Dr. Brown's Natural Flow bottles reviewed by the people who know them best - moms. See what these moms have to say about Dr. Brown's bottles and how they have helped their babies. At Dr. Brown’s, our focus has always been to create innovative feeding products to promote good health and optimal nutrition for baby. Dr. Brown’s Natural Flow is the only baby bottle to feature an internal vent system that: helps preserve vitamins C, A, & E by minimizing oxidation of breastmilk and formula (read the nutrient study now); provides positive-pressure vacuum-free feeding similar to breastfeeding; and helps reduce colic, spit-up, burping and gas by eliminating negative pressure and air bubbles. Dr. Brown’s Natural Flow baby bottles are BPA-free and have received numerous design awards and acclaim from the medical community. In fact, many of our bottles go to hospitals, NICUs, and doctor offices. Most important, moms are talking and they’re sharing with excitement the improved feeding habits of their babies. Happy feeding.