The bacterial species Lactobacillus reuteri is a star in the world of intestinal microbes, one that yields spectacular effects for its human host. Up until the mid-twentieth century, most people in the Western world enjoyed the benefits of this bacterial species dwelling in their GI tracts, which they had acquired from their mothers as infants by passage through the birth canal and breastfeeding. Indigenous people living in jungles and mountains, as well as chickens, pigs, and other creatures, carry this microorganism, suggesting that it plays an essential role in survival.
But modern life has eradicated this species from 96 percent of people in the Western world. Today, only 4 percent—fewer than one in twenty people—continue to enjoy the presence of this marvelous species.[16,17] Among the many benefits of