Did you know that you are just 10% human? For every one of your cells, there are nine impostors hitching a ride. It turns out that you are not just flesh and bone, you are also bacteria and fungi. Today, we are going to explore how microorganisms present in our bodies influence us and find out what role they play in our everyday life.
Your gut contains about 1.5 kg of bacteria, which is about the same weight as your liver. The bacteria found in your intestines are a signature of our health and dietary status, not only personally, but as a society as well.
In what way do these microorganisms influence our bodies?
Your impostors are not taking advantage of you in any way. There are there for your benefit – and they help you in a number of ways. For example, Vitamin B12, which is essential for proper functioning of the nervous system, is not coded for by DNA, but it is made by the Klebsiella and Citrobacter species. The Bacteroides species shape your intestinal walls. The disruption to your body’s microbial balance is currently studied as a possible cause in skin conditions such as acne, psoriasis, and dermatitis and in diseases such as inflammatory bowel disease, cancers of the digestive track, obesity and even mental health conditions.
The difference between microbiology and biology
Biology is a natural science that studies life and living organisms, their physical structure, chemical processes molecular interactions, physiological mechanisms, development, and evolution. The branch of biology that studies microorganisms is called microbiology. To put it simply – microbiology is biology studying very small organisms.
Discovery of microorganisms
People have hypothesized the existence of microorganisms for many centuries before their discovery. The first person to observe and experiment on bacteria was Antonie van Leeuwenhoek – a Dutch businessman and scientist, who used a single-lens microscope of his own design in his experiments. Ferdinand Cohn was a botanist who described several bacteria and formulated a scheme for their taxonomic classification, thus founding bacteriology (a subdiscipline of microbiology). However, the two men considered to be the fathers of microbiology are Louis Pasteur and Robert Koch. Pasteur is best known for disproving the widely held in his time's theory of spontaneous generation, as well as designing methods for food preservation and vaccines against several diseases. Koch is most famous for his work on the germ theory of disease, proving that specific diseases were caused by specific pathogenic microorganisms. He was also the first scientist to isolate bacteria in pure culture and he described several new bacteria species.
Microbiology in our everyday life
We depend on microorganisms not only in scientific studies and medical applications (e.g. antibiotic production and as DNA vectors to transfer it to more complex organisms) but also in our everyday life. They are responsible for many beneficial processes, such as fermentation, which is necessary for the production of alcohol, vinegar, and dairy products. They are also used to produce biopolymers and they help us degrade waste, which is called biodegradation or bioremediation. As mentioned previously, we have a symbiotic interaction with many species that help us produce many vitamins and amino acids as well as suppress pathogenic microbes.
As Alanna Collen in her book ‘10% human: How Your Body’s Microbes Hold the Key to Health and Happiness’ puts it: ‘We have come to depend on our microbes, and without them, we would be a mere fraction of our true selves’. Microorganisms are crucial for the proper functioning of our bodies and they are intensively researched for the treatment of many diseases.
Written by: Marta Luterek
Marta Luterek is volunteering for Voyager Space Outreach to write Blog posts on Space/STEM oriented topics.