Farrell, Jeanette. 2005. INVISIBLE ALLIES. New York: FSG. ISBN 037433083
INVISIBLE ALLIES: MICROBES THAT SHAPE OUR LIVES by Jeanette Farrell is the companion to her previously published (1998)
book entitled INVISIBLE ENEMIES: STORIES OF INFECTIOUS DISEASE. (Yes, the book has been revised and issued as a second edition
this year.) Full of “I didn’t know that facts,” INVISIBLE ALLIES is a fascinating presentation of how microbes
“shape our lives” both inside and outside our bodies. After presenting a brief history of the key scientists who
discovered the microbe world—including Antony van Leeuwenhoek and Louis Pasteur—the text follows a simple premise:
to follow a simple meal of a cheese sandwich and chocolate bar from creation through digestion.
INVISIBLE ALLIES is divided into five main chapters. “Microbes at the Table” is a detailed summary of the history
of cheese and cheese production. You may or may not be surprised to know that there are scientists who are “cheese microbiologists”
who study just how cheese is made by the microbes. “As an expert on cheese microbiology once said, looking for the activity
of a particular microbe in a cheese is a bit like looking for the Loch Ness monster. On the scale of a microbe, the cheese
is as big as the 600-foot-deep lake in Scotland—it offers many living creatures plenty of room to hide. Tools for microbial
explorations invented in the last twenty years of the twentieth century improved our ability to find and distinguish microbes,
and some of these tools are being used to explore the microbial wilderness that is cheese” (34). Likewise, “Our
Daily Bread” is a detailed summary of how bread is made—specifically leavened bread. This chapter is devoted to
the wonderful (yet diverse) microbe yeast. Included in this section is a “try this at home” experiment for making
your own sour dough bread. In addition it chronicles the lives of the brothers Fleischmann and their yeast-selling company.
“Food of the Gods” begins as a chapter devoted to the history of the cacao bean, which was thought by many cultures
to be “the food of the gods” (in fact it was money!) Toward the end of the chapter, however, Farrell goes slightly
off topic to present brief histories of cultural and ethnic foods from around the world that rely on microbes in their production.
Included, for example, is a discussion of kimchee, soy sauce, cassava, sausage, and fermented fish. She also touches on the
idea that these foods (along with cheese, bread, and chocolate) are an important part of our individual cultures. “Microbes
Are Us” presents how the human body uses microbes (in the mouth, stomach, and intestines) to digest food. She stresses
the point that these microbes in our bodies are crucial to making our human bodies function properly. We couldn’t live
long without them. The final chapter “Rot Away” discusses how microbes are used to rid the world of human waste.
Perhaps the grossest chapter, it discusses how microbes decompose poop—her words not mine—and dead people, plants,
INVISIBLE ALLIES is a fascinating book. Although she includes illustrations (photographs, sketches, drawings, etc.) they
are all in black and white. But the text itself should be engaging enough to hold the attention span. The narrative style
is informative yet at times slips into light conversation. Included are a glossary, index, and endnotes with selected bibliography.
It is definitely an enjoyable read.