Part 1: Anatomy of the Human MicroBiome
Please see the other sections of the article; once they are completed the links will be active:
Part 2: micro-organisms on the skin
Part 3: micro-organisms in the mouth
Part 4: micro-organisms in the gut
Part 5: implications for modern medicine
Your ability to think of yourself as one whole being is an incredible phenomenon; especially considering that the human body is made up of 37.2 trillion human cells that can act somewhat independently, which is really a gross estimate at this point. What is really interesting is that the majority of the cells in your body are actually bacteria cells, mostly that reside in the human gut. Modern estimates say the proportion is about 10 to 1 (baceria to human cells). That means there are possibly over 300 trillion bacteria cells in your body. In fact, there is evidence to suggest 90% of our cells are microbes or micro-organisms. (small animals,fungi, bacteria, archaea, algae, and protozoa). Outside of the body, on the skin, there are also a fair amount of micro-animals that are excluded from the human microbiota, or the aggregate of the micro-organism genomes on the skin, in the gastrointestinal tract, in the saliva, oral mucosa, and conjunctiva.
Your body might have a proportion of 10 to 1 micro-organisms to human cells, according to one study, which makes it important to consider your body as an environment. Basically, you have an entire ecosystem in your digestive track and this aspect of your body is what merges you with your environment. The digestive tract, from the mouth to the rectum and anus, is essentially a part of the outside world which is why there is so much bacteria and other micro-organisms living there. This is also the reason behind recent skepticism of the effectiveness of antibiotics for certain illnesses and why there is so much emphasis on probiotic in modern nutrition science.
With our new understanding of the micro-organisms that co-exist within humans, we have also begun to study and catalogue the different genomes, however, scientists have found a nearly infinite variation in how the micro-organisms interact and function. The same bacteria cells might function completely differently within the body of another, making the biome extremely difficult to study. The Human Microbiome Project (HMP) is the organization fueling the majority of this research and they are attempting to catalogue the different bacteria and their functions in the body in a similar way to how the Human Genome Project catalogued the human genome.
What this means is that there are not baseline calculations for micro-biome health because it varies so greatly from person to person. Also, different sites on the body have their own distinctive communities; skin and vaginal sites have a smaller amount of diversity than the mouth and gut. Different bacteria like to inhabit different places in the mouth from person to person and can also have different, specialized functions. Over 500 types of bacteria live in the gut alone, mostly in the large intestine or colon. These bacteria are incredibly useful because they break down food and allow for the absorption of nutrients into the human body, however, in times of lowered immunity they can also act as opportunistic pathogens (meaning they can cause disease). E. Coli is one of the bacteria that exist in the gut, and certain mutated strains of this can also cause disease (as you probably heard in the news). But this is a healthy bacteria that when balanced against a strong immune system provides enormous benefit to the digestion and absorption of nutrients.
Here are the elements that create the chemical balance of your body and their associated proportional mass:
- Oxygen = 65%
- Carbon = 18%
- Hydrogen = 10%
- Nitrogen = 3%
- Calcium = 1.4%
- Phosphorus = 1.1%
- Potassium = .25% (can be radioactive)
- Sulfur = .25%
- Sodium = .15%
- Chlorine = .15%
- Magnesium = .05%
- Iron = .006%
- Fluorine = .0037% (toxic in large amounts)
- Zinc = .0032%
- Silicon = .002%
- Rubidium = .00046%
- Strontium = .00046%
- Bromine = .00029%
- Lead = .00017% (toxic in high amounts)
- Copper = .0001%
- Aluminum = .00000087%
- Cadmium = .00000072% (toxic in high amounts)
- Cerium = .00000057%
- Barium = .00000031% (toxic in high amounts)
- Tin = .00000024%
- Iodine = .00000016%
- Titanium = .00000013%
- Boron = .00000069%
- Selenium = .00000019% (toxic in high amounts)
- Nickel = .00000014%
- Chromium = .000000024%
- Manganese = .00000017%
- Arsenic = .00000026% (toxic in high amounts)
- Lithium = .000000031% (toxic in high amounts)
- Mercury = .00000019% (toxic in high amounts)
- Caesium = .000000021%
- Molybdenum = .00000013%
- Cobalt = .000000021%
- Antimony = .00000011% (toxic in high amounts)
- Silver = .00000001%
- Niobium = .0000016%
- Zirconium = .000006%
- Lanthanum = .00000137%
- Tellurium = .00000012%
- Gold = .000000140%
- Vanadium = .00000026%
- Uranium = .0000000013% (toxic in high amounts)
- Beryllium = .00000000005% (toxic in high amounts)
- Radium = .0000000000000000001% (toxic in high amounts)
You’ll notice a few very interesting things about some of these elements. The first is that many substances can be toxic in high dosages, and obviously you can be malnourished if you have less of these elements. The second is that there are radioactive elements in your body; yes you are radioactive, just like the Earth. The radioactive elements are particularly interesting: Potassium40 has over 4,000 events per second in the human body; Carbon14 has over 3,000; Rubidium has over 100; and Lead210, Tritium, Uranium238, Radium228, and Radium226 all have under 20 events per second. To me, this emphasizes the need for balance in the human body; not too much and not too little.
It is astonishing to think that there is a hole, a series of tubes really, inside of you that is really a part of the outside environment. But this makes perfect sense to a Taoist, who would say that a human ‘is the same’ as the environment they are in. Two sides of Yin and Yang that are always playing together to continue life. Most research suggests that our gut flora (or the collective bacteria in an ecosystem) is symbiotic and has a direct relationship with the functioning of the body.
The functions of the flora are the following (though it has been found that some people can function without gut bacteria): fermenting unused energy substrates, training the immune system, preventing growth of harmful species, regulating the development of the gut, producing vitamins, and producing hormones. Extensive modification and imbalances of the gut microbiota and its micro-biome or gene collection are associated with obesity. However, in certain conditions, some species are thought to be capable of causing disease by causing infections or increasing risk for cancer (paraphrased from Wikipedia).
So obesity might be better understood as an imbalance in gut bacteria that leads to slower digestion and less nutrient absorption. It also makes sense that there is a cascade type of effect, where the body has “momentum” to digest with large amounts of built up gut bacteria. So a ‘fast metabolism’ might be summarized as healthy gut flora. Interesting stuff right? In my opinion this is some of the most exciting science being researched today.
This is part of the reason why a balanced diet is key to being healthy. There is a lot more information coming, I’m especially excited to get into the gut flora and their implications for mental and cognitive health. The next article will be about the skin, and all of the micro-organisms that live on you. Stay tuned, hoping to have it out tomorrow.