have used pbx in the past to repopulate gut microflora after abx, back when I was misnourished and very susceptible to infection.
since then have worked to balance the right nutrient intake, so that the GI tract provides the right habitat for a healthy array of gut microorganisms.
certain of the essential minerals act as abx by discouraging unwanted bacteria, only unlike meds they can do it without killing the healthful desirable micororganisms.
READ ME key info on nutrient targets - www.thisisms.com/ftopict-2489.html
my approach: no meds so far - just nutrient-dense anti-inflammatory whole foods, and supplements where needed
info: www.whfoods.com, www.nutritiondata.com