Lactobacillus reuteri CRL1101 beneficially modulate lipopolysaccharide-mediated inflammatory response in a mouse model of endotoxic shock

Antimicrobial activity of the Lacticaseibacillus rhamnosus CRL 2244 and its impact on the phenotypic and transcriptional responses in carbapenem resistant Acinetobacter baumannii

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a recognized nosocomial pathogen with limited antibiotic treatment options. Lactic acid bacteria (LAB) constitute a promising therapeutic alternative. Here we studied the antibacterial properties of a collection of LAB strains using phenotypic and transcriptomic analysis against A. baumannii clinical strains. One strain, Lacticaseibacillus rhamnosus CRL 2244, demonstrated a potent inhibitory capacity on A. baumannii with a significant killing activity. Scanning electron microscopy images showed changes in the morphology of A. baumannii with an increased formation of outer membrane vesicles. Significant changes in the expression levels of a wide variety of genes were also observed. Interestingly, most of the modified genes were involved in a metabolic pathway known to be associated with the survival of A. baumannii. The paa operon, Hut system, and fatty acid degradation were some of the pathways that were induced. The analysis reveals the impact of Lcb. rhamnosus CRL 2244 on A. baumannii response, resulting in bacterial stress and subsequent cell death. These findings highlight the antibacterial properties of Lcb. rhamnosus CRL 2244 and its potential as an alternative or complementary strategy for treating infections. Further exploration and development of LAB as a treatment option could provide valuable alternatives for combating CRAB infections.

Phenotypic and transcriptional analysis of the antimicrobial effect of lactic acid bacteria on carbapenem-resistant Acinetobacter baumannii: Lacticaseibacillus rhamnosus CRL 2244 an alternative strategy to overcome resistance?"

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a recognized nosocomial pathogen with limited antibiotic treatment options. Lactic acid bacteria (LAB) constitute a promising therapeutic alternative. Here we studied the antibacterial properties of a collection of LAB strains using phenotypic and transcriptomic analysis against A. baumannii clinical strains. One strain, Lacticaseibacillus rhamnosus CRL 2244, demonstrated a potent inhibitory capacity on A. baumannii with a significant killing activity. Scanning electron microscopy images showed changes in the morphology of A. baumannii with an increased formation of outer membrane vesicles. Significant changes in the expression levels of a wide variety of genes were also observed. Interestingly, most of the modified genes were involved in a metabolic pathway known to be associated with the survival of A. baumannii . The paa operon, Hut system, and fatty acid degradation were some of the pathways that were induced. The analysis reveals the impact of Lcb. rhamnosus CRL 2244 on A. baumannii response, resulting in bacterial stress and subsequent cell death. These findings highlight the antibacterial properties of Lcb. rhamnosus CRL 2244 and its potential as an alternative or complementary strategy for treating infections. Further exploration and development of LAB as a treatment option could provide valuable alternatives for combating CRAB infections.

The probiotic and immunomodulation effects of Limosilactobacillus reuteri RGW1 isolated from calf feces

Introduction

Limosilactobacillus reuteri is a gut symbiont with multiple remarkable beneficial effects on host health, and members of L. reuteri are valuable probiotic agents. However, L. reuteri showed obvious host specificity.

Methods

In our study, a novel L. reuteri RGW1 was isolated from feces of healthy calves, and its potential as a probiotic candidate were assessed, by combining in vitro, in vivo experiments and genomic analysis.

Results and discussion

RGW1 was sensitive to all the antibiotics tested, and it did not contain any virulence factor-coding genes. This isolate showed good tolerance to acid (pH 3.0), 0.3% bile salt, and simulated gastric fluid. Moreover, this isolate showed a high hydrophobicity index (73.7 ± 4.6%) and was able to adhere to Caco-2 cells, and antagonize Escherichia coli F5. Treatment of LPS-induced mice with RGW1 elevated TGF-β and IL-10 levels, while RGW1 cell-free supernatant (RCS) decreased TNF-α levels in the sera. Both RGW1 and RCS increased the villus height and villus height/crypt depth ratio of colon. Genomic analysis revealed the mechanism of the probiotic properties described above, and identified the capacity of RGW1 to biosynthesize L-lysine, folate, cobalamin and reuterin de novo. Our study demonstrated the novel bovine origin L. reuteri RGW1 had multiple probiotic characteristics and immunomodulation effects, and provided a deeper understanding of the relationship between these probiotic properties and genetic features.

Protective effect of Limosilactobacillus fermentum HFY06 on dextran sulfate sodium-induced colitis in mice

Ulcerative colitis is one of the main gastrointestinal diseases that threaten human health. This study investigated the effect of Limosilactobacillus fermentum HFY06 (LF-HFY06) on dextran sulfate sodium (DSS)-induced murine colitis. The protective effect of LF-HFY06 was evaluated by examining the length and histopathological sections of colon, related biochemical indicators, and genes related to inflammation. Direct and microscopic observations showed that LF-HFY06 increased the length of the colon and ameliorated the pathological damage induced by DSS. The biochemical indicators showed that LF-HFY06 enhanced the activities of antioxidant enzymes total superoxide dismutase (T-SOD) and catalase (CAT) in serum, while reducing the level of malondialdehyde (MDA). It was also observed that the serum inflammatory cytokines levels of tumor necrosis factor-α (TNF-α), interferon (IFN)-γ, interleukin (IL)-1β, IL-6, and IL-12 were decreased, and the anti-inflammatory cytokine IL-10 level was increased. The qPCR experiment revealed that LF-HFY06 downregulated the mRNA expression levels of nuclear factor-κB-p65 (Rela), Tnf, Il 1b, Il 6, and prostaglandin-endoperoxide synthase 2 (Ptgs2) in colon tissues, and upregulated the mRNA expression of NF-κB inhibitor-α (Nfkbia) and Il 10. These data indicated that LF-HFY06 inhibited inflammation through the NF-κB signaling pathway to prevent the occurrence and development of colitis. This research demonstrates that probiotics LF-HFY06 have the potential to prevent and treat colitis.

Bacillus coagulans TL3 Inhibits LPS-Induced Caecum Damage in Rat by Regulating the TLR4/MyD88/NF-κB and Nrf2 Signal Pathways and Modulating Intestinal Microflora

Background

Bacillus coagulans has been widely used in food and feed additives, which can effectively inhibit the growth of harmful bacteria, improve intestinal microecological environment, promote intestinal development, and enhance intestinal function, but its probiotic mechanism is not completely clear.

Aim

The aim of this study is to discuss the effect and mechanism of Bacillus coagulans TL3 on oxidative stress and inflammatory injury of cecum induced by LPS.

Method

The Wistar rats were randomly divided into four groups, each containing 7 animals. Two groups were fed with basic diet (the LPS and control, or CON, groups). The remaining groups were fed with basic diet and either a intragastric administration high or low dose of B. coagulans, forming the HBC and LBC groups, respectively. The rats were fed normally for two weeks. On the 15th day, those in the LPS, HBC, and LBC groups were injected intraperitoneally with LPS—the rats in the CON group were injected intraperitoneally with physiological saline. After 4 hours, all the rats were anesthetized and sacrificed by cervical dislocation, allowing samples to be collected and labeled. The inflammatory and antioxidant cytokine changes of the cecum were measured, and the pathological changes of the cecum were observed, determining the cecal antioxidant, inflammation, and changes in tight junction proteins and analysis of intestinal flora.

Result

The results show that LPS induces oxidative damage in the cecal tissues of rats and the occurrence of inflammation could also be detected in the serum. The Western blot results detected changes in the NF-κB- and Nrf2-related signaling pathways and TJ-related protein levels. Compared with the LPS group, the HBC group showed significantly downregulated levels of expression of Nrf2, NQO1, HO-1, GPX, and GCLC. The expression of TLR4, MYD88, NF-κB, IL-6, TNFα, and IL-1β was also significantly downregulated, while the expression of other proteins (ZO-1, occludin, and claudin-1) increased significantly. Bacillus coagulans TL3 was also found to increase the relative abundance of the beneficial bacterium Akkermansia muciniphila in the intestines. There is also a significant reduction in the number of harmful bacteria Escherichia coli and Shigella (Enterobacteriaceae).

Conclusion

Bacillus coagulans TL3 regulates the TLR4/MyD88/NF-κB and Nrf2 signaling pathways in the cecal tissue of rats, protects the intestine from inflammation and oxidative damage caused by LPS, and inhibits the reproduction of harmful bacteria and promotes beneficial effects by regulating the intestinal flora bacteria grow, thereby enhancing intestinal immunity.

Protective effects of a novel Lactobacillus rhamnosus strain with probiotic characteristics against lipopolysaccharide-induced intestinal inflammation in vitro and in vivo

Lipopolysaccharides (LPS), a main component of the Gram-negative bacterial cell wall, can damage the epithelial wall barrier and induce chronic intestinal inflammation. The purpose of this study is to evaluate whether the novel L. rhamnosus could alleviate intestinal inflammation and damage induced by LPS and explore the possible underlying molecular mechanism. L. rhamnosus JL-1 was selected from five L. rhamnosus strains due to its strong adherence capacity to Caco-2 cells (92.89%) and it could survive in simulated gastrointestinal juices. Whole genome sequencing analysis showed that there were no translocation and inversion regions in the genome of L. rhamnosus JL-1 compared with L. rhamnosus GG. Comparative genomic analysis showed that there were encoding genes related to adhesion, acid resistance and bile salt resistance in the genome of L. rhamnosus JL-1. Both in vitro and in vivo experiments indicated that LPS challenge inhibited the mRNA and protein expression of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6). However, the mRNA and protein expressions of pro-inflammatory cytokines were inhibited by pre-treatment with L. rhamnosus JL-1 in a dose-dependent manner. The result of histopathology analysis of ileum showed that oral administration of L. rhamnosus JL-1 reduced pathological damage induced by LPS. Furthermore, it was revealed that L. rhamnosus JL-1 could inhibit the mRNA and protein expressions of TLR4 and NF-κB. These results strongly suggested that L. rhamnosus JL-1 relieved LPS-induced intestinal inflammation by inhibiting the TLR4/NF-κB signaling pathway. To sum up, L. rhamnosus JL-1 has a potential probiotic function and plays an important role in preventing LPS-induced intestinal inflammation and damage.

Drops of Lactiplantibacillus plantarum CRL 759 culture supernatant attenuates eyes inflammation induced by lipopolysaccharide

Anti-inflammatory effect of soluble secreted compounds of probiotic bacteria was widely demonstrated as therapy for different inflammatory diseases, but was not investigated in inflammatory eye disorders. The aim of this study was to determine whether Lactiplantibacillus plantarum CRL759 cell-free supernatant reduced inflammatory parameters and clinical signs in ocular inflammations. First, we evaluated the effect of L. plantarum CRL759 supernatant in vitro on human retinal cell line, ARPE-19 cells, stimulated with lipopolysaccharide (LPS). Then, we investigated in vivo its capacity to decrease inflammation by local administration on the eyes of mice with endotoxin induced inflammation. In vitro assays demonstrated that L. plantarum CRL759 supernatant reduced the production of interleukin (IL)-6, IL-8, nitric oxide and thiobarbituric acid reactive substances in LPS-stimulated ARPE-19 cells. Our in vivo data proved that L. plantarum supernatant significantly reduced the clinical score of endotoxin treated mice and diminished levels of tumour necrosis factor alpha, interferon gamma and protein concentration in aqueous humour. Histological examination showed reduction of infiltrating inflammatory cells in the posterior segment of the eyes. As far as we know, this is the first report showing that Lactobacillus spp. supernatant administered as drops reduces some parameters of ocular inflammation. This promising strategy is safe and could alleviate symptoms and signs of ocular inflammation in people that are refractories to the conventional therapies.

Alginate oligosaccharide improves lipid metabolism and inflammation by modulating gut microbiota in high-fat diet fed mice

Alginate oligosaccharides are associated with some beneficial health effects. Gut microbiota is one of the most recently identified factors in the development of several metabolic diseases induced by high-fat diet. Our objective was to evaluate how alginate oligosaccharides impact on high-fat diet‑induced features of metabolic disorders and whether this impact is related to modulations in the modulation of the gut microbiota. C57BL/6J mice were fed with chow diet, high-fat diet, or high-fat diet supplemented with alginate oligosaccharides for 10 weeks. Alginate oligosaccharide treatment improved lipid metabolism, such as reducing levels of TG and LDL-C and inhibiting expression of lipogenesis genes. Alginate oligosaccharide administration reduced the levels of fasting blood glucose and increased the levels of serum insulin. Alginate oligosaccharide treatment was found to lower the expression of markers of inflammation, including IL1β and CD11c. Alginate oligosaccharide treatment modulated gut microbial communities and markedly prompted the growth of Akkermansia muciniphila, Lactobacillus reuteri, and Lactobacillus gasseri. Additionally, alginate oligosaccharide intervention significantly increased concentrations of short-chain fatty acids, such as acetic acid, propionic acid, and butyric acid, as well as decreased levels of endotoxin. Alginate oligosaccharides exert beneficial effects via alleviating metabolic metrics induced by high-fat diet, which is associated with increase in A. muciniphila, L. reuteri, and L. gasseri, as well as the release of microbiota-dependent short-chain fatty acids and inhibition of endotoxin levels.

Lactobacillus reuteri ZJ617 maintains intestinal integrity via regulating tight junction, autophagy and apoptosis in mice challenged with lipopolysaccharide

Live probiotics are effective in reducing gut permeability and inflammation. We have previously reported that Lactobacillus reuteri ZJ617 (ZJ617) with high adhesive and Lactobacillus rhamnosus GG (LGG) can ameliorate intestine inflammation induced by lipopolysaccharide (LPS). The present study was aimed at elucidating the roles of ZJ617 and LGG in alleviating the LPS-induced barrier dysfunction of ileum in mice. Six C57BL/6 mice per group were orally inoculated with ZJ617 or LGG for one week (1× 10⁸ CFU/mouse) and intraperitoneally injected with LPS (10 mg/kg body weight) for 24 h. The results demonstrated that pretreatment with ZJ617 and LGG attenuated LPS-induced increase in intestinal permeability. The probiotics supplementation suppressed LPS-induced oxidative stress. Both ZJ617 and LGG strongly reversed the decline of occludin and claudin-3 expression induced by LPS challenge. ZJ617 relieved LPS-induced apoptosis by decreasing caspase-3 activity. Noticeably, ratio of microtubule-associated light chain 3 (LC3)-II/LC3-I and LC3 activity were elevated by LPS stimulation, whereas such increases were obviously attenuated by both of the probiotics treatment. Moreover, phosphorylated mammalian target of rapamycin (p-mTOR) was significantly inhibited by LPS, whereas complementation of ZJ617 and LGG markedly increased the expression of p-mTOR. Collectively, our results indicated that ZJ617 could protect LPS-induced intestinal barrier dysfunction via enhancing antioxidant activities and tight junction and attenuating apoptosis and autophagy via mTOR signaling pathway. These findings could serve as systematic mechanisms through which probiotics promote and maintain gut homeostasis.

Doses Lactobacillus reuteri depend on adhesive ability to modulate the intestinal immune response and metabolism in mice challenged with lipopolysaccharide

The objective of this study was to evaluate the modulatory effects of Lactobacillus reuteri ZJ617 and ZJ615, which have high and low adhesive abilities, respectively, and Lactobacillus rhamnosus GG (LGG) on immune responses and metabolism in mice stimulated with lipopolysaccharide (LPS). Six C57BL/6 mice per group were orally inoculated with ZJ617, ZJ615 or LGG for one week (1 × 10(8) CFU/mouse) and i.p. injected with LPS (10 mg/kg) for 24 h. Compared with the LPS stimulation group, ZJ615, ZJ617 and LGG significantly decreased TNF-α levels in the sera of mice stimulated by LPS. ZJ615 and LGG significantly down-regulated mRNA levels of cytokines and Toll-like receptors, and suppressed activation of MAPK and NF-κB signaling, while ZJ617 up-regulated anti-inflammatory cytokine IL-10 mRNA levels in the ilea of mice stimulated by LPS. Correlation analysis confirmed that adhesive ability is relative with the immunomodulation in the ilea of mice. There were 24, 7 and 10 metabolites and 10, 9 and 8 major metabolic pathways with significant differences (VIP > 1, P < 0.05) between the LPS and ZJ617 + LPS groups, the LPS and ZJ615 + LPS groups, and the ZJ617 + LPS and ZJ615 + LPS groups, respectively. The results indicated that both ZJ617 and ZJ615 could modulate the intestinal immune responses and metabolism in LPS-stimulated mice.

Soluble factors from Lactobacillus reuteri CRL1098 have anti-inflammatory effects in acute lung injury induced by lipopolysaccharide in mice

We have previously demonstrated that Lactobacillus reuteri CRL1098 soluble factors were able to reduce TNF-α production by human peripheral blood mononuclear cells. The aims of this study were to determine whether L. reuteri CRL1098 soluble factors were able to modulate in vitro the inflammatory response triggered by LPS in murine macrophages, to gain insight into the molecular mechanisms involved in the immunoregulatory effect, and to evaluate in vivo its capacity to exert anti-inflammatory actions in acute lung injury induced by LPS in mice. In vitro assays demonstrated that L. reuteri CRL1098 soluble factors significantly reduced the production of pro-inflammatory mediators (NO, COX-2, and Hsp70) and pro-inflammatory cytokines (TNF-α, and IL-6) caused by the stimulation of macrophages with LPS. NF-kB and PI3K inhibition by L. reuteri CRL1098 soluble factors contributed to these inhibitory effects. Inhibition of PI3K/Akt pathway and the diminished expression of CD14 could be involved in the immunoregulatory effect. In addition, our in vivo data proved that the LPS-induced secretion of the pro-inflammatory cytokines, inflammatory cells recruitment to the airways and inflammatory lung tissue damage were reduced in L. reuteri CRL1098 soluble factors treated mice, providing a new way to reduce excessive pulmonary inflammation.