I Contain Multitudes is a wonderful book by Ed Young on the microbes within us.
Time and again, bacteria and other microbes have allowed animals to transcend their basic animalness and wheedle their way into ecological nooks and crannies that would be otherwise inaccessible; to settle into lifestyles that would be otherwise intolerable; to eat what they could not otherwise stomach; to succeed against their fundamental nature. And the most extreme examples of this mutual assured success can be found in the deep oceans, where some microbes supplement their hosts to such a degree that the animals can eat the most impoverished diets of all – nothing.
This is another book exploring the wonders of biology and the complexity of the interaction between animals and microbes.
For hundreds of years, doctors have used dioxin to treat people whose hearts are failing. The drug – a modified version of a chemical from foxglove plants – makes the heart beat more strongly, slowly, and regularly. Or, at least, that’s what it usually does. In one patient out of every ten, digoxin doesnt’ work. Its downfall is a gut bacterium called Eggerthella lenta, which converts the drug to an inactive and medically useless form. Only some strains of E. lenta do this.
The complex interactions within us are constantly at work helping us and occasionally causing problems. This obviously creates enormous challenges in health care and research on human health. See related posts: Introduction to Fractional Factorial Designed Experiments, “Grapefruit Juice Bugs” – A New Term for a Surprisingly Common Type of Surprising Bugs and 200,000 People Die Every Year in Europe from Adverse Drug Effects – How Can We Improve?.
Every person aerosolized around 37 million bacteria per hour. This means that our microbiome isn’t confined to our bodies. It perpetually reaches out into our environment.
Avoiding bacteria is not feasible. Our bodies have evolved with this constant interaction with bacteria for millions of years. When we are healthy bacteria have footholds that make it difficult for other bacteria to gain a foothold (as does our immune system fighting off those bacteria it doesn’t recognize or that it recognized as something to fight).
A few pages later he discusses the problem of hospital rooms that were constantly cleaned to kill bacteria and largely sealed to reduce airflow. What happened is those bacteria the sick people had in them were the bacteria that were flourishing (the number of other bacteria to compete for space was small). Opening the windows to welcome the outside air resulted in better results.
Outdoors, the air was full of harmless microbes from plants and soils. Indoors, it contained a disproportionate number of potential pathogens, which are normally rare or absent in the outside world
Human health is a fascinating topic. It is true antibiotics have provided us great tools in the service of human health. But we have resorted to that “hammer” far too often. And the consequences of doing so is not understood. We need those scientists exploring the complex interactions we contain to continue there great work.
Related: People are Superorganisms With Microbiomes of Thousands of Species (2013) – Bacteria are Always Living in Our Bodies (2014) – Gut Bacteria Explored as Medical Treatment – even for Cancer