KA-FF 1-4 reduces vancomycin-resistant enterococci and impacts the human gut microbiome.

Probiotic is an alternative method to treat intestinal infection disease caused by antibiotic-resistant bacteria. In this study, KA-FF 1-4 demonstrated to have the potential to inhibit the growth of Vancomycin-resistant enterococci (VRE) by producing anti-microbial substance. In co-culture, KA-FF 1-4 (10 CFU/mL) inhibited the growth of VRE from 10-10 CFU/mL to zero after 6 h of exposure. However, in a gut model contained human gut microbiota, this anti-VRE activity of KA-FF 1-4 was reduced to only 3.59-6.12%. The unexpected difference in efficacy between the experimental models could be explained by the fact that the growth of KA-FF 1-4 was stable in the gut model. Leaving aside these limitations, we observed that adding KA-FF 1-4 into the human gut model containing VRE was able to enhance microbial richness and diversity. Specifically, a higher abundance of beneficial microbes from the group of spp. and . KA-FF 1-4 also enhanced the abundance of , , and and promoted the production of lactic acid in the gut model. However, these effects were not observed in the gut model without KA-FF 1-4. Even though this study could not demonstrate a significant anti-VRE effect of the KA-FF 1-4 in a gut model, our results still offer evidence that KA-FF 1-4 could positively modulate the gut microbiota by promoting the growth of beneficial microbes and their metabolite. KA-FF 1-4 has probiotic properties to fight against VRE infection, therefore further investigation in animal model is needed.