It was the Greek physician Hippocrates who said 2,000 years ago that all diseases begin in the gut. Even before the Greeks people knew of the essential role of digestion in our overall health. Traditional Indian and Chinese Medicine from 5,000 years ago supported this belief.
As medicine advanced, doctors separated the human body into different organs and systems. This created specialists like cardiologists, gastroenterologists, ENT doctors, gynecologists, and more.
But what if the root cause of all disease is in the gut? What if the gut holds the secret to optimal health? Research from the last few decades suggests it’s very plausible. Some serious diseases that start in the gut include:
There are a few explanations that support the crucial role of the gut in health and disease. We’ll explore this connection further in this article.
The Second “Brain” and the Gut-Brain Axis
The enteric nervous system (ENS) is the largest collection of neurons and support cells outside of the central nervous system. The brain and spinal cord make up the central nervous system. In fact, there are more neurons in the gut compared to the spinal cord.
More than 100 million neurons reside within the walls of the digestive system. Their main roles are to support gut reflexes involved in motility and fluid transport. We’re familiar with serotonin as the feel-good brain chemical. However, the gut makes a majority of serotonin, not the brain, along with other neurotransmitters.
The vagus nerve connects the gut and the brain, forming the gut-brain axis. This bidirectional connection communicates information between the gut and the brain. Impairments of the gut-brain axis are often caused by inflammation in the body or stress. These factors lead to various symptoms felt throughout the body.
The close connection between the gut and brain explains why digestive problems like irritable bowel syndrome (IBS) and Crohn’s disease affect the brain. Some symptoms include fatigue or brain fog. It also explains why brain conditions like depression cause various digestive symptoms.
The gut-brain axis also works with another key element of the gut: gut flora. This is also known as the gut microbiota.
The Role of Gut Microbiota in Health and Disease
Gut flora contains over 100 trillion bacteria and other microorganisms. It weighs about five pounds and researchers now consider it an organ on its own.
The majority of these friendly microbes live in the gut. However, they live in other organs in their own microbial communities such as:
The gut microbiota plays essential functions in the body. For example, it supports immune system function from the day you’re born.
Gut flora is heavily involved in the digestion process and nutrition. It helps break down dietary compounds into smaller molecules. The gut also creates some B vitamins and Vitamin K within the digestive tract.
“Friendly” bacteria in the gut flora maintain optimal intestinal permeability and fight disease-causing bacteria. The gut microbiota also influences your mood and emotions. Research linked depression and anxiety with certain microbial imbalances.
But, probiotic supplements that restore microbiota balance show antidepressant and anti-anxiety effects. It’s worth mentioning that gut flora also regulates the expression of genes. These genes include those related to autoimmunity and inflammation.
Researchers associate virtually all major diseases with altered gut flora. Some of these diseases include:
You may be wondering why you’ve never heard about gut microbiota and its functions before. We really didn’t know much about it until the late 1990s. Scientists from the Human Microbiome Project started to share their research then.
We don’t know for sure if all diseases begin in the gut. Research shows that digestive health is essential to maintain optimal health. It also helps prevent diseases.
So, how can you use this information to improve your health? The answer is simple: improve your digestion.
To maintain a healthy microbiota, consume a diet with the following foods:
Probiotic-rich foods like kefir, yogurt, and pickled vegetables also support a healthy gut. You can also take probiotic supplements.