text: Yo, we checked the skills of four probiotic bacteria,
  Lactobacillus acidophilus, Lactobacillus reuteri,
  Lactobacillus casei GG, and Bifidobacterium animalis, hear me?
  They wanted to colonize, infect, and stimulate immune responses,
  In them gnotobiotic beige-athymic (bg/bg-nu/nu) and beige-euthymic (bg/bg-nu/+) mice, oh please!
  
  These bacteria took over the alimentary tracts, no doubt,
  In both mouse strains, they stayed throughout,
  For the whole study period, which lasted 12 weeks,
  They were persistent, not weak!
  
  In adult beige-euthymic mice, no one died,
  But in beige-athymic pups, infant mortality did arise,
  This happened when the moms were colonized,
  With pure cultures of L. reuteri or L. casei GG, oh my!
  
  These probiotic bacteria, they had their own game,
  Some adhered to surfaces, others spread without shame,
  They affected body weight and neonatal growth,
  And stimulated immune responses, representing their oath.
  
  While they were safe for the adult mice, no harm done,
  It's crucial to be cautious when dealing with the young ones,
  Especially neonates and immunodeficient hosts,
  Further studies needed, safety claims they must boast!