I personally think that we will look back at the symbiotic relationships that bacteria provide, and be amazed by the way we currently live - with hand sanitisers, and even antibiotic dish soap - plus antibiotics in our meat and water... Sure we will look back on this time in the same way we look at Romans and lead water pipes.
I would think that it is transferred to the child at birth. Some factors that could lead to a higher incident of peanut allergies if this bacteria is vital to preventing it:
- Child was delivered via cesarean w/o a vaginal swab transfer. The rate of c-sectons has certainly increased quite a bit in the last few decades.
- The Mother did not have a health population to begin with.
- The use of antibiotics that could wipe these strains out. Either in the mother prior to delivery or in the child after being born.
- lack of introduction through other sources (some yoghurts and cheeses)
The importance of this work is that with the simultaneous introduction of this bacteria the effect is maintained for years. The bacteria plays a important role in allowing the body to retain the immunity.
"Moreover, because there was no convincing evidence that allergen OITalone was effective in promoting sustained unresponsiveness at the time our randomized controlled trial (RCT) was designed and initiated, we elected to undertake a clinical trial evaluating whether coadministration of Lactobacillus rhamnosus CGMCC 1.3724 (NCC4007) and peanut OIT can induce sustained unresponsiveness to peanut among children with peanut allergy (Australian New Zealand Clinical Trials Registry ACTRN 12608000594325, 25/11/2008). This probiotic was selected based on its demonstrated tolerance-promoting effects, including induction of regulatory T and TH1 cytokine responses."