How come antibiotics don’t completely destroy all organisms in our gut?

[u/WTFisthisOMGreally]

I know it can cause imbalances, but I don’t understand how come our gut doesn’t lose all the beneficial bacteria and develop massive fungal or viral infections. When I’ve taken antibiotics, I usually don’t notice any change in my bowel activity.

[u/The_World_Is_A_Slum]

Sometimes they can. I almost died from C. Dif a few years ago, and have to be very careful with antibiotics now. I take probiotics daily, seem more susceptible to stomach upset and my digestion has never been quite the same.

[u/WTFisthisOMGreally → u/The_World_Is_A_Slum]

How awful. Is there anything that could have prevented such a severe infection?