Project description:To characterize the effect of lactic acid on the L. plantarum growth and adaptation, we investigated the transcriptome under hydrochloride (HCl) or lactic acid at the early stage of the growth.
Project description:Nowadays, Western diets and lifestyle lead to an increasing occurrence of chronic gut inflammation, that represents an emerging health concern with still a lack of successful therapies. Fermented foods, and their associated Lactic Acid Bacteria, have recently regained popularity for their probiotic potential including the maintenance of gut homeostasis by modulating the immune and inflammatory response. Our study aims to investigate the cross-talk between the food-borne strain Lactiplantibacillus plantarum C9O4 and intestinal epithelial cells in an in vitro inflammation model. Cytokines profile shows the ability of C9O4 to significantly reduce levels of IL-2, IL-5, IL-6, and IFN-γ. Proteomic functional analysis reveals an active host-microbe interaction that highlights an immunoregulatory role of C9O4, able to revert both the detrimental effects of IFN-γ through the JAK/STAT pathway and the apoptosis process in inflamed cells. These results suggest a promising therapeutic role of fermented food-associated microbes for the management of gastrointestinal inflammatory diseases.
Project description:Some commensal bacteria stimulate the immune system but do not present specific antigenicity. Such adjuvant effects have been reported for the bacterial species Lactobacillus plantarum. To study in vivo human responses to L. plantarum, a randomised double-blind placebo-controlled cross-over study was performed. Healthy adults were provided preparations of living and heat-killed L. plantarum bacteria, biopsies were taken from the intestinal mucosa and altered transcriptional profiles were analysed. Transcriptional profiles of human epithelia displayed striking differences upon exposure to living L. plantarum bacteria harvested at different growth phases. Modulation of NF-κB-dependent pathways was central among the major altered cellular responses. This unique in vivo study shows which cellular pathways are associated with the induction of immune tolerance in mucosal tissues towards common adjuvanticity possessing lactobacilli. Keywords: mucosal response of healthy adult humans to lactic acid bacteria
Project description:Kimchi is a traditional Korean food widely recognized for its probiotic properties and potential health benefits. Several lactic acid bacteria (LAB) from Kimchi exhibit immunomodulatory properties, and their efficacy has been evaluated for various immune-related diseases. However, the mechanisms underlying the immunomodulatory effects of LAB are not yet fully understood. In this study, we demonstrated the immunomodulatory effects of Latilactobacillus sakei Wikim0185, isolated from sweet potato Kimchi, in an ovalbumin (OVA)-induced allergic asthma mouse model by inducing tolerogenic dendritic cells (DCs) and regulatory T cells (Tregs). Bone marrow-derived dendritic cells (BMDCs) and OVA-peptide-stimulated splenocytes isolated from OT-II mice co-cultured with Wikim0185 exhibited increased secretion of the anti-inflammatory cytokine IL-10. Oral administration of Wikim0185 in allergic asthma experimental mice alleviated symptoms, including airway hyperresponsiveness (AHR), leukocyte infiltration, and reduced Th2-type cytokine levels in bronchoalveolar lavage (BAL) fluid. Notably, Wikim0185-treated mice displayed an increased proportion of Foxp3+ Tregs in mediastinal lymph nodes. Additionally, mediastinal lymph node cells restimulated with OVA exhibited decreased secretion of Th2-type cytokines while showing increased IL-10 production. Interestingly, RNA sequencing and chromatin immunoprecipitation (ChIP)-qPCR analysis revealed that Wikim0185 induced tolerogenic DCs through epigenetic histone modifications, increasing active chromatin marks (H3K4me3, H3K9ac, and H3K27ac) on the promoter regions of tolerogenic marker genes (Pdl1, Il10, Socs1, and Socs3). These findings suggest that Wikim0185 modulates immune responses by epigenetically reprogramming DCs, thereby promoting Treg differentiation and suppressing excessive Th2 immune responses in an allergic asthma mouse model.
