Can good bacteria cause disease?

NO. No; they assist us with digestion, produce b12, they produce natural antibiotics that keep other bacteria, fungus and parasites out of the systems. So keeping the gut well flourished with probiotics is ideal. I recommend 2 caps three times daily till gas, bloating and odor are eliminated then reducing to 1-2 caps daily for maintenance. Repeat as often as needed www.Medac4u.Com.
Yes. In certain people, especially people with a weakened immune system " due to aids, or sick people in the hospital, " good bacteria can become harmful, please note that good bacterial is not a medical term though....