RESUMO
Background: The burden of oral diseases is increasing, which constitute a major public health problem. The use of probiotics as an adjuvant, along with routine dental care practice by an individual, can produce additional benefits in the maintenance of one's oral health. The study aimed to investigate the effect of Bifidobacterium as a probiotic on oral health. Material and Methods: Six databases and registers were searched from the start of the database to December 2021 without any restrictions. Randomized controlled trials (RCTs) evaluating the clinical effects of Bifidobacterium as a probiotic on oral health were included in the study. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed to conduct this systematic review. The included studies were analyzed for the risk of bias using the Cochrane risk-of-bias tool for randomized trial (RoB 2) tool as well as quality of available evidence using GRADE criteria. Results: From the 22 qualified studies, four studies showed non-significant results. There was a high risk of bias in 13 studies and some concerns of bias in nine studies. No adverse effects were reported, and the quality of available evidence was moderate. Conclusion: The effect of Bifidobacterium on oral health is questionable. Further high-quality RCTs are required on the clinical effects of bifidobacteria and also the optimum level of probiotic needed, and ideal mode of administration to provide oral health benefits. Furthermore, synergistic effects of the combined use of various strains of probiotics need to be studied.
RESUMO
The FimH subunit of type 1-fimbriated Escherichia coli has been implicated as an important determinant of bacterial adherence and colonization of the urinary tract. Here, we sought to localize the functionally important domain(s) within the FimH molecule and to determine if antibodies against this domain would block adherence of type 1-fimbriated E. coli to the bladder mucosa in situ and in vivo in an established mouse model of cystitis. We generated translational fusion proteins of disparate regions of the FimH molecule with an affinity tag MalE, and tested each of the fusion products in vitro for functional activity. The minimum region responsible for binding mouse bladder epithelial cells and a soluble mannoprotein, horseradish peroxidase, was contained within residues 1-100 of the FimH molecule. We validated and extended these findings by demonstrating that antibodies directed at the putative binding region of FimH or at synthetic peptides corresponding to epitopes within the binding domain could specifically block type 1 fimbriae-mediated bacterial adherence to bladder epithelial cells in situ and yeast cells in vitro. Next, we compared the ability of mice passively immunized intraperitoneally with antisera raised against residues 1-25 and 253-264 of FimH or 1-13 of FimA to resist bladder colonization in vivo after intravesicular challenge with type 1-fimbriated E. coli. Only the antibody directed at the putative binding region of FimH (anti- s-FimH1-25) significantly reduced E. coli bladder infections in the experimental mouse model of urinary tract infections. Similar results were obtained when the mice were actively immunized with synthetic peptides corresponding to residues 1-25 and 253-264 of FimH or 1-13 of FimA. The mechanism of protection was attributed, at least in part, to inhibition of bacterial adherence to the bladder surface by s-FimH1-25-specific antibody molecules that had filtered through the kidneys into the urine. The level of FimH antibodies entering the bladder from the circulatory system of the immunized mice was found to be markedly enhanced upon bacterial challenge. The potential broad spectrum activity of the protective FimH antibody was indicated from its serologic cross-reactivity with various urinary tract bacterial isolates bearing type 1 fimbriae. These findings could be relevant in the design of an efficacious and broadly reactive FimH vaccine against urinary tract infections.