A few months ago I went on antibiotic regimen when my dentist said I needed a root canal. So he put me on penicillin for a few days before the procedure. after about 3 or 4 days on the antibiotics I began to feel a renewed sense of energy and vitality....something I haven't felt in almost 10 years. I quit taking the penicillin and slowly the brain fog and fatigue came back. A couple of weeks ago I got an upper respiratory infection and I started back on the penicillin. The brain fog and fatigue went away again. This is strange to me and I can't figure out why. Of course, I'm not complaining, but I'm baffled as to why the antibiotics would do that. I will certainly not going to keep taking antibiotics because I know all the problems continued use can cause, so I'd like to know what natural things I can take that will do the same thing as the antibiotics to keep me energized. Any thoughts? Thank you in advance!