Protective Effects of Clostridium Butyricum in a Murine Model of Dextran Sodium Sulfate-Induced Colitis That Involve Inhibition of the TLR2 Signaling Pathway and T Helper 17 Cells

Clostridium butyricum, a future star in sepsis treatment

Sepsis is a systemic inflammatory response syndrome of multiorgan failure caused by dysregulation of the host response to infection and is a major cause of death in critically ill patients. In recent years, with the continuous development of sequencing technology, the intestinal microecology of this disease has been increasingly studied. The gut microbiota plays a host-protective role mainly through the maintenance of normal immune function and the intestinal barrier. Recent evidence suggests that intestinal flora dysbiosis plays a crucial role in sepsis. Clostridium butyricum (C. butyricum), which has been used as a probiotic in poultry feed since its discovery, has been found to play a potential protective role in intestinal infections, inflammatory bowel disease (IBD), colorectal cancer, and other diseases in recent studies. In this review, we continue to focus on the important role and mechanism of C. butyricum as a probiotic in human diseases, especially intestinal diseases. Additionally, we evaluate the research progress of C. butyricum in treatment of sepsis to identify more therapeutic targets for the clinical treatment of sepsis.

Toll-Like Receptor 2 Deficiency Exacerbates Dextran Sodium Sulfate-Induced Intestinal Injury through Marinifilaceae-Dependent Attenuation of Cell Cycle Signaling

BACKGROUND

Ulcerative colitis (UC) is an intestinal disorder marked by chronic, recurring inflammation, yet its underlying mechanisms have not been fully elucidated.

METHODS

The current research dealt with examining the biological impacts of toll-like receptor 2 (TLR2) on dextran sulfate sodium (DSS)-triggered inflammation in the intestines of wild-type (WT) and TLR2-knockout (TLR2-KO) colitis mouse models. To elucidate the protective function of TLR2 in DSS-triggered colitis, RNA-sequencing (RNA-Seq) was carried out to compare the global gene expression data in the gut of WT and TLR2-KO mice. Further, 16S rRNA gene sequencing revealed notable variations in gut microbiota composition between WT and TLR2-KO colitis mice.

RESULTS

It was revealed that TLR2-KO mice exhibited increased susceptibility to DSS-triggered colitis. RNA-Seq results demonstrated that cell cycle pathway-related genes were notably downregulated in TLR2-KO colitis mice (enrichment score = 30, p < 0.001). 16S rRNA gene sequencing revealed that in comparison to the WT colitis mice, the relative abundance of Marinifilacea (p = 0.006), Rikenellacea (p = 0.005), Desulfovibrionaceae (p = 0.045), Tannerellaceae (p = 0.038), Ruminococcaceae (p = 0.003), Clostridia (p = 0.027), and Mycoplasmataceae (p = 0.0009) was significantly increased at the family level in the gut of TLR2-KO colitis mice. In addition, microbiome diversity-transcriptome collaboration analysis highlighted that the relative abundance of Marinifilaceae was negatively linked to the expression of cell cycle signaling-related genes (p values were all less than 0.001).

CONCLUSION

Based on these findings, we concluded that TLR2-KO exacerbates DSS-triggered intestinal injury by mitigating cell cycle signaling in a Marinifilaceae-dependent manner.

Combining Gut Microbiota Modulation and Enzymatic-Triggered Colonic Delivery by Prebiotic Nanoparticles Improves Mouse Colitis Therapy

The efficacy of ulcerative colitis (UC) therapy is closely connected to the composition of gut microbiota in the gastrointestinal tract. Prebiotic-based nanoparticles (NPs) provide a more precise approach to alleviate UC via modulating gut microbiota dysbiosis. The present study develops an efficient prebiotic-based colon-targeted drug delivery system (PCDDS) by using prebiotic pectin (Pcn) and chitosan (Csn) polysaccharides as a prebiotic shell, with the anti-inflammatory drug sulfasalazine (SAS) loaded into a poly(lactic-co-glycolic acid) (PLGA) core to construct SAS@PLGA-Csn-Pcn NPs. Then, we examine its characterization, cellular uptake, and in vivo therapeutic efficacy. The results of our study indicate that the Pcn/Csn shell confers efficient pH-sensitivity properties. The gut microbiota-secreted pectinase serves as the trigger agent for Pcn/Csn shell degradation, and the resulting Pcn oligosaccharides possess a substantial prebiotic property. Meanwhile, the formed PCDDSs exhibit robust biodistribution and accumulation in the colon tissue, rapid cellular uptake, efficient in vivo therapeutic efficacy, and modulation of gut microbiota dysbiosis in a mouse colitis model. Collectively, our synthetic PCDDSs demonstrate a promising and synergistic strategy for UC therapy.

Clostridium butyricum isolated from giant panda can attenuate dextran sodium sulfate-induced colitis in mice

Objective

Probiotics are beneficial to the intestinal barrier, but few studies have investigated probiotics from giant pandas. This study aims to explore the preventive effects of giant panda-derived Clostridium butyricum on dextran sodium sulfate (DSS)-induced colitis in mice.

Methods

Clostridium butyricum was administered to mice 14 days before administering DSS treatment to induce enteritis.

Results

Clostridium butyricum B14 could more effectively prevent colitis in mice than C. butyricum B13. C. butyricum B14 protected the mouse colon by decreasing the histology index and serum interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) levels, which improved intestinal inflammation-related symptoms. In addition, the treatment led to the regulation of the expression of Tifa, Igkv12-89, and Nr1d1, which in turn inhibited immune pathways. The expression of Muc4, Lama3, Cldn4, Cldn3, Ocln, Zo1, Zo2, and Snai is related the intestinal mucosal barrier. 16S sequencing shows that the C. butyricum B14 significantly increased the abundance of certain intestinal probiotics. Overall, C. butyricum B14 exerted a preventive effect on colitis in mice by inhibiting immune responses, enhancing the intestinal barrier and increasing the abundance of probiotic species. Thus, C. butyricum B14 administration helps regulate the balance of the intestinal microecology. It can suppress immune pathways and enhance barrier-protective proteins.

Randomized double-blinded controlled trial on the effect of synbiotic supplementation on IL-17/IL-23 pathway and disease activity in patients with axial spondyloarthritis

BACKGROUND

Interleukin 17 (IL17)-expressing CD4⁺ T cells and IL-17/IL-23 pathway play a key role in the pathogenesis of axial spondyloarthritis (axSpA). Synbiotics have been suggested due to their immunomodulatory effects in the treatment of autoimmune diseases. This randomized double-blind, placebo-controlled trial was designed to assess the effects of synbiotic supplement on IL-17/IL-23 pathway and disease activity in patients with axSpA.

METHODS

Forty-eight axSpA patients were randomly allocated to use one synbiotic capsule or placebo daily for 12 weeks. Disease activity was assessed using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and ASAS-endorsed disease activity score-C-reactive protein (ASDAS-CRP). The secondary outcome was proportion of IL17-expressing CD4+ T cells, IL-17 and IL-23 gene expression, and supernatant levels of IL-17 and IL-23, which were measured at the baseline and end of the trial.

RESULTS

A total of 48 patients were randomized into the synbiotic and placebo groups. Thirty-eight patients completed the study. Synbiotic supplementation significantly reduced the proportion of IL17-expressing CD4⁺ T cells (4.88 ± 2.47 vs. 2.16 ± 1.25), gene expression of IL-17 (1.03 ± 0.24 vs. 0.65 ± 0.26) and IL-23 (1.01 ± 0.13 vs. 0.68 ± 0.24) and serum IL-17 (38.22 ± 14.40 vs. 24.38 ± 11.68) and IL-23 (51.77 ± 17.40 vs. 32.16 ± 12.46) compared with baseline. Significant differences between groups were noticed only in the proportion of IL17-expressing CD4⁺ T cells, and IL-17 and IL-23 gene expression. Synbiotic supplementation did not significantly alter BASDAI and ASDAS-CRP compared with baseline and placebo group at the end of trial.

CONCLUSION

Present study indicated beneficial effect of synbiotic supplement on IL-17/IL-23 pathway without improving disease activity in axSpApatients.HighlightsSynbiotic supplementation reduced IL17-expressing CD4⁺ T cells proportion in axSpA.Synbiotic supplementation decreased IL-17 and IL-23 gene expression in axSpA.Synbiotic supplementation did not change disease activity score in axSpA.

Protective Effect of Clostridium butyricum on Escherichia coli-Induced Endometritis in Mice via Ameliorating Endometrial Barrier and Inhibiting Inflammatory Response

Endometritis is a common reproductive disease occurs both in human and animals. Clostridium butyricum is a Gram-positive anaerobic bacterium that can ferment various carbohydrates into butyric acid. In this study, we investigated the effects of C. butyricum on Escherichia coli-induced endometritis and clarified the underlying mechanism. We first verified the protective effect of C. butyricum in vivo by establishing a mouse model of E. coli-induced endometritis. It was determined that C. butyricum pretreatment significantly reversed E. coli-induced uterine histopathological changes. Meanwhile, C. butyricum pretreatment significantly decreased the production of pro-inflammatory mediators and the levels of myeloperoxidase (MPO) and malondialdehyde (MDA). We found that C. butyricum could inhibit TLR4-mediated phosphorylation of NF-κB and the activity of histone deacetylase (HDAC). Furthermore, C. butyricum significantly increased the expression of the tight junction proteins (TJPs) ZO-1, claudin-3, and occludin. Additionally, treatment with C. butyricum culture supernatant dramatically suppressed the degree of inflammation in the uterus, and inactivated C. butyricum did not exert a protective effect. We subsequently investigated butyrate levels in both the uterus and blood and observed a marked augment in the C. butyricum treatment group. Collectively, our data suggest that C. butyricum maintains epithelial barrier function and suppresses inflammatory response during E. coli-induced endometritis and that the protective effect of C. butyricum may be related to the production of butyrate. IMPORTANCE Endometritis is a common reproductive disease both in human and animals. It impairs female fertility by disrupting endometrial function. Antibiotics are widely used to treat endometritis in clinical practice, but the misuse of antibiotics often leads to antibiotic resistance. Therefore, there is an urgent need for new therapeutic agents to treat bacterial endometritis and overcome bacterial resistance. In this study, we found that C. butyricum could protect from E. coli-induced endometritis.

Probiotic-Based Intervention in the Treatment of Ulcerative Colitis: Conventional and New Approaches

Although there are number of available therapies for ulcerative colitis (UC), many patients are unresponsive to these treatments or experience secondary failure during treatment. Thus, the development of new therapies or alternative strategies with minimal side effects is inevitable. Strategies targeting dysbiosis of gut microbiota have been tested in the management of UC due to the unquestionable role of gut microbiota in the etiology of UC. Advanced molecular analyses of gut microbiomes revealed evident dysbiosis in UC patients, characterized by a reduced biodiversity of commensal microbiota. Administration of conventional probiotic strains is a commonly applied approach in the management of the disease to modify the gut microbiome, improve intestinal barrier integrity and function, and maintain a balanced immune response. However, conventional probiotics do not always provide the expected health benefits to a patient. Their benefits vary significantly, depending on the type and stage of the disease and the strain and dose of the probiotics administered. Their mechanism of action is also strain-dependent. Recently, new candidates for potential next-generation probiotics have been discovered. This could bring to light new approaches in the restoration of microbiome homeostasis and in UC treatment in a targeted manner. The aim of this paper is to provide an updated review on the current options of probiotic-based therapies, highlight the effective conventional probiotic strains, and outline the future possibilities of next-generation probiotic and postbiotic supplementation and fecal microbiota transplantation in the management of UC.

Immunomodulatory functions of FXR

The Farnesoid-x-receptor (FXR) is a bile acids sensor activated in humans by primary bile acids. FXR is mostly expressed in liver, intestine and adrenal glands but also by cells of innate immunity, including macrophages, liver resident macrophages, the Kupffer cells, natural killer cells and dendritic cells. In normal physiology and clinical disorders, cells of innate immunity mediate communications between liver, intestine and adipose tissues. In addition to FXR, the G protein coupled receptor (GPBAR1), that is mainly activated by secondary bile acids, whose expression largely overlaps FXR, modulates chemical communications from the intestinal microbiota and the host's immune system, integrating epithelial cells and immune cells in the entero-hepatic system, providing a mechanism for development of a tolerogenic state toward the intestinal microbiota. Disruption of FXR results in generalized inflammation and disrupted bile acids metabolism. While FXR agonism in preclinical models provides counter-regulatory signals that attenuate inflammation-driven immune dysfunction in a variety of liver and intestinal disease models, the clinical relevance of these mechanisms in the setting of FXR-related disorders remain poorly defined.

Clostridium butyricum and Its Derived Extracellular Vesicles Modulate Gut Homeostasis and Ameliorate Acute Experimental Colitis

Microbiological treatments are expected to have a role in the future management of inflammatory bowel disease (IBD). Clostridium butyricum (C. butyricum) is a probiotic microorganism that exhibits beneficial effects on various disease conditions. Although many studies have revealed that C. butyricum provides protective effects in mice with colitis, the way C. butyricum establishes beneficial results in the host remains unclear. In this study, we investigated the mechanisms by which C. butyricum modifies the gut microbiota, produces bacterial metabolites that may be involved, and, specifically, how microbial extracellular vesicles (EVs) positively influence IBD, using a dextran sulfate sodium (DSS)-induced colitis murine model in mice. First, we showed that C. butyricum provides a protective effect against colitis, as evidenced by the prevention of body weight loss, a reduction in the disease activity index (DAI) score, a shortened colon length, decreased histology score, and an improved gut barrier function, accompanied by reduced levels of pathogenic bacteria, including Escherichia/Shigella, and an increased relative abundance of butyrate-producing Clostridium sensu stricto-1 and Butyricicoccus. Second, we also confirmed that the gut microbiota and metabolites produced by C. butyricum played key roles in the attenuation of DSS-induced experimental colitis, as supported by the profound alleviation of colitis effects following fecal transplantation or fecal filtrate insertion supplied from C. butyricum-treated mice. Finally, C. butyricum-derived EVs protected the gut barrier function, improved gut microbiota homeostasis in ulcerative colitis, and contributed to overall colitis alleviation.

IMPORTANCE This study indicated that C. butyricum provided a prevention effect against colitis mice, which involved protection of the intestinal barrier and positively regulating gut microbiota. Furthermore, we confirmed that the gut microbiota and metabolites that were induced by C. butyricum also contributed to the attenuation of DSS-induced colitis. Importantly, C. butyricum-derived EVs showed an effective impact in alleviating colitis.

Single and Combined Effects of Clostridium butyricum and Coccidiosis Vaccine on Growth Performance and the Intestinal Microbiome of Broiler Chickens

Avian coccidiosis is an important intestinal protozoan disease that has caused major economic losses to the poultry industry. Clostridium butyricum can not only maintain the stability of the intestinal barrier, but can also improve the production performance of broiler chickens. We studied the effects of feeding C. butyricum alone, administration of coccidiosis vaccine alone, and the combined administration of C. butyricum and coccidiosis vaccine on body weight gain, feed consumption, and feed conversion ratio of broilers. Meanwhile, intestinal contents of 8- and 15-day-old broilers were collected, and their intestinal microbiome was characterized by high-throughput sequencing of the V3–V4 region of 16S rDNA. We analyzed the oocysts per gram values and lesion scores in the C. butyricum alone group, in a group challenged with the coccidiosis-causing parasite, Eimeria, and in groups simultaneously challenged Eimeria and pretreated with C. butyricum, the coccidiosis vaccine, or combined C. butyricum and coccidiosis vaccine. Intestinal tissue samples were collected from 32-day-old broilers for microbiome analysis. Our results showed that combination of C. butyricum with coccidiosis vaccine significantly improved the performance of broiler chickens and also significantly reduced the oocysts per gram value and intestinal lesions caused by Eimeria sp. infection. Furthermore, C. butyricum and coccidiosis vaccine administered alone or in combination significantly increased the relative abundance of the immune biomarker genus Barnesiella. The significant increase in the abundance of the Clostridia_UCG.014, Eubacterium coprostanoligenes group and Bacteroides was a key factor in controlling Eimeria sp. infection.

Intestinal bacteria flora changes in patients with Mycoplasma pneumoniae pneumonia with or without wheezing

Mycoplasma pneumoniae (MP) infection is a common cause of community-acquired pneumonia in children. Furthermore, many children with Mycoplasma pneumoniae pneumonia (MPP) have recurrent wheezing and reduced small airway function after their clinical symptoms have resolved, eventually leading to asthma. MPP can trigger immune disorders and systemic inflammatory responses. Hence, the intestine is the largest immune organ of the body. Therefore, we sought to investigate whether the alteration of intestinal flora is correlated with the development of wheezing in children with MPP. We collected 30 healthy children as group A, 50 children with nonwheezing MPP as group B, and 50 children with wheezing MPP as group C. We found that the percentage of eosinophil cells (EC) was significantly higher in group C than that in group B for routine blood tests and serum inflammatory factors. The serum cytokines, including IL-4, IL-17, TNF-α, and TGF-β, were significantly higher in group C than in group B. In addition, the level of IL-10 was significantly lower in group C than in group B. The distribution characteristics of intestinal flora strains in children with MPP were detected by sequencing of 16S rRNA gene amplicon sequencing. There were differences in the abundance of intestinal flora between children with MPP and healthy children, with lower abundance of Ruminococcus flavefaciens, Clostridium butyricum, Lactobacillus, and Bifidobacterium in the intestine of children with MPP compared to healthy children. The abundance of Ruminococcus flavefaciens and Clostridium butyricum was significantly lower in the intestine of children with wheezing MPP compared to children without wheezing MPP. In the correlation analysis between children with MPP and inflammatory factors, Ruminococcus flavefaciens was found to be negatively correlated with IL-17. Clostridium butyricum was negatively correlated with L-4, IL-17, TNF-α, and TGF-β; however, it positively correlated with IL-10. Thus, it was concluded that alterations in intestinal flora play a crucial role in the immune response to MPP, where a significant decline in intestinal Ruminococcus flavefaciens and Clostridium butyricum leads to an exacerbation of the inflammatory responses, which may promote the development of children with wheezing MPP.

Clostridium butyricum alleviates dextran sulfate sodium-induced experimental colitis and promotes intestinal lymphatic vessel regeneration in mice

Background

Inflammatory bowel disease (IBD) is the most common precancerous lesion of colitis-associated colon cancer (CAC). Studies have confirmed that pathological changes in intestinal lymphatic vessels (LVs) significantly promoted the development of IBD-associated carcinogenesis. An imbalance in the microecology of the intestinal flora is a key factor in the progression of IBD. As a result, therapeutic techniques that focus on the relationship between LV regeneration and flora management might be a potential treatment strategy.

Methods

We investigated the role of Clostridium butyricum (C butyricum) in a dextran sulfate sodium (DSS)-induced IBD mouse model. Balb/c mice were given 3% DSS in their drinking water for 8 days to produce acute colitis and simultaneously administrated with C butyricum for 12 days. Hematoxylin and eosin (H&E) staining was used to evaluate the degree of colitis tissue damage. Levels of the lymphatic endothelial cell (LEC)-specific marker LYVE-1 and intestinal expressions of pro-lymphatic vascular endothelial growth factor (VEGF)-C and VEGF-D were determined using immunohistochemical assays.

Results

In a DSS-induced IBD mouse model, we found that butyric acid-producing C butyricum significantly reduced disease activity index (DAI) scores in mice, reversed the shortening of the colon, weakened the degree of damage to colonic epithelial tissues, inhibited lymphocyte infiltration, and reduced pathological damage to the colon. To our knowledge, this is the first time that tissue expressions of LYVE-1, VEGF-C, and VEGF-D have been seen to increase in IBD-model mice after treatment with C butyricum.

Conclusions

Our findings suggest that C butyricum might alleviate IBD in DSS-induced IBD-model mice by promoting intestinal LV regeneration.

Clostridium butyricum Supernatant Regulates the Expression of RORγt in HCT-116 Cells by Inhibiting the TLR2/MyD88/NF-κB Signaling Pathway

In this study, we treated HCT-116 cells with Clostridium butyricum (C. butyricum) supernatant and observed its effects on the TLR2/MyD88/NF-κB signaling pathway and RORγt, to further explore the possible immune regulatory mechanism of C. butyricum. Our results showed that C. butyricum supernatant downregulated the mRNA and protein levels of TLR2, MyD88, NF-κBp65, and RORγt in HCT-116 cells and the protein levels of phospho-NF-κBp65. Partial blockage of TLR2 by CD282 weakened the inhibitory effects of C. butyricum supernatant on the above pathway components. Those component levels were still inhibited by C. butyricum supernatant after Pam3CSK4 activation of TLR2. In summary, C. butyricum supernatant can inhibit the TLR2/MyD88/NF-κB signaling pathway and the expression of RORγt in HCT-116 cells. These effects are at least partly achieved through inhibition of TLR2.