Comment on publications regarding probiotics and microbiota restoration

Two recent publications from the Weizmann Institute of Science in Israel are interpreted by media as “probiotics are almost useless”.

Suez et al. 2018 Cell
Post-Antibiotic Gut Mucosal Microbiome Reconstitution Is Impaired by Probiotics and Improved by Autologous FMT

Zmora et al. 2018 Cell
Personalized Gut Mucosal Colonization Resistance to Empiric Probiotics Is Associated with Unique Host and Microbiome Features

The two studies are done on a multi-strain probiotic product containing 11 different probiotics, none of them are of the Lactobacillus reuteri species and none of them are defined on strain level.

Important to notice is that no conclusions can be drawn concerning the efficacy of BioGaia’s probiotic strains of the L. reuteri species.

The publication by Suez et al. shows that taking a mix of 11 probiotic species may lead to delayed restoration of the microbiome compared to no intervention or fecal transplantation. Clinical efficacy was not evaluated and thereby no benefits were shown in the study participants. The clinical relevance of the findings in the study by Suez still needs to be proven.

The publication by Zmora et al. shows that the capacity of a probiotic species to colonize cannot be proven solely by fecal sampling. Colonization capacity of L. reuteri Protectis has been shown in other studies by using biopsy techniques, suggested by the author as relevant. It should also be noted that colonization and/or effect on the microbiota composition are not the sole parameters relevant for clinical efficacy of a probiotic. Direct effect on the immune system is one well documented example.

Clinical benefits of reduced antibiotic associated side-effects have been shown in numerous clinical studies with L. reuteri Protectis. This indicates that L. reuteri Protectis might have a positive effect on gut microbiota, as opposed to the product, containing 11 different species, used in these experimentally designed studies in a few healthy adults.


For other comments on the publications see:

More information regarding BioGaia’s probiotic strains of L. reuteri are available at biogaia/clinical studies.