Lacticaseibacillus rhamnosus GG and Saccharomyces cerevisiae boulardii supplementation exert protective effects on human gut microbiome following antibiotic administration in vitro

Abstract
Antibiotic-induced dysbiosis of the microbial community has been associated with several gastrointestinal symptoms. The impact of repeated administration of Lacticaseibacillus rhamnosus GG (CNCM-I-4798) (formerly known as Lactobacillus rhamnosus GG), Saccharomyces cerevisiae boulardii (CNCM-I-1079) and their combination (associated in Smebiocta/Smectaflora Protect®) in supporting recovery of gut microbiota functionality and composition during and following amoxicillin:clavulanic acid administration was evaluated in vitro. Antibiotic dosage negatively affected SCFA production, coinciding with detrimental effects on Bacteroidetes, Firmicutes and Bifidobacterium spp. in the simulated proximal colon, while Akkermansia muciniphila was significantly reduced in the distal colon. L. rhamnosus GG and S. boulardii were able to thrive in both colon regions upon dosing, with S. boulardii even showing protective effects on the survival of L. rhamnosus GG during antibiotic administration. The impact of the probiotic strains on microbiome recovery revealed that supplementation with L. rhamnosus GG and/or S. boulardii resulted in a stimulating effect on the most abundant bacterial groups within the bacterial community of each donor. For one of the donors tested, co-dosing of L. rhamnosus GG and S. boulardii resulted in superior short-chain fatty acid recovery accompanied by a stronger increase in abundance of Bifidobacteriaceae. Overall, the current study provides first evidence that combined supplementation of L. rhamnosus GG and S. boulardii might be an interesting candidate in limiting detrimental effects of amoxicillin:clavulanic acid on the human gut microbiome, though further studies are warranted to confirm these findings.