This has helped some folks' IBS symptoms: https://www.vsl3.com/

Contains:

  Streptococcus thermophilus 
  Bifidobacterium breve 
  Bifidobacterium lactis (previously classified as B. longum)
  Bifidobacterium lactis (previously classified as B. infantis)
  Lactobacillus acidophilus
  Lactobacillus plantarum
  Lactobacillus paracasei
  Lactobacillus helveticus (previously classified as L. delbrueckii subsp. bulgaricus)

I'll have to research L Reuteri, thank you for mentioning it.