So where do you start a state of the science conference on lactose intolerance. At the beginning. Rimshot. But where's the beginning? Birth? Not early enough. How about with the fetus?
After the usual opening remarks, the conference began with an overview. Appropriately enough, the first presentation started with the basics.
Early Feeding, Human Milk, and the Transition
Josef Neu, M.D.
Professor of Pediatrics
Director of Neonatology Fellowship Training Program
Department of Pediatrics
Division of Neonatology
University of Florida College of Medicine
We're all designed to be introduced to lactose through mother's milk. That introduction happens shortly after birth. And that creates an unexpected dilemma. Since a fetus will never be exposed to lactose, there's no real reason for one to make any lactase. Yet that lactase has to be there and available when the mother's milk comes flowing in.
The body's response is to gradually ramp up lactase availability. Scientists first detect lactase at about 8 weeks of development. Even at 34 weeks, lactase is only at 30% of what will be needed.
That leaves about six weeks for it to reach the needed 100%. (Actually a tiny bit longer. Mothers make what is known as colostrum for the first couple of days of feeding, a special type of milk designed to add to and stimulate the infant's immune system. Colostrum is especially low in lactose.)
What about premature infants? They face a double whammy. Not only are they not fully developed but they are lacking in a critical enzyme to help digest the one food they can eat. No wonder that premature babies faced such long odds in the days before modern science.
Here's where the science gets weird. Despite all this, studies have shown that feeding lactose to premature infants will help them increase lactase levels faster. It's better to give them mother's milk than lactose-free formulas. (After a month or so, the difference disappears as the lactase-making ability increases naturally.)
Even weirder, the partial lactose intolerance that ensues is itself helpful. Some of the lactose reaches the colon, because there's not enough lactase to digest it all. Babies are born with sterile guts: no bacteria. The bacteria enter after birth because bacteria are everywhere and the world is far from sterile. Which bacteria are in the colon make all the difference. The presence of lactose selects for bacteria that are more beneficial. In other words, lactose acts as a prebiotic. "Prebiotics are non-digestible food ingredients that stimulate the growth and/or activity of bacteria in the digestive system which are beneficial to the health of the body."
Think about that. Food companies are spending millions to create prebiotics to add to foods to make them healthier. Humans do it naturally to help premature babies drink their mother's milk. Mind-boggling.
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