A hidden cost of the Agricultural Revolution (both the original 10,000 yrs ago and the one this century) is that human beings varied their diet without being able to vary their digestive system. Things like the caveman diet, paired with genetically modified food may allow more food to be fine tuned for our fickle systems:

“Human milk has 1,600 times more lysozyme than cow and goat milk,” said Elizabeth Maga, an animal scientist at the University of California at Davis who, along with a team of researchers, conducts similar research to that of Li’s group. “This protein plays a big role in putting a good set of bacteria in the intestine.”

Human milk is, as you might expect, good for humans. “There are a lot of studies that have shown that breast-fed human babies are much healthier than ones that get formula, and one of the reasons seems to be that they have much better gut bacteria, which are better at protecting against diarrhea,” Maga told Life’s Little Mysteries, a sister site to LiveScience.