[idkwia]

I often read anecdotal reports that antibiotics kill off a lot of your good bacteria. As a layperson this seems to make sense but on the other hand why would doctors want to risk compromising the health of your gut. In addition, there have been recent trials with the antibiotic Rifaxamin and it seems very likely that it will now be approved by the FDA for use in IBS patients.So my question is do antibiotics compromise your gut flora or is it just a myth? I would prefer no anecdotal evidence if possible and hope that people who really know could provide the right answer please.

 

[Kathleen M.]

You take Rifaxamin to kill off normal colonic flora (just what lives in small intestine rather than in the colon where it belongs).I can't imagine it refuses to kill normal colon flora when you take it for a pathogen. It isn't like it knows which bugs you want dead and which you want left alone.http://www.medicinenet.com/clostridium_difficile_colitis/page3.htm lists which antibiotics tend to cause that (so which effect the colon flora more than others).Lots of antibiotics kill off normal colon bacteria, that is why people get C. diff infections after antibiotics. There isn't enough normal flora and that particular bad guy can get a toe hold and cause problems.How much this effects someone health probably varies and I think a lot of people make it sound way more dangerous than it really is.Here is an article about it from Pubmed.

Eur J Clin Microbiol. 1982 Feb;1(1):38-48.Effect of erythromycin and clindamycin on the indigenous human anaerobic flora and new colonization of the gastrointestinal tract.Heimdahl A, Nord CE.AbstractErythromycin and clindamycin were given orally to ten subjects in recommended doses for seven days in order to study the effects of these antibiotics on human flora. Saliva and faecal specimens were collected for up to 29 days after administration of the antibiotics. Erythromycin caused only minor changes in the saliva flora while the aerobic and anaerobic colon flora were considerably disturbed. Clindamycin depressed both the anaerobic saliva and colon flora. Both erythromycin and clindamycin induced new colonization of the oral cavity and colon. The levels of free volatile fatty acids sank in saliva and faeces when erythromycin and clindamycin were given. The ecological disturbances caused by antibiotics require further investigation and should be taken into consideration in therapy.

http://www.ncbi.nlm.nih.gov/pubmed/7173170There are lots more like it if you need more.