Protective Effect of Pediococcus pentosaceus LI05 Against Clostridium difficile Infection in a Mouse Model

Interplay between Bile Acids and Intestinal Microbiota: Regulatory Mechanisms and Therapeutic Potential for Infections

Bile acids (BAs) play a crucial role in the human body's defense against infections caused by bacteria, fungi, and viruses. BAs counteract infections not only through interactions with intestinal bacteria exhibiting bile salt hydrolase (BSH) activity but they also directly combat infections. Building upon our research group's previous discoveries highlighting the role of BAs in combating infections, we have initiated an in-depth investigation into the interactions between BAs and intestinal microbiota. Leveraging the existing literature, we offer a comprehensive analysis of the relationships between BAs and 16 key microbiota. This investigation encompasses bacteria (e.g., Clostridioides difficile (C. difficile), Staphylococcus aureus (S. aureus), Escherichia coli, Enterococcus, Pseudomonas aeruginosa, Mycobacterium tuberculosis (M. tuberculosis), Bacteroides, Clostridium scindens (C. scindens), Streptococcus thermophilus, Clostridium butyricum (C. butyricum), and lactic acid bacteria), fungi (e.g., Candida albicans (C. albicans) and Saccharomyces boulardii), and viruses (e.g., coronavirus SARS-CoV-2, influenza virus, and norovirus). Our research found that Bacteroides, C. scindens, Streptococcus thermophilus, Saccharomyces boulardii, C. butyricum, and lactic acid bacteria can regulate the metabolism and function of BSHs and 7α-dehydroxylase. BSHs and 7α-dehydroxylase play crucial roles in the conversion of primary bile acid (PBA) to secondary bile acid (SBA). It is important to note that PBAs generally promote infections, while SBAs often exhibit distinct anti-infection roles. In the antimicrobial action of BAs, SBAs demonstrate antagonistic properties against a wide range of microbiota, with the exception of norovirus. Given the intricate interplay between BAs and intestinal microbiota, and their regulatory effects on infections, we assert that BAs hold significant potential as a novel approach for preventing and treating microbial infections.

Protective effect of Pediococcus pentosaceus Li05 on diarrhea-predominant irritable bowel syndrome in rats

Pediococcus pentosaceus Li05 (Li05) has demonstrated potential benefits in various intestinal and liver diseases, but its potential and mechanisms in relieving diarrhea have not been understood. The objective of this research was to examine the effects and mechanisms of Li05 in rats with diarrhea-predominant irritable bowel syndrome (IBS-D) induced by wrap restrain stress (WRS) and 4% acetic acid. The results demonstrated that Li05 effectively alleviated weight loss, visceral sensitivity and diarrhea in rats with IBS-D. It also improved intestinal and systemic inflammation by reducing the levels of chemokines and proinflammatory cytokines (GRO/KC, RANTES, IL-1β, IL-7, and IL-18). The 5-hydroxytryptamine (5-HT) signaling pathway is involved in regulating excessive intestinal motility and secretion in IBS-D. Li05 effectively reduced the expression levels of the 5-HT3B receptor (5-HT3BR) (p < 0.01) in the intestine. Additionally, Li05 intervention had a regulatory effect on the gut composition, with a decrease in the abundance of [Ruminococcus] gauvreauii group, Dubosiella, Erysipelatoclostridium and Blautia, and an increase in the abundance of Alloprevotella, Anaerotruncus and Mucispirillum. Furthermore, Li05 induced significant changes in fatty acid and amino acid metabolism in the gut of rats with IBS-D. These findings indicate that Li05 exhibits an effective improvement in IBS-D symptoms by reducing inflammation and modulating gut microbiota and metabolism. Based on the above results, Li05 holds promise as a potential probiotic for managing IBS-D.

Strategies for applying probiotics in the antibiotic management of Clostridioides difficile infection

The vital role of probiotics in the food field has been widely recognized, and at the same time, probiotics are gradually exhibiting surprising effects in the field of nutraceuticals, especially in regulating gut inflammation and the nutritional environment. As a dietary supplement in clinical nutrition, the coadministration of probiotics with antibiotics model has been applied to prevent intestinal infections caused by Clostridioides difficile. However, the mechanism behind this "bacteria-drug combination" model remains unclear. In particular, the selection of specific probiotic strains, the order of probiotics or antibiotics, and the time interval of coadministration are key issues that need to be further explored and clarified. Here, we focus on the issues mentioned above and give reasonable opinions, mainly including: (1) probiotics are safer and more effective when they intervene after antibiotics have been used; (2) the choice of the time interval between coadministration should be based on the metabolism of antibiotics in the host, differences in probiotic strains, the baseline ecological environment of the host's intestine, and the host immune level; in addition, the selection of the coadministration regime should also take into account factors such as the antibiotic sensitivity of probiotics and dosage of probiotics; and (3) by encapsulating probiotics, combining probiotics with prebiotics, and developing next-generation probiotics (NGPs) and postbiotic formulations, we can provide a more reasonable reference for this type of "bacteria-drug combination" model, and also provide targeted guidance for the application of probiotic dietary supplements in the antibiotic management of C. difficile infection.

Probiotics: insights and new opportunities for Clostridioides difficile intervention

Clostridioides difficile infection (CDI) is a life-threatening disease caused by the Gram-positive, opportunistic intestinal pathogen C. difficile. Despite the availability of antimicrobial drugs to treat CDI, such as vancomycin, metronidazole, and fidaxomicin, recurrence of infection remains a significant clinical challenge. The use of live commensal microorganisms, or probiotics, is one of the most investigated non-antibiotic therapeutic options to balance gastrointestinal (GI) microbiota and subsequently tackle dysbiosis. In this review, we will discuss major commensal probiotic strains that have the potential to prevent and/or treat CDI and its recurrence, reassess the efficacy of probiotics supplementation as a CDI intervention, delve into lessons learned from probiotic modulation of the immune system, explore avenues like genome-scale metabolic network reconstructions, genome sequencing, and multi-omics to identify novel strains and understand their functionality, and discuss the current regulatory framework, challenges, and future directions.

The diarrheal mechanism of mice with a high-fat diet in a fatigued state is associated with intestinal mucosa microbiota

Growing evidence has demonstrated that fatigue and a high-fat diet trigger diarrhea, and intestinal microbiota disorder interact with diarrhea. However, the association of intestinal mucosal microbiota with fatigue and high-fat diet trigger diarrhea remains unclear. The specific pathogen-free Kunming male mice were randomly divided into the normal group (MCN), standing group (MSD), lard group (MLD), and standing united lard group (MSLD). Mice in the MSD and MSLD groups stood on the multiple-platform apparatus for four h/d for fourteen consecutive days. From the eighth day, mice in the MLD and MSLD groups were intragastric lard, 0.4 mL/each, twice a day for seven days. Subsequently, we analyzed the characteristics and interaction relationship of intestinal mucosal microbiota, interleukin-6 (IL-6), interleukin-17 (IL-17), malondialdehyde (MDA), superoxide dismutase (SOD), and secretory immunoglobulin A (sIgA). Results showed that mice in the MSLD group had an increased number of bowel movements. Compared with the MCN group, the contents of IL-17, and IL-6 were higher (p > 0.05), and the content of sIgA was lower in the MSLD group (p > 0.05). MDA and SOD increased in MLD and MSLD groups. Thermoactinomyces and Staphyloccus were the characteristic bacteria of the MSLD group. And Staphyloccus were positively correlated with IL-6, IL-17, and SOD. In conclusion, the interactions between Thermoactinomyces, Staphyloccus and intestinal inflammation, and immunity might be involved in fatigue and high-fat diet-induced diarrhea.

Pediococcus pentosaceus PR-1 modulates high-fat-died-induced alterations in gut microbiota, inflammation, and lipid metabolism in zebrafish

Introduction

Obesity is a health issue worldwide. This study aimed to evaluate the beneficial effects of Pediococcus pentococcus PR-1 on the modulating of gut microbiota, inflammation and lipid metabolism in high-fat-diet (HFD)-fed zebrafish.

Methods

Adult zebrafish were fed a commercial (C), high fat (H, 25% fat), probiotic (P, 10⁶ CFU/g), or high fat with probiotic (HP) diets twice daily for 5 weeks. Gut microbiota were analysed using 16S rRNA gene sequencing. Gene expressions of intestinal cytokine, intestinal TJ protein, and liver lipid metabolism were analysed by quantitative real-time polymerase chain reaction. Biochemical and histological analysis were also performed.

Results and discussion

P. pentosaceus PR-1 reduced body weight and BMI, indicating its anti-obesity effect. The 16S rRNA sequencing results showed HFD induced a distinct gut microbiota structure from C group, which was restored by probiotic. P. pentosaceus PR-1 improved gut health by decreasing the abundance of Ralstonia and Aeromonas which were increased induced by HFD. Moreover, probiotic restored abundance of Fusobacteria, Cetobacterium and Plesiomonas, which were decreased in HFD-fed zebrafish. The results of quantitative real-time polymerase chain reaction showed probiotic suppressed HFD-induced inflammation by decreasing the expressions of IL-1b and IL-6. Levels of hepatic TNF-α, IL-1ß, and IL-6 were reduced by probiotic in HFD-fed zebrafish. Probiotic also ameliorated gut barrier function by increasing the expressions of occludin, Claudin-1, and ZO-1. Probiotic exerted anti-adipogenic activity through regulating the expressions of SREBP1, FAS and LEPTIN. Levels of hepatic triglyceride, total cholesterol, low density lipoprotein were also reduced by probiotic. Histological analysis showed probiotic alleviated liver steatosis and injury induced by HFD. P. pentosaceus PR-1 might be useful as a dietary health supplement, especially for reducing obesity.

Modulation of Lactobacillus rhamnosus GG on the gut microbiota and metabolism in mice with Clostridioides difficile infection

Clostridioides difficile infection (CDI) is a common nosocomial infection and is an urgent threat to public health. Vancomycin is the preferred antibiotic treatment for CDI but is associated with recurrence. Lactobacillus rhamnosus GG is an adjunctive treatment for gastroenteritis and diarrhea and exerts its effects by modulating the immune responses and repairing the intestinal barrier. This study explored the effect of LGG on restoring the intestinal microbiota in mouse models. Primary and recurrent CDI models were constructed, and LGG was administered to C57BL/6 mice. Structural changes in the mouse gut microbiota were determined using 16S rRNA gene analysis based on Illumina sequencing. In the CDI model, 6 days after infection, 33.3% mortality, significant weight loss and colonic injury were observed. LGG can ameliorate these events. In the R-CDI mouse model, vancomycin combined with LGG prevented weight loss, improved the histopathological scores, and effectively reduced the mortality. LGG + vancomycin administration promoted the recovery of the intestinal flora by inhibiting Enterococcus and counteracting the side effects of vancomycin treatment. In both the preventive and therapeutic CDI mouse models, the oral LGG strain showed the ability to protect against primary and recurrent infections, indicating that probiotics have potential for treating intestinal diseases. Overall, these observations suggest that LGG can be applied as a preventive treatment for CDI or in combination with antibiotics to reduce recurrence.

Akkermansia muciniphila Ameliorates Clostridioides difficile Infection in Mice by Modulating the Intestinal Microbiome and Metabolites

Clostridioides difficile is a common cause of nosocomial infection. Antibiotic-induced dysbiosis in the intestinal microbiota is a core cause of C. difficile infection (CDI). Akkermansia muciniphila plays an active role in maintaining gastrointestinal balance and might offer the protective effects on CDI as probiotics. Here, we investigated the effects and mechanisms of A. muciniphila on CDI. C57BL/6 mice (n = 29) were administered A. muciniphila Muc T (3 × 109 CFUs, 0.2 mL) or phosphate-buffered saline (PBS) by oral gavage for 2 weeks. Mice were pretreated with an antibiotic cocktail and subsequently challenged with the C. difficile strain VPI 10463. A. muciniphila treatment prevented weight loss in mice and reduced the histological injury of the colon. And it also alleviated inflammation and improved the barrier function of the intestine. The administration effects of A. muciniphila may be associated with an increase in short-chain fatty acid production and the maintenance of bile acids' steady-state. Our results provide evidence that administration of A. muciniphila to CDI mice, with an imbalance in the microbial community structure, lead to a decrease in abundance of members of the Enterobacteriaceae and Enterococcaceae. In short, A. muciniphila shows a potential anti-CDI role by modulating gut microbiota and the metabolome.

Therapeutic Effects of Bifidobacterium breve YH68 in Combination with Vancomycin and Metronidazole in a Primary Clostridioides difficile-Infected Mouse Model

Probiotics have been widely used to prevent primary Clostridioides difficile infection (pCDI); however, there are fewer studies on their therapeutic aspects for pCDI. In this study, high doses of Bifidobacterium breve YH68 were used alone or in combination with vancomycin (VAN) and metronidazole (MTR) to treat pCDI mice. Mouse feces were collected from preinfection, postinfection, and posttreatment stages. Subsequently, the C. difficile number and toxin level in feces were detected by plate count method and C. difficile toxin enzyme-linked immunosorbent assay (ELISA). Simultaneously, 16S rRNA amplicon sequencing and untargeted metabolomics were employed to explore the changing patterns and characteristic markers of fecal microbiota and metabolome. The results indicated that high doses of YH68 used alone or in combination with VAN and MTR were more effective than the combination of VAN and MTR for pCDI mice and improved their final survival rate. This probiotic strain and its combination with antibiotics reduced C. difficile numbers and toxin levels in the feces, downregulated proinflammatory cytokine levels in colon tissue, and alleviated cecum tissue hyperplasia. Meanwhile, the level of fecal microbiota diversity increased significantly in pCDI mice after treatment, with an increase in the relative abundance of Bifidobacterium, Akkermansia, Oscillospira, unidentified_S24-7, and Ruminococcus, and this process was accompanied by elevated levels of secondary bile acid, butyric acid, and gentamicin C1a and reduced levels of primary bile acid and indoles. Most notably, the combination of YH68 with VAN and MTR diminished the damaging effect of antibiotic treatment alone on the microbiota. Our findings suggested that high doses of YH68 used in combination with VAN and MTR have a better therapeutic effect on pCDI mice than the combination of VAN and MTR alone. IMPORTANCE Many studies have focused on the preventive effects of probiotics against pCDI, but few studies have investigated in depth the therapeutic effects of probiotics, especially at the postinfection stage. We demonstrated that high doses of Bifidobacterium breve YH68 used alone or in combination with vancomycin (VAN) and metronidazole (MTR) exerted outstanding efficacy in the treatment of pCDI mice. This probiotic-antibiotic combination regimen has the potential to be a new option for the clinical treatment of pCDI.

Pediococcus pentosaceus Enhances Host Resistance Against Pathogen by Increasing IL-1β Production: Understanding Probiotic Effectiveness and Administration Duration

Probiotic administration is a potential strategy against enteric pathogen infection in either clinical treatment or animal nutrition industry, but the administration duration of probiotics varied and the underlying mechanisms remain unclear. A strain (YC) affiliated to Pediococcus pentosaceus, a commonly used probiotic, was isolated from fish gut and the potential role of YC against Aeromonas hydrophila was detected in zebrafish. We found that 3- or 4-week YC administration (YC3W or YC4W) increased the resistance against A. hydrophila while 1- or 2-week treatment (YC1W or YC2W) did not. To determine the possible reason, intestinal microbiota analysis and RNAseq were conducted. The results showed that compared with CON and YC1W, YC4W significantly increased the abundance of short-chain fatty acids (SCFAs) producing bacteria and elevated the gene expression of nlrp3. Higher butyrate content and enhanced expression of IL1β were subsequently found in YC4W. To identify the causal relationship between butyrate and the higher pathogen resistance, different concentrations of sodium butyrate (SB) were supplemented. The results suggested that 10 mmol/kg SB addition mirrored the protective effect of YC4W by increasing the production of IL-1β. Furthermore, the increased IL-1β raised the percentage of intestinal neutrophils, which endued the zebrafish with A. hydrophila resistance. In vivo knockdown of intestinal il1b eliminated the anti-infection effect. Collectively, our data suggested that the molecular mechanism of probiotics determined the administration duration, which is vital for the efficiency of probiotics. Promoting host inflammation by probiotic pretreatment is one potential way for probiotics to provide their protective effects against pathogens.

Lacticaseibacillus casei Strain T21 Attenuates Clostridioides difficile Infection in a Murine Model Through Reduction of Inflammation and Gut Dysbiosis With Decreased Toxin Lethality and Enhanced Mucin Production

Clostridioides difficile is a major cause of diarrhea in patients with antibiotic administration. Lacticaseibacillus casei T21, isolated from a human gastric biopsy, was tested in a murine C. difficile infection (CDI) model and colonic epithelial cells (Caco-2 and HT-29). Daily administration of L. casei T21 [1 × 108 colony forming units (CFU)/dose] for 4 days starting at 1 day before C. difficile challenge attenuated CDI as demonstrated by a reduction in mortality rate, weight loss, diarrhea, gut leakage, gut dysbiosis, intestinal pathology changes, and levels of pro-inflammatory cytokines [interleukin (IL)-1β, tumor necrosis factor (TNF)-α, macrophage inflammatory protein 2 (MIP-2), and keratinocyte chemoattractant (KC)] in the intestinal tissue and serum. Conditioned media from L. casei T21 exerted biological activities that fight against C. difficile as demonstrated in colonic epithelial cells by the following: (i) suppression of gene expression and production of IL-8, an important chemokine involved in C. difficile pathogenesis, (ii) reduction in the expression of SLC11A1 (solute carrier family 11 member 1) and HuR (human antigen R), important genes for the lethality of C. difficile toxin B, (iii) augmentation of intestinal integrity, and (iv) up-regulation of MUC2, a mucosal protective gene. These results supported the therapeutic potential of L. casei T21 for CDI and the need for further study on the intervention capabilities of CDI.

Evaluation of the therapeutic effect and dose-effect of Bifidobacterium breve on the primary Clostridioides difficile infected mice

Probiotics are widely used as an adjuvant agent for the prevention of primary Clostridioides difficile infection (pCDI) and are less commonly used in the treatment of pCDI. Here, the different doses of Bifidobacterium breve YH68 were used to treat the pCDI mouse model and the actual therapeutic effect was evaluated. Fecal samples of pCDI mice were collected from the pre-infection, post-infection, and post-treatment stages. Simultaneous 16S rRNA amplicon sequencing and non-targeted metabolite assays were performed on these mouse feces, followed by correlation analysis. We found that high doses of B. breve YH68 exerted prominent therapeutic effects and no side effects in pCDI mice, resulted in a high survival rate, accompanied by a dose-effect relationship. YH68 enhanced the levels of caffeine, butyric acid, secondary bile acids in the feces of pCDI mice and significantly upregulated the abundance of genera associated with these metabolites, including Akkermansia, Coprococcus, Oscillospira, and Ruminococcus. Meanwhile, YH68 downregulated the levels of cortisol and phytosphingosine, and these metabolites were positively correlated with the abundance of the Klebsiella and Pseudomonas genera. These findings indicated that YH68 has outstanding therapeutic effects on the pCDI mouse model and is expected to be a potential new option for clinical pCDI therapy.Key points• Bifidobacterium breve YH68 has therapeutic effects on the pCDI mice and was accompanied by a dose-effect relationship.• Bifidobacterium breve YH68 enhanced the levels of caffeine, butyric acid, secondary bile acids in the feces of pCDI mice after treatment, as well as upregulated the abundance of beneficial microbes.• Bifidobacterium breve YH68 decreased the levels of cortisol and phytosphingosine and downregulated the abundance of harmful microbes.

Effects of Pediococcus pentosaceus LI05 on immunity and metabolism in germ-free rats

Many Pediococcus spp. have health-promoting benefits, and Pediococcus pentosaceus LI05 is one such species that was proved to be beneficial in previous studies. Our research aimed to determine the immune and metabolic effects of P. pentosaceus LI05 on germ-free rats. Germ-free rats were gavaged with P. pentosaceus LI05 suspensions (1 × 10⁹ CFU) for 2 weeks, and 3 weeks later, blood, spleen, intestine and liver samples were gathered for metabolome, intestine morphology, immunity, and transcriptomics analyses. Oral gavage of P. pentosaceus LI05 reduced the bodyweight of rats, which manifested as increased fecal carbohydrate concentrations, decreased intestinal fat intake and the hepatic fat synthesis gene expression, and accelerated fat-to-glycogen conversion. In addition, P. pentosaceus LI05 exhibited an anti-inflammatory ability, reducing serum proinflammatory cytokine levels and increasing intestinal subepidermal CD4⁺ cell levels. Furthermore, administration of P. pentosaceus LI05 increased the antimicrobial ability and enhanced the liver detoxification function. These results indicate that as a probiotic, P. pentosaceus LI05 ameliorates the hampered immune response of GF animals and improves the metabolism of fat and toxic substances.

Impact of encapsulating a probiotic (Pediococcus pentosaceus Li05) within gastro-responsive microgels on Clostridium difficile infections

Antibiotic treatment is often followed by Clostridium difficile infection (CDI), which causes severe diarrhea and other health issues. Oral administration of Pediococcus pentosaceus Li05 (Li05) has been shown to have great potential in preventing CDI. However, the viability of Li05 is greatly reduced during storage and passage through the gastrointestinal (GI) tract, which limits its biological activity. In this study, a gastro-responsive microgel was designed to encapsulate and protect Li05 to enhance its efficacy against CDI. The viability of Li05 encapsulated within the microgels was significantly enhanced during long-term storage and after exposure to simulated GI fluids. Moreover, this gastro-responsive microgel led to greater sustained release of the probiotic. In a mouse CDI model, we found that encapsulated Li05 was better at inhibiting C. difficile infection than nonencapsulated Li05, as demonstrated through analysis of the probiotic survival rate, spleen weight, colonic histology, and inflammatory cytokine levels. Moreover, the gut microbial diversity was enriched by treatment with encapsulated Li05. These results suggest that encapsulating Li05 within biopolymer microgels may enhance its ability to prevent and treat CDI using functional foods, supplements, or pharmaceuticals.

Pediococcus pentosaceus, a future additive or probiotic candidate

Background

Pediococcus pentosaceus, a promising strain of lactic acid bacteria (LAB), is gradually attracting attention, leading to a rapid increase in experimental research. Due to increased demand for practical applications of microbes, the functional and harmless P. pentosaceus might be a worthwhile LAB strain for both the food industry and biological applications.

Results

As an additive, P. pentosaceus improves the taste and nutrition of food, as well as the storage of animal products. Moreover, the antimicrobial abilities of Pediococcus strains are being highlighted. Evidence suggests that bacteriocins or bacteriocin-like substances (BLISs) produced by P. pentosaceus play effective antibacterial roles in the microbial ecosystem. In addition, various strains of P. pentosaceus have been highlighted for probiotic use due to their anti-inflammation, anticancer, antioxidant, detoxification, and lipid-lowering abilities.

Conclusions

Therefore, it is necessary to continue studying P. pentosaceus for further use. Thorough study of several P. pentosaceus strains should clarify the benefits and drawbacks in the future.

New strain of Pediococcus pentosaceus alleviates ethanol-induced liver injury by modulating the gut microbiota and short-chain fatty acid metabolism

BACKGROUND

Intestinal dysbiosis has been shown to be associated with the pathogenesis of alcoholic liver disease (ALD), which includes changes in the microbiota composition and bacterial overgrowth, but an effective microbe-based therapy is lacking. Pediococcus pentosaceus (P. pentosaceus) CGMCC 7049 is a newly isolated strain of probiotic that has been shown to be resistant to ethanol and bile salts. However, further studies are needed to determine whether P. pentosaceus exerts a protective effect on ALD and to elucidate the potential mechanism.

AIM

To evaluate the protective effect of the probiotic P. pentosaceus on ethanol-induced liver injury in mice.

METHODS

A new ethanol-resistant strain of P. pentosaceus CGMCC 7049 was isolated from healthy adults in our laboratory. The chronic plus binge model of experimental ALD was established to evaluate the protective effects. Twenty-eight C57BL/6 mice were randomly divided into three groups: The control group received a pair-fed control diet and oral gavage with sterile phosphate buffered saline, the EtOH group received a ten-day Lieber-DeCarli diet containing 5% ethanol and oral gavage with phosphate buffered saline, and the P. pentosaceus group received a 5% ethanol Lieber-DeCarli diet but was treated with P. pentosaceus. One dose of isocaloric maltose dextrin or ethanol was administered by oral gavage on day 11, and the mice were sacrificed nine hours later. Blood and tissue samples (liver and gut) were harvested to evaluate gut barrier function and liver injury-related parameters. Fresh cecal contents were collected, gas chromatography–mass spectrometry was used to measure short-chain fatty acid (SCFA) concentrations, and the microbiota composition was analyzed using 16S rRNA gene sequencing.

RESULTS

The P. pentosaceus treatment improved ethanol-induced liver injury, with lower alanine aminotransferase, aspartate transaminase and triglyceride levels and decreased neutrophil infiltration. These changes were accompanied by decreased levels of endotoxin and inflammatory cytokines, including interleukin-5, tumor necrosis factor-α, granulocyte colony-stimulating factor, keratinocyte-derived protein chemokine, macrophage inflammatory protein-1α and monocyte chemoattractant protein-1. Ethanol feeding resulted in intestinal dysbiosis and gut barrier disruption, increased relative abundance of potentially pathogenic Escherichia and Staphylococcus, and the depletion of SCFA-producing bacteria, such as Prevotella, Faecalibacterium, and Clostridium. In contrast, P. pentosaceus administration increased the microbial diversity, restored the relative abundance of Lactobacillus, Pediococcus, Prevotella, Clostridium and Akkermansia and increased propionic acid and butyric acid production by modifying SCFA-producing bacteria. Furthermore, the levels of the tight junction protein ZO-1, mucin proteins (mucin [MUC]-1, MUC-2 and MUC-4) and the antimicrobial peptide Reg3β were increased after probiotic supplementation.

CONCLUSION

Based on these results, the new strain of P. pentosaceus alleviated ethanol-induced liver injury by reversing gut microbiota dysbiosis, regulating intestinal SCFA metabolism, improving intestinal barrier function, and reducing circulating levels of endotoxin and proinflammatory cytokines and chemokines. Thus, this strain is a potential probiotic treatment for ALD.

Human Gut Commensal Membrane Vesicles Modulate Inflammation by Generating M2-like Macrophages and Myeloid-Derived Suppressor Cells

Immunomodulatory commensal bacteria modify host immunity through delivery of regulatory microbial-derived products to host cells. Extracellular membrane vesicles (MVs) secreted from symbiont commensals represent one such transport mechanism. How MVs exert their anti-inflammatory effects or whether their tolerance-inducing potential can be used for therapeutic purposes remains poorly defined. In this study, we show that MVs isolated from the human lactic acid commensal bacteria Pediococcus pentosaceus suppressed Ag-specific humoral and cellular responses. MV treatment of bone marrow-derived macrophages and bone marrow progenitors promoted M2-like macrophage polarization and myeloid-derived suppressor cell differentiation, respectively, most likely in a TLR2-dependent manner. Consistent with their immunomodulatory activity, MV-differentiated cells upregulated expression of IL-10, arginase-1, and PD-L1 and suppressed the proliferation of activated T cells. MVs' anti-inflammatory effects were further tested in acute inflammation models in mice. In carbon tetrachloride-induced fibrosis and zymosan-induced peritonitis models, MVs ameliorated inflammation. In the dextran sodium sulfate-induced acute colitis model, systemic treatment with MVs prevented colon shortening and loss of crypt architecture. In an excisional wound healing model, i.p. MV administration accelerated wound closure through recruitment of PD-L1-expressing myeloid cells to the wound site. Collectively, these results indicate that P. pentosaceus-derived MVs hold promise as therapeutic agents in management/treatment of inflammatory conditions.

Pediococcus pentosaceus LI05 alleviates DSS-induced colitis by modulating immunological profiles, the gut microbiota and short-chain fatty acid levels in a mouse model

The gut microbiota is considered a key factor in pathogenesis and progression of inflammatory bowel disease (IBD). The bacterium Pediococcus pentosaceus LI05 alleviated host inflammation by maintaining the gut epithelial integrity, modulating the host immunity, gut microbiota and metabolism, but its effect on IBD remains unclear. The present study aimed to investigate the role and mechanisms of P. pentosaceus LI05. Mice were administered P. pentosaceus LI05 or phosphate-buffered saline once daily by oral gavage for 14 days, and colitis was induced by providing mice 2% DSS-containing drinking water for 7 days. P. pentosaceus LI05 ameliorated colitis in mice and reduced the body weight loss, disease activity index (DAI) scores, colon length shortening, intestinal permeability and the proinflammatory cytokine levels. Furthermore, a significantly altered gut microbiota composition with increased diversity and short-chain fatty acid (SCFA) production was observed in mice treated with P. pentosaceus LI05. Several genera, including Akkermansia and Faecalibacterium, were differentially enriched in the P. pentosaceus LI05-treated mice and were negatively correlated with colitis indices and positively correlated with gut barrier markers and SCFA levels. The P. pentosaceus LI05 treatment alleviated intestinal inflammation by maintaining the intestinal epithelial integrity and modulating the immunological profiles, gut microbiome and metabolite composition. Based on our findings, P. pentosaceus LI05 might be applied as potential preparation to ameliorate colitis.

In vitro probiotic properties of Pediococcus pentosaceus L1 and its effects on enterotoxigenic Escherichia coli-induced inflammatory responses in porcine intestinal epithelial cells

This study aimed to evaluate in vitro probiotic characteristics of Pediococcus pentosaceus strain L1 from pickled radish and investigate its impacts on inflammatory responses in porcine intestinal epithelial cells (IEC) to enterotoxigenic Escherichia coli (ETEC) F4⁺. The abilities of P. pentosaceus L1 to tolerate gastrointestinal conditions and to antagonize ETEC F4⁺ growth were determined. Adhesion of P. pentosaceus L1 and its effect on ETEC F4⁺ adhesion to porcine IPEC-J2 IEC were evaluated. Furthermore, the effects of this strain on proinflammatory gene expression and cytokines/chemokine production in porcine IPEC-J2 IEC induced by ETEC F4⁺ were determined. P. pentosaceus L1 showed good tolerance to the medium adjusted at pH 2.5 and consequently supplemented with 0.3% oxgall. Reduction of ETEC F4⁺ growth in co-culture with L1 was found. Effective adhesion of L1 to porcine. IPEC-J2 IEC was observed under these conditions. P. pentosaceus L1 decreased the adhesion of ETEC F4⁺ to IPEC-J2 IEC and the extent of inhibition of ETEC F4⁺ adhesion depended on the timing of L1 addition. Further analysis revealed down-regulation of expression of ETEC F4⁺-induced proinflammatory genes encoding interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-8 (IL-8) in IPEC-J2 IEC. Expression of the genes involved in NF-κB pathway, including RELA and NFKB1, were also repressed, as was production of IL-6, TNF-α, and IL-8. These results indicate that P. pentosaceus L1 may have potential as a probiotic for control of ETEC infection in pigs.

In vitro and in vivo anti-clostridial activity of newly isolated Pediococcus acidilactici SPM138 against Clostridium difficile

Clostridium difficile infection (CDI) has become a growing health concern, as evident from the increase in the mortality rate among elderly or hospitalized patients. Treatment of CDI is usually based on antibiotics (metronidazole and vancomycin), but it has some limitations, including cost and antibiotic resistance. Probiotics could offer an effective remedy to prevent CDI and could be an auxiliary agent in treatment CDI. Here, the anti-clostridial activity of a newly isolated probiotic strain, Pediococcus acidilactici SPM138 (SPM138) was evaluated. The cultivation of C. difficile (CD) with SPM138, inhibited the growth of CD and significantly reduced CD toxins level. The result of MTT assay showed that, incubation with 25% CD culture supernatant decreased the survival rate of HT-29 cells to less than 20%. However, the survival rate of these cells increased to 98% in the presence of the 25% CD + SPM138 supernatant. The mRNA expression of IL-6, IL-8 and PTGS2 in HT-29 cells decreased by more than 60% upon incubation with CD + SPM138 co-cultures as compared to the levels observed after treatment with CD supernatant only. The concentration of IL-8 also decreased by more than 60% upon treatment with CD + SPM138 co-culture supernatant. In a C. difficile PCR ribotype 027-infected mouse model, the concentration of CD toxin in stool samples of SPM138-fed mice was only 37% of that reported in C. difficile 027-infected group. These findings show that P. acidilactici SPM138 may be a promising probiotic in CDI.

Pediococcus pentosaceus xy46 Can Absorb Zearalenone and Alleviate its Toxicity to the Reproductive Systems of Male Mice

Zearalenone (ZEA) contamination is a very serious problem around the world as it can induce reproductive disorders in animals and affect the health of humans. Therefore, reducing the damage it causes to humans and animals is a current focus of research. In this study, we assess the removing capacity of Pediococcus pentosaceus xy46 towards ZEA and investigate the mechanism responsible for its action, thus confirming if it can alleviate ZEA toxicity to the reproductive systems of male mice. Our results show that the rate at which the strain removes ZEA is as high as 89.2% in 48 h when the concentration of ZEA is 4 μg/mL in the liquid medium. Heat and acid treatment significantly enhanced the ability of the bacteria to remove ZEA. The animal experiments results show that the oral administration of xy46 to mice (0.2 mL daily at a concentration of 10⁹ CFU/mL for 28 days) significantly reduces the degree of testicular pathomorphological changes and apoptosis induced by ZEA when the mice are intragastric administration with 40 mg/kg ZEA daily for 28 days. Moreover, oral administration of xy46 enhances the decrease in the testosterone level and improves the oxidative stress injury induced by ZEA. Furthermore, oral administration of xy46 reverts the expression of these genes and proteins in the testicular tissues of the mice involved in the blood-testis barrier and apoptosis (e.g., Vim, caspase 12, Cldn11, N-cad, Bax, and Bcl-2). However, xy46 cannot significantly revert in some of these evaluated parameters, especially in sperm quantity and quality when the mice were given 70 mg/kg ZEA daily for 28 days. In conclusion, our results suggest that the strain Pediococcus pentosaceus xy46 can efficiently remove ZEA from the liquid medium, the mechanism responsible for its action is absorption, and it can alleviate the toxicity of ZEA to the reproductive systems of male mice when the mice are given 40 mg/kg ZEA daily, However, it cannot completely alleviate the reproductive toxicity of higher dosage of zearalenone through its ability to adsorb ZEA.

Non-antibiotic therapy for Clostridioides difficile infection: a review

Clostridioides difficile infection (CDI) is a common infectious disease that is mainly caused by antibiotics. Antibiotic therapy is still the dominant treatment for CDI, although it is accompanied by side effects. Probiotics, fecal microbiota transplantation (FMT), engineered microorganisms, bacteriophages, diet, natural active substances, nanoparticles and compounds are examples of emerging non-antibiotic therapies that have received a great amount of attention. In this review, we collected data about different non-antibiotic therapies for CDI and provided a comprehensive analysis and detailed comparison of these therapies. The mechanism of action, therapeutic efficacy, and the strengths and weaknesses of these non-antibiotic therapies have been investigated to provide a basis for the reasonable alternative of non-antibiotic therapies for CDI. In summary, probiotics and FMT are currently the best choice for non-antibiotic therapy for CDI.

Antibacterial Activity of Bifidobacterium breve Against Clostridioides difficile

Bifidobacterium breve (YH68) is widely used in the fields of food fermentation and biomedicine. In this study, we explored the antibacterial activity of the cell free culture supernatant (CFCS) of YH68 against Clostridioides difficile ATCC 9689 (CD) by measuring multiple indexes, including the growth, spores production, toxin A/B production, and the expression levels of the tcdA and tcdB genes of CD. In addition, we examined the changes in major cellular functional groups, structures, permeability, integrity, and the proton motive force (PMF) of the cytoplasmic membrane. The results showed that double-dilution ratio of YH68-CFCS (3 × 10⁹ CFU/mL) was the MIC value. The cell density, spores production, and the toxin production of CD treated with YH68-CFCS were lower than that of the control (p < 0.05). In addition, the gene expression levels of tcdA and tcdB in CD treated with YH68-CFCS were significant downregulated (p < 0.05). Marked differences were observed in the cell membrane and cell wall by a FT-IR spectroscopy and SEM. Analysis of the cell membrane permeability and integrity of the CD cells revealed that YH68-CFCS induced the leakage of a large amount of intracellular K⁺, inorganic phosphate, ATP, nucleic acids and proteinaceous substances. Furthermore, PMF analysis indicated that there was a significant change in Δψ and ΔpH. These findings demonstrated that the antibacterial activity of YH68-CFCS against CD involved the inhibition of growth, spore production, toxin production, and virulence genes expression; a consumption of PMF in the cytoplasmic membrane, the formation of pore in the cell membrane, together with the enhanced cell membrane permeability; and, eventually, cell completely disintegration.