Your microbiome should be renamed your “megabiome.” It is enormous in its physical span, the number of species it is comprised of, and in its scope—all of which are critical in providing you with physical, mental, and emotional health.

To begin, you are very hospitable, by default. You are host to more than 100 trillion microorganisms both in—and on—your body, including at least 1000 different species of known bacteria with more than 3 million genes (150 times more than human genes). You have ten times more microbial genetic material than you do human genetic material. There are more microbes in you than there are stars in the sky. And these microscopic species can add up to nearly five pounds of weight that you carry around! You are literally a walking ecosystem.

In addition, you are the only organism in the universe with your exact microbiome. It’s your internal whole-body fingerprint—like an individual identity card—and its overall composition is established by the time you are three years old, with some variations based on your changing exposure and environment. If scientists were to study your microbiome it would provide them with some interesting information, such as your biological sex, whether or not you own a pet, and if you get migraines.

The composition of your microbiome evolves throughout your entire life, from birth to old age, and is the result of different environmental influences. Gut microbiota’s balance can be affected during the aging process and, consequently, the elderly have substantially different microbiota to younger adults. While the general composition of the intestinal microbiota is similar in most healthy people, the species composition is highly personalized and largely determined by our environment and our diet. The composition of gut microbiota may become accustomed to dietary components, either temporarily or permanently. Japanese people, for example, can digest seaweed (part of their daily diet) thanks to specific enzymes that their microbiota has acquired from marine bacteria, just as babies can digest lactose in breastmilk.

What is a microbiome exactly?

The collection of microbes that live in and on the human body are known as the microbiota, whereas the microbiome refers to the combined genetic material of all these microbes. It is a biomarker, just like your fingerprint, only it encapsulates the bio-individuality of your whole body and not just the tip of your finger. These microbial species include bacteria, fungi, viruses, and other microorganisms, which congregate in their “mini ecosystems” (microbiomes). These microbes are generally harmless and are often advantageous for human health. Since we all know the harmful effects of certain bacteria (such as the type that cause diarrhea from food poisoning), I instead will focus on the beneficial impact of our microbiomes.

The Bacterial World

These tiny buggers are everywhere—in us (most abundantly in the colon), on us (our skin has its own microbiome), and around us (bacterial life comprises every organism on the planet). Bacteria are the most successful species to ever exist on our planet. They were the first lifeforms in the very beginning of planet Earth. We are descendants of bacteria and they have evolved with us from the beginning of human existence. They are so multitudinous, it’s impossible to know just how many there are. And just like there are many varieties of humans, in terms of our diverse interests, job responsibilities, sizes, shapes, etc., there too are many characters in the bacteria kingdom, all with varying profiles and responsibilities.

What’s so great about a Microbiome?

While you may shudder at the grotesqueness of these microbial visuals I’m painting for you, understand that these microorganisms do so much good for you: they break apart indigestible foods for us to assimilate; they supply the gut with energy; they manufacture some vitamins (certain B vitamins and vitamin K); they degrade toxins and medications; they help us combat aggressions from other microorganisms—which maintains the wholeness and balanced diversity of the intestinal mucosa; and they play an important role in the immune system, performing a protective barrier from external invaders. A healthy and balanced gut microbiota is key to ensuring proper digestive functioning, as well as healthy mental and emotional functioning.

Sometimes we alter our microbiome and sometimes it alters us.

We are our microbiota’s whole universe. We are their climatic factors, their food source, their home. In exchange, these microbiota can either take care of us or poison us. However, they typically only poison us when we have created an extreme internal imbalance, which throws their ecological stability off-kilter. A prime example of this is when we take broad-spectrum antibiotics and overuse topical disinfectants for fear of germs. These antibiotics and disinfectants are just that—anti-life. They kill ALL bacteria, both good and bad, in their massacre of the bad bacteria. So, while they may successfully kill the bacterial infection that we originally utilized them for, they also carpet-bomb all of the beneficial bacteria that helps us digest our food, defend against harmful pathogens, keep our intestinal tracts intact, to name just a few key roles. This then makes our internal landscape vulnerable to further imbalances and infections, which makes us feel unwell. And although our microbiomes are quite adaptable and resilient, a repeated loss of balance in gut microbiota is called ‘Dysbiosis’. Dysbiosis is linked to many health problems such as gastrointestinal disorders, inflammatory  diseases, allergies, obesity, diabetes, and even depression and anxiety.

 The Gut-Brain Axis

Modern science has learned that the gut and brain are not as separate as we once thought. In fact, the gut is now referred to as the “second brain,” or the “enteric brain” (“enteric” means “intestine”) in medical communities. This is not a huge leap when you think about those times you are nervous and fearful and your gut responds in kind, producing bowel disturbances. Another example of the gut-brain connection is that bacteria can produce particles that are small enough to cross your blood-brain-barrier, such as tyrosine and tryptophan. These two amino acids are then converted into dopamine and serotonin, in the brain. A deficiency in these two neurotransmitters causes depression. Adequate amounts make us feel content and maybe even sleepy (such as after a big meal). So, the working theory in the scientific community is this: our gut bacteria reward us when we reward them with food that they like, by making us feel pleasant and satiated. They communicate their delight by producing feel-good substances, which affect us, and by also increasing the body’s production of transmitters. In other words, when out guts are happy, our minds and emotions follow suit. So it’s a win/win situation for all.

How to Rekindle Your Relationship with Your Microbiome

Of primary importance to achieving optimal health lies in decoding and comprehending your gut’s messages to you and appreciating and acting on that communication, so that your gut continues working well. An example of this may be recognizing that every time you eat ice cream, you experience digestive issues. It would be wise to investigate what it is about eating ice cream that brings on this discomfort: is it a certain ingredient such as dairy, sugar, or a food chemical additive? Perhaps it’s the extreme cold temperature that upsets your digestive system? Or do you eat it laying down very late at night, right before bed, when your digestive function is very weak?

In addition, understanding that absolute cleanliness and sanitization is NOT the goal in strengthening your gut and your relationship with it. We happen to live in a germ-phobic world, with fear-driven hygiene. In fact, the higher the hygiene standards in a population, the higher that population’s incidence of allergies and auto-immune disorders. At the same time, the number of infections has not fallen dramatically, proving that this is not smart medicine. More than 95% of the world’s bacteria are harmless to humans. Many are extremely beneficial. But, even the minority of harmful bacteria can be useful for us when the immune system uses them for “training.” For example, a few thousand salmonella bacteria in the kitchen sink provide our immune system with a chance to “get acquainted” with these microbes before waging a full-blown inflammatory war. The salmonella only becomes dangerous when their numbers grow. So, being armed with this vital knowledge will help you to avoid over-sanitizing your world and your body, which will only leave you defenseless against truly harmful pathogens and those whose population’s grow out of control.

We should all be Pro-Probiotics

To be pro-probiotics is to literally be “pro-life,” (not to be confused with those who picket outside of Planned Parenthood). Without probiotics, we would cease to exist—they are that important! Traditionally, probiotics have been consumed in fermented food and drink in every culture in the world, since the beginning of recorded history. Just as anti-biotics are “anti-life,” probiotics are “for life.” Probiotics are the beneficial bacteria that have been mentioned throughout this article. Today, they can either be eaten, drunk, or taken in powder or pill form. Popular probiotic foods are yogurt, kefir, raw sauerkraut, miso, natto, tempeh, lassi, and kombucha.

Many studies have demonstrated the beneficial effects of probiotics and prebiotics on our gut microbiota. To reiterate, probiotics help gut microbiota keep their balance, integrity, and diversity. Probiotics also help to “crowd out” the harmful bacteria we may be hosting. The good bacteria will take up more real estate on our gut walls, leaving no space for the harmful bacteria to hide and/or colonize and multiply. Prebiotics are simply foods that only your beneficial bacteria consume. Prebiotic foods are certain fibers that are solely eaten and bioavailable by and for our beneficial bacteria. This is important, as they help strengthen the diverse array of probiotics you are already hosting, helping them to grow in size and numbers so that they can provide you with all their health-giving properties.

Thanks to technological progress, the picture of your microbial world is becoming clearer. Researchers now use a range of techniques, including the tools derived from molecular biology, to further clarify the vast universe of the microbiome. Many specific strains of microbes have been isolated and researched, providing valuable information as to their specific roles and functions as cast members of the microbiota world.  While we are still only on the precipice of discovering, understanding, and working with this internal and sophisticated universe, more and more findings are presented every day. I believe that this type of medicine will soon be able to provide an individual with everything one needs to know about their particular microbiome, such as which foods and diets are best for them, how to balance out their brain chemistry, and how to rebuild microbial diversity and immunity after antibiotic use.

I’ll end with the same final paragraph from the prolific book, Gut by Giulia Enders, which was a huge inspiration for and the main reference source for writing this piece, as she says it best:

“Seen under the microscope, bacteria look like nothing but little, bright spots against a dark background. But taken together, their sum is much greater than their parts. Each one of us hosts an entire population. Most sit in our mucus membrane, diligently training our immune system, soothing our villi, eating what we don’t need, and producing vitamins for us. Others keep close to the cells of the gut, needling them or producing toxins. If the good and the bad are in equilibrium, the bad ones can make us stronger and the good ones can take care of us and keep us healthy.”

Thanks microbiome!