From what I know (And I will link the FAQ for you that addresses this). While OO kills of a ton of stuff, it (by way of nature or god or luck or whatever) seems to only target very undesireable microbes. While i'm sure it kills off some things it probably shouldn't, in a perfect world, over all it will kill off things like yeast, fungus, pseudo, and staph. In the realm of wide spectrum antibiotics in the human body, these antibiotics are looked at more like daisy cutter bombs, while OO is looked at more like hand grenades. Sure both can and probably will kill more than their intended target, but one is much more destructive than the other.
I have been on probiotic treatment while on just OO, and I have not been on probiotic treatment while on OO. And while I know it's important for nearly all CF patients to always be on probiotics due to our good bacteria constantly being carpet bombed by our antibiotics, i seriously doubt being on OO has any bearing on if we should take it or not.
Do you take prophalactic antibiotics in any form for CF? Then yes, in my opinion you need to be on a good probiotic supplement. Our "good bacteria" is decimated frequently due to oral, inhaled, and IV antibiotics. We (the scientific community) are just recently understanding that our "good bacteria" do tons of important tasks like actually creating vitamins for our bodies, regulating metabolism, controling hormones, and actually effecting brain chemistry. What do you think happens to your body as a whole when you take a wide spectrum antibiotic? That's right, it kills EVERYTHING. So while we might say "Wow I feel like crap", and the docs say "Take this" antibiotic wise, not only do we kill a large part of the bad bacteria off, and probably feel better for the short term, we also kill of tons of our good bacteria, which were helping us in the first place, so our recovery and general internal ecosystem is totally fried.
I don't think Oregano Oil is the total end all answer, but it's a start of a different perspective with regards to the wonderful world of essential plant oils, that hold a wealth of potential healing for us, that get us away from the very strong ecosystem disrupting antibiotics. Like many on here have said (me included): Battling CF isn't just about being on X, Y, Z, and Q^4 drugs...It's about proper diet, environment, mental aspect, massive exercise/lifting weights, and will to live. Drugs help, but don't fully rely on them. I personally think EVERYTHING we could ever need is here for us, we just have to find where it grows, and how to deliver it for whatever ailment.
Here is the FAQ I was refering to. It's not the word of God, but it is still very informative, and the information (to the best of my cross referencing ability) is correct:
<a target=_blank class=ftalternatingbarlinklarge href="http://www.thepowermall.com/oreganoproducts/faq.htm#1
">http://www.thepowermall.com/oreganoproducts/faq.htm#1
</a>
In case you are very lazy and don't want to click on that and go down to #7 on the FAQ, here is what they say regarding probiotics and OO (copied and pasted):
7 Should I take probiotics, or friendly bacteria, with Oreganol P73 and Oregacyn P73 in the same manner as I take them with antibiotics?
No. Antibiotics are capable of wiping out and destroying all of the good bacteria in your colon in as little as one cycle of treatment. Oreganol P73 and Oregacyn P73 used as recommended will not disrupt the balance of friendly bacteria. A study conducted by Laura L. Zaika and John C. Kissinger entitled "Inhibitory and Stimulatory Effects of Oregano on Lactobacillus Plantarum and Pediococcus Cerevisiae" and printed in volume 46 of the Journal of Food Science stated "that although oregano can be bactericidal toward lactic acid bacteria, these organisms (friendly bacteria) can become resistant towards the effect of oregano." Dr. Cass Ingram suggests that friendly bacteria may be inhibited by oregano added to foods. However, friendly bacteria will also develop resistance to the inhibitory effect of the spice. Furthermore, Dr. Ingram proposes that because of oregano's place in traditional herbal medicine, most of our ancestors have consumed oregano in one form or another for thousands of years. In fact, the Tractatus de Herbis, written in the early fourteenth century in southern Italy, was compiled as a medical handbook for a doctor of medieval Europe and contained direct evidence of the medicinal properties of oregano in an illustrated format. Moreover, after centuries of apparently hopeless scientific and theological disputes, botanical and folklore research of the preceding decades leaves no doubt that oregano is actually the hyssop of the Bible. The Biblical hyssop originally known to the ancient Hebrews is first mentioned in Exodus 12:22, and descriptions of its use in the purification rights are given by Moses when expounding to the people the law received by him on Mount Sinai (Leviticus 14:6). We may assume that oregano was growing on the spot, and Moses could show it to the people. The fact that oregano has been used for so many years and is recognized by the body as a food stands as proof that unlike synthetic antibiotics, which are foreign to the body, oregano has become an integral part of our collective cellular genetic makeup. It appears that although certain herbal remedies with powerful pharmacological properties have been used in a regional manner, oregano is a food and is not intolerable for long periods of time like goldenseal, echinacea and many other Far Eastern formulas. This begs the question: If a food source can strengthen and heal without causing microbial resistance (as is the case with antibiotics), shouldn't you be taking it?
Dr. Ingram does point out that for people who are taking large doses of oregano for chronic conditions it will prove very beneficial to supplement with friendly bacteria. Dr. Ingram recommends taking your friendly bacteria at night before you go to bed and taking Oreganol P73 and Oregacyn P73 with breakfast, lunch and dinner. He also points out that oregano will help eliminate so much of the bad bacteria that it creates even more fertile ground for your friendly bacteria.