This book review was written by Eugene Kernes
“This genetic wealth, combined with their rapid evolution, makes them virtuosos of biochemistry, able to adapt to any possible challenge. They help to digest our food, releasing otherwise inaccessible nutrients. They produce vitamins and minerals that are missing from our diet. They break down toxins and hazardous chemicals. They protect us from disease by crowding out more dangerous microbes or killing them directly with antimicrobial chemicals. They produce substances that affect the way we smell. They are such an inevitable presence that we have outsourced surprising aspects of our lives to them.“– Ed Yong, Chapter 1: Living Islands, Page 18
“Each of us has our own distinctive microbiome, sculpted by the genes we inherited, the places we’ve lived in, the drugs we’ve taken, the food we’ve eaten, the years we’ve lived, the hands we’ve shaken. Microbially, we are similar but different. When microbiologists first started cataloguing the human microbiome in its entirety they hoped to discover a “core” microbiome: a group of species that everyone shares. It’s now debatable if that core exists. Some species are common, but none is everywhere. If there is a core, it exists at the level of functions, not organisms. There are certain jobs, like digesting a certain nutrient or carrying out a specific metabolic trick, that are always filled by some microbe – just not always the same one.” – Ed Yong, Chapter 1: Living Islands, Page 23
“We like our black-and-white narratives, with clear heroes and villains. In the last few years, I’ve seen the viewpoint that “all bacteria must be killed” slowly give ground to “bacteria are our friends and want to help us”, even though the latter is just as wrong as the former. We cannot simply assume that a particular microbe is “good” just because it lives inside us. Even scientists forget this. The very term symbiosis has been twisted so that its original neutral meaning – “living together” – has been infused with positive spin, and almost flaky connotations of cooperation and harmony. But evolution doesn’t work that way. It doesn’t necessarily favour cooperation, even if that’s in everyone’s interests. And it saddles even the most harmonious relationships with conflict.” – Ed Yong, Chapter 4: Terms and Conditions Apply, Page 89
Is This An Overview?
Human individuals are never alone. Each contains a multitude of microbes. Humans live together with the microbes, in symbiosis. Microbes follow humans throughout life. Sharing food. Upon death, microbes consume humans. Microbes are part of the ecosystem, influencing much of life. Many functions in ecology, and even in the human body, have been delegated to microbes.
The associations about microbes have changed. Microbes were thought to be a dangerous threat to be removed. Microbes make their presence felt with traumatic human experiences such as ravaging diseases. As more research was done, microbes were found to produce many wanted and beneficial effects. Microbes have become seen as a much needed ally. Many health and ecological problems, are associated with bad microbiomes.
The symbiosis of human and microbes can be managed, but like any symbiosis, there is always an inherent conflict. The symbiosis is a complex partnership. Microbes educate the immune system, or threaten the host when the immune system is compromised. Microbes can be very beneficial within a context and location, but the same microbes can be harmful in other locations. Different host activities and environmental factors develop different microbiomes. Every human has a different microbiome. Rather than there being a core microbiome that a species share, microbe similarities appear in their function. Different microbes can perform the same tasks.
What Are Microbes And What Do They Do?
Most microbes are bacteria. Other microbes include fungi, archaea, and viruses. Bacteria can photosynthesis, and produce oxygen. Some microbes can survive even without oxygen, which is claimed to be an essential gas.
Microbes break down material elements to be used by the flora and fauna. They can decompose the organic bodies which provides nutrition for the soil. Bacteria can even break down pollutants, harmful chemical. Microbes can protect the human from harmful microbes. Some facilitate food digestion, allowing humans to obtain otherwise inaccessible and needed nutrients. They effect human smell. Develop the human body.
Microbes are very genetically diverse. Microbes can exchange DNA with each other with ease. Microbe evolution appears to be quick to the host, but is still a slow and gradual process of change.
How To Have A Relationship With Microbes?
Microbes were discovered by Antony van Leeuwenhoek during the 17th century, using handmade lenses to observe a drop of water. After bacterium were proved to cause anthrax, they were perceived to be avatars of death. Various other deadly diseases had after that been seen as caused by microbes. It was not until the late 19th century in which microbes were seen as anything but deadly sources. Martius Beijerinck studies their impact on the soil and atmosphere.
The perspective that the presence of microbes is a sign of contaminants is a problematic stereotype, because there are relatively few microbes that cause problems for humans. There are many more that are just passengers, or are integral to the human processes. Many human processes have been delegated to microbes.
Human immune system is not just composed of cells, but also microbes. As microbes allow the immune system to react to threats without overreacting. The immune system is more about managing the relationships between microbes, rather than just defense and destruction.
Microbes are a factor in determining weight. Antibiotics in animals has tended to make the animals heavier, with the antibiotics claimed to be growth promoters. Antibiotics disrupts microbiomes. The indiscriminate use of antibiotics has caused the bacteria to evolve to resist the antibiotics. Making antibiotics obsolete. Antibiotics need to be used judiciously with understanding of the risks and benefits. Probiotics are an antithesis to antibiotics, for probiotics deliberately attempt to add microbiomes rather than remove them.
There are consequences to a world without microbes. For that removes the microbes that are also very beneficial. Microbes matter, but so does their hosts behavior. It is an ecosystem, where all parts influence to each other. Humans can manage the partnerships with microbes. To manipulate the partnerships intentionally.
There is an inherent complexity to how microbes influence life. Research on microbes is ongoing, with many associations acknowledged to not be consistent. Microbes are part of a dynamic system, in which there are other influencing factors.