Not sure about NPIP but...
Antibiotics treat specific things. FF is not a substitute for antibiotics any more than vitamin C is. Both boost the immune system and get the whole body functioning better so that it's natural defenses can fight back against disease and illness. Some things the body can't fight back against and that's when antibiotics are normally used. They're not mutually exclusive. You can be a very healthy individual and still get a condition that need antibiotics. It's just you need them less often.
I think in most back yard style chicken practices it's about keeping pathogen levels low enough by doing things like deep litter that you never have an issue so severe that a bird with a good immune system can't fight it off. And then the FF helps keep the bird's immune system healthy. But if you stuck a FF bird in a pathogen-heavy environment you'd still probably get a sick bird, and your options would be antibiotics or cull. Even Bee's birds could easily get sick in a commercial-type environment. So if you bird gets sick from a one-time incident (say, going to a county fair to be shown, for example) at that point it's up to you whether that bird is worth using antibiotics on or culling. If a bird is getting sick regularly then it's an issue of a weak immune system and that's not normally worth keeping around. But even strong immune systems can contract illness. So it's a two pronged effort; Low pathogen levels and strong immune systems.
At least that's how I see it.
Vitamin C is thought to boost the immune system on a cellular level but has no way of killing or inhibiting pathogens, though it is thought to possibly to help the body fend off the effects of a bacterial onslaught in the system.
FF is a type of antibiotic but it works differently, being a prebiotic and probiotic, so they don't work by killing harmful bacteria but they do inhibit their growth patterns so that they stay in low enough numbers as to not effect the host.
An antibiotic, on the other hand, destroys bacteria to decrease their numbers...both provide the action of decreasing the numbers of the disease pathogen, one just does it quicker and is nonspecific, so it kills or decreases both the good and the bad pathogens. You can see where prebiotics and probiotics in FF and other fermented foods have the power to
keep pathogens to a harmless level, whereas antibiotics lose their effectiveness if they are used prophylactic-ally and one has to keep switching antibiotic agents to get the same desired effect~so they are best used in a curative way.
The way prebiotics and probiotics decrease the number of harmful bacteria~but still do not remove them altogether~ is to colonize the walls of the intestines, thereby leaving no point of attachment for the harmful bacteria. They also emit chemicals, as a by-product of their metabolism, that inhibits the ability of the harmful bacteria to recreate or grow in numbers.
Antibiotic~
Antibiotics, also known as antibacterials, are types of medications that destroy or slow down the growth of bacteria. The Greek word anti means "against", and the Greek word bios means "life" (bacteria are life forms). When a person takes
antibiotics, both the harmful bacteria and the beneficial bacteria are killed.
Prebiotics~
Prebiotics are non-digestible food ingredients that stimulate the growth and/or activity of bacteria in the digestive system.
Probiotics~ are live
bacteria that may confer a health benefit on the host. Probiotics may beneficially affect the host by augmenting its intestinal microbial population beyond the amount already existing, thus possibly inhibiting
pathogens.
Lactic acid bacteria (LAB) and
bifidobacteria are the most common types of
microbes used as probiotics, but certain
yeasts and
bacilli may also be used. Probiotics are commonly consumed as part of
fermented foods with specially added active live cultures, such as in
yogurt,
soy yogurt, or as
dietary supplements. Probiotics are also delivered in
fecal transplants, in which stool from a healthy donor is delivered like a suppository to an infected patient.
You can give antibiotics to animals for a specific purpose and it may or may not kill all bacteria causing the problem and it may kill even beneficial bacteria as well. That's when using FF or something similar comes in real handy, as the bad bacteria have a faster growth rate than do LAB and Acetobacter, so feeding a strong mix of both can really get those established in the bowels rather quickly after the use of an antibiotic. It also helps if the intestinal culture is of an acid nature as well, as this also inhibits the growth of the harmful pathogens.