Numerous studies have attempted to experimentally infect and subsequently induce Johne’s disease in various ruminants and non-ruminants. It’s proven to be very difficult.

If MAP is a major cause of CD and IBS, does killing significant quantities of intestinal bacterial make it easier for MAP to get a ‘foothold’ in the intestines of a potential human host? It’s been noted that Crohn’s development may follow antibiotic use. And it’s also been noted that IBS development may also follow antibiotic use.

A study by Donaghy JA and colleagues, found that specific probiotic strains (Lb. paracasei isolates) inhibited MAP growth in milk. And several studies have noted disease/symptom improvement in CD/IBS sufferers taking probiotic supplements.

If specific bacteria have the ability to inhibit MAP growth, they may also hinder MAP's ability to initially infect a potential host.

Therefore, studies involving experimental MAP-infection may be more successful at inducing intestinal disease by first wiping out most of a potential host’s intestinal bacteria, via multiple courses of broad-spectrum antibiotics, before MAP inoculation.