Nathan Bryan describes a study of breast milk from 70 mothers showing colostrum is high in nitrite, which converts to nitric oxide in a newborn's sterile gut before bacteria arrive. This pathway may protect preterm infants from necrotizing enterocolitis, a serious intestinal disease that breastfed babies rarely develop.
We got an IRB approved. We tested over 70 mothers that were admitted to Memorial Herman labor and Delivery, and we just sampled breast milk throughout postpartum, different time periods from day two all the way up to four and five weeks postpartum. And what we found was that the ratio of these anions changed with the transition of milk. So, as you're probably aware, the early milk is the colostrum. So it's this what people think is high in immunoglobulins. It's really what's the essential nutrients for these first days of life. And then after day four, to five to two weeks, you get what you call transition milk. And then from two weeks on is what's classified as mature milk. So what we found was, and we reported in that paper, was that that early colostrum contains really high concentrations of nitrite relative to nitrate. But then as the milk transitions into mature milk, then the ratio of these anions change. And, in fact, there's little nitrite in mature milk. And physiologically, what we think is happening is when the infant's born, they have a sterile gut. There's no bacteria that are colonized in their gut. And so we as humans don't have a functional nitrate reductase. We rely on the bacteria in our mouth and in our gut to perform this. So as the gut becomes colonized over the period of the first several days, then nature's provided a way, or what we think is providing a way, as a source of nitric oxide. So it's the nitrite in the milk that when the baby takes the colostrum, that's reduced to nitric oxide in the stomach, in the gut. But then as the bacteria begin to colonize, there's really a perfect overlap in the time of colonization to the time at which the change in these anions take place. So once the bacteria are colonized, then they have the machinery on place then to reduce the nitrate in the milk to nitrite, which then becomes nitric oxide. Now, this becomes really exciting and important clinically, in particularly a condition called necrotizing entericolitis. Premature babies that are subjected to hypoxia and in the NICU and our fed formulas, developed this. And I think it's still about a 20% mortality rate for this. But babies that are breastfed don't develop next. But we have some very preliminary data showing that if we replete, and we have animal models of this, that if we replete the missing nitrite in the breast milk and just fortify it in the formula, we can completely prevent the development of necrotizing enterocolitis. And in fact, we're about to take this into the clinics. But I think from a neonatal standpoint, this nitric oxide story stays with us from the time of birth until we pass on. So it's something that we can't ignore at any point in life.
