My Lyme doc recommended a yeast-based probiotic (that is, not acidophilus) so that it could be taken at any time of day and taken with food. One brand I am aware of Florastor, but there are others.
The more usual acidophilus-based probiotics cannot be taken with or near antibiotics, because acidophilus is a 'good' bacteria, but the antibiotics don't know it's 'good' and go ahead and kill it anyway. If you want to take acidophilus-based probiotics, then it has to be taken away from the antibiotics [an hour? two hours? I don't remember -- ask a pharmacist].
I am apparently sensitive to yeast (which is in Florastor), so I had to change to acidophilus-based probiotics.
Follow directions on the label, whatever you take. Prices vary. Shelf life is marked on the label.
I take a Jarrow formula probiotic. Sorry, I don't have a bottle left and can't remember the name.