What pro-and prebiotics do you recommend, including foods and supplements?

What symptoms U have: Your choice of probiotics (& accordingly prebiotics) may depend on what symptoms you have +/- how long on antibiotics. Also, different probiotics work in different ways. Lactobacillus & acidophilus grow rapidly to crowd out "bad" bacteria, bifidobacter helps reduce "gas", & sacchromyces boulardes retards growth of clostridum difficile with the added advantage of being antibiotic resistant.