Biodiversity loss could be making us sick – here’s why
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UNCCD Library
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Web resource
By 2050, 70% of the world’s population is expected to live in towns and cities. Urban living brings many benefits, but city dwellers worldwide are seeing a rapid increase in noncommunicable health problems, such as asthma and inflammatory bowel disease.
Some scientists now think this is linked to biodiversity loss – the ongoing depletion of the varied forms of life on Earth. The rate at which different species go extinct is currently a thousand times higher than the historical background rate.
Microbial diversity is a large part of the biodiversity that is being lost. And these microbes – bacteria, viruses and fungi, among others – are essential for maintaining healthy ecosystems. Because humans are a part of these ecosystems, our health also suffers when they vanish, or when barriers reduce our exposure to them.
The inner ecosystem
Our gut, skin and airways harbour distinct microbiomes – vast networks of microbes that exist in different environments. The human gut alone harbours up to 100 trillion microbes, which outnumbers our own human cells. Our microbes provide services that are integral to our survival, such as processing food and providing chemicals that support brain function.
Contact with a diverse range of microbes in our environment is also essential for bolstering our immune system. Microbes found in environments closer to the ones we evolved in, such as woodlands and grasslands, are called “old friend” microbes by some microbiologists. That’s because they play a major role in “educating” our immune systems.
Part of our immune system is fast-acting and non-specific, which means it attacks all substances in the absence of proper regulation. Old friend microbes from our environment help provide this regulatory role. They can also stimulate chemicals that help to control inflammation and prevent our bodies from attacking our own cells, or innocuous substances like pollen and dust.
Exposure to a diverse range of microbes allows our bodies to mount an effective defensive response against pathogens. Another part of our immune system produces tiny armies of “memory cells” that maintain a record of all the pathogens our bodies encounter. This enables a rapid and effective immune response to similar pathogens in the future. Read further from the source
Some scientists now think this is linked to biodiversity loss – the ongoing depletion of the varied forms of life on Earth. The rate at which different species go extinct is currently a thousand times higher than the historical background rate.
Microbial diversity is a large part of the biodiversity that is being lost. And these microbes – bacteria, viruses and fungi, among others – are essential for maintaining healthy ecosystems. Because humans are a part of these ecosystems, our health also suffers when they vanish, or when barriers reduce our exposure to them.
The inner ecosystem
Our gut, skin and airways harbour distinct microbiomes – vast networks of microbes that exist in different environments. The human gut alone harbours up to 100 trillion microbes, which outnumbers our own human cells. Our microbes provide services that are integral to our survival, such as processing food and providing chemicals that support brain function.
Contact with a diverse range of microbes in our environment is also essential for bolstering our immune system. Microbes found in environments closer to the ones we evolved in, such as woodlands and grasslands, are called “old friend” microbes by some microbiologists. That’s because they play a major role in “educating” our immune systems.
Part of our immune system is fast-acting and non-specific, which means it attacks all substances in the absence of proper regulation. Old friend microbes from our environment help provide this regulatory role. They can also stimulate chemicals that help to control inflammation and prevent our bodies from attacking our own cells, or innocuous substances like pollen and dust.
Exposure to a diverse range of microbes allows our bodies to mount an effective defensive response against pathogens. Another part of our immune system produces tiny armies of “memory cells” that maintain a record of all the pathogens our bodies encounter. This enables a rapid and effective immune response to similar pathogens in the future. Read further from the source
Keywords
biodiversity
human health impacts
urbanization
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