Resilience of Gut Microbial Community Structure  How does
colonization resistance become compromised in the first place?
Evidence suggests that insults to the microbiome, such as
antibiotic treatment, can have long-lasting effects on the
indigenous microbial community. Young and colleagues treated
mice with antibiotics, let the animals recover from the
antibiotic stress in a sterile environment, and then observed
what happened when they were either left alone in a sterile
environment or co-housed with a donor mouse (Antonopoulos et
al., 2009). They found that mice left alone, with no donor mouse
present to repopulate their guts, had microbiota that looked
very similar to each other but very different from microbiota in
mice that had been co-housed with donors. Even 6 weeks after
stopping antibiotic treatment, mice left alone had much lower
microbiota diversity than the other mice. However, as with
humans, if fecal transplantation is done, diversity can return
to normal.  Subsequent mouse research showed that