In his celebrated poem “Song of Myself,” Walt Whitman explored the multifaceted complexity of human nature, writing “Do I contradict myself?/Very well then I contradict myself;/(I am large, I contain multitudes.)” These lines, long exalted for their poetic and psychological insight, may contain more scientific truth than even Whitman himself imagined. That’s the premise of Ed Yong’s latest work, I Contain Multitudes: The Microbes Within Us and a Grander View of Life.
In promotion of this fascinating book, Yong took time to do an interview for NPR’s popular “Shots” segment. Over the course of the discussion, which you can read and/or listen to here, Yong spoke about a variety of trending topics in the world of microbiome research. These included:
How Can Diet Influence the Composition of the Microbiome?
Though this question is still hotly debated in scientific circles, Yong points out that many carbohydrates found in dietary fibers are, in fact, completely impossible for the human body to digest on its own. They serve instead as nutrition for many distinct species of bacteria that live in our guts--and people who eat diets lacking in dietary fibers tend to lack biodiversity in their intestinal microbiomes.
Are Humans Evolutionarily Designed to Foster Diverse Microbiomes?
Yong goes on to mention that a certain type of sugar found in breast milk (oligosaccharides, for the curious) is also impossible for babies to digest. Rather, it feeds the beneficial bacteria B. infantis--essentially helping the body develop a healthy microbiome from the very start!
What Does the Decreasing Diversity of the Human Microbiome Imply for the Future?
Many alarmists are quick to argue that the overuse of hand sanitizer, antibiotics, and a general obsession with excessive hygiene have decreased diversity within the average human microbiome. Yong’s response to this may come across as surprisingly calm: he simply reminds the interviewer that these changes could actually be due to the modern diet, and that the long-term effects of such a change are still unknown. He finishes by asserting that such unknowns are, in fact, still quite common--thus underlining the need for further research.