The emerging importance of the human microbiome
Research suggests your gut plays a big role in your mental health, sudden changes to what you eat can affect you in ways you probably have never realised
Lets get specific, in terms of cell numbers you are made up of 43% of cells that are your body cells and the remaining 57% are microorganisms that live alongside you¹. The estimates for the amount of human cells you have are always changing, but the most estimated update suggested theres a ratio of 1.3 bacteria per human cell. In the past they actually used to believe the ratio was closer to 10:1.
These organisms live in your guts, in your mouth, on your teeth … crazy. You will have a unique-ish set of roughly 160 species of microorganisms that live inside of you which make up your microbiome out of a total of around 1000 that have been characterised already ². (3x10¹⁸⁹). To put that number in perspective it has been estimated that there are 1x10⁸⁰ atoms in the observable universe³. I don’t actually have a feasible way of putting that into perspective but just know its HUGE. (Maybe one day if I am not lazy, I’ll term a calculation that illustrates the number.)
The microbiomes function is not entirely understood and like most things its currently being researched. However reasonable observations have been made, I am not here to critically analyse them but just to make you aware of some functions.
Hormone Control
The microbiome inside you can actually create hormones your body can recognise⁴. In women in particular the microbiome actually has a role within the cycle of oestrogen. The microbiome has an ‘estrobolome’ and this is defined as products created by the organisms within your microbiome that have the ability to interact with and metabolise estrogen in your system. The microbiome interacts by creating for example hormonal intermediates which can then participate in further reactions and affect the levels found within the body.
Neurotransmitters
One of the microbiomes critical functions is regulating your hormones and neurotransmitters. The microorganisms inside you can actually create hormones your body can recognise. They have been shown to produce and consumer a wide range of neurotransmitters, ones that you might know, dopamine and serotonin⁵.
90-95% of serotonin actually resides in the gastrointestinal tract, AKA the microbiome⁶.
It brings a whole new meaning to feel good foods, these neuro chemicals can have a direct effect on your mood. This is also a good place to mention on the surface level, I have referenced this article however the study was completed on mice. So, does it really apply to us? Who knows, however mice are a pretty decent model organism nevertheless.
The future
The human microbiome may one day become a target for therapeutics. Some current therapies actually involve the transfer of faecal matter between people, and there are actually some big advocates for it.
Faecal matter transplants are actually a relatively common procedure that occurs in hospital during extreme bacterial infections. Some people use them as a home therapy and firmly stand by the benefits of faecal transplants. Just to clarify a faecal matter transplant would introduce a foreign microbiome into yours and would potentially change yours.
Don’t take my word for it
Slightly anecdotal but I remember in first year I tried a vegetarian diet and I remember towards the end of the week being really irritable and generally quite sad. And I genuinely think it had something to do with my diet, so I stopped. However knowing this information, I did it again in second year and managed to pull through the first week it was tough like the first time I tried it but I was prepared this time and carried on with the diet.
That’s when it clicked for me. I realised how much of an effect changing diet can actually have on your wellbeing, obviously this section isn’t fact it’s how I feel but I do feel like there was a big impact. I think as humans we always like to try and find reasons for the unkown and it is way more fitting to have a potential reason than no reason at all. We all fear the unknown.
Why have I said all of this
Why have I said all of this? I’m not here to convince you on anything but rather to get you to think about things, you should try to come to your own conclusion. As I said at the start, sudden changes to your diet can affect you. When I say you I mean the other 57% of you that you live alongside of. If you upset the other 57% of you it can have changes on your mental health.
Also not sure about you but I personally don’t think it’s a good idea to annoy the trillions of microorganisms in your microbiome.
Don’t feel pressured into making big changes into your diet so you have a “summer body” by June 21st, take it slowly and most importantly have fun whilst you do it.
Learn to cook new foods in healthier ways
Learn new ways to exercise
Take small steps to build the person you want to be
Most importantly take it slowly and ease yourself in. Thanks for reading.
References are for nerds. So me?
- Sender R, Fuchs S, Milo R. Revised Estimates for the Number of Human and Bacteria Cells in the Body. PLoS Biol. 2016;14(8):e1002533. Published 2016 Aug 19. doi:10.1371/journal.pbio.1002533
- Lloyd-Price J, Abu-Ali G, Huttenhower C. The healthy human microbiome. Genome Med. 2016;8(1):51. Published 2016 Apr 27. doi:10.1186/s13073–016–0307-y
- https://www.universetoday.com/36302/atoms-in-the-universe/
4. Kwa M, Plottel CS, Blaser MJ, Adams S. The Intestinal Microbiome and Estrogen Receptor-Positive Female Breast Cancer. J Natl Cancer Inst. 2016;108(8):djw029. Published 2016 Apr 22. doi:10.1093/jnci/djw029
5. Strandwitz P. Neurotransmitter modulation by the gut microbiota. Brain Res. 2018;1693(Pt B):128–133. doi:10.1016/j.brainres.2018.03.015
6. Yano JM, Yu K, Donaldson GP, et al. Indigenous bacteria from the gut microbiota regulate host serotonin biosynthesis [published correction appears in Cell. 2015 Sep 24;163:258]. Cell. 2015;161(2):264–276. doi:10.1016/j.cell.2015.02.047
