Anti-inflammatory and immunomodulatory effects of Lactobacillus spp. as a preservative and therapeutic agent for IBD control.

Background: Probiotics have a beneficial effect on inflammatory responses and immune regulation, via Janus kinase/signal transduction and activator of transcription (JAK/STAT) and NF-κB signaling pathways. To evaluate the precise effects of Lactobacillus spp. as a protective and therapeutic agent, we aimed to investigate the efficacy of Lactobacillus spp. in modulating JAK/STAT and nuclear factor kappa B (NF-κB) inflammatory signaling pathways.

Methods: A quantitative real-time polymerase chain reaction (qPCR) assay was used to analyze the expression of JAK/STAT and inflammatory genes (TIR-associated Protein [TIRAP], Interleukin 1 Receptor Associated Kinase[IRAK4], Nuclear factor-kappa B Essential Modulator [NEMO], and receptor interacting protein [RIP]) followed by treatment of the HT-29 cell line with sonicated pathogens before, after, and simultaneously with Lactobacillus spp. A cytokine assay was also used to evaluate interleukin (IL)-6 and IL-1β production after treatment with Lactobacillus spp.

Results: Lactobacillus spp. downregulated JAK and TIRAP, IRAK4, NEMO, and RIP genes in the NF-κB pathway compared to sonicate-treated cells. The expression of STAT genes was different after treatment with probiotics. The production of IL-6 and IL-1β decreased after probiotic treatment.

Conclusions: Our Lactobacillus spp. cocktail showed anti-inflammatory effects on HT-29 cells by modulating JAK/STAT and NF-κB signaling pathways in all three treatment variants. Therefore, Lactobacillus spp. as a dietary supplement can both prevent and reduce inflammation-related diseases such as inflammatory bowel disease.