Your digestive tract contains “good” microorganisms-probiotics – and bad. Probiotics help to maintain healthy digestion and a strong immune system by keeping harmful bacteria in check. Intentionally or accidentally, you have probably consumed foods containing probiotics. Such as Bifidobacterium, Lactobacillus acidophilus, Lb. casei, Lb. paracasei or Lb. rhamnosus. These bacteria are the live cultures found in yogurt. You can also find probiotics in raw cheeses.