Evaluation of the Immunomodulatory Activities of the Probiotic Strain Lactobacillus fermentum UCO-979C

Abstract

Lactobacillus fermentum UCO-979C, a strain isolated from a human stomach, was previously characterized by its potential probiotic properties. The UCO-979C strain displayed the ability to beneficially regulate the innate immune response triggered by Helicobacter pylori infection in human gastric epithelial cells. In this work, we conducted further in vitro studies in intestinal epithelial cells (IECs) and in vivo experiments in mice in order to characterize the potential immunomodulatory effects of L. fermentum UCO-979C on the intestinal mucosa. Results demonstrated that the UCO-979C strain is capable to differentially modulate the immune response of IECs triggered by Toll-like receptor 4 (TLR4) activation through the modulation of TLR negative regulators' expression. In addition, we demonstrated for the first time that L. fermentum UCO-979C is able to exert its immunomodulatory effect in the intestinal mucosa in vivo . The feeding of mice with L. fermentum UCO-979C significantly increased the production of intestinal IFN-γ, stimulated intestinal and peritoneal macrophages and increased the number of Peyer's patches CD4 + T cells. In addition, L. fermentum UCO-979C augmented intestinal IL-6, reduced the number of immature B220 + CD24 high B cells from Peyer's patches, enhanced the number of mature B B220 + CD24 low cells, and significantly increased intestinal IgA content. The results of this work revealed that L. fermentum UCO-979C has several characteristics making it an excellent candidate for the development of immunobiotic functional foods aimed to differentially regulate immune responses against gastric and intestinal pathogens.

The Exopolysaccharide of Lactobacillus fermentum UCO-979C Is Partially Involved in Its Immunomodulatory Effect and Its Ability to Improve the Resistance against Helicobacter pylori Infection

“…Some studies have described the ability of probiotic lactobacilli to differentially modulate the expression of inflammatory factors in gastric epithelial cells through the suppression of NF-κB activation [39,62]. Recently, we described the ability of L. fermentum UCO-979C to modify the expression of negative regulators of TLR4 signaling in intestinal epithelial cells [18]. The UCO-979C strain diminished the expression of MKP-1 and Tollip in intestinal epithelial cells after the activation of TLR4, conducting the down-regulation in the expression of inflammatory factors such as IL-8, CXCL9, CXCL10, CXCL11, and C3.…”

“…For this purpose, adult immunocompetent mice were treated with the UCO-979 strain, as described in detail in materials and methods, and then challenged with H. pylori. The non-immunomodulatory strain L. fermentum CRL973 [18] was used for comparison. As shown in Figure 1, mice treated with L. fermentum UCO-979C had lower H. pylori colony counts associated with the stomachs, as well as reduced urease activity when compared to the control group.…”

“…Besides, L. fermentum UCO-979C was able to differentially modulate the production of TNF-α, IFN-γ and IL-10 by gastric epithelial cells and macrophages, which may offer advantages in the protection against H. pylori infection by improving the clearance of the pathogen and the protection against inflammatory damage [17]. Futher in vitro studies demonstrated that the UCO-979C strain is a remarkable immunomodulatory agent due to its ability to differentially modulate the immune response triggered by Toll-like receptor 4 (TLR4) activation through the modulation of TLR negative regulators' expression in epithelial cells [18].…”

Lactobacillus fermentum JX306 Restrain D-galactose-induced Oxidative Stress of Mice through its Antioxidant Activity

“…In recent years, due to long history of safe use and potential therapeutic benefits (Mokoena 2017;Garcia-Castillo et al 2019;Zhao et al 2019) for human health of probiotics, the antioxidative activity of LAB has attracted more and more attention (Amaretti et al 2013;Tang et al 2016;Zhao et al 2018). Traditional Chinese fermented vegetables contain abundant LABs.…”

Assessment of the Immunomodulatory Properties of the Probiotic Strain Lactobacillus paracasei K5 In Vitro and In Vivo

“…Similarly, the probiotic strain Lactobacillus casei BL23 promoted a Th17-biased immune response, followed by the expression of proinflammatory cytokines (IL-6, IL-17, IL-10, and TGF-β), in a mouse model of intestinal inflammation [19]. Moreover, it has recently been demonstrated that oral treatment of BALB/c mice with the probiotic strain L. fermentum UCO-979C caused a significant increase in the production of interferon-γ (IFN-γ) and IL-6, as well as the stimulation of intestinal and peritoneal macrophages and the maturation of B cells [20].…”