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Application Of The Human Microbiome
Applications of the Human Microbiome
Hanson Wen
In 2007, The United States National Institutes of Health research started a project called the Human Microbiome Project [1], which means from then on, the science community had accepted the human microbiome as an important subject. The human microbiome has been chosen as one of the ten science breakthroughs of the year in 2011 by the Science magazine [2]. Other famous science magazines have also started including the Microbiome section from then on. But what is it? The definition of it in simple terms is all of the microorganisms in a human in a specific area such as skin, lungs, mammary glands, placenta and so on. The microbiome can take up to 4% of your weight and can do many things. For example, scientists have discovered that humans cannot digest seaweed because no enzymes coded by the human genome can break down the carbohydrates that are tangled with sulfur molecules which are within the plant. But what happens when we eat seaweed? There is a type of marine bacteria (Zobellia galactanivorans) that can digest seaweed, and the same kind of enzyme that these bacteria produce has been found in the human-gut bacteria of Japanese individuals [3]. The microbiome can give us power where we are lacking.
The microbiome also aids us in other ways. One of them is that it helps your immune system defend your body. Bacillus subtilis is a bacterium that has been found to contribute to the activation of the production of antibodies and other useful molecules to help white blood cells fight infection [4]. Another ability of microbiomes is that it can affect your emotions, and even affect your brain. A study [5] shows that bacteria in your gut produce 95% of the feel-good hormone, serotonin, in your body. If you extract the gut microbiome of a person in depression and place it in mice, the mice will have symptoms of depression too. How can the microbiome affect our emotions?
There are three routes to our brain. First is the endocrine system [6]. The hormones that the bacteria produce can diffuse straight into the blood from the brain. The second route is the vagus nerve [7]. The vagus nerve system can not only go from the brain to the body, but it can also be bi-directional and go from the body to the brain. Last is the lymphatic system [8]. The microbiome can influence the brain through this system, but this system is also bidirectional. A study shows that gut microbiome inflammation can affect depression and anxiety [9]. These systems, combined, can largely influence the host’s everyday life, even for things such as choosing what you eat. As you can see, the microbiome can affect the human body quite a lot, but how can we manipulate the microbiome to help us?
Applications in Medicine
There is an infection called Clostridioides Difficile Infection (CDI). It is caused by a spore-forming bacteria called Clostridioides difficile. It produces spores in the gut of the host’s body. One way of treating it is to perform a Fecal Microbiota Transplantation (FMT), which is transplanting the gut microbiome of a healthy person to the gut of a person with CDI. FMT is an effective treatment for CDI [10]. Traditionally, CDI was treated using antibiotics such as vancomycin. However, with this method, we have to face the risk of superbugs and also disrupting the balance of the microbiota in the gut. In contrast, FMT restores the beneficial bacterias in the guts, restoring the microbiome, and it also has a high cure rate and low recurrence rate.
Applications in Skincare
Skincare can be a large market for human microbiome technology, as microorganisms can significantly affect the skin. [11] “Physiological effect of a probiotic on skin” shows that S. epidermidis could inhibit acne caused by P. acnes by fermenting glycerol. [12] Many companies are working on microbiota skincare [13]; for example, this [14] “face vinegar” (See Fig. 1) uses the same principle as the research I have mentioned above. It contains glycerol which can inhibit the growth of P. Acnes.
Fig 1. A picture of “face vinegar” [15]
Wild Imagination
For now, these are only the cultivated applications of the human microbiome, but as this technology develops, it will change how we live. This is a wild imagination of the future as this technology develops.
Photo by Isabel Chau
You open your groggy eyes, lug yourself off the bed and drag your body to the kitchen. The coffee maker screeches so you pick it up and add coffee powder. You then add a small packet of gooey stuff into it. It dissolves into your hot coffee and as you drink it. You can feel the smooth lubricating feeling of the coffee going down your throat. The microorganisms in the packet stick to your throat, keeping your throat moisturised for 2 hours. As it finally touches down on the stomach, the rest of the living organism reaches your gut. It slowly spreads, causing a nice warm feeling in your body that makes you happy for the rest of the day. You are on your way to work and touch the sticky handle of the metro. There are harmful bacteria that cause flu if it gets in your body fluid. The micro-hand sanitizer you applied this morning is coming into effect. The microbiome is attacking the harmful germs, and your hands turn blue because the signalling bacteria is notifying you when there is a battle going on. You realize it and quickly spray disinfectant alcohol on your hands. Unfortunately, some of the bacteria survived the alcohol. It managed to get into your mouth because you were going to be late and ended up eating your breakfast in your working space. The immune system is actively killing the germs, while the bacteria in your mouth signals the immune system to produce more antibodies. After 5 hours of work, the bacteria is finally killed, and your microbiome and immune system prevent you from catching the flu. However during the fight, you arrived at the office, and while you were picking up the stack of paper on your desk, you accidentally got a paper cut. You go to the first aid box and take out a flat plastic cylinder. It contains microorganisms that can heal your wound in a matter of hours. As you place this cylinder on your wound, the fungus gets into action. It builds a bridge across the wound, then pulls it together. Then the fungi form a solid structure. They then self-destruct. You take the plastic cylinder off and wait for your wound to heal. Tonight, as you shower, the shampoo you use contains the microbiome which inhibits oil and keeps your hair healthy. The shower gel contains anti-odour organisms and the toothpaste inhibits odour and kills germs in your mouth. That is a normal day of a person living in a highly microbiome developed society. It is not certain if this will ever happen to us, but there is lots of potential in the applications of the Human Microbiome.
Bibliography
[1] “Human Microbiome Project.” Wikipedia, Wikimedia Foundation, 10 Apr. 2020, en.wikipedia.org/wiki/Human_Microbiome_Project.
[2] Cohen, J., et al. “Breakthrough of the Year, 2011.” Science/AAAS | Special Issue: Breakthrough of the Year, 2011, 2011, www.sciencemag. org/site/special/btoy2011/.
[3] Keim, Brandon. “Gut Bacteria Give Super Seaweed-Digestion Power to Japanese.” Wired, Conde Nast, 4 June 2017, www.wired. com/2010/04/sushi-guts/.
[4] “B Subtilis Probiotic – Why Is It Useful?” Bacillus Subtilis Probiotic Benefits - Probiotics.org, probiotics.org/bacillus-subtilis/.
[5] FeaturedNeurosciencePsychology·June 6, 2020, et al. “How Gut Bacteria Negatively Influences Serotonin and Blood Sugar Levels.” Neuroscience News, 17 Sept. 2019, neurosciencenews.com/gutbacteria-serotonin-blood-sugar-14930/#:~:text=Summary%3A%20 A%20new%20study%20shows,serotonin%20levels%20causes%20 metabolic%20problems.
[6] C;, Rastelli M;Cani PD;Knauf. “The Gut Microbiome Influences Host Endocrine Functions.” Endocrine Reviews, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/31081896/.
[7] Bonaz, Bruno, et al. “The Vagus Nerve at the Interface of the Microbiota-Gut-Brain Axis.” Frontiers in Neuroscience, Frontiers Media S.A., 7 Feb. 2018, www.ncbi.nlm.nih.gov/pmc/articles/ PMC5808284/#:~:text=The%20microbiota%2C%20the%20gut%2C%20 and,afferent%20and%2020%25%20efferent%20fibers.
[8] Tsunoda, Ikuo. “Lymphatic System and Gut Microbiota Affect Immunopathology of Neuroinflammatory Diseases, Including Multiple Sclerosis, Neuromyelitis Optica and Alzheimer’s Disease.” Clinical & Experimental Neuroimmunology, U.S. National Library of Medicine, Aug. 2017, www.ncbi.nlm.nih.gov/pmc/articles/PMC5703598/.
[9] Peirce, Jason M., and Karina Alviña. “The Role of Inflammation and the Gut Microbiome in Depression and Anxiety.” Wiley Online Library, John Wiley & Sons, Ltd, 29 May 2019, onlinelibrary.wiley.com/ doi/10.1002/jnr.24476.
[10] Nood, Els van, et al. “Duodenal Infusion of Donor Feces for Recurrent Clostridium Difficile: NEJM.” New England Journal of Medicine, 31 Jan. 2013, www.nejm.org/doi/10.1056/NEJMoa1205037.
[11] Muizzuddin N;Maher W;Sullivan M;Schnittger S;Mammone T; “Physiological Effect of a Probiotic on Skin.” Journal of Cosmetic Science, U.S. National Library of Medicine, pubmed.ncbi.nlm.nih. gov/23286870/.
[12] D. Blank-Porat, T. Gruss-Fischer, et al. “Staphylococcus Epidermidis in the Human Skin Microbiome Mediates Fermentation to Inhibit the Growth of Propionibacterium Acnes : Implications of Probiotics in Acne Vulgaris.” Applied Microbiology and Biotechnology, Springer Berlin Heidelberg, 1 Jan. 1970, link.springer.com/ article/10.1007/s00253-013-5394-8.
[13] “35 Microbiome Skincare Products.” TrendHunter.com, TREND HUNTER Inc., 19 Feb. 2019, www.trendhunter.com/slideshow/ microbiome-skincare.
[14] “Hibiscus Vinegar Toners.” TrendHunter.com, TREND HUNTER Inc., 29 Jan. 2019, www.trendhunter.com/trends/face-vinegar.
[15] “Face Vinegar 200ml.” Know To Glow, knowtoglow.com/products/ face-vinegar-200ml.
