The Harmless Nature of Most Micro-organisms

Most micro-organisms are harmless. They are essential for life and are constantly present in our environment and body, such as in our gut system where they aid in digestion.
Many micro-organisms work together with other species in symbiotic relationships, in which both organisms benefit. An example of this is the nitrogen-fixing bacteria in plant roots, which aids in nutrient absorption.
Micro-organisms are crucial for cycling of nutrients in ecosystems. They facilitate processes such as decomposition, which returns nutrients to the soil for re-use by plants.
In the field of biotechnology, harmless micro-organisms are employed for various purposes. Saccharomyces cerevisiae, a yeast, is used in baking and brewing, while other types are employed in the production of cheese and yoghurt.
However, a minority of micro-organisms can be pathogenic, meaning they cause diseases. It is this group that our body’s immune system defends against.
Diseases caused by pathogenic bacteria include Tuberculosis and Salmonella food poisoning. Viruses can cause diseases like the common cold or more serious illnesses like HIV/AIDS.
Fungi can also be pathogens, causing diseases like Athlete’s foot, while Protoctists cause diseases like Malaria.
Importantly, the majority of micro-organisms are not pathogenic and actually provide numerous benefits to us and to our ecosystem. By understanding the role and nature of micro-organisms, we can both harness their positive traits and better fight against the diseases caused by the minority that are harmful.
There are also instances where normally harmless micro-organisms can cause disease if they enter a part of the body where they don’t normally live. This includes E.Coli, which are normally harmless in our gut system but can cause infections if they enter the urinary tract.