When it comes to holistic health, one of the most important topics to discuss is digestion. The gut is often referred to as the ‘second brain’, because it operates independently from the brain, producing its own hormones and firing neurons to the brain that alter your mood, cognitive performance and immune system, to name a few. Your digestive health is reflective of your general health and an unhappy gut manifests as an unhappy you.
What is your digestive health important?
When you consume food, your digestive system is responsible for moving food through the gastrointestinal (GI) tract from the mouth to the necessary point of need, whether this is for cellular absorption or to be excreted as waste. This system comprises the GI tract, the pancreas, liver and gallbladder, and the GI tract comprises the small intestine, large intestine (including the colon and rectum) and stomach.
During this journey through the digestive system, food is broken down by digestive enzymes and bile acids, releasing nutrients from the food for absorption into the bloodstream and transportation. The rest of the food continues down and is excreted as stool. Digestion can be a stressful event for your biology, which is why poor digestion can result in malabsorption, bloating or constipation. To help with this, we have a diverse and complex ecosystem of bacteria in our GI tract, known as the gut flora. In fact, we have more bacterial cells in our body than human cells, around ten times more! The health and diversity of our gut flora contributes to digestive health and general host health, so maintaining a healthy gut is the key to good health.
Good digestive health means the maximum amount of nutrients are absorbed from the food you eat, toxins and waste are expelled regularly (characterized by regular, healthy looking bowel movements), inflammation is low and the host has good overall health. Poor digestive health is characterized by a range of digestive symptoms including abdominal discomfort, bloating, constipation, diarrhea, unhealthy looking stools (check out this link to see what your poop should look like!), excessive gas or hemorrhoids. Poor digestive health can also manifest as skin conditions like acne, a weakened immune system, bruising more easily, healing slower or weight gain, which are all caused by elevated inflammation. When the digestive system is compromised for long periods of time, conditions like irritable bowel syndrome (IBS), gallstones, gastroesophageal reflux disease (GERD), celiac, Crohn’s, ulcerative colitis or diverticulitis become more likely.
Digestion and the immune system
Healthy digestion boosts the immune system; if you have problems digesting your food, your immune system will suffer. In a healthy person, bacteria in the gut is kept within the intestinal lining so that it doesn’t leak through into the bloodstream, spreading potentially harmful bacteria around the body and increasing the risk of disease. However, in a person with compromised digestion, they may have little holes in the junctions of the intestinal lining, a condition known as leaky gut. For these individuals, gut bacteria goes into the bloodstream easily through the intestinal lining and weakens the immune system.
This is partially why researchers claim that a huge portion of the immune system is in the GI tract, about 70 percent, in the form of gut-associated lymphoid tissue (GALT). One of the key components of the immune system is plasma cells that release protective antibodies; and these predominantly reside in the gut. What you eat has a range of bacteria in it, both good and bad, which goes to your gut and must fight off or welcome in. When harmful bacteria is consumed and the gut can’t destroy it, the immune system responds to this threat. Similarly, when healthy bacteria is consumed, the immune system is boosted.
Digestion and mental health
There is also preliminary research to suggest that digestive health is closely related to mental health, via the bidirectional communication of the vagus nerve. The vagus nerve, also referred to as the gut-brain axis, connects the gut to the brain to report on any unusual activity so the brain can respond accordingly. A stressed out digestive system results in a stressed out brain, which manifests as anxiety, depression, brain fog or low cognitive performance. For example, individuals with IBS are disproportionately affected (50 to 90 percent) by depression and anxiety, compared to the population without this condition.
So what affects digestive health?
Your gut is populated with bacteria from the moment of birth. The variety and density of bacterial strains in your GI tract depend on a number of factors including mode of delivery at birth (vaginal or caesarean), genetics, infant feeding (breast or bottle fed), antibiotic use and frequency, exposure to germs in early life, frequency of infection, and your diet. While you can’t go back in time to alter the way you were delivered at birth, you can improve your digestive health by adjusting your diet. A diet rich in dietary fiber, particularly non-starch polysaccharides (NSPs), probiotic and prebiotic foods and diversity of nutrients from fruits and vegetables is linked to a healthy gut flora and digestive system.
Fiber is found only in plant foods and helps to support healthy digestion by bulking out stools to encourage regular, easy bowel movements. If you don’t consume sufficient fiber (approximately 30g per day), your body is unable to excrete toxins and bile through your feces and so inflammation is created which affects your mental state and physical health almost immediately. Examples of these types of fiber include blackberries, blueberries, chia seeds, lentils, black beans, avocados, broccoli or brussels sprouts.
Another type of fiber is prebiotic fiber, which remains undigested throughout digestion to provide fuel for the bacterial population in the GI tract. In the gut, prebiotics are fermented by the bacteria to nourish, strengthen and increase the good bacteria. Examples of these types of fiber include onion, garlic, asparagus, chicory root or artichoke.
Probiotics are live bacterial organisms that help to populate the gut with healthy bacteria. Studies have supported the use of probiotics, whether as high-strain supplements or as food, to treat digestive disturbances. One study found that probiotic consumption reduced diarrhea by 42 percent after antibiotic use, and another study found that them to be noticeably beneficial at alleviating symptoms in IBS patients. Probiotic rich foods include fermented foods like tempeh, tofu, sauerkraut, kimchi, and high-quality dairy produce.
Consuming a diverse range of whole foods like fruits, vegetables and plant foods has a profound effect on digestive health, due to the fiber and nutrients they provide. Consuming processed foods that are refined and high in sugar have a negative impact on digestive health by spiking blood sugar, causing inflammation and damaging the gut flora, as shown in research published in the journal Neuroscience in 2015.
Alongside a healthy diet, regular exercise and managing stress are two key components of maintaining happy digestion. Exercise improves gut health and boosts the anti-inflammatory response system to regulate inflammation. Managing stress can also help to improve digestive health because as we said earlier: a stressed out mind is a stressed out gut, and visa versa.
Your digestive health is integral to your health and happiness. Improving your digestive health from the inside out can have a profound impact on your mental health – via the gut-brain axis, your skin, your weight, your cognitive performance and your disease risk. Make daily decisions that promote internal health, for long term, internal and external happiness.