2′-Fucosyllactose supplementation results in a transient improvement in gut microbial resilience after vancomycin use in adults with overweight or obesity: a randomized, double-blind, placebo-controlled intervention

Antibiotic-induced perturbations of the gut microbiome can be long-lasting and potentially affect host metabolic health. Strategies supporting microbial resilience are needed to mitigate the negative impact of antibiotics. We investigated the potential of 2'-fucosyllactose (2'-FL) supplementation after vancomycin use in a double-blind placebo-controlled randomized intervention among adults with overweight/obesity. Participants received oral vancomycin for seven days followed by 2'-FL or placebo for eight weeks. At baseline, after vancomycin use and after supplementation, glucose tolerance, insulin sensitivity, plasma lipids, glucagon-like peptide 1, inflammatory cytokines, fecal short-chain fatty acids (SCFAs) and branched-chain fatty acids were analyzed. Gut microbial diversity, composition and resilience were analyzed using 16S rRNA gene sequencing. Vancomycin use decreased gut microbial richness and diversity and disrupted microbiota composition and fecal SCFA concentrations. 2'-FL improved gut microbial resilience compared to placebo (<i>p</i>Treatment*Time = 0.043) after two weeks of supplementation, but differences were no longer observed at the end of the intervention. Two-week 2'-FL supplementation also differentially impacted specific bacterial taxa. Eight-week 2'-FL supplementation decreased fasting plasma interleukin-6 (IL-6) concentrations (<i>p</i>Treatment*Time = 0.041). 2'-FL intake led to transient improvements in gut microbial resilience after vancomycin use, indicating its beneficial potential to limit antibiotic-induced perturbations. Subsequent effects on metabolic health were limited and require further study.