The Good Gut

High-Level Thoughts

Commonly known as "The Forgotten Organ," gut microbiota health across western society is abysmal. Switching to a more ancestral diet of high plant fiber foods (quinoa, beans, & lentils) and adding fermented foods (saur kraut, yogurt, kefir) can vastly improve gut health.

Summary Notes

Four factors have greatly changed gut flora in individuals in our population over the past few decades. They are: 1) increasing consumption of industrialized, processed foods, 2) widespread use of antibiotics, 3) the alarming rise in Caesarean deliveries, now accounting for one in every three births, and 4) the decline in breast-feeding. (Foreword)

From the birth of humanity until about twelve thousand years ago (a time span of about two hundred thousand years), humans obtained their food exclusively through hunting and gathering. The ancient human diet consisted of sour, fibrous, wild plants and lean, gamey wild meat, or fish. The birth of agriculture marked a dramatic change in the way people ate. (Page 15)

Humans are the evolutionary product of a lineage of organisms that continually figured out how to play nice with their gut microbes. Because the colonization of our gut by microbes was inevitable, our body had to learn how to interact with them in a positive way. (Page 19)We rely on genes within our microbiome to make up for deficiencies we have in our own genome. (Page 22)

Man doesn't just have a bacterial population in his intestinal tract, man is a product of this bacterial population. (Page 25)

After passing through the microbe-containing birth canal, the typical rear-facing presentation of human infants, combined with the compression of the mother's distal colon during delivery (think of a tube of toothpaste), exposes newborns to a faceful of mommy microbiota. While this may seem unhygienic, it is likely no evolutionary accident that our introduction into the microbial world would be accompanied by a healthy dose of mother-approved bacteria. (Page 37)

One of the main ingredients in breast milk is not digestible by the infant who is drinking it. Why would a mother put precious energy into making something her baby can't use? The answer is that HMOs aren't for feeding the baby, they're to provide sustenance for his microbiota. (Page 46)

The Western world has seen a sharp rise in allergies and autoimmune diseases in the past half century. Why are these immune-system related diseases so common now? Evidence points to the microbiota and the immune system as central to the development of these diseases. (Page 61, 62)

Based on the original observation that allergies were less prevalent in children with many siblings, the hygiene hypothesis suggested that children of large families were exposed to more sickness within their household, and so their immune system was occupied fighting infections and didn't have "time" to overreact to pollen or gluten and cause problems. (Page 67)

If microbial exposure happens too late in life, a critical early window of time during development is missed and the immune system is locked into an underdeveloped state.(Page 75)

How did people keep food fresh before the modern refrigerator, before the wooden armoire-like icebox, even before the underground pits filled with snow or ice used by the ancient Greeks, Romans, and Chinese? How did our prehistoric ancestors, especially those living in tropical climates with no access to ice or snow, keep food from spoiling? The answer is that often they didn't, but instead learned how to control spoilage in a way that allowed rotten food to remain edible. (Page 87)

The network of neurons in the gut is as plentiful and complex as the network of neurons in our spinal cord. (Page 138)

Recent evidence indicates that not only is our brain "aware" of our gut microbes, but these bacteria can influence our perception of the world and alter our behavior. (Page 139)

Eating two yogurts a day for one month is enough to change the pattern of your brain's activity in a measurable way. (Page 157)

Taking a round of antibiotics is like setting our microbial ecosystems ablaze. As in the aftermath of a forest fire, close inspection will show that while a few things survive, overall the landscape changes dramatically. (Page 165)

Our microbiome contains one hundred times more genes than our human genome, so in fact there is about 99 percent of associated genetic material that we have the potential to mold in ways that are beneficial to us. (Page 210)