction to gluten, a protein found in wheat, barley or rye that causes the small intestine to become inflamed and unable to absorb nutrients. In this case, the immune system of people with this condition mistakenly attacks the body’s healthy tissues for gliadin, a substance found in gluten. Gliadin proteins have the ability to provoke an autoimmune enteropathy caused by an abnormal immune response. This abnormality of the immune system attracts several different antibodies that can affect a number of different organs. The antibodies that are produced cause the surface of the intestine to become inflamed, which causes the flattening of the villi, reducing their ability to help with digestion and thus inhibiting the digestive functions of the intestines.
To ensure that our digestive tract is well and fully functional, it is important to maintain a healthy gut. This is because the gut is usually described as the engine of our body, by filling our ‘engines’ with premium fuel such as high-quality foods that contain lots of vitamins, minerals, and antioxidants, we can perform our daily routines efficiently. Besides providing fuel to our bodies to keep us in tip-top shape, our gastrointestinal tract is lined with a hundred million nerve cells, or neurons that produce a type of neurotransmitter called serotonin that helps provoke sleep and appetite, mediate moods, and inhibit pain. It makes sense that the inner workings of your digestive system don’t just help you digest food, but also guide your emotions such as our anxiety levels, perception of stress, and mental outlook. "Most digestive problems are to do with lifestyle, the foods we've eaten, or stress. Which means that taking steps to change your lifestyle can help, and often prevent, many of these problems," said Dr Emmanuel, a consultant gastroenterologist at University College Hospital in London.
In addition, the food that we consume plays an essential role in maintaining the diversity and proper functioning of the gut microbiota. Our gut microbiota, also known as gut flora, consists of trillions of microorganisms that reside in our guts. Each individual contains about 1000 different species of known bacteria and 1/3 of these are commonly found in everyone else while the other 2/3 are specific to each one of us, basically the gut flora acts like a fingerprint to each one of us, they are all different. While we all have unique microbiota, they all fulfil similar physiological functions that directly impacts our health, this includes digesting certain types of food that are ingestible by the stomach or intestine, helping with the synthesis of vitamins and also, combatting aggressive microorganisms to maintain a homeostatic environment of the intestinal mucosa. In a nutshell, the gut microbiota plays a key role in the immune system and the digestive system, conserving it for the right purposes is absolutely important in our daily life likewise choosing the right diet for our lifestyle. When talking about gut microbiota, it could be said that “we are what we eat", as what we consume also feeds off the hundreds of trillions of bacteria living in our digestive system. For this reason, a varied and balanced diet is essential. People with little gut microbiota can also take in supplements nowadays to replenish and restore the gut flora, prebiotics and probiotics are considered beneficial for the gut microbiota which impacts various functions of the body such as the digestive condition.
Knowing the harm that can be caused to our bodies if we don’t take good care of our gut, we have to take immediate actions to protect our gut to maintain its optimal condition.
“We humans have known since time immemorial something that science is only now discovering: our gut feeling is responsible in no small measure for how we feel.” (Gut Book p.116) Upon gaining a superficial understanding of the gut, doctors have step upon ways to treat fix inflammation and disease by nourishing the gut. We have to embrace the gut-brain connection and use a holistic approach to find the cause instead of treating the symptoms of a disease and masking it with pain medication. Thus, it is crucial to understand our gut microbiota if we want to find solutions to the many uprising diseases and illnesses that may just wipe out human existence one day, it is never too late to cat now.