My husband and I decided the purchase these bottles when our little one showed signs of possible acid reflux. I don't know if these bottles have definitely helped him with it as he still has some symptoms. We were using Chicco bottles and what I like about the Dr. Brown bottles is that the nipple does not collapse - at least when using the venting system. The downside to these bottles is that you must follow the assembly instructions carefully as we've had these bottles leak on us a few times until we finally figured things out. Because of that, the bottles aren't easy to use as you can't just place in a bottle warmer and then just feed. You have to loosen the collar when warming or remove the venting system completely and then after warming you can put the venting system back in or if you've left it in you need to tighten the collar back up, but you can't over tighten because that can also cause leaking. So it's a little inconvenient. I cannot speak towards the claims of anti-colic or anti-gas. My little one hasn't been colicky and is still burped on a regular basis.