Why we must act to conserve microbial diversity

With 1,276 vertebrate and plant species becoming extinct in the last five centuries, the impact of human activity on biodiversity is apparent. However, awareness of the threat to microbial life has not yet reached the forefront of scientific discourse despite growing evidence that modern medicine and agriculture pose significant risks to the diversity of microorganisms.

About 3.8 billion years ago, microorganisms were Earth’s first inhabitants, predating all other forms of life and producing the geochemical environment that allowed for the evolution of complex species. Today, microbes represent the vast majority of biodiversity, with over a trillion species thriving in remarkably diverse environments — ranging from deep sea hydrothermal vents and acidic volcanic springs to the digestive systems of virtually all animals. While microbes are primarily associated with disease, only 1,415 species of microorganisms are known to be pathogenic. The remaining 999 billion species of bacteria, fungi, and viruses sustain all life on Earth by regulating major biogeochemical cycles, degrading environmental contaminants, and supporting plant growth. 

“The remaining 999 billion species of bacteria, fungi, and viruses sustain all life on earth by regulating major biogeochemical cycles, degrading environmental contaminants, and supporting plant growth.”

Just as Earth depends on microbial activity, humans are dependent upon the 38 trillion microorganisms living within the body to digest key nutrients, simulate immune system function, and synthesize certain vitamins and amino acids. Moreover, humans harness the unique abilities of microbes to perform complex industrial chemical reactions, produce enzymes and medicines, and treat sewage waste, making microbial diversity not only vital for human health and ecological balance, but also for technological and medical advancements.

However, human activity continues to threaten microbial diversity. The widespread overuse of antibiotics in medicine and agriculture, coupled with the excessive use of broad-spectrum disinfectants in daily life, could lead to the unintended destruction of essential microbial species. These modern tools are only intended to target pathogenic microbes, but they lack the specificity necessary to avoid harming symbiotic microbes. In agriculture, antibiotics are administered to livestock and crops to prevent disease and promote growth, but often end up in surrounding soil and water where they can be detrimental to existing microbial ecosystems. In healthcare, antibiotics are frequently overprescribed for viral infections, contributing to the depletion of microbial diversity within the human body. 

Action must be taken to protect microbial species, not only because of their importance to human health, but to ensure the stability and resilience of Earth’s ecosystems. Curbing the overprescription and misuse of antibiotics in both medicine and agriculture, where their extensive use is harmful to beneficial microbes, is the first step to preserving microbial diversity.