I also have taken Culturelle. I never noticed any difference with my breathing or respiratory issues. I switched to a different, lower cost probotic because Culturelle was costing $20 for a 15 day (if taken twice daily) supply. Yes, you can use it as medical tax credit, but that money doesnt do me any good right now. I will have to do research on the respiratory sytems relationship because I have never heard of it helping that, just the digestive system.