The human microbiome (microbes and their genes) is perhaps the hottest research subject in the scientific community at the moment, and recent findings show that the microorganisms living iun and on our bodies impact most aspects of our health. Although the information is slowly starting to spread into the general community through newspapers and blogs, a large percentage of people have no idea that humans live symbiotically with trillions of microorganisms and that these germs seem to determine if we are healthy or sick. Although it’s to early to determine the exact composition of a healthy microbiome, we know a lot about the lifestyle factors that impact the bacterial communities in our body. This article is for those people that are just getting into the idea of humans as superorganisms and want some scientifically proven steps that will allow the “good” bugs to flourish …
1. Eat mostly nutrient-rich whole foods
Eat primarily grass-fed meats, seafood, eggs, berries, fruits, vegetables, and some nuts. Dairy products such as butter, GHEE and fermented dairy are also well tolerated by the majority of people. If whole grains and legumes are eaten regularly, they should be traditionally prepared. Soaking, sprouting and/or fermentation will neutralize many toxins and antinutrients and increase the bioavailability of many nutrients found in grains and legumes.
Limit the consumption of sugar, refined foods, and hydrogenated vegetable oils.
Studies and observations show that hunter-gatherers and people eating traditional diets are virtually free from chronic non-communicable disease (1,2, 3,4,5). While other factors such as sun-exposure, physical activity and exposure to germs also affect health, it’s clear that the transition from eating a diet rich in nutrient-rich whole foods to a typical western diet is a major cause of chronic disease seen in the industrialized world.
2. Consume fermented food on a regular basis
Fermented foods such as sauerkraut and kimchi contain probiotic bacteria that exert positive health effects. While it’s unclear to which extent bacteria from fermented foods are able to permanently colonize the gastrointestinal tract, studies show that beneficial bacteria such as Lactobacillus compete with pathogenic microorganisms for adhesion sites and modulate the host’s immune response (6,7) Besides the probiotic value, fermentation increases the bioavilability of many nutrients, breaks down antinutrients, and makes the food easier to digest.
3. Eat plenty of fermentable carbohydrates
Prebiotics are non-digestible food ingredients that stimulate the growth and/or activity of bacteria in the digestive system in ways claimed to be beneficial to health. While only a few nutrients such as inulin and oligofructose are officially classified as prebiotics, it seems that most fermentable carbohydrates (polysaccharides with the exception of starch) found in fruits and vegetables boost the growth of good bacteria.
Consumption of these fermentable substrates leads to growth of beneficial microorganisms in the digestive system, and most people will benefit from including several types of fermentable carbohydrates in their diet (8,9,10). Onions, leeks, chicory roots, green bananas, apples and traditionally prepared legumes are foods that are especially rich in prebiotic fibre.
Moderate-severe alterations in gut flora (e.g., small intestinal bacterial overgrowth, simplified gut flora) could lead to poor breakdown of fermentable substrates.
4. Don’t be too hygienic
While hand sanitizers, soaps, food pasteurization and other measures of removing bacteria decrease exposure to rare pathogens, the fact is that humans have evolved for millions of years in a symbiotic relationship with microorganisms. This contact with both beneficial and potentially harmful germs is important in the development of the immune system, and it’s also a way of increasing the diversity of the microbiome. Hunter-gatherers routinely come in contact with bacteria from dirt, water, food, other humans, and animals, and this is likely one of the reasons why these societies remain free of non-communicable chronic disease.
While it seems that early life exposure to microorganisms is especially important (10), adults will also benefit from reducing the use of soap and antibacterials and getting some more dirt into the diet.
5. Avoid antibiotics
Although oral antibiotics are used to kill potentially pathogenic bacteria, they are also effective against a wide-range of beneficial microbes in the body. The use of antibiotics could lead to permanent changes to the protective flora in the gut, poor digestion,and increased inflammation (11).
Healthy gut microbiota provides protection against infection from bacterial pathogens as long as the community remains undisturbed. When oral antibiotics disrupt the community of microbes, several enteric pathogens get the opportunity to grow in the gut (12).
Other drugs have also been linked to increased intestinal permeability and/or alterations in gut flora, but antibiotics are by far the worst offenders.
Other factors that affect the human microbiome
Other factors such as time outdoors, home microbiome, exercise, stress, contact with other humans and animals, breastfeeding and vaginal vs. caesarean birth also affect the bacterial communities in our body.