In the June issue of LandMarks, we explored just the surface facts of our microbiome. We learned that it is simply a bustling community of microbes on and within the body that significantly influences the body’s overall wellbeing.
Bacteria are by far the most numerous members of the human microbiome estimated to be between 75–200 trillion individual organisms, while the entire human body consists of about 50 trillion–100 trillion body cells. The area that contains the largest amount of microbiota is the intestinal area, especially the large intestine. Five hundred to 1,000 different species of bacteria may live in the intestine, totaling at least 38 trillion cells. It is said by some that if you could only focus on one aspect of health it should be gut health.
Did you know? Over half of the cells in your body are not even human cells.
We also learned that the microbiota interact with almost every body system, and that the gut microbiome has been called the “second brain” because it interacts so closely with our brain, brain chemistry, and its many functions. The microbiome is very active in the metabolism of our food. Chronic and infectious disease risks are also affected by our microbiome. The gut also is intimately connected to our immune system—70% to 80% of the immune system is in the gut.
We also know that our microbiome affects our mood and behavior. Digestion, sleep, immune health, brain function, mental health, metabolism and cardiovascular health are closely linked to the microbiome, emphasizing its importance in maintaining a healthy living human. The microbiome may help prevent or help fight some forms of cancer, and help prevent or treat some forms of dementia.
Given the importance of a healthy microbiome on the wellbeing of the human body, our question should be, How do I help my gut have a healthy, diverse group of microbiota? To help answer this question, let me share with you the very interesting findings of cultural and health studies of two groups of people, the Hadza tribe from Tanzania and the Yanomami tribe from Venezuela, some of the last hunter-gatherers on our planet.
Approximately 200 of the Hadza tribe stick to a strictly nomadic, hunter-gatherer lifestyle. They survive on foraged plants and animals hunted with handmade bows and arrows and live in temporary grass and stick shelters. It’s believed that the Hadza people have some of the healthiest gut microbiomes on the planet. Their diet consists of about 70% plant foods including tubers that contain a range of indigestible fibers that are ideal gut fuel. They get a huge 150 grams of fiber per day. This results in the Hadza having a greater variety of gut microbes than that of 17 other cultures around the world. Most Americans get just 10-15 grams of fiber per day. The Hadza have about 40% more microbial biodiversity in their gut than Americans. This exceptionally high fiber intake seems to be a main contributor to their very healthy gut microbiomes—fiber is fuel for your gut microbes, allowing them to multiply and produce health-promoting compounds.
Getting fiber from a variety of plants helps to create microbial diversity. Research from 2018 found that people who ate more than 30 different plant types per week had a healthier gut microbiome than those who ate fewer plant types. Our focus should be to eat more whole, fiber-rich plant foods such as leafy greens, berries, cruciferous veggies (broccoli, Brussel sprouts, cauliflower, to name a few), Jerusalem artichoke, avocado, beans, and lentils. Sautés and salads are an excellent way to get many different plant foods into a single meal.
Another contributing factor to the Hadza people’s healthiest, most diverse gut microbiomes is that their food source is natural, with no processed foods or agriculturally farmed foods, high in fiber and phytochemicals, and devoid of processed sugars, all of which contribute to the fact that the Hadza experience almost no autoimmune diseases, obesity, diabetes, colon cancer, Crohn’s disease, and other chronic ailments. This is very unlike our modern Western diets which are often low in fiber and phytochemicals, and high in refined carbohydrates, processed foods, unhealthy fats, and contain high levels of sugar.
A third factor in the robust and healthy gut microbiomes of the Hadza people is that they do not live in “sterile environments.” They don’t just admire nature, but interact with it. They are in constant contact with the earth, walking barefoot, working or digging in the ground and with animals when they hunt. So we can increase our contact with our environment by growing indoor and outdoor plants, tending gardens, and through being outside with our families and pets.
A similar study was conducted in Venezuela with the Yanomami tribe. It was found that they had a 50% greater microbial diversity than the average American. They too were hunter-gatherers with a diet high in plant foods. So it seems that the farther away a person’s diet gets from our modern western diet, the more diverse the range of microbes in our intestines. This includes a number of bacteria that are completely missing from the modern American gut. Clearly, a person’s diet plays a major role in the gut microbiome.
The modern Western diet is largely deficient in fiber and high in processed junk, fat, refined sugars, and refined carbohydrates. The research strongly suggests that this diet is effectively wiping out many bacterial species from our digestive tracts.
Surprisingly, the Hadza microbiome fluctuated over the course of the year depending upon the specific season of the year. During the long dry periods, the Hadza people eat considerably more meat, much like a Westerner. Some species of bacteria prevalent during the wet seasons disappeared or their numbers fell to an undetectable level, similar to that seen when analyzing the Western microbiome. During the wet seasons, these missing microbes return.
So cutting the amount of fat, processed food, processed carbohydrates and processed sugars, and having a high fiber diet and interacting with the natural environment may be the vital keys to having a healthy, diverse microbiome that greatly improves the overall health of the microbiome, body and mind.
Sources: vitalplan.com/blogs/blog/the-6-secrets-of-the-hadza-tribe-what-we-can-learn-about-health-and-longevity; ncbi.nlm.nih.gov/books/NBK154100; Britannica.com/science/human-microbiome#Overview