I wished to write about 2 remarkable popular science books on microbes and infectious diseases that I recently read.

The first is British science journalist Ed Yong’s “I Contain Multitudes: The Microbes Within Us and a Grander View of Life”. An extraordinary book – marred only by the slight (but perhaps understandable) hyperbole – on microbes (mostly bacteria) and the microbiome and their proper place in life, this book made me realise that I understood very little about microbiology and infectious diseases. Some of the concepts and examples are actually decades old and have been put into practice, i.e. human milk oligosaccharides (HMOs) are now present in virtually all formula milk, but these are not actually digested by the human baby, but goes towards selecting and nourishing particular species of gut bacteria such as Bifidobacterium infantis, that then seem to go on to modulate the immune system beneficially. But it is nonetheless interesting to learn about them and the complex interplay between the microbiome and multicellular organisms including humans.

The concepts that we are actually “islands” for our microbes, that they have co-evolved with us influencing our own evolution, and that they are critical for the development of the vast majority of multicellular organisms including animals and humans are powerful ones. These are all now being cautiously explored and applied in health research. Take for instance, this amusing but powerful idea of the “Anna Karenina” principle of “unhappy microbiomes”.

multitudes
Screen capture of the two available covers for Ed Yong’s book, obtained from the author’s blog.

The second book is “Plucked: The Truth about Chickens” by science journalist and author Maryn McKenna. I had read her previous popular science book on methicillin-resistant Staphylococcus aureus and was not too impressed, but this book really blew me away.

Big chicken
Screen capture from Amazon.

It is truly an in-depth (perhaps the word “epic” is also appropriate) view of antibiotic use in animal husbandry and the implications of such practice, with chickens as the main “star attraction”. In the process, she described how chickens went from being a rare treat to becoming the ubiquitous cheap meat, how the discovery of antibiotics as growth promoters were made, and how people began to piece together the link between antibiotic use in meat production and human disease. There were many historical and obscure gems, including the process of “acronization” – where meat was soaked in a diluted solution of antibiotics (chlortetracycline) as the animals were butchered, leaving a film on the meat as it was packed for sale, extending the time to which they could be offered for sale weeks. How the animal industry in the US fought against regulation of antibiotic use in agriculture was also sobering and illuminating.

Maryn McKenna also detailed how things have begun to change in the poultry industry, with more and more of the big conglomerates either stopping the use of human antibiotics as growth promoters (ionophores have no human antibiotic equivalent) or else discontinuing the practice of antibiotic growth promoters entirely. Part of this is due to FDA’s persistence, the rest due to consumer preferences and pressure, and – the most curious of all – that the effect of antibiotics as growth promoters had begun to wane in the setting of the American industrial poultry farm.

The main criticism for this book is that it is too America-centric. There are descriptions of what the French and Dutch did, and detail about a couple of large U.K. outbreaks linked to antibiotic use in food, but it would have been nice to have had an overview of events in other parts of the world. But overall, this is a minor issue, and this book is highly recommended for those curious about antibiotic use in animals as well as for those embarking on activities to curb their use, especially in the light of the Global Action Plan against Antimicrobial Resistance.

You might not view the chicken on your plate the same way again!

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