The other thing that has helped significantly for me is Vitex agnus-castus for this problem. Again, I have lots of speculation about how/why, but it's only speculation. No other effects/side effects, though I think it's fair to say it helps my digestion a wee bit as well. This has made a bigger difference in my breathing than the baking soda thing. If I keep it up with the Vitex, about a gram twice a day every day, breathing issues don't surface in the first place.