Comparative Lipidomic Analysis of Extracellular Vesicles Derived from Lactobacillus plantarum APsulloc 331261 Living in Green Tea Leaves Using Liquid Chromatography-Mass Spectrometry.

Lactobacillus plantarum is a popular probiotic species due to its safe and beneficial effects on humans; therefore, novel L. plantarum strains have been isolated and identified from various dietary products. Given that bacteria-derived extracellular vesicles (EVs) have been considered as efficient carriers of bioactive materials and shown to evoke cellular responses effectively, L. plantarum-derived EVs are expected to efficiently elicit health benefits. Herein, we identified L. plantarum APsulloc 331261 living in green tea leaves and isolated EVs from the culture medium. We performed quantitative lipidomic analysis of L. plantarum APsulloc 331261 derived EVs (LEVs) using liquid chromatography-mass spectrometry. In comparison to L. plantarum APsulloc 331261, in LEVs, 67 of 320 identified lipid species were significantly increased and 19 species were decreased. In particular, lysophosphatidylserine(18:4) and phosphatidylcholine(32:2) were critically increased, showing over 21-fold enrichment in LEVs. In addition, there was a notable difference between LEVs and the parent cells in the composition of phospholipids. Our results suggest that the lipidomic profile of bacteria-derived EVs is different from that of the parent cells in phospholipid content and composition. Given that lipids are important components of EVs, quantitative and comparative analyses of EV lipids may improve our understanding of vesicle biogenesis and lipid-mediated intercellular communication within or between living organisms.

Lactobacillus plantarum-derived extracellular vesicles induce anti-inflammatory M2 macrophage polarization in vitro.

Probiotics offer various health benefits. Lactobacillus plantarum has been used for decades to enhance human intestinal mucosal immunity and improve skin barrier integrity. Extracellular vesicles (EVs) derived from eukaryotic or prokaryotic cells have been recognized as efficient carriers for delivery of biomolecules to recipient cells, and to efficiently regulate human pathophysiology. However, the mechanism underlying the beneficial effects of probiotic bacteria-derived EVs on human skin is unclear. Herein, we investigated how L. plantarum-derived EVs (LEVs) exert beneficial effects on human skin by examining the effect of LEVs on cutaneous immunity, particularly on macrophage polarization. LEVs promoted differentiation of human monocytic THP1 cells towards an anti-inflammatory M2 phenotype, especially M2b, by inducing biased expression of cell-surface markers and cytokines associated with M2 macrophages. Pre- or post-treatment with LEVs under inflammatory M1 macrophage-favouring conditions, induced by LPS and interferon-γ, inhibited M1-associated surface marker, HLA-DRα expression. Moreover, LEV treatment significantly induced expression of macrophage-characteristic cytokines, IL-1ß, GM-CSF and the representative anti-inflammatory cytokine, IL-10, in human skin organ cultures. Hence, LEVs can trigger M2 macrophage polarization in vitro, and induce an anti-inflammatory phenomenon in the human skin, and may be a potent anti-inflammatory strategy to alleviate hyperinflammatory skin conditions.

Lactobacillus helveticus HY7801 ameliorates vulvovaginal candidiasis in mice by inhibiting fungal growth and NF-κB activation.

The anti-inflammatory effects of hydrogen peroxide-producing lactic acid bacteria (LAB) against Candida albicans-induced vulvovaginal candidiasis in ß-estradiol-immunosuppressed mice were examined. Oral and intravaginal treatment with these LABs significantly decreased the level of viable C. albicans within the vaginal cavity as well as the quantitated myeloperoxidase activity in the vaginal tissues when compared with control untreated mice. Out of all of the LABs tested, Lactobacillus helveticus HY7801 (LH) most potently inhibited vulvovaginal candidiasis. LH also inhibited the expression of the pro-inflammatory cytokines including TNF-α, IL-1ß and IL-6, and inflammatory enzymes, COX-2 and iNOS, as well as the activation of NF-κB. However, the addition of LH led to an increase in IL-10 cytokine expression in the vaginal tissues. In addition, the decrease of Lactobacillaceae and the increase of Pasteurellaceae caused by treatment with C. albicans were reversed with oral and intravaginal administration of LH, suggesting a potential shift in the vaginal microflora present. Addition of LH was toxic to C. albicans in vitro when cultured with HeLa cells. Oral administration of LH inhibited lipopolysaccharide (LPS)-induced TNF-α and IL-1ß expressions in ß-estradiol-immunosuppressed mice but reversed the expression of anti-inflammatory cytokine IL-10 in comparison to levels observed in the normal control group. LH also inhibited the expression of the pro-inflammatory cytokines, TNF-α and IL-1ß, and the activation of NF-κB in LPS-stimulated peritoneal macrophages. Based on these findings, LH may ameliorate vulvovaginal candidiasis by suppressing the NF-κB pathway, as well as through inhibition of the growth of C. albicans.

Lactobacillus johnsonii HY7042 ameliorates Gardnerella vaginalis-induced vaginosis by killing Gardnerella vaginalis and inhibiting NF-κB activation.

Hydrogen peroxide-producing lactic acid bacteria (LAB) were isolated from women's vaginas and their anti-inflammatory effects against Gardnerella vaginalis-induced vaginosis were examined in ß-estradiol-immunosuppressed mice. Oral and intravaginal treatment with five LABs significantly decreased viable G. vaginalis numbers in vaginal cavities and myeloperoxidase activity in mouse vaginal tissues. Of the LABs examined, Lactobacillus johnsonii HY7042 (LJ) most potently inhibited G. vaginalis-induced vaginosis. This LAB also inhibited the expressions of IL-1ß, IL-6, TNF-α, COX-2, and iNOS, and the activation of NF-κB in vaginal tissues, but increased IL-10 expression. Orally administered LJ (0.2×10(8) CFU/mouse) also inhibited the expression of TNF-α by 91.7% in ß-estradiol-immunosuppressed mice intraperitoneally injected with LPS. However, it increased IL-10 expression by 63.3% in these mice. Furthermore, LJ inhibited the expressions of the pro-inflammatory cytokines, TNF-α and IL-1ß, and the activation of NF-κB in lipopolysaccharide-stimulated peritoneal macrophages. LJ also killed G. vaginalis attached with and without HeLa cells. These findings suggest that LJ inhibits bacterial vaginosis by inhibiting the expressions of COX-2, iNOS, IL-1ß, and TNF-α by regulating NF-κB activation and by killing G. vaginalis, and that LJ could ameliorate bacterial vaginosis.