Bifidobacterium longum HY8004 attenuates TNBS-induced colitis by inhibiting lipid peroxidation in mice

Bifidobacterium longum subsp. infantis FJSYZ1M3 ameliorates DSS-induced colitis by maintaining the intestinal barrier, regulating inflammatory cytokines, and modifying gut microbiota

B. longum subsp. infantis is a subspecies of Bifidobacterium longum, and very few strains are shown to have immunomodulatory effects. In the present study, the improvement of dextran sulphate sodium (DSS)-induced colitis by four B. longum subsp. infantis strains was compared. The results showed that B. longum subsp. infantis FJSYZ1M3 could significantly decrease disease activity index (DAI), inhibit weight loss and colon shortening, and attenuate colon tissue damage in DSS-induced colitis mice. And B. longum subsp. infantis FJSYZ1M3 intervention improved the integrity of intestinal tight junctions, relieved mucus layer damage and inhibited epithelial cell apoptosis, thereby maintaining the intestinal barrier. Additionally, B. longum subsp. infantis FJSYZ1M3 significantly affected the levels of inflammatory cytokines IL-6, IL-1β, and IL-10 in the colon, thus relieving inflammation in colitis mice. Furthermore, B. longum subsp. infantis FJSYZ1M3 could ameliorate gut microbiota disturbance caused by DSS exposure and increase the level of butyric acid in cecal contents. In general, these findings suggested that B. longum subsp. infantis FJSYZ1M3 alleviated DSS-induced colitis by maintaining the intestinal barrier, regulating inflammatory cytokines, and modifying the gut microbiota.

Intestinal Engineered Probiotics as Living Therapeutics: Chassis Selection, Colonization Enhancement, Gene Circuit Design, and Biocontainment

Intestinal probiotics are often used for the in situ treatment of diseases, such as metabolic disorders, tumors, and chronic inflammatory infections. Recently, there has been an increased emphasis on intelligent, customized treatments with a focus on long-term efficacy; however, traditional probiotic therapy has not kept up with this trend. The use of synthetic biology to construct gut-engineered probiotics as live therapeutics is a promising avenue in the treatment of specific diseases, such as phenylketonuria and inflammatory bowel disease. These studies generally involve a series of fundamental design issues: choosing an engineered chassis, improving the colonization ability of engineered probiotics, designing functional gene circuits, and ensuring the safety of engineered probiotics. In this review, we summarize the relevant past research, the progress of current research, and discuss the key issues that restrict the widespread application of intestinal engineered probiotic living therapeutics.

Comparison of Selenium-Enriched Lactobacillusparacasei, Selenium-Enriched Yeast, and Selenite for the Alleviation of DSS-Induced Colitis in Mice

Patients with inflammatory bowel disease (IBD) have been found to have decreased immune function. Selenium (Se) is an essential trace element that is beneficial for human health, which has a significant stimulating effect on immune function. We compared the effects of different Se forms on the alleviation of colitis in DSS-induced mice. Moreover, we also aimed to determine whether Se-enriched Lactobacillus paracasei CCFM 1089 could be used as a new organic Se supplement. Different Se supplements (Se-enriched L. paracasei CCFM 1089, Se-enriched yeast and sodium selenite) were given to Se-deficient mice suffering from colitis. Se-enriched L. paracasei CCFM 1089, which is based on selenocysteine (SeCys), had similar effects in terms of reducing oxidative stress and inhibiting pro-inflammatory factors to Se-enriched yeast; however, selenase activity in the Se-enriched L. paracasei CCFM 1089-treated mice was higher than that in other treatment groups. In addition, Se-enriched L. paracasei CCFM 1089 could better protect the intestinal mucosa, which increased the expression of tight junction proteins (ZO-1 and occludin) in mice. Thus Se-enriched L. paracasei CCFM 1089 was shown to alleviate IBD, suggesting that it has potential as a good organic Se supplement.

Bifidobacterium longum Ameliorates Dextran Sulfate Sodium-Induced Colitis by Producing Conjugated Linoleic Acid, Protecting Intestinal Mechanical Barrier, Restoring Unbalanced Gut Microbiota, and Regulating the Toll-Like Receptor-4/Nuclear Factor-κB Signaling Pathway

This study aimed to explore the effects and differences of conjugated linoleic acid (CLA)-producing Bifidobacterium longum on the alleviation of dextran sulfate sodium (DSS)-induced colitis and to explore its patterns. Different B. longum strains were administered at 10⁹ cfu/day 7 days before DSS treatment. B. longum CCFM681 significantly increased goblet cells, mucin2 (MUC2), claudin-3, α-catenin1, and ZO-1, but neither B. longum CCFM760 nor B. longum CCFM642 had those protective effects. Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were downregulated, while IL-10 was upregulated by B. longum CCFM681 but neither by B. longum CCFM760 nor by B. longum CCFM642. Moreover, B. longum CCFM681 treatment inhibited the toll-like receptor-4 (TLR4)/nuclear factor kappa-B (NF-κB) pathway. Furthermore, B. longum CCFM681 treatment rebalanced gut microbiota via regulating the diversity and key microorganisms. Colonic CLA concentrations in mice fed with B. longum CCFM681 were significantly higher than that of DSS-exposed mice, while those in B. longum CCFM760 and B. longum CCFM642 groups showed insignificant difference compared with the DSS group. Moreover, CLA showed a significantly positive correlation with the effectiveness of relieving colitis. B. longum CCFM681 alleviated colitis by protecting the intestinal mechanical barrier, modulating the gut microbiota, and inhibiting the TLR4/NF-κB pathway and associated pro-inflammatory cytokines. These results will help the clinical trials of probiotics and the development of functional products for colitis.

Protective effect of Bifidobacterium bifidum FSDJN7O5 and Bifidobacterium breve FHNFQ23M3 on diarrhea caused by enterotoxigenic Escherichia coli

Enterotoxigenic Escherichia coli (ETEC) is the main bacterial cause of diarrhea among children in developing countries and of traveler's diarrhea. In this study, a mouse model was used to evaluate the effect of Bifidobacterium on alleviating diarrhea caused by ETEC. The results showed that B. breve FHNFQ23M3 and B. bifidum FSDJN7O5 could relieve the symptoms of diarrhea. Both strains significantly reduced the stool water content, restored the villi structure in the jejunum and ameliorated the fecal short-chain fatty acid (SCFA) content. In addition, B. breve FHNFQ23M3 restored body weight to the level before ETEC challenge and significantly reduced interferon-γ (IFN-γ), while B. bifidum FSDJN7O5 significantly improved interleukin (IL)-10. Furthermore, all the Bifidobacterium strains used in this study could significantly downregulate tumor necrosis factor-α (TNF-α) and restore the unbalanced gut microbiota, which had a high content of pathogenic Escherichia-Shigella and low content of Blautia and Clostridium innocuum groups due to ETEC. All the results proved that Bifidobacterium could be a potential probiotic for alleviating diarrhea from ETEC infection.

Evaluation of the Effects of Different Bacteroides vulgatus Strains against DSS-Induced Colitis

Although the strain-dependent effects of Bacteroides vulgatus on alleviating intestinal inflammatory diseases have been demonstrated, the literature has rarely focused on the underlying causes of this effect. In this study, we selected four B. vulgatus strains (FTJS5K1, FTJS7K1, FSDTA11B14, and FSDLZ51K1) with different genomic characteristics and evaluated their protective roles against dextran sulfate sodium- (DSS-) induced colitis. Compared to the other three tested strains, B. vulgatus 7K1 more strongly ameliorated the DSS-induced weight loss, shortening of the colon length, increased disease activity index scores, colonic tissue injury, and immunomodulatory disorder. In contrast, B. vulgatus 51K1 significantly worsened the DSS-induced alterations in the tumor necrosis factor-alpha (TNF-α) concentration and colonic histopathology. A comparative genomic analysis of B. vulgatus 7K1 and 51K1 showed that the beneficial effects of B. vulgatus 7K1 may be associated with some of its specific genes involved in the production of short-chain fatty acids or capsular polysaccharides and enhancement of its survivability in the gut. In conclusion, these findings indicate that the supplementation of B. vulgatus 7K1 is a potentially efficacious intervention for alleviating colitis and provides scientific support for the screening of probiotics with anticolitis effect.

Bifidobacterium pseudocatenulatum Ameliorates DSS-Induced Colitis by Maintaining Intestinal Mechanical Barrier, Blocking Proinflammatory Cytokines, Inhibiting TLR4/NF-κB Signaling, and Altering Gut Microbiota

This study was designed to explore the effects and discrepancy of different CLA-producing Bifidobacterium pseudocatenulatum on relieving colitis and to investigate the potential mechanisms. B. pseudocatenulatum MY40C and CCFM680 were administered to mice with DSS-induced colitis. The content of tight junction proteins and mucin2 was significantly upregulated. TNF-α and IL-6 were downregulated, while IL-10 and PPAR-γ were upregulated. TLR4/NF-κB pathway activation was significantly inhibited. Moreover, each treated strain increased Allobaculum and decreased Sutterella, Bacteroides, and Oscillospira. The colonic conjugated linoleic acid (CLA) concentrations were significantly and positively correlated with the effectiveness of strain in relieving colitis. In conclusion, MY40C and CCFM680 supplementation alleviated DSS-induced colitis by protecting intestinal mechanical barrier, modulating gut microbiota, blocking proinflammatory cytokines, and inhibiting TLR4/NF-κB pathway. These results are conducive to promote clinical trials and product development of probiotics for colitis.

Alleviation effects of Bifidobacterium breve on DSS-induced colitis depends on intestinal tract barrier maintenance and gut microbiota modulation

PURPOSE

The study aimed to investigate the discrepancy and potential mechanisms of different CLA-producing B. breve on dextran sulphate sodium (DSS)-induced colitis.

METHODS

Colitis was induced in C57BL/6 J mice using DSS. Disease activity index (DAI), histopathological changes, epithelial barrier integrity and epithelial apoptosis were determined. Gut microbiota were gauged to evaluate the systemic effects of CLA-producing B. breve.

RESULTS

Oral administration of different B. breve showed different effects, in which B. breve M1 and B. breve M2 alleviated the inflammation induced by DSS as well as significantly increased the concentration of mucin2 (MUC2) and goblet cells, but neither B. breve M3 nor B. breve M4 had those protective effects. Meanwhile, B. breve M1 and B. breve M2 treatments significantly up-regulated the tight junction (TJ) proteins and ameliorated the epithelial apoptosis lead by DSS challenge. Moreover, inflammatory cytokines (TNF-α, IL-6) were modulated by B. breve M1 and B. breve M2, neither B. breve M3 nor B. breve M4. Furthermore, B. breve M1 and B. breve M2 reduced the abundance of Bacteroides and increased the abundance of Odoribacter, then rebalanced the damaged gut microbiota. Colonic CLA concentrations in mice fed with B. breve M1, B. breve M2, B. breve M3 and B. breve M4 decreased successively, which showed significant positive correlation with the effectiveness of relieving colitis.

CONCLUSIONS

Bifidobacterium breve M1 and B. breve M2 alleviated DSS-induced colitis by producing CLA, inhibiting the inflammatory cytokines, maintaining of the intestinal epithelial barrier and regulating the gut microbiota.

Infants born to mothers with IBD present with altered gut microbiome that transfers abnormalities of the adaptive immune system to germ-free mice

BACKGROUND AND AIMS

Prenatal and early life bacterial colonisation is thought to play a major role in shaping the immune system. Furthermore, accumulating evidence links early life exposures to the risk of developing IBD later in life. We aimed to assess the effect of maternal IBD on the composition of the microbiome during pregnancy and on the offspring's microbiome.

METHODS

We prospectively examined the diversity and taxonomy of the microbiome of pregnant women with and without IBD and their babies at multiple time points. We evaluated the role of maternal IBD diagnosis, the mode of delivery, antibiotic use and feeding behaviour on the microbiome composition during early life. To assess the effects of IBD-associated maternal and infant microbiota on the enteric immune system, we inoculated germ-free mice (GFM) with the respective stool and profiled adaptive and innate immune cell populations in the murine intestines.

RESULTS

Pregnant women with IBD and their offspring presented with lower bacterial diversity and altered bacterial composition compared with control women and their babies. Maternal IBD was the main predictor of the microbiota diversity in the infant gut at 7, 14, 30, 60 and 90 days of life. Babies born to mothers with IBD demonstrated enrichment in Gammaproteobacteria and depletion in Bifidobacteria. Finally, GFM inoculated with third trimester IBD mother and 90-day infant stools showed significantly reduced microbial diversity and fewer class-switched memory B cells and regulatory T cells in the colon.

CONCLUSION

Aberrant gut microbiota composition persists during pregnancy with IBD and alters the bacterial diversity and abundance in the infant stool. The dysbiotic microbiota triggered abnormal imprinting of the intestinal immune system in GFM.

Bifidobacteria attenuate the development of metabolic disorders, with inter- and intra-species differences

Host gut microbiota dysbiosis occurs for multiple reasons and is often accompanied by chronic inflammation induced by a high-fat-high-sucrose (HFHS) diet and related metabolic disorders. Intervention with probiotics is a novel strategy for amelioration of metabolic syndrome, which is believed to regulate the gut microbiota composition to some extent. We investigated the relationship amongst bifidobacteria treatment, HFHS diet-induced metabolic disorders and the gut microbiota composition. Seven strains of bifidobacteria from four species were individually administered to rats fed a HFHS diet for 12 weeks. Various bifidobacteria strains showed various effects on the recovery of metabolic disorders and gut microbiota dysbiosis, and these effects seemed to be inter- or intra-species specific. Bifidobacterium longum, B. adolescentis and B. bifidum seemed to affect the blood glucose balance, whilst two strains of B. breve showed extremely different effects in this area. However, only one strain of B. longum and the B. adolescentis displayed significant regulation of blood lipid levels. The protective effects of bifidobacteria on the pancreas were strongly correlated with those on blood glucose. Furthermore, the influence of bifidobacteria on gut microbiota dysbiosis also showed a potential relationship with symptoms of metabolic disorders. Of these seven strains, B. adolescentis Z25 displayed an outstanding ability to alleviate metabolic syndrome, including glucose and lipid metabolism disorders, tissue damage and gut microbiota dysbiosis. This strain, coupled with other prebiotics and probiotics, could be used as a potential treatment approach for metabolic syndrome induced by a HFHS diet.

Protective Effects of Bifidobacterial Strains Against Toxigenic Clostridium difficile

Probiotics might offer an attractive alternative to prevent and control Clostridium difficile (C. difficile) infection (CDI). Limited information is available on the ability of commercially used bifidobacterial strains to inhibit C. difficile. This study examined the anti-clostridial effects of Bifidobacterium longum JDM301, a widely used commercial probiotic strain in China, in vitro and in vivo. In vitro evaluation revealed a significant reduction in C. difficile counts when JDM301 was co-cultured with C. difficile, which was correlated with the significant decrease in clostridial toxin titres (TcdA and TcdB). Furthermore, the cell-free culture supernatants (CFS) of JDM301 inhibited C. difficile growth and degraded TcdA and TcdB. Notably, the results showed that acid pH promoted the degradation of TcdA by CFS from JDM301. Furthermore, comparative studies among 10 B. longum strains were performed, which showed that the inhibitory effect of CFS from JDM301 was similar with the other 8 B. longum strains and higher than strain BLY1. However, when it was neutralized, the significant different was lost. When present together, it was suggested that the acid pH induced by probiotics not only played important roles in the growth inhibition against C. difficile resulting in the reduction of toxins titres, but also directly promoted the degradation of clostridial toxin. In vivo studies proved that JDM301 partially relieved damage to tissues caused by C. difficile and also decreased the number of C. difficile and toxin levels. In summary, our results demonstrated that the commercial strain, JDM301 could be considered a probiotic able to exert anti-toxin capability and most of the CFS from Bifidobacterium were able to inhibit the growth of C. difficile, depending on acid pH. These results highlighted a potential that JDM301 could be helpful in preventing CDI and that most of the bifidobacterial strains could (at least partially) exert protective effects by reducing toxin titres through growth inhibition against toxigenic C. difficile.

Bifidobacterium adolescentis IM38 ameliorates high-fat diet-induced colitis in mice by inhibiting NF-κB activation and lipopolysaccharide production by gut microbiota

Gut microbiota play essential roles in the regulation of human metabolism via symbiotic interactions with the host. Prolonged consumption of high-fat diet (HFD) elevates the Firmicutes to Bacteroidetes ratio and lipopolysaccharide (LPS) production by gut microbiota, thereby increasing the probability of developing metabolic and immune disorders such as obesity and colitis. The use of probiotics with anti-inflammatory properties has been suggested to counteract this effect. Here, we tested whether Bifidobacterium adolescentis IM38, which inhibited nuclear factor-kappa B (NF-κB) activation in Caco-2 cells and peritoneal macrophages and inhibited Escherichia coli LPS production, exerted an anticolitic effect in mice with HFD-induced obesity. Oral administration of IM38 (2×10⁹CFU/mouse per day) for 6 weeks in mice with HFD-induced obesity inhibited whole-body and epididymal fat weight gain. IM38 also increased HFD-suppressed expression of interleukin (IL)-10 and tight junction proteins but significantly downregulated HFD-induced NF-κB activation and tumor necrosis factor expression in the colon. IM38 inhibited differentiation into helper T17 cells and reduced IL-17 levels in the colon of mice with HFD-induced obesity but increased HFD-suppressed differentiation into regulatory T cells and IL-10 levels. Furthermore, treatment with IM38 lowered the HFD-induced LPS levels in blood and colonic fluid, as well as the Proteobacteria to Bacteroidetes ratio in gut microbiota. Therefore, we suggest that IM38 can inhibit HFD-induced LPS production in gut microbiota through the regulation of Proteobacteria to Bacteroidetes ratio and NF-κB activation in the colon, which ultimately attenuates colitis. Thus, IM38 may be a suitable ingredient of functional foods designed for treating or preventing colitis.

Effect of a probiotic Lactobacillus plantarum TN8 strain on trinitrobenzene sulphonic acid-induced colitis in rats

This study aimed to investigate the potential effects of an oral treatment by a newly isolated probiotic Lactobacillus plantarum TN8 strain on trinitrobenzene sulphonic acid (TNBS)-induced colitis in Wistar rats. Thus, 18 rats were divided into three groups (n = 6 per group): group 1 (control) - rats not receiving TNBS application; group 2 - rats receiving an intrarectal TNBS infusion (100 mg/kg TNBS dissolved in ethanol); and group 3 - rats treated with intragastrical TN8 strain once per day (for 5 days before TNBS induction). The performance and the effects of the probiotic treatment were evaluated using a series of histological, biophysical and biochemical analyses. The results have shown that the treatment with the L. plantarum TN8 strain improves the body weight and reduces the diarrhoea, colonic mucosal inflammation and colon shortening. TN8-treated rats showed a significant decrease in the total cholesterol content from 1.86 (for group 2) to 1.32 mmol/l and in triglyceride (TG) content from 2.09 (for group 2) to 1.23 mmol/l. Furthermore, the findings revealed that the high-density lipoprotein (HDL) cholesterol contents increased from 0.95 to 1.02 mmol/l. The histological studies have confirmed that the architecture of the liver and kidney tissues of the TN8-treated rats were found to be improved. Overall, the results suggest that the L. plantarum TN8 presents promising perspectives for the development of safe and cost-effective agents for the prevention or alleviation of several intestinal pathologies.

A diet with lactosucrose supplementation ameliorates trinitrobenzene sulfonic acid-induced colitis in rats

Chronic intestinal inflammation contributes to an increased risk of colon cancer.

Lactosucrose attenuates intestinal inflammation by promoting Th2 cytokine production and enhancing CD86 expression in colitic rats

Some oligosaccharides have immunoregulatory and anti-inflammatory functions in the intestine. This study investigated the immunoregulatory effect of lactosucrose (LS) on 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitic rats. Alkaline phosphatase activity was increased but myeloperoxidase activity was decreased in the LS-TNBS group, as compared with the TNBS group (colitis rats without receiving LS). LS supplementation stimulated IL-4 and IL-10 production, while up-regulating CD86 expression in dendritic cells. LS supplementation reduced the ratio of CD80/CD86 and the ratio of IFN-γ/IL-4 compared to the TNBS group. Moreover, IFN-γ was significantly correlated with CD80 (r = 0.764, p < 0.01), whereas IL-4 was significantly correlated with CD86 (r = 0.489, p < 0.05). These results indicated that LS attenuated colitis by promoting the production of Th2-type cytokines and rebalancing the ratio of Th1/Th2 and that enhanced IL-4 production is correlated with enhanced CD86 expression in the gut. Therefore, LS is a functional food for patients with inflammatory bowel disease.

Protective effect of Laminaria japonica with probiotics on murine colitis

Inflammatory bowel disease (IBD) is a chronically relapsing inflammatory disorder of the gastrointestinal tract. Most IBD treatments are unsatisfactory; therefore, various dietary supplements have emerged as promising interventions. Laminaria japonica (LJ) is an edible seaweed used to regulate digestive symptoms. Probiotics have been reported to improve digestive problems and their simultaneous administration with seaweeds has been shown to produce synergistic therapeutic effects. Here, we investigated the effect of LJ combination with probiotics on dextran sodium sulfate-induced colitis model in mice. Aqueous LJ extracts (LJE) at doses from 100 to 300 mg/kg and probiotics at a dose of 300 mg/kg were orally administered for 7 days. Body weight, colon length, histological score, macroscopic damage, and the levels of cytokines IFN- γ , IL-1 β , IL-6, IL-10, IL-12 (P40), IL-12 (P70), IL-17, and TNF- α were assessed. LJE alone caused a significant improvement of colitis signs such as colon length, histological score, and IL-1 β and IL-6 production. LJE and probiotics demonstrated a synergistic effect by the histological score and levels of IL-1 β , IL-6, and IL-12 (P40) but not IFN- γ , IL-10, and IL-12 (P70). In conclusion, LJE was effective in inducing protection against colitis in mice and acted synergistically with probiotics.

Lactobacillus plantarum CLP-0611 ameliorates colitis in mice by polarizing M1 to M2-like macrophages

The TNF-α expression-inhibitory effect of lactic acid bacteria (LAB) isolated from kimchi were measured in lipopolysaccharide (LPS)-stimulated peritoneal macrophages. Among the LAB evaluated, Lactobacillus plantarum CLP-0611 inhibited the IL-1β and IL-6 expression, as well as the NF-κB and AP1 activation in LPS-stimulated peritoneal macrophages. Therefore, we investigated its inhibitory effect on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice. TNBS significantly induced colon shortening, as well as myeloperoxidase activity and macroscopic score. Oral administration of CLP-0611 significantly reduced TNBS-induced body weight loss, colon shortening, myeloperoxidase activity, IRAK-1 phosphorylation, NF-κB and MAP kinase (p38, ERK, JNK) activation, and iNOS and COX-2 expression. CLP-0611 also inhibited TNBS-induced expression of TNF-α, IL-1β, and IL-6. However, IL-10 expression was induced. CLP-0611 also induced the production of M2 macrophage markers (IL-10, arginase I and CD206). Based on these findings, CLP-0611 inhibits TLR-4-linked NF-κB and MAPK signaling pathways and polarizes M1 to M2-like macrophages, thus ameliorating colitis.

Lactobacillus casei Zhang modulate cytokine and toll-like receptor expression and beneficially regulate poly I:C-induced immune responses in RAW264.7 macrophages

Lactobacilli are frequently used as probiotics due to their beneficial effects on health. Lactobacillus casei Zhang (LcZ), which has favorable probiotic properties, was first isolated from koumiss. In this study, the immunomodulating effects of LcZ on cytokine and toll-like receptor expression in RAW264.7 macrophages was assessed and it was found that live LcZ promotes production of nitric oxide (NO), tumor necrosis factor (TNF)-α, interleukin (IL)-6 and interferon (IFN)-β. Transcription of inducible nitric oxide synthase (iNOS) was also enhanced by viable LcZ. The immunostimulating effects of live LcZ are significantly attenuated in heat-killed LcZ. Live LcZ promotes TLR2 mRNA transcription, whereas heat-killed LcZ enhances transcription of TLR2, TLR3, TLR4 and TLR9. Furthermore, live LcZ significantly suppresses polyinosinic:polycytidylic acid (poly I:C)-stimulated NO, iNOS and TNF-α expression while enhancing expression of IFN-β. It was also found that poly I:C-induced interferon regulatory factor 3 (IRF-3) reporter gene activity was significantly up-regulated by live LcZ. These results suggest that LcZ keeps the innate immune system alert by increasing transcription of Toll-like receptors and enhancing production of pro-inflammatory mediators and type I IFN in macrophages. The synergistic effect of live LcZ with poly I:C on IFN-β expression is associated with increased activity of IRF-3. LcZ has the potential to be used as an adjuvant against viral infections.

Lactobacillus brevis G-101 ameliorates colitis in mice by inhibiting NF-κB, MAPK and AKT pathways and by polarizing M1 macrophages to M2-like macrophages

AIM

We isolated Lactobacillus brevis G-101 from kimchi lactic acid bacteria (LAB) strains, which induced IL-10 expression in lipopolysaccharide (LPS)-stimulated peritoneal macrophages. To evaluate the inflammatory effect of G-101, we examined its inhibitory effect in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitic mice.

MATERIALS AND RESULTS

The colitic mice were prepared by intrarectal injection of TNBS. We measured intestinal mucosal cytokines by enzyme-linked immunosorbent assay; activation of transcription factors, by immunoblotting; and macrophage polarization markers, by real-time polymerase chain reaction. Of 200 LAB strains tested, Lact. brevis G-101 showed most potent activity for induction of IL-10 expression in LPS-stimulated peritoneal macrophages. However, it significantly inhibited the expression of TNF-α, IL-1β and IL-6 and the phosphorylation of IRAK1 and AKT, and activated NF-κB and MAPKs. Treatment with TNBS caused colon shortening; increased myeloperoxidase activity; and increased IL-1β, IL-6 and TNF-α expression in mice. Oral administration of Lact. brevis G-101 significantly inhibited these activities. Lactobacillus brevis G-101 inhibited TNBS-induced IRAK-1 phosphorylation and NF-κB activation, as well as the expression of COX-2 and iNOS. Lactobacillus brevis G-101 inhibited the expression of M1 macrophage markers, but increased the expression of M2 macrophages in the colons of TNBS-treated mice.

CONCLUSIONS

Lactobacillus brevis G-101 may improve colitis by inhibiting the IRAK1/NF-κB, MAPK and AKT pathways and by polarizing M1 macrophages to M2-like macrophages.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results suggest that IL-10 expression-inducing LAB can ameliorate colitis by inhibiting NF-κB activation and macrophage polarization.

Expression of catalase in Lactobacillus fermentum and evaluation of its anti-oxidative properties in a dextran sodium sulfate induced mouse colitis model

Lactic acid bacteria are generally sensitive to hydrogen peroxide (H₂O₂). Lactobacillus plantarum ATCC14431 is one of the few lactic acid bacteria able to degrade H₂O₂ through the action of a manganese-dependent catalase (containing the katA gene). However, it is not a natural inhabitant of the intestinal tract and its bio-efficacy and survival in the gastrointestinal tract have never been tested. In this study, we successfully expressed the katA gene from L. plantarum ATCC14431 in L. fermentum I5007 and the recombinant L. fermentum exhibited almost 20-fold higher catalase activity than the empty vector control. The anti-oxidative properties of this catalase-producing L. fermentum were evaluated using a dextran sodium sulphate (DSS) induced colitis mice model. Compared with the control, mice receiving DSS alone had increased diarrhea and mucosa histological scores (P < 0.05), as well as lipid peroxidation (P < 0.05), myeloperoxidase (P < 0.05), and active NF-κB in colonic tissue (P < 0.05). Similar to vitamin E, treatment with recombinant L. fermentum mitigate these effects accompanied by a improvement in mucosa histological scores in the proximal colon (P < 0.05) and decreased lipid peroxidation (P < 0.05), myeloperoxidase (P < 0.05) and active NF-κB in colonic tissue (P < 0.05). In conclusion, the expression of catalase in L. fermentum increased its ability to survive when exposed to aerated environment in vitro and conferred the anti-oxidative and anti-inflammatory effects in the DSS induced colitis model.

Inhibitory effect of Lactobacillus plantarum K-1 on passive cutaneous anaphylaxis reaction and scratching behavior in mice

Lactobacillus plantarum K-1 (LP) inhibiting AP-1 (c-Jun) and NF-κB activations was isolated from kimchi, and its inhibitory activity against scratching behavior and passive cutaneous anaphylaxis reaction in mice was investigated. Heat-inactivated LP (heated at 60°C for 30 min) potently inhibited the expression of TNF-α and IL-4 as well as the activation of their transcription factors, NF-κB and c-jun, in phorbol 12'-myristate 13'-acetate-stimulated RBL-2H3 cells. LP (1 × 10(10) CFU per mouse) showed a potent inhibition against passive cutaneous anaphylaxis reaction induced by the IgE-antigen complex in mice, inhibiting it by 87.5%. LP (1 × 10(10) CFU/mouse) inhibited histamine-induced scratching behavior by 58.9% compared to the control group. LP significantly inhibited vascular permeability induced by histamine. The inhibitory activity of LP against vascular permeability was in proportion to its inhibition against scratching behavior. LP potently inhibited histamine-induced cytokine production: it (1 × 10(10) CFU per mouse) inhibited IL-4, IL-1β, and TNF-α expression by 88.9%, 88.6%, and 98.9%, respectively. LP also inhibited IgE level increased by histamine by 85.3%. It inhibited histamine-induced the activations of their transcription factors, NF-κB and c-Jun. Based on these findings, LP may improve allergic diseases, such as anaphylaxis, atopic dermatitis, rhinitis, and pruritus by inhibiting the expression of IgE-switching cytokine IL-4 and proinflammatory cytokines IL-1β and TNF-α via NF-κB and AP-1 signaling pathways.

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 β-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-1β, 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 β-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-1β, 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-1β, and TNF-α by regulating NF-κB activation and by killing G. vaginalis, and that LJ could ameliorate bacterial vaginosis.

Bojanggunbi-tang, a traditional Korean herbal prescription, ameliorates colonic inflammation induced by dextran sulfate sodium and 2,4,6-trinitrobenzene sulfonic acid in mice

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Korean medicine, Bojanggunbi-tang (BGT), which consists of 16 herbs, is one of the most frequently used herbal prescriptions in South Korea for treating intestinal disorders such as colitis.

AIM OF THE STUDY

This study investigated whether BGT could show a protective action on 2 different mice models of experimental colitis induced by dextran sulfate sodium (DSS) and 2,4,6-trinitrobenzene sulfonic acid (TNBS), which have been popularly used as inflammatory bowel disease models.

MATERIALS AND METHODS

Colitis was induced by DSS and TNBS in institute of cancer research mice. BGT at doses of 50, 150, or 450 mg/kg were orally administered twice a day for 7d in the DSS model and for 3d in the TNBS model. The body weight of the mice was measured daily. Colon length and histological damages were assessed on day 7 in the DSS model and on day 3 in the TNBS model.

RESULTS

BGT showed protective effects in both types of experimental colitis. In the DSS model, BGT dose dependently inhibited weight loss, shortening of colon length, and histological damages of the colon. In the TNBS model, BGT inhibited shortening of colon length and improved the survival rate of mice; however, it did not inhibit weight loss.

CONCLUSION

The current results indicate that BGT ameliorates both DSS- and TNBS-induced colitis in mice. Further investigations to unveil the exact mechanisms are needed.

Treatment with Bifidobacterium bifidum 17 partially protects mice from Th1-driven inflammation in a chemically induced model of colitis

Probiotics have been suggested as an alternative therapeutical approach in the intervention of inflammatory disorders of the gastrointestinal tract (GIT). Application of single strains or probiotic mixtures has shown promising results in animal models and patients of inflammatory bowel disease (IBD). We recently demonstrated potent inhibitory capacity of a Bifidobacterium bifidum S17 on LPS-induced inflammatory events in cell culture models using intestinal epithelial cells and verified these anti-inflammatory effects in two mouse models of colitis. In the present study we analyze the anti-inflammatory effect of this potential probiotic strain in a chemically-induced model of colitis in C57BL/6 mice. This model is characterized by a strong type 1T helper (Th1) response resembling Crohn's disease, one of the two most prevalent forms of IBD. We performed macroscopic analysis and determined the effect of B. bifidum S17 on the cytokine balance in biopsies of the colonic mucosa. While treatment with B. bifidum S17 only had a marginal effect on weight loss, no difference was observed in the macroscopic parameters. However, a significant reduction in histology scores and the levels of pro-inflammatory cytokines interleukin 1β (IL-1β), interleukin 6 (IL-6), keratinocyte-derived chemokine (KC) and the inflammatory markers cyclooxigenase 2 (Cox-2) and myeloperoxidase (MPO) was observed. These results indicate that treatment with B. bifidum S17 is able to partially inhibit the strong Th1-driven intestinal inflammation induced in our model of colitis.