AUTHOR=ElFeky Dalia Saad , Awad Alaa Reda , Shamseldeen Asmaa Mohammed , Mowafy Hagar Lotfy , Hosny Sara Adel 

TITLE=Comparing the therapeutic potentials of Lactobacillus johnsonii vs. Lactobacillus acidophilus against vulvovaginal candidiasis in female rats: an in vivo study

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1222503

DOI=10.3389/fmicb.2023.1222503

ISSN=1664-302X

ABSTRACT=<sec id="sec1"><title>Background</title><p>Vulvovaginal candidiasis (VVC) is a highly prevalent illness affecting women globally. Lactobacilli, which make up the majority of healthy vaginal microbiota (VMB), serve as a powerful barrier against infections. Probiotic therapy has been recommended for the treatment or prevention of VVC.</p></sec><sec id="sec2"><title>Aim of work</title><p>To compare the <italic>in vivo</italic> therapeutic effects of <italic>Lactobacillus johnsonii</italic> (B-2178) vs. <italic>Lactobacillus acidophilus</italic> (LA-5<sup>®</sup>) on VVC in a rat model, particularly highlighting the immune response of the host vaginal epithelium.</p></sec><sec id="sec3"><title>Methods</title><p>In total, 30 female Sprague-Dawley rats were divided into 5 groups; Group 1: no intervention, Group 2: ovariectomy group, while animals in Groups 3–5 were subjected to ovariectomy and an intravaginal inoculation of <italic>Candida albicans (C. albicans)</italic> to establish VVC. The animals in Groups 4 and 5 received intravaginal lactobacilli treatment with <italic>L. acidophilus</italic> (LA-5<sup>®</sup>) and <italic>L. johnsonii</italic> (B-2178) strains, respectively, for 7 days. <italic>C. albicans</italic> load was measured in a vaginal lavage 1, 3, and 7 days after the stoppage of the treatment. Histological, morphometric, and immunohistochemical studies of the vaginal tissues were done. IFN-γ, IL-4, and IL-17 were measured in the vaginal tissue.</p></sec><sec id="sec4"><title>Results</title><p>Both <italic>L. johnsonii</italic> and <italic>L. acidophilus</italic> significantly reduced <italic>C. albicans</italic> vaginal load (250 ± 77.46 and 133.33 ± 40.82 CFU/mL) compared to the count before treatment in both groups (4,850 ± 1419.51 and 4966.67 ± 852.45 CFU/mL) even after 7 days of stoppage of lactobacilli treatment. A statistically significant reduction of the pro-inflammatory cytokines IL-17 and IFN-γ was reported in both treated groups compared to the infected untreated group. <italic>L. johnsonii</italic> has a significant effect on the reduction of hyphae formation of <italic>C. albicans</italic> as well as the nuclear factor kappa B (NF-κB) immunostaining density of vaginal tissue compared to <italic>L. acidophilus.</italic> Moreover, treatment with <italic>L. johnsonii</italic> significantly minimized the epithelium damage triggered by <italic>C. albicans</italic> infection and restored normal vaginal architecture as evidenced by the histologic and morphometric studies when compared to <italic>L. acidophilus.</italic></p></sec><sec id="sec5"><title>Conclusion</title><p>Through maintaining an immune tolerant state in the vaginal epithelium and ameliorating the undesirable uncontrolled inflammatory response in the vaginal tissue, <italic>L. johnsonii</italic> (B-2178) has the potential to be utilized alone or in combination with other lactobacilli species in probiotic clinical trials to treat or prevent VVC.</p></sec>