Your Options Have Never Been Better With Dr. Brown’S Natural Flow Anti-Colic Options Wide-Neck Glass Baby Bottle. The Anti-Colic Internal Vent System Is Clinically Proven To Reduce Colic. Dr. Brown’S® Bottles Provide A More Comfortable Feeding Experience For Baby By Decreasing Spit-Up, Burping And Gas. This Vacuum-Free Feeding Is Closest To Breastfeeding And Dr. Brown’S® Silicone Nipples Provide A Consistent Flow So Baby Can Feed At Their Own Pace. The Breast-Like Nipple Shape Encourages A Proper Latch For A More Natural Bottle Feeding Experience And Eases The Transition From Breast To Bottle And Back Again.