Could probiotics cause a gastrointestinal ecology disaster?by Martin Macouzet, Ph. D. on 03/28/12
When a curious ecologically responsible student asked me that question, I answered confidently: “the conditions of the gastrointestinal (GI) tract are too harsh for probiotics, so they don’t stay around for long enough to modify the microbial ecology irreversibly. After probiotics accomplish their intended function and the individual stops consuming them, they get gradually washed out and the GI microbiota equilibrium is rapidly restored”
While I stick to my answer in the case of the currently available probiotics, I wonder if a new generation of probiotics will eventually pose that risk. New probiotic screening methods facilitate the selection of microbial strains with the desired profile. Accordingly, new probiotics will be each time more resistant and will have “enhanced functions”. We know safety of new probiotics has to be demonstrated but, what if in the long term a “safe super strain” dominates over certain native species leading to their exclusion?
Examples of ecological disasters caused by the introduction of foreign species into new ecosystems are abundant and our ignorance about the GI microbiome is huge, so… should we be afraid of probiotics? Definitely not, just keep in mind this matter for future developments and probiotic safety assessments. I wouldn’t like to meet the student in the future and face the embarrassing comment: “I told you”.
What do you think?