This is the third in a series of articles discussing the human microbiome. Now that we have learned about the importance of a healthy microbiome, we need to know how to keep our microbiome healthy. Many diseases that develop in humans are directly caused by one’s lifestyle choices. Hence, much is within our control as to whether we develop a particular disease or not. As with prevention of disease itself, it is also possible to make lifestyle changes to improve the health of our microbiome.
DIET
The gut microbiome coevolves within the individual—bacteria eat what people eat.
As we learned, the type of diet we eat directly impacts our gut microbiome. Therefore, changing our diet can potentially either cure a particular disease or prevents its occurrence. Evidence shows that long-term dietary changes can reshape one’s microbiome. For example, if one moves from a high-fat, high-sugar diet to a leaner, more high-fibre diet, it is possible to reshape one’s microbiome into giving it a healthier profile. The effect will be improved immune function, lower inflammation, and overall better health.
What has also been discovered is that not just a healthy diet, but a more varied diet may be key to fostering a more diverse and healthy microbiome.
The indigenous Hadza tribe of Tanzania have a gut microbiome that is among the richest on this planet. The diversity of their microbiome is 40% higher than the average North American’s. In studying their diet, the average Hadza individual eats around 600 species of plants and animals in a year. They have virtually none of the common Western diseases such as obesity, allergies, heart disease, and cancer. In contrast, the Western diet contains fewer than 50 species in their diet and are dealing with an epidemic of illness and obesity.
Our diet is the most important modifiable factor affecting the composition of bacteria living in our gut. In other words, our diet directly impacts the composition and diversity of our gut microbiome. Eating a diet composed of energy-dense and highly processed foods, containing chemicals to preserve, stabilize, and sweeten, appear to compromise the barrier lining our gut. Once the gut barrier is weakened, small particles that should not pass through the lining escape into the blood stream; this includes bacteria, toxins, and small bits of undigested food. Once this happens, the body sees them as intruders, and triggers the immune system into action, causing widespread inflammation throughout the body. Inflammation has been a causative factor in many diseases. The breakdown of the gut lining is a condition known as “Leaky Gut”, and there is increasing evidence that Leaky Gut is a factor in disease.
SUGAR
Artificial sweeteners and highly processed sugar support an overgrowth of unwanted bacteria that can lead to sugar cravings, brain fog, infections, and an increased risk of obesity. One example is candida, a bacteria that is typically present in small amounts in our intestines; an overgrowth of candida occurs by consuming highly processed sugars. Once this overgrowth of bacteria occurs, it begins to crave sugar to survive, and we eat more sugar to satisfy the bacteria’s appetite. When eating foods that satisfy these bacteria, it starves the beneficial bacteria of their needed nutrients. To combat the effect of sugar on the microbiome, we must lower sugar from all sources of food; processed sugars should be avoided. Eat healthy sugars contained in grains and vegetables.
Another impact of sugar is that it results in slower transit times, i.e. it takes food longer to move through the gut. This can alter the gut microbiome, leading to gut dysbiosis, and an increase in the production of endotoxins, which lead to disease. Over time, this may lead to issues that are caused by chronic inflammation, such as obesity, heart disease, type 2 diabetes, metabolic syndrome, fatty liver, and irritable bowel syndrome. Many people consume artificial sweeteners when trying to avoid sugar, especially when there are concerns with high blood sugar levels. However, long-term consumption of artificial sweeteners disrupt the balance and diversity of the gut bacteria, increasing the risk for developing type 2 diabetes.
The bacteria in our gut trigger cravings for specific foods that they thrive on. So, if you eat a lot of sugar you feed the unhelpful bacteria that love it and they secrete the proteins to make you crave sugar more. It’s a vicious cycle. Fat and sugar nourish bad bacteria, thereby increasing the prevalence of those bacteria that cause disease
NON-ORGANIC AND GMO FOODS
Non-organic and GMO foods contain high levels of glyphosate—an herbicide known for a long list of adverse reactions in the body. Glyphosate damages the gut lining, weakening the junctions between cells and leading to leaky gut, and contributing to an overgrowth of harmful bacteria. Because exposure to glyphosate is ongoing, the toxic effect and changes to the balance of the gut manifests over time, potentially creating long-term changes to the makeup of one’s microbiome. When purchasing food, look for organic or non-GMO labels to guide your food choices. Wheat is not a GMO food; however, wheat farmers use glyphosate to speed up the drying process of the wheat prior to harvest. Glyphosate has been shown to increase gluten intolerance and celiac disease. When buying wheat products, look for an organic label.
TAP WATER
Tap water often contains many problematic chemicals like chlorine, fluoride, and aluminum. The problems with chlorine stem from the very reason it is so useful—its ability to kill bacteria. When chlorine is added to water, it kills pathogenic, disease-causing bacteria. However, when it is introduced into the human body, it destroys our beneficial gut bacteria. Fluoride, added to water as a way to prevent dental cavities, decreases good bacteria and increases bad bacteria in our gut. Increases in aluminum puts pressure on gut health by impairing several biological processes which then may contribute to Inflammatory Bowel Disease. Aluminium ingestion affects the microbiome and the immune function of the intestines.
PREBIOTICS AND PROBIOTICS
People often get confused by the words “prebiotic” and “probiotic”. Both are important to human health, but they each play different roles. Probiotics are live bacteria found in certain foods or supplements. Probiotics is also the term which refers to the beneficial, healthy bacteria in our intestines. Like all living things, probiotics need to be fed in order to remain active and healthy. Prebiotics are substances that come from types of carbohydrates (mostly fiber) that humans cannot digest. However, prebiotics are food for the probiotics living in our gut. A helpful metaphor to understand the difference between a prebiotic and a probiotic is to consider a garden. You add seeds—the probiotic bacteria—while the prebiotic fiber is the water and fertilizer that helps the seeds to grow and flourish.
PREBIOTIC FIBRES
Dietary fibre is the part of a carbohydrate (plant) food that does not get absorbed by the small intestine. Therefore, it is not used for nutrition for our body. It moves, undigested, to the large intestine (colon), where it plays a role in keeping our microbiome and our colon healthy.
The term, prebiotic fibre, was first used in 1995. It is one of the types of fibre and is present in certain foods. When prebiotic fibre moves to the large colon it is fermented by the bacteria in the colon. This fermentation process “feeds” beneficial bacteria colonies (including probiotic bacteria) and helps to increase the number and activity of desirable (good) bacteria in our digestive system that are associated with better health and reduced disease risk. The more prebiotics that probiotics have to eat, the more efficiently the good bacteria work, and the healthier the gut will be. Prebiotics help the gut bacteria produce nutrients for the colon cells, leading to a healthier digestive system. It has been shown that increasing prebiotic fibre intake supports immunity, digestive health, bone density, regularity, weight management, and brain health. Beneficial gut bacteria such as Lactobacilli and Bifidobacteria feed on fibrous foods. Supporting the growth of the beneficial bacteria will also help control the growth of harmful bacteria.
As not all fibre is fermentable in the colon, therefore knowing which foods are high in prebiotic fibre is essential when wanting to increase the good bacteria in the gut. Vegetables that are high in prebiotic fibre include Jerusalem artichokes, raw dandelion greens, carrots, cucumbers, asparagus, bell peppers, onions, beets, yams, garlic, chicory root, sweet potatoes, leeks, and cabbage. Fruits high in prebiotic fibre include tomatoes, apples (the skin), berries, bananas, and mangos. Other food sources of prebiotic fibre include honey, flax seeds, hemp seeds, pumpkin seeds, chia seeds, legumes, quinoa, coconut flour, and wild
rice. The composition of prebiotic fibre food change when they are cooked. Once cooked, they lose some of the prebiotic fibre that they contain. Try to eat your prebiotics raw or steam them if you want them cooked. The recommendation is to consume at least 5 grams of prebiotic fibre daily. Prebiotic fibre supplements are also available.
OTHER DIETARY FIBRES
Foods also contain other fibres, which are essential to digestive tract health. Insoluble fibres speed up the passage of waste through the colon. Food that sits in the digestive tract for too long can begin to putrefy, creating harmful toxins, and feeding the “bad” bacteria in the gut. Soluble fibres help decrease cholesterol levels and control blood sugar. Diets low in fiber can not only starve healthy bacteria in the gut, but also contribute to a degrading of the mucosal barrier along the gut lining, causing leaky gut and imbalances in our gut microbiome. High-fibre foods include avocados, berries, legumes, wholegrain breads, cruciferous vegetables such as broccoli and Brussels sprouts, and leafy green vegetables. Many fruits are also high in fibre, but tend to contain a lot of sugar. Aim for 30 grams of fibre per day.
Autism is one example in which an imbalanced gut microbiome can bring on disease. There has been a dramatic increase in the number of cases of autism in children. One of the potential causal factors which contribute to autism is an imbalance in the microbiome. Natural strategies to improve the symptoms of autism include improving gut health and balancing the microbiome. Diet plays a huge role in improving the symptoms of autism. Removing processed and conventionally grown foods is important, as well as adding supplements to support gut health.
PROBIOTICS
The human digestive tract contains about 400 types of probiotic bacteria that reduce the growth of harmful bacteria and promote a healthy digestive system. The largest group of probiotic bacteria in the intestine is lactic acid bacteria, of which Lactobacillus acidophilus is the best known. Probiotics in food are live, beneficial bacteria, naturally created by the process of fermentation in foods like sauerkraut, miso soup, kimchi, kombucha, and tempeh. They are also available in pill form and are added into foods such as yogurt and health drinks. Their role is to provide the introduction of a very specific strain of bacteria into the microbiome to treat various symptoms. While many types of bacteria are classified as probiotics, most come from two groups: Lactobacillus—the most common probiotic found in yogurt and other fermented foods. It can help with diarrhea and may help with people who cannot digest milk sugar (lactose). Bifidobacterium—may ease symptoms of irritable bowel syndrome (IBS) and related conditions.
These two bacteria are naturally present in the large intestine. Their role is to fight harmful bacteria in the intestines, prevent constipation, and to give immune system a boost. They also help reduce intestinal concentrations of certain carcinogenic enzymes, reducing the risk of colon cancer. These healthy bacteria also replenish organisms whose numbers have been depleted and have caused illness.
When supplementing with probiotics, use strains that are able to counteract specific pathogens which cause illness. Probiotics are used for patients on antibiotics, to repopulate the colon with desirable bacteria after the course of antibiotics has wiped out both beneficial and undesirable bacteria. Often the use of antibiotics leads to an overgrowth of candida bacteria which leads to yeast infections. Probiotics work to reduce the overgrowth of unhealthy bacteria.
When using probiotic supplements, it is important to make sure that the bacteria are alive. Probiotic bacteria are fragile, and can easily be killed by stomach acid, time, and heat. All probiotic supplements should be refrigerated. The use of probiotics is developing into a new field of science, where probiotics can be used to confer a variety of health benefits. Currently they are being used to lower blood pressure, treat cardiovascular issues, lower cholesterol levels, treat depression and anxiety, improve survival in premature babies, treat irritable bowel syndrome, constipation, fungal infections, and antibiotic-acquired diarrhea. Future treatments are being looked at in multiple sclerosis, Parkinson’s, and dementia.
GET DIRTY
Our outdoor surroundings improve our gut microbiome. Animals, plants, and dirt all harbour their own bacterial microbiome. By coming in contact with soil and animals, we actually acquire unique and diverse bacteria that improve the health of our microbiome. Just getting skin contact with the earth can be beneficial. If you get fresh organic produce from local sources, simply rinse them in water before eating to leave behind some of the beneficial soil based organisms. Another great way to have contact with the earth is to start a garden. Having a pet can also greatly benefit your gut microbiome. Children who are raised with pets actually have lower rates of allergies and obesity. The current trend of protecting children from dirt, and keeping them in as hygienic an environment as possible has had detrimental effects on the health of a child’s microbiome, as it prevents the natural exposure to external microbiomes, increasing the risk for inflammatory illnesses. It has been proven that children who grow up on farms have less allergies and autoimmune illnesses. Soil-based bacteria have been proven to treat a wide variety of health conditions. These include: allergies, asthma, ulcerative colitis, nausea, indigestion, irritable bowel syndrome, malabsorption, nutritional deficiencies, autoimmune and inflammatory diseases, and bacterial, fungal and viral infections.
STRESS
Stress, although it is a mental state, can physically affect the health of our gut, and the microbiome contained in the gut. A recent study showed that high levels of stress can affect the gut microbiome to a similar degree as a high-fat diet. A study found that a group of people with depression had increased levels of unhealthy bacteria, and reduced levels of healthy bacteria. When we look at the converse, studies have shown that reducing the number of bacteria in our gut can produce stress-induced activities. Therefore, it is a two-way street. Stress alters our microbiome, and an altered gut microbiome can increase stress levels. Take some time every day to meditate, pray, and express gratitude in some form to reduce stress levels.
EXERCISE
As we know, the more diverse our gut microbiome is, the healthier we are. Studies show that exercise diversifies one’s gut bacteria; athletes have more varied intestinal microbes than their non-athlete peers. There is also a strong correlation between a person’s cardiovascular fitness and a diverse gut microbiome. Exercise improves the intestinal bacteria’s ability to produce an important metabolic product known as butyrate; it is an important short chain fatty acid necessary for maintaining the health of the gut in general; it has a powerful anti-inflammatory function, and reduces the risk of colon cancer. It also helps maintain the integrity of the gut lining. Changes to the gut microbiome are more pronounced in lean individuals. The benefits of exercise on our microbiome dramatically diminish if exercise is discontinued. Therefore, a regular, ongoing exercise regime is crucial for our gut health.
THE FUTURE
It is clear that the human microbiome plays an important role in the health of humans, and that it is implicated in the development of a wide variety of diseases. Now that researchers have been able to identify the components of the human microbiome, the next step is to investigate exactly how the human microbiome is involved in causing or preventing disease. Identifying the variations in microbiomes between healthy and unhealthy people can further lead to understanding microbiome-based diseases. Recent research has been done in knowing how potential germs/pathogens from outside the body invade the human body, and how this relates to the gut microbiota. This will help to identify ways to limit the invasion of potentially harmful microbes and their disease-causing effects. Science has developed techniques that can predict the function of the various microbes in the gut. The goal for this type of research is to identify microbiome-based diagnoses, and then develop treatment strategies that manipulate the bacterial colonies to treat disease, by inserting specific strains of bacteria into an existing microbiome. This approach will result in very personalized treatments for each individual person, based on their microbiome, with improved outcomes.
With the knowledge of the function of the different components of the microbiome, specific probiotic treatments can be used. Probiotics have been used to restore the health of flu patients more quickly. Another probiotic reduced the severity of liver disease in patients with cirrhosis. In cancer treatment, an intact microbiome improves the immune response to certain cancer drugs. Many studies have shown that probiotics have shown outstanding effects on the treatment of allergic diseases, especially those in infants.
Current treatments include fecal transplants for people with difficult-to-treat c. difficile bacterial infections. A solution of healthy feces is introduced into the sick person’s colon. The feces have healthy gut bacteria that can fight the infection, and has been found to be more effective than antibiotic treatments. Ongoing research is looking at using this procedure in other conditions.
Some scientists believe analysis of our microbiome will one day be as common as routine blood tests. Doctors could discuss the results with you and develop strategies that address the long-term management of your gut bacteria to maintain its health. Current research could one day lead to customized probiotics that would offset whatever disease-promoting microbiome you might harbor. One researcher stated, “You could envision a therapy, where people are actually taking specific microbiota, that actually helps them prevent obesity or diabetes.”