They examined the guts of 25 volunteers by administering upper endoscopies and colonoscopies. Fifteen of the volunteers were then divided into two groups: one that consumed generic probiotic strains and another that had a placebo. About three weeks later, both groups then underwent a second round of upper endoscopies and colonoscopies before being followed for two months. “Surprisingly, we saw that many healthy volunteers were actually resistant in that the probiotics couldn’t colonize their GI tracts,” senior author Eran Elinav said in a statement. For the second part of the trial, the scientists wanted to explore whether probiotics have the ability to counter the adverse effects of antibiotics.
Probiotics on the shop
The scientists learned that the probiotics’ gut colonization prevented both the host gut’s gene expression and their microbiome from returning to their normal pre-antibiotic configurations months later. This was considered „a new and potentially alarming adverse side effect of probiotic use with antibiotics that might even bring long-term consequences.” Almost 4 million adults take either probiotics or prebiotics in the U.S.. Americans spent $1.4 billion on probiotic supplements in 2014. This study „suggests that probiotics should not be universally given as a ‘one-size-fits-all’ supplement. Instead, they could be tailored to the needs of each individual.”