Do anti-colic bottles actually reduce gas and spit-up?

Reviewers are divided. Dr. Brown's vented design has the strongest 'clinically proven' marketing and a large base of verified-purchase reviewers who credit it with less gas, while several community voices in r/NewParents say they noticed little difference and disliked the extra parts. The consensus is that anti-colic venting helps some babies meaningfully and does little for others, so most parents are advised to buy one or two before committing to a full set.