A clinical study confirms that babies using new Playtex VentAire Advanced bottles had less gas, spit-up, colic and other discomforts than with other leading bottles. Here"s why: Breakthrough Micro-Channel Vent Technology. Unlike ordinary bottles that vent through the nipple, VentAire Advanced keeps air at the back of the bottle as baby drinks, so virtually NO AIR mixes with the milk and gets into baby"s tummy.