Each moment, between 1,5- and 2 kilograms of bacteria are teaming up with each of us in order to digest food, keep germs away, improve our mood or with many other purposes. It is our gut microbiota, billions of microbes, growing with(in) us since the day we are born. Here are some interesting facts:
- 99% of our body genes are non-human, 90% of our body cells are non-human, they belong to our microbes (gut’s, mouth’s, skin’s, etc.). It is not mainly our genes which make us different, but our microbiome.
- Gut microbes are producing vital vitamins and hormones. For instance, 95% of the entire body serotonin (one of the happiness hormones, with roles also in bones and blood health, sleep quality) is produced by the gut microbiota. Not by the brain.
- Also, gut microbes can “steal” genes from the food to better digest it (let’s keep this in mind for later)
- Microbes may influence stress response capacity and allies with our immune system in case outside pathogens invade us.
- Apparently, there is a link and causality between chronic affections and microbiota composition (i.e. type 2 diabetes reversal)
- “I have a gut feeling” – some choices, related to food, curiosity, courage, social connections are influenced by gut microbe composition (mice lab tests only)
- Microbes can talk to the brain and vice versa (by connecting to the nervous system, by emitting chemical signals or reading them).
However, all the above will function properly only if we have a large variety of gut microbes as each type of these little guys is specialized in a certain job, thus cannot do them all. And each kind of microbe is thriving with a certain type of food. Most of them need plants, and some need animal-based food. So, the more diverse the food and the higher the weight of unprocessed one, the higher chance to increase the diversity of our gut microbiota. In a study run by University of Colorado Boulder and UCSD within the American Gut Project it was observed that the higher the weight of plant based food the higher the diversity of microbes, while in a meat based diet a reduced variety of microbes are prospering on the expense of diversity.
How we are born (natural or through caesarian section), how we live and where we live also matters for gut microbiota prosperity. The antibiotics intake is also a decisive factor for evolution of this community.
I was mentioning above the capacity of some microbes to “steal” genes from food to improve its digestion. In fact, it is a copy paste mechanism of DNA segments, which allow us do digest in good conditions food we ingest for the first time or which could harm us. Not all microbes however can do this. So, the higher diversity of our microbiota, the higher our chances to avoid all kind of troubles, including “modern” diseases like diabetes, obesity, gluten intolerance, Crohn’s disease, different allergies.
In a recent research published this summer in the Nature magazine (Wibowo, M.C., Yang, Z., Borry, M. et al, May 12th 2021), the research team have analyzed the gut microbiota composition from ancient times (1000 – 2000 years old) and compare it with today microbiotas from today industrialized and non-industrialized areas. Conclusion was that there still is some resemblance between non industrialized areas samples and ancient ones (however diversity was by far lower) while the samples from industrialized area showed a totally different gut bacteria composition, and not in a good direction. Basically, a mass extinction of our gut microbiota took place in the last period and many microbes with high adaptability to changing environment have disappeared. Researchers are linking this with the lack in food diversity in our times, with increased antibiotics consumption, and living a rather similar lifestyle all year around.
There are still a lot of aspects to be studied going forward, but scientists are saying that there are already enough evidences to make links between composition of gut microbiota and our eating habits. And this with impact on our predisposition to certain diseases, our mood, our reaction to medication, to dietary prescriptions, and even to our choices and social preferences. So, stay tuned for further discoveries 😊.