America's best baby bottle now in India. Designed by a doctor in ***6 and patented in ***7, Dr. Brown’s Natural Flow® is the only baby bottle to feature an internal vent system that: helps maintain vitamins C, A, & E by minimizing oxidation of breastmilk and formula 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.