Timely Use of Probiotics in Hospitalized Adults Prevents Clostridium difficile Infection: A Systematic Review With Meta-Regression Analysis

Clostridioides difficile infection: history, epidemiology, risk factors, prevention, clinical manifestations, treatment, and future options

SUMMARYClostridioides difficile infection (CDI) is one of the major issues in nosocomial infections. This bacterium is constantly evolving and poses complex challenges for clinicians, often encountered in real-life scenarios. In the face of CDI, we are increasingly equipped with new therapeutic strategies, such as monoclonal antibodies and live biotherapeutic products, which need to be thoroughly understood to fully harness their benefits. Moreover, interesting options are currently under study for the future, including bacteriophages, vaccines, and antibiotic inhibitors. Surveillance and prevention strategies continue to play a pivotal role in limiting the spread of the infection. In this review, we aim to provide the reader with a comprehensive overview of epidemiological aspects, predisposing factors, clinical manifestations, diagnostic tools, and current and future prophylactic and therapeutic options for C. difficile infection.

Standards for fecal microbiota transplant: Tools and therapeutic advances

Fecal microbiota transplantation (FMT) has been demonstrated to be efficacious in preventing recurrent Clostridioides difficile (C. difficile) infections, and is being investigated for treatment of several other diseases including inflammatory bowel disease, cancer, obesity, liver disease, and diabetes. To speed up the translation of FMT into clinical practice as a safe and standardized therapeutic intervention, additional evidence-based technical and regulatory guidance is needed. To this end in May of 2022, the International Alliance for Biological Standardization (IABS) and the BIOASTER Microbiology Technology Institute hosted a second webinar to discuss key issues still impeding the advancement and standardization of FMT. The goal of this two-day webinar was to provide a forum for scientific experts to share and discuss data and key challenges with one another. Discussion included a focus on the evaluation of safety, efficacy, clinical trial design, reproducibility and accuracy in obtained microbiome measurements and data reporting, and the potential for standardization across these areas. It also focused on increasing the application potential and visibility of FMT beyond treating C. difficile infections.

Clostridioides difficile infection in inflammatory bowel disease: a clinical review

INTRODUCTION

Strong clinical data demonstrate that inflammatory bowel disease (IBD) is an independent risk factor for Clostridiodes difficile infection (CDI) and suggest a globally increased prevalence and severity of C. difficile coinfection in IBD patients (CDI-IBD). In addition to elderly individuals, children are also at higher risk of CDI-IBD. Rapid diagnosis is essential since the clinical manifestations of active IBD and CDI-IBD are indistinguishable. Antibiotics have been well established in the treatment of CDI-IBD, but they do not prevent recurrence.

AREAS COVERED

Herein, the authors focus on reviewing recent research advances on the new therapies of CDI-IBD. The novel therapies include gut microbiota restoration therapies (such as prebiotics, probiotics and FMT), immunotherapy (such as vaccines and monoclonal antibodies) and diet strategies (such as groningen anti-inflammatory diet and mediterranean diet). Future extensive prospective and placebo-controlled studies are required to evaluate their efficacy and long-term safety.

EXPERT OPINION

Available studies show that the prevalence of CDI-IBD is not optimistic. Currently, potential treatment options for CDI-IBD include a number of probiotics and novel antibiotics. This review updates the knowledge on the management of CDI in IBD patients, which is timely and important for GI doctors and scientists.

Randomised, Placebo-Controlled Investigation of the Impact of Probiotic Consumption on Gut Microbiota Diversity and the Faecal Metabolome in Seniors

Aging has been associated with a changed composition and function of the gut microbiota (GM). Here, we investigate the effects of the multi-strain probiotic HOWARU® Restore on GM composition and function in seniors. Ninety-eight healthy adult volunteers aged ≥75 years were enrolled in a randomised, double-blinded intervention (NCT02207140), where they received HOWARU Restore (1010 CFU) or the placebo daily for 24 weeks, with 45 volunteers from each group completing the intervention. Questionnaires monitoring the effects on gastro-intestinal discomfort and bowel movements were collected. Faecal samples for GM characterisation (qPCR, 16S rRNA gene amplicon sequencing) and metabolomics (GC-FID, 1H NMR) were collected at the baseline and after 24 weeks. In the probiotic group, self-reported gastro-intestinal discomfort in the form of flatulence was significantly decreased during the intervention. At the baseline, 151 'core species' (present in ≥95% of samples) were identified. Most core species belonged to the Lachnospiraceae and Ruminococcaceae families. Neither alpha diversity nor beta diversity or faecal metabolites was affected by probiotic intake. On the contrary, we observed high intra-individual GM stability, with 'individual' accounting for 72-75% of variation. In conclusion, 24 weeks of HOWARU Restore intake reduced gastro-intestinal discomfort in the form of flatulence in healthy seniors without significantly influencing GM composition or activity.

Effectiveness of Bio-K+ for the prevention of Clostridioides difficile infection: Stepped-wedge cluster-randomized controlled trial

OBJECTIVE

To evaluate the impact of administering probiotics to prevent Clostridioides difficile infection (CDI) among patients receiving therapeutic antibiotics.

DESIGN

Stepped-wedge cluster-randomized trial between September 1, 2016, and August 31, 2019.

SETTING

This study was conducted in 4 acute-care hospitals across an integrated health region.

PATIENTS

Hospitalized patients, aged ≥55 years.

METHODS

Patients were given 2 probiotic capsules daily (Bio-K+, Laval, Quebec, Canada), containing 50 billion colony-forming units of Lactobacillus acidophilus CL1285, L. casei LBC80R, and L. rhamnosus CLR2. We measured hospital-acquired CDI (HA-CDI) and the number of positive C. difficile tests per 10,000 patient days as well as adherence to administration of Bio-K+ within 48 and 72 hours of antibiotic administration. Mixed-effects generalized linear models, adjusted for influenza admissions and facility characteristics, were used to evaluate the impact of the intervention on outcomes.

RESULTS

Overall adherence of Bio-K+ administration ranged from 76.9% to 84.6% when stratified by facility and periods. Rates of adherence to administration within 48 and 72 hours of antibiotic treatment were 60.2% -71.4% and 66.7%-75.8%, respectively. In the adjusted analysis, there was no change in HA-CDI (incidence rate ratio [IRR], 0.92; 95% confidence interval [CI], 0.68-1.23) or C. difficile positivity rate (IRR, 1.05; 95% CI, 0.89-1.24). Discharged patients may not have received a complete course of Bio-K+. Our hospitals had a low baseline incidence of HA-CDI. Patients who did not receive Bio-K+ may have differential risks of acquiring CDI, introducing selection bias.

CONCLUSIONS

Hospitals considering probiotics as a primary prevention strategy should consider the baseline incidence of HA-CDI in their population and timing of probiotics relative to the start of antimicrobial administration.

The Role of Probiotics in the Prevention of Clostridioides difficile Infection in Patients with Chronic Kidney Disease

In patients suffering from chronic kidney disease (CKD), substantial unfavourable alterations in the intestinal microbiota composition, i.e., dysbiosis, have been noted. The main causes of such dysbiosis among others are insufficient dietary fibre content in the diet, fluid restrictions, medications used, and physical activity limitation. One clinically important consequence of dysbiosis in CKD patients is high risk of Clostridioides difficile infection (CDI). In observational studies, it was found that CDI is more frequent in CKD patients than in the general population. This appears to be related to high hospitalization rate and more often antibiotic therapy use, leading up to the occurrence of dysbiosis. Therefore, the use of probiotics in CKD patients may avert changes in the intestinal microbiota, which is the major risk factor of CDI. The aim of this review paper is to summarize the actual knowledge concerning the use of probiotics in CDI prevention in CKD patients in the context of CDI prevention in the general population.

Gut Microbiota-Gut Metabolites and Clostridioides difficile Infection: Approaching Sustainable Solutions for Therapy

Clostridioides difficile (C. difficile) infection (CDI) is the most common hospital-acquired infection. With the combination of a high rate of antibiotic resistance and recurrence, it has proven to be a debilitating public health threat. Current treatments for CDI include antibiotics and fecal microbiota transplantation, which contribute to recurrent CDIs and potential risks. Therefore, there is an ongoing need to develop new preventative treatment strategies for CDI. Notably, gut microbiota dysbiosis is the primary risk factor for CDI and provides a promising target for developing novel CDI therapy approaches. Along with gut microbiota dysbiosis, a reduction in important gut metabolites like secondary bile acids and short-chain fatty acids (SCFAs) were also seen in patients suffering from CDI. In this review study, we investigated the roles and mechanisms of gut microbiota and gut microbiota-derived gut metabolites, especially secondary bile acids and SCFAs in CDI pathogenesis. Moreover, specific signatures of gut microbiota and gut metabolites, as well as different factors that can modulate the gut microbiota, were also discussed, indicating that gut microbiota modulators like probiotics and prebiotics can be a potential therapeutic strategy for CDI as they can help restore gut microbiota and produce gut metabolites necessary for a healthy gut. The understanding of the associations between gut microbiota-gut metabolites and CDI will allow for developing precise and sustainable approaches, distinct from antibiotics and fecal transplant, for mitigating CDI and other gut microbiota dysbiosis-related diseases.

The Efficacy of a Mix of Probiotics (Limosilactobacillus reuteri LMG P-27481 and Lacticaseibacillus rhamnosus GG ATCC 53103) in Preventing Antibiotic-Associated Diarrhea and Clostridium difficile Infection in Hospitalized Patients: Single-Center, Open-Label, Randomized Trial

BACKGROUND

Antibiotic-associated diarrhea is a condition reported in 5-35% of patients treated with antibiotics, especially in older patients with comorbidities. In most cases, antibiotic-associated diarrhea is not associated with serious complications, but it can prolong hospitalization and provoke Clostridium difficile infection. An important role in the prevention of antibiotic-associated diarrhea is carried out by some probiotic strains such as Lactobacillus GG or the yeast Saccharomyces boulardii that showed good efficacy and a significant reduction in antibiotic-associated diarrhea. Similarly, the Limosilactobacillus reuteri DSM 17938 showed significant benefits in acute diarrhea, reducing its duration and abdominal pain.

AIM

The aim of this study was to test the efficacy of a mix of two probiotic strains (Limosilactobacillus reuteri LMG P-27481 and Lacticaseibacillus rhamnosus GG ATCC 53103; Reuterin GG®, NOOS, Italy), in association with antibiotics (compared to antibiotics used alone), in reducing antibiotic-associated diarrhea, clostridium difficile infection, and other gastrointestinal symptoms in adult hospitalized patients.

PATIENTS AND METHODS

We enrolled 113 (49M/64F, mean age 69.58 ± 21.28 years) adult patients treated with antibiotics who were hospitalized at the Internal Medicine Department of the San Carlo di Nancy Hospital in Rome from January 2023 to September 2023. Patients were randomized to receive probiotics 1.4 g twice/day in addition with antibiotics (Reuterin GG® group, total: 56 patients, 37F/19M, 67.16 ± 20.5 years old) or antibiotics only (control group, total: 57 patients, 27F/30 M, 71 ± 22 years old).

RESULTS

Patients treated with Reuterin GG® showed a significant reduction in diarrhea and clostridium difficile infection. In particular, 28% (16/57) of patients in the control group presented with diarrhea during treatment, compared with 11% (6/56) in the probiotic group (p < 0.05). Interestingly, 7/57 (11%) of patients treated only with antibiotics developed clostridium difficile infection compared to 0% in the probiotic group (p < 0.01). Finally, 9% (5/57) of patients in the control group presented with vomiting compared with 2% (1/56) in the probiotic group (p < 0.05).

CONCLUSIONS

Our study showed, for the first time, the efficacy of these two specific probiotic strains in preventing antibiotic-associated diarrhea and clostridium difficile infection in adult hospitalized patients treated with antibiotic therapy. This result allows us to hypothesize that the use of specific probiotic strains during antibiotic therapy can prevent dysbiosis and subsequent antibiotic-associated diarrhea and clostridium difficile infection, thus resulting in both patient and economic health care benefits.

Probiotics for Prevention and Treatment of Clostridium difficile Infection

Probiotics have been claimed as a valuable tool to restore the balance in the intestinal microbiota following a dysbiosis caused by, among other factors, antibiotic therapy. This perturbed environment could favor the overgrowth of Clostridium difficile, and in fact, the occurrence of C. difficile-associated infections (CDI) is increasing in recent years. In spite of the high number of probiotics able to in vitro inhibit the growth and/or toxicity of this pathogen, its application for treatment or prevention of CDI is still scarce since there are not enough well-defined clinical studies supporting efficacy. Only a few strains, such as Lactobacillus rhamnosus GG and Saccharomyces boulardii, have been studied in more extent. The increasing knowledge about the probiotic mechanisms of action against C. difficile, some of them reviewed here, makes promising the application of these live biotherapeutic agents against CDI. Nevertheless, more effort must be paid to standardize the clinical studies conducted to evaluate probiotic products, in combination with antibiotics, in order to select the best candidate for C. difficile infections.

Recommendations to Improve Quality of Probiotic Systematic Reviews With Meta-Analyses

Importance

Systematic reviews and meta-analyses often report conflicting results when assessing evidence for probiotic efficacy, partially because of the lack of understanding of the unique features of probiotic trials. As a consequence, clinical decisions on the use of probiotics have been confusing.

Objective

To provide recommendations to improve the quality and consistency of systematic reviews with meta-analyses on probiotics, so evidence-based clinical decisions can be made with more clarity.

Evidence Review

For this consensus statement, an updated literature review was conducted (January 1, 2020, to June 30, 2022) to supplement a previously published 2018 literature search to identify areas where probiotic systematic reviews with meta-analyses might be improved. An expert panel of 21 scientists and physicians with experience on writing and reviewing probiotic reviews and meta-analyses was convened and used a modified Delphi method to develop recommendations for future probiotic reviews.

Findings

A total of 206 systematic reviews with meta-analysis components on probiotics were screened and representative examples discussed to determine areas for improvement. The expert panel initially identified 36 items that were inconsistently reported or were considered important to consider in probiotic meta-analyses. Of these, a consensus was reached for 9 recommendations to improve the quality of future probiotic meta-analyses.

Conclusions and Relevance

In this study, the expert panel reached a consensus on 9 recommendations that should promote improved reporting of probiotic systematic reviews with meta-analyses and, thereby, assist in clinical decisions regarding the use of probiotics.

Combination of Bifidobacterium breve and antibiotics against Clostridioides difficile: effect of the time interval of combination on antagonistic activity

Co-administration of probiotics and antibiotics has been used to prevent or treat primary Clostridioides difficile (pCDI), and the closer the interval between the combination, the more effective it is, but the reason behind this is unknown. In this study, the cell-free culture supernatant (CFCS) of Bifidobacterium breve YH68 was used in combination with vancomycin (VAN) and metronidazole (MTR) to treat C. difficile cells. The growth and biofilm production of C. difficile under different co-administration time interval treatments were determined by optical density and crystalline violet staining, respectively. The toxin production of C. difficile was determined by enzyme immunoassay, and the relative expressions of C. difficile virulence genes tcdA and tcdB were determined by real-time qPCR method. Meanwhile, the types and contents of organic acids in YH68-CFCS were investigated by LC-MS/MS. The results showed that YH68-CFCS in combination with VAN or MTR significantly inhibited the growth, biofilm production, and toxin production of C. difficile in the effective time interval range (0-12 h) but did not affect the expression level of C. difficile virulence genes. In addition, the effective antibacterial component of YH68-CFCS is lactic acid (LA).

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.

Revisiting the Intestinal Microbiome and Its Role in Diarrhea and Constipation

The gut microbiota represents a community of microorganisms (bacteria, fungi, archaea, viruses, and protozoa) that colonize the gut and are responsible for gut mucosal structural integrity and immune and metabolic homeostasis. The relationship between the gut microbiome and human health has been intensively researched in the past years. It is now widely recognized that gut microbial composition is highly responsible for the general health of the host. Among the diseases that have been linked to an altered gut microbial population are diarrheal illnesses and functional constipation. The capacity of probiotics to modulate the gut microbiome population, strengthen the intestinal barrier, and modulate the immune system together with their antioxidant properties have encouraged the research of probiotic therapy in many gastrointestinal afflictions. Dietary and lifestyle changes and the use of probiotics seem to play an important role in easing constipation and effectively alleviating diarrhea by suppressing the germs involved. This review aims to describe how probiotic bacteria and the use of specific strains could interfere and bring benefits as an associated treatment for diarrhea and constipation.

Role of probiotics in preventing Clostridioides difficile infection in older adults: an integrative review

Clostridioides difficile infection (CDI) is the leading cause of healthcare-associated diarrhea. This infection can particularly affect older adults, the most susceptible to CDI. Currently, the standard therapeutic measure is antibiotic therapy, which in turn increases the risk of recurrence of the infection by its collateral damage to the patient's microbiota. Probiotics are live microorganisms capable of maintaining balance in the intestinal microbiota. This study aims to perform an integrative review of the protective benefit of probiotics in CDI and diarrhea associated with C. difficile. The PubMed, Scopus, and Web of Science databases, the 10-year time cutoff, and the Prism Flow diagram were used for data collection. We observed no consensus among the studies; however, three of the seven evaluated studies demonstrated that the use of probiotics in older adults could contribute to reducing the incidence of hospital-onset CDI. We also found that the studies evaluated a wide variety of microorganisms, particularly Saccharomyces boulardii, associated with beneficial effects. More research is needed to understand the successful use of probiotics in the prevention of CDI in hospitalized older adults receiving antibiotics.

Probiotics in Orthopedics: From Preclinical Studies to Current Applications and Future Perspective

In recent years, probiotics have been emerging as an attractive therapeutic strategy for several diseases. In orthopedics, probiotics seem to be a promising supplementation for treatment of osteoporosis, osteoarthritis, muscle loss-related disease, wound and ulcer issues, and prevention of surgical antibiotic prophylaxis side effects. Although probiotics are still not included in guidelines for these conditions, several studies have reported theoretical benefits of their administration. Further high-level clinical trials are necessary to convert research into solid clinical practice. However, probiotics represent a cost-effective future perspective and may play a role in association with traditional orthopedic therapies.

Fecal microbiota transplantation in patients with metabolic syndrome and obesity: A randomized controlled trial

BACKGROUND

Metabolic syndrome is a multifactorial disease, and the gut microbiota may play a role in its pathogenesis. Obesity, especially abdominal obesity, is associated with insulin resistance, often increasing the risk of type two diabetes mellitus, vascular endothelial dysfunction, an abnormal lipid profile, hypertension, and vascular inflammation, all of which promote the development of atherosclerotic cardiovascular disease.

AIM

To evaluate the outcomes of fecal microbiota transplantation (FMT) in patients with metabolic syndrome.

METHODS

This was a randomized, single-blind placebo-controlled trial comparing FMT and a sham procedure in patients with metabolic syndrome. We selected 32 female patients, who were divided into eight groups of four patients each. All of the patients were submitted to upper gastrointestinal endoscopy. In each group, two patients were randomly allocated to undergo FMT, and the other two patients received saline infusion. The patients were followed for one year after the procedures, during which time anthropometric, bioimpedance, and biochemical data were collected. The patients also had periodic consultations with a nutritionist and an endocrinologist. The primary end point was a change in the gut microbiota.

RESULTS

There was evidence of a postprocedural change in microbiota composition in the patients who underwent FMT in relation to that observed in those who underwent the sham procedure. However, we found no difference between the two groups in terms of the clinical parameters evaluated.

CONCLUSION

There were no significant differences in biochemical or anthropometric parameters, between the two groups evaluated. Nevertheless, there were significant postprocedural differences in the microbiota composition between the placebo group. To date, clinical outcomes related to FMT remain uncertain.

Probiotics for primary prevention of Clostridioides difficile infection: revisiting the evidence

Prophylactic probiotics have been shown to be effective in preventing Clostridioides difficile infection (CDI), according to multiple meta-analyses. However, different medical societies have varying recommendations on their use for preventing CDI. In this commentary, we discuss current evidence for probiotic use in primary prevention of CDI and the issues raised by professional societies when evaluating the evidence. We highlight four areas for future improvement: considering baseline risk for CDI, timing of probiotics with antibiotics, combining efficacy data from different probiotic strains, and safety. All societies agree on the need for more high-quality and adequately powered randomized controlled trials to further strengthen the evidence.

Prescribed probiotic usage to prevent Clostridioides difficile infection among older patients receiving antibiotics: A retrospective cohort study

OBJECTIVES

Clostridioides difficile infection (CDI) is a leading cause of antimicrobial-associated colitis and is a global clinical concern. Probiotics are considered a CDI-preventive measure; however, highly inconsistent data have been previously reported. Thus, we evaluated the CDI-preventive effect of prescribed probiotics in high-risk older patients receiving antibiotics.

METHODS

Older patients (aged ≥65 years) admitted to the emergency department who received antibiotics between 2014 and 2017 were enrolled in this single-center retrospective cohort study. Propensity score-matched analysis was used to compare the CDI incidence in patients who took the prescribed probiotics within 2 days of receiving antibiotics for at least 7 days with those who did not. The rates of severe CDI and associated hospital mortality were also evaluated.

RESULTS

Among 6148 eligible patients, 221 were included in the prescribed probiotic group. A propensity score-matched (221 matched pairs) well-balanced for patient characteristics was obtained. The incidence of primary nosocomial CDI did not differ significantly between the prescribed and non-prescribed probiotic groups (0% [0/221] vs. 1.0% [2/221], p = 0.156). Of the 6148 eligible patients, 0.5% (30/6148) developed CDI, with a severe CDI rate of 33.3% (10/30). Furthermore, no CDI-associated in-hospital mortality was observed in the study cohort.

CONCLUSIONS

The evidence from this study does not support recommendations for the routine use of prescribed probiotics to prevent primary CDI in older patients receiving antibiotics in situations where the CDI is infrequent.

Future Modulation of Gut Microbiota: From Eubiotics to FMT, Engineered Bacteria, and Phage Therapy

The human gut is inhabited by a multitude of bacteria, yeasts, and viruses. A dynamic balance among these microorganisms is associated with the well-being of the human being, and a large body of evidence supports a role of dysbiosis in the pathogenesis of several diseases. Given the importance of the gut microbiota in the preservation of human health, probiotics, prebiotics, synbiotics, and postbiotics have been classically used as strategies to modulate the gut microbiota and achieve beneficial effects for the host. Nonetheless, several molecules not typically included in these categories have demonstrated a role in restoring the equilibrium among the components of the gut microbiota. Among these, rifaximin, as well as other antimicrobial drugs, such as triclosan, or natural compounds (including evodiamine and polyphenols) have common pleiotropic characteristics. On one hand, they suppress the growth of dangerous bacteria while promoting beneficial bacteria in the gut microbiota. On the other hand, they contribute to the regulation of the immune response in the case of dysbiosis by directly influencing the immune system and epithelial cells or by inducing the gut bacteria to produce immune-modulatory compounds, such as short-chain fatty acids. Fecal microbiota transplantation (FMT) has also been investigated as a procedure to restore the equilibrium of the gut microbiota and has shown benefits in many diseases, including inflammatory bowel disease, chronic liver disorders, and extraintestinal autoimmune conditions. One of the most significant limits of the current techniques used to modulate the gut microbiota is the lack of tools that can precisely modulate specific members of complex microbial communities. Novel approaches, including the use of engineered probiotic bacteria or bacteriophage-based therapy, have recently appeared as promising strategies to provide targeted and tailored therapeutic modulation of the gut microbiota, but their role in clinical practice has yet to be clarified. The aim of this review is to discuss the most recently introduced innovations in the field of therapeutic microbiome modulation.

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.

A Case of Lactobacillus casei Endocarditis Associated With Probiotic Intake in an Immunocompromised Patient

Probiotics are microorganisms, typically bacteria, similar to beneficial microbiota found in the human gut, usually consumed as dietary supplements or fermented foods. Although probiotics are generally safe, several cases of bacteremia, sepsis, and endocarditis associated with probiotics have been reported. Here we report a rare case of Lactobacillus casei endocarditis in a 71-year-old female, immunocompromised due to chronic steroid intake, who presented with a productive cough and low-grade fever. Blood cultures grew L. casei resistant to vancomycin and meropenem. Transesophageal echocardiography showed mitral and aortic vegetations; valve replacement was done after successfully removing vegetations. She was treated with a six-week course of daptomycin and recovered.

Change in the Gut Microbiome and Immunity by Lacticaseibacillus rhamnosus Probio-M9

With the exploding growth of the global market for probiotics and the rapid awakening of public awareness to manage health by probiotic intervention, there is still an active debate about whether the consumption of probiotics is beneficial for nonpatients, which is due to the lack of systematic analysis based on time series multiomics data sets. In this study, we recruited 100 adults from a college in China and performed a random case-control study by using a probiotic (Lacticaseibacillus rhamnosus Probio-M9) as an intervention for 6 weeks, aiming to achieve a comprehensive evaluation and understanding of the beneficial effect of Probio-M9 consumption. By testing advanced blood immunity indicators, sequencing the gut microbiome, and profiling the gut metabolome at baseline and the end of the study, we found that although the probiotic intervention has a limited impact on the human immunity and the gut microbiome and metabolome, the associations between the immunity indicators and multiomics data were strengthened, and further analysis of the gut microbiome's genetic variations revealed inhibited generation of single nucleotide variants (SNVs) by probiotic consumption. Taken together, our findings indicated an underestimated influence of the probiotic, not on altering the microbial composition but on strengthening the association between human immunity and commensal microbes and stabilizing the genetic variations of the gut microbiome. IMPORTANCE Although the global market for probiotics is growing explosively, there is still an active debate about whether the consumption of probiotics is beneficial for nonpatients. In this study, we recruited 100 adults from a college in China and performed 6 weeks of intervention for half of the volunteers. By analyzing the time series multiomics data in this study, we found that the probiotic intervention (i) has a limited effect on human immunity or the global structure of the gut microbiome and metabolome, (ii) can largely influence the correlation of the development between multiomics data and immunity, which was not able to be discovered by conventional differential abundance analysis, and (iii) can inhibit the generation of SNVs in the gut microbiome instead of promoting it.

Controversies in the Prevention and Treatment of Clostridioides difficile Infection in Adults: A Narrative Review

Clostridioides difficile remains a problematic pathogen resulting in significant morbidity and mortality, especially for high-risk groups that include immunocompromised patients. Both the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America (IDSA/SHEA), as well as the American College of Gastroenterology (ACG) and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) recently provided guideline updates for C. difficile infection (CDI). In this narrative review, the authors reviewed available literature regarding the prevention or treatment of CDI in adults and focused on disagreements between the IDSA/SHEA and ACG guidelines, as well as articles that have been published since the updates. Several options for primary prophylaxis are available, including probiotics and antibiotics (vancomycin, fidaxomicin). The literature supporting fidaxomicin is currently quite limited. While there are more studies evaluating probiotics and vancomycin, the optimal patient populations and regimens for their use have yet to be defined. While the IDSA/SHEA guidelines discourage metronidazole use for mild CDI episodes, evidence exists that it may remain a reasonable option for these patients. Fidaxomicin has an advantage over vancomycin in reducing recurrences, but its use is limited by cost. Despite this, recent studies suggest fidaxomicin's cost-effectiveness as a first-line therapy, though this is highly dependent on institutional contracts and payment structures. Secondary prophylaxis should focus on non-antimicrobial options to lessen the impact on the microbiome. The oral option of fecal microbiota transplantation (FMT), SER109, and the now FDA-approved RBX2660 represent exciting new options to correct dysbiosis. Bezlotoxumab is another attractive option to prevent recurrences. Further head-to-head studies of newer agents will be needed to guide selection of the optimal therapies for CDI primary and secondary prophylaxis.

ADS024, a Bacillus velezensis strain, protects human colonic epithelial cells against C. difficile toxin-mediated apoptosis

Clostridioides difficile infection (CDI) causes intestinal injury. Toxin A and toxin B cause intestinal injury by inducing colonic epithelial cell apoptosis. ADS024 is a Bacillus velezensis strain in development as a single-strain live biotherapeutic product (SS-LBP) to prevent the recurrence of CDI following the completion of standard antibiotic treatment. We evaluated the protective effects of the sterile filtrate and ethyl acetate extract of conditioned media from ADS024 and DSM7 (control strain) against mucosal epithelial injury in toxin-treated human colonic tissues and apoptosis in toxin-treated human colonic epithelial cells. Ethyl acetate extracts were generated from conditioned culture media from DSM7 and ADS024. Toxin A and toxin B exposure caused epithelial injury in fresh human colonic explants. The sterile filtrate of ADS024, but not DSM7, prevented toxin B-mediated epithelial injury in fresh human colonic explants. Both sterile filtrate and ethyl acetate extract of ADS024 prevented toxin-mediated apoptosis in human colonic epithelial cells. The anti-apoptotic effects of ADS024 filtrate and ethyl acetate extract were dependent on the inhibition of caspase 3 cleavage. The sterile filtrate, but not ethyl acetate extract, of ADS024 partially degraded toxin B. ADS024 inhibits toxin B-mediated apoptosis in human colonic epithelial cells and colonic explants.

Microbiota of the gastrointestinal tract: Friend or foe?

The gut microbiota is currently considered an external organ of the human body that provides important mechanisms of metabolic regulation and protection. The gut microbiota encodes over 3 million genes, which is approximately 150 times more than the total number of genes present in the human genome. Changes in the qualitative and quantitative composition of the microbiome lead to disruption in the synthesis of key bacterial metabolites, changes in intestinal barrier function, and inflammation and can cause the development of a wide variety of diseases, such as diabetes, obesity, gastrointestinal disorders, cardiovascular issues, neurological disorders and oncological concerns. In this review, I consider issues related to the role of the microbiome in the regulation of intestinal barrier function, its influence on physiological and pathological processes occurring in the body, and potential new therapeutic strategies aimed at restoring the gut microbiome. Herewith, it is important to understand that the gut microbiota and human body should be considered as a single biological system, where change of one element will inevitably affect its other components. Thus, the study of the impact of the intestinal microbiota on health should be considered only taking into account numerous factors, the role of which has not yet been fully elucidated.

Immunomodulation of B Lymphocytes by Prebiotics, Probiotics and Synbiotics: Application in Pathologies

INTRODUCTION

Prebiotics, probiotics and synbiotics are known to have major beneficial effects on human health due to their ability to modify the composition and the function of the gut mucosa, the gut microbiota and the immune system. These components largely function in a healthy population throughout different periods of life to confer homeostasis. Indeed, they can modulate the composition of the gut microbiota by increasing bacteria strands that are beneficial for health, such as Firmicute and Bifidobacteria, and decreasing harmful bacteria, such as Enteroccocus. Their immunomodulation properties have been extensively studied in different innate cells (dendritic cells, macrophages, monocytes) and adaptive cells (Th, Treg, B cells). They can confer a protolerogenic environment but also modulate pro-inflammatory responses. Due to all these beneficial effects, these compounds have been investigated to prevent or to treat different diseases, such as cancer, diabetes, allergies, autoimmune diseases, etc. Regarding the literature, the effects of these components on dendritic cells, monocytes and T cells have been studied and presented in a number of reviews, but their impact on B-cell response has been less widely discussed.

CONCLUSIONS

For the first time, we propose here a review of the literature on the immunomodulation of B-lymphocytes response by prebiotics, probiotics and synbiotics, both in healthy conditions and in pathologies.

DISCUSSION

Promising studies have been performed in animal models, highlighting the potential of prebiotics, probiotics and synbiotics intake to treat or to prevent diseases associated with B-cell immunomodulation, but this needs to be validated in humans with a full characterization of B-cell subsets and not only the humoral response.

Management of Clostridioides difficile infection in adults and challenges in clinical practice: review and comparison of current IDSA/SHEA, ESCMID and ASID guidelines

Clostridioides difficile infection (CDI) remains a significant clinical challenge both in the management of severe and severe-complicated disease and the prevention of recurrence. Guidelines released by the Infectious Diseases Society of America and Society for Healthcare Epidemiology of America (IDSA/SHEA) and ESCMID had some consensus as well as some discrepancies in disease severity classification and treatment recommendations. We review and compare the key clinical strategies from updated IDSA/SHEA, ESCMID and current Australasian guidelines for CDI management in adults and discuss relevant issues for clinicians, particularly in the management of severe-complicated infection. Updated IDSA/SHEA and ESCMID guidelines now reflect the increased efficacy of fidaxomicin in preventing recurrence and have both promoted fidaxomicin to first-line therapy with an initial CDI episode in both non-severe and severe disease and endorsed the role of bezlotoxumab in the prevention of recurrent infection. Vancomycin remains acceptable therapy and metronidazole is not preferred. For severe-complicated infection the IDSA/SHEA recommends high-dose oral ± rectal vancomycin and IV metronidazole, whilst in an important development, ESCMID has endorsed fidaxomicin and tigecycline as part of combination anti-CDI therapy, for the first time. The role of faecal microbiota transplantation (FMT) in second CDI recurrence is now clearer, but timing and mode of FMT in severe-complicated refractory disease still requires further study.

Clostridium difficile colitis portends poor outcomes in lower extremity orthopaedic trauma surgery

INTRODUCTION

Clostridium difficile is the most common cause of healthcare-associated infectious diarrhea and colitis, and carries the potential for high morbidity, particularly in frail patient populations. The purpose of this study was to utilize a large nationally representative database in order to report 1.) the incidence of CDC in patients with operative lower extremity fractures, 2.) risk factors for the development of CDC, 3.) the association of CDC with length of stay (LOS), readmission, and 30-day mortality rates.

METHODS

The ACS-NSQIP (2015-2019) was queried for patients who underwent surgical fixation of lower extremity fractures. A backward elimination multivariate regression model was used to identify risk factors for CDC. Chi squared and multivariate regression that controlled for preoperative variables and comorbidities were used to compare outcomes in patients with and without CDC.

RESULTS

95,532 patients were included, 681 (0.71%) of whom developed CDC. Risk factors for CDC were advanced age, ASA class ≥ 3, smoking, dialysis, anemia, hypoalbuminemia, preoperative SIRS, preoperative wound infections, preoperative sepsis, and the use of spinal anesthesia or MAC/IV sedation. Patients with CDC had significantly increased 30-day mortality rates (10.6% vs 4.4%; OR 1.80, 95% CI 1.41-2.31), readmission (34.2% vs 7.5%; OR 5.13, 95% CI 4.36-6.05, and length of stay (7.5 days vs 5.3 days) compared to patients without CDC.

CONCLUSION

The incidence of CDC in lower extremity orthopedic trauma patients was 0.71%. An occurrence of CDC was associated with approximately a 2.5 times increase in 30-day mortality, five times the readmission rate, and a longer hospital stay compared to patients without CDC. Mitigating the spread of c. diff through improved antibiotic stewardship and prompt treatment of CDC is paramount to decreasing the burden this infection imposes on orthopedic trauma patients and the healthcare system.

Gastrointestinal Microbiome and Multiple Health Outcomes: Umbrella Review

In recent years, there has been growing concern about the impact of the gastrointestinal microbiome on human health outcomes. To clarify the evidence for a link between the gastrointestinal microbiome and a variety of health outcomes in humans, we conducted an all-encompassing review of meta-analyses and systematic reviews that included 195 meta-analyses containing 950 unique health outcomes. The gastrointestinal microbiome is related to mortality, gastrointestinal disease, immune and metabolic outcomes, neurological and psychiatric outcomes, maternal and infant outcomes, and other outcomes. Existing interventions for intestinal microbiota (such as probiotics, fecal microbiota transplant, etc.) are generally safe and beneficial to a variety of human health outcomes, but the quality of evidence is not high, and more detailed and well-designed randomized controlled trials are necessary.

Antagonistic activity of selenium-enriched Bifidobacterium breve against Clostridioides difficile

Probiotics have the potential to be used in the prevention of Clostridioides difficile infection (CDI). In this study, selenium (Se)-enriched Bifidobacterium breve YH68-Se was obtained under optimal culture conditions with single-factor and response surface optimization. The overall environmental resistance of YH68-Se was superior to that of the parental strain YH68, mainly reflected in the substantial improvement of antioxidant activity and gastrointestinal tolerance. YH68-Se dramatically inhibited C. difficile growth, spore, biofilm, toxin production, and virulence gene expression, rapidly disrupted C. difficile cell membrane permeability and integrity, and altered the membrane proton motive force (PMF), induced a large outflow of intracellular substances and eventually caused bacterial death. The main factor inducing this process originated from the lactic acid (LD) in YH68-Se. In addition, the LD production of YH68 increased with increasing selenite concentration and was accompanied by enhanced activities of thioredoxin reductase (TrxR), glutathione peroxidase (GSH-Px), and increased concentration of autoinducer-2 (AI-2), which may be the crucial factors contributing to the outstanding probiotic properties of YH68-Se and their potent antagonism of C. difficile. KEY POINTS: • Compared with the parental strain B. breve YH68, the environmental resistance of YH68-Se was improved. • YH68-Se was able to produce more lactic acid, which suppressed the important physiological activities of C. difficile and rapidly disrupted their cell membrane structures. • Sodium selenite in the suitable concentration range gradually increases the yield of lactic acid and phenylacetic acid, increased the concentration of autoinducer-2, and enhanced the activities of antioxidant enzymes TrxR and GSH-Px in YH68.

Association Between Immunosuppressive Therapy and Outcome of Clostridioides difficile Infection: Systematic Review and Meta-Analysis

BACKGROUND

Patients with Clostridioides difficile infection (CDI) often have coexisting medical problems requiring immunosuppressive therapy. However, limited data are available on the association between immunosuppressive therapy and CDI outcomes.

AIM

To determine the association between immunosuppressive therapy and CDI outcomes.

METHODS

PubMed, Embase, and Cochrane Library were searched through February 2021. Two reviewers independently reviewed and included studies that compared adult CDI patients who received immunosuppressive therapy to those who did not. The primary outcome was complicated CDl, including death, surgery, shock, or ICU admission. Raw data or unadjusted odds ratios (ORs) were used to calculate pooled ORs with 95% confidence intervals (CIs).

RESULTS

Twenty-two studies with a total of 5759 CDI patients were selected. Immunosuppressive therapy was significantly associated with both primary outcome and death, with pooled ORs of 1.61 (95% CI 1.33-1.96) and 1.73 (95% CI 1.39-2.15) separately. The association between corticosteroids and primary outcome was also significant with OR of 1.73 (95% CI 1.41, 2.12). In subgroup analysis, the factors explaining differences in study results included study quality, patient age, and whether individual studies had adjusted for potential confounders. In a systematic review, most studies suggested a positive association between immunosuppressive therapy and complicated outcomes of CDI in patients comorbid for IBD.

CONCLUSIONS

Our systematic review and meta-analysis demonstrate that immunosuppressive therapy is a risk factor for complicated outcomes of CDI.

The Current Knowledge on Clostridioides difficile Infection in Patients with Inflammatory Bowel Diseases

Clostridioides difficile (C. difficile) represents a major health burden with substantial economic and clinical impact. Patients with inflammatory bowel diseases (IBD) were identified as a risk category for Clostridioides difficile infection (CDI). In addition to traditional risk factors for C. difficile acquisition, IBD-specific risk factors such as immunosuppression, severity and extension of the inflammatory disease were identified. C. difficile virulence factors, represented by both toxins A and B, induce the damage of the intestinal mucosa and vascular changes, and promote the inflammatory host response. Given the potential life-threatening complications, early diagnostic and therapeutic interventions are required. The screening for CDI is recommended in IBD exacerbations, and the diagnostic algorithm consists of clinical evaluation, enzyme immunoassays (EIAs) or nucleic acid amplification tests (NAATs). An increased length of hospitalization, increased colectomy rate and mortality are the consequences of concurrent CDI in IBD patients. Selection of CD strains of higher virulence, antibiotic resistance, and the increasing rate of recurrent infections make the management of CDI in IBD more challenging. An individualized therapeutic approach is recommended to control CDI as well as IBD flare. Novel therapeutic strategies have been developed in recent years in order to manage severe, refractory or recurrent CDI. In this article, we aim to review the current evidence in the field of CDI in patients with underlying IBD, pointing to pathogenic mechanisms, risk factors for infection, diagnostic steps, clinical impact and outcomes, and specific management.

Gut Microbiota Composition Associated with Clostridioides difficile Colonization and Infection

Clostridioides difficile is an anaerobic Gram-positive and spore-forming bacterium. The majority of C. difficile strains produce two toxins, A and B, associated with the development of acute diarrhea and/or colitis. In this review, two situations are distinguished: C. difficile infection (CDI) and asymptomatic colonization (AC). The main objective of this review is to explore the available data related to the link between the gut microbiota and the development of CDI. The secondary aim is to provide more information on why some people colonized with toxigenic C. difficile develop an infection while others show no signs of disease. Several factors, such as the use of antibiotics and proton pump inhibitors, hospitalization, and age, predispose individuals to C. difficile colonization and/or C. difficile infection. The gut microbiota of people with AC showed decreased abundances of Prevotella, Alistipes, Bacteroides, Bifidobacterium, Dorea, Coprococcus, and Roseburia. The gut microbiota of people suffering from CDI showed reductions in the abundances of Lachnospiraceae, Ruminococcaceae, Blautia spp., Prevotella spp., Dialister spp., Bifidobacterium spp., Roseburia spp., Anaerostipes spp., Faecalibacterium spp. and Coprococcus spp., in comparison with healthy people. Furthermore, increases in the abundances of Enterococcaceae and Enterococcus were associated with C. difficile infection.

Early use of probiotics might prevent antibiotic-associated diarrhea in elderly (>65 years): a systematic review and meta-analysis

Background

Antibiotic-associated diarrhea (AAD) is diarrhea associated with consuming antibiotics that cannot be explained by other causes. AAD prolongs admission time and increases mortality and financial costs. Elderly individuals are more prone to receive antibiotic treatment and develop AAD. The finding that living probiotic microorganisms decrease AAD incidence in adults (<65 years) has been clarified. However, it is controversial among elderly individuals.

Methods

We aimed to explore whether probiotics could prevent AAD in elderly individuals. We searched three electronic databases (PubMed, EMBASE, and The Cochrane Library), and two reviewers independently screened and assessed the studies. RevMan5.4 software was used to perform a meta-analysis according to the PRISMA guidelines.

Results

Eight RCTs of 4691 participants were included. We excluded two large studies because probiotics were used 48 hours after the first dose of antibiotics, and there was no effect. Subgroup analysis of 6 RCTs showed that probiotics given within two days of antibiotic treatment produced a lower AAD prevalence rate in elderly individuals.

Conclusion

We recommend that elderly individuals could be routinely distributed probiotics to prevent AAD development when receiving antibiotic treatment.

Trial registration

The review was not registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03257-3.

Probiotics or Synbiotics for Preventing Postoperative Infection in Hepatopancreatobiliary Cancer Patients: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

Postoperative infection of hepatopancreatobiliary cancer (HPBC) is a major cause of morbidity and mortality. Probiotics and synbiotics are potential prevention strategies, but evidence on the efficacy of probiotics or synbiotics in the prevention of postoperative infection for HPBC remains controversial. This study aimed to define the impact of probiotics or synbiotics on the incidence of postoperative infection in HPBC patients.

METHODS

A systematic search of the Cochrane Library, PubMed, Embase, and Web of Science databases was conducted from inception to February 2, 2021 to identify randomized controlled trials (RCTs) evaluating the efficacy of probiotics or synbiotics in HPBC. Data were pooled and expressed as the risk ratio (RR) and mean difference (MD) with 95% confidence intervals.

RESULTS

Eight RCTs involving 445 participants were included. Supplementation with probiotics or synbiotics significantly reduced the incidence of postoperative infection (RR 0.55) in HPBC patients, and both probiotics (RR 0.68) and synbiotics (RR 0.41) were effective in reducing the incidence of postoperative infection. In addition, probiotics or synbiotics can reduce duration of antibiotic use (MD -3.52) and length of hospital stay (MD -4.21).

CONCLUSION

Probiotics or synbiotics are effective strategies for the prevention of postoperative infection in HPBC patients.

Battling Enteropathogenic Clostridia: Phage Therapy for Clostridioides difficile and Clostridium perfringens

The pathogenic Clostridioides difficile and Clostridium perfringens are responsible for many health care-associated infections as well as systemic and enteric diseases. Therefore, they represent a major health threat to both humans and animals. Concerns regarding increasing antibiotic resistance (related to C. difficile and C. perfringens) have caused a surge in the pursual of novel strategies that effectively combat pathogenic infections, including those caused by both pathogenic species. The ban on antibiotic growth promoters in the poultry industry has added to the urgency of finding novel antimicrobial therapeutics for C. perfringens. These efforts have resulted in various therapeutics, of which bacteriophages (in short, phages) show much promise, as evidenced by the Eliava Phage Therapy Center in Tbilisi, Georgia (https://eptc.ge/). Bacteriophages are a type of virus that infect bacteria. In this review, the (clinical) impact of clostridium infections in intestinal diseases is recapitulated, followed by an analysis of the current knowledge and applicability of bacteriophages and phage-derived endolysins in this disease indication. Limitations of phage and phage endolysin therapy were identified and require considerations. These include phage stability in the gastrointestinal tract, influence on gut microbiota structure/function, phage resistance development, limited host range for specific pathogenic strains, phage involvement in horizontal gene transfer, and-for phage endolysins-endolysin resistance, -safety, and -immunogenicity. Methods to optimize features of these therapeutic modalities, such as mutagenesis and fusion proteins, are also addressed. The future success of phage and endolysin therapies require reliable clinical trial data for phage(-derived) products. Meanwhile, additional research efforts are essential to expand the potential of exploiting phages and their endolysins for mitigating the severe diseases caused by C. difficile and C. perfringens.

Translating Microbiome Research From and To the Clinic

Extensive research has elucidated the influence of the gut microbiota on human health and disease susceptibility and resistance. We review recent clinical and laboratory-based experimental studies associating the gut microbiota with certain human diseases. We also highlight ongoing translational advances that manipulate the gut microbiota to treat human diseases and discuss opportunities and challenges in translating microbiome research from and to the bedside.

Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The Challenges of Eradicating Pediatric Helicobacter pylori Infection in the Era of Probiotics

Helicobacter pylori (H. pylori), the most common infection of childhood, results in life-threatening complications during adulthood if left untreated. Most of these complications are related to H. pylori-induced chronic inflammation. The dysbiosis caused by H. pylori is not limited to the gastric microenvironment, but it affects the entire gastrointestinal tract. Eradication of H. pylori has recently become a real challenge for clinicians due to both the persistent increase in antibiotic resistance worldwide and the wide spectrum of side effects associated with the eradication regimens resulting; therefore, there is an urgent need for more effective and less noxious treatment options. Thus, probiotics might be a promising choice in both adults and children with H. pylori infection since their role in improving the eradication rate of this infection has been proved in multiple studies. The positive effects of probiotics might be explained by their abilities to produce antimicrobial compounds and antioxidants, alter local gastric pH, and subsequently decrease H. pylori colonization and adherence to gastric epithelial cells. Nevertheless, if used alone probiotics do not considerably increase the eradication rate.

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.

The development of live biotherapeutics against Clostridioides difficile infection towards reconstituting gut microbiota

Clostridioides difficile is the most prevalent pathogen of nosocomial diarrhea. In the United States, over 450,000 cases of C. difficile infection (CDI), responsible for more than 29,000 deaths, are reported annually in recent years. Because of the emergence of hypervirulent strains and strains less susceptible to vancomycin and fidaxomicin, new therapeutics other than antibiotics are urgently needed. The gut microbiome serves as one of the first-line defenses against C. difficile colonization. The use of antibiotics causes gut microbiota dysbiosis and shifts the status from colonization resistance to infection. Hence, novel CDI biotherapeutics capable of reconstituting normal gut microbiota have become a focus of drug development in this field.

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.

Gut Dysbiosis in Pancreatic Diseases: A Causative Factor and a Novel Therapeutic Target

Pancreatic-related disorders such as pancreatitis, pancreatic cancer, and type 1 diabetes mellitus (T1DM) impose a substantial challenge to human health and wellbeing. Even though our understanding of the initiation and progression of pancreatic diseases has broadened over time, no effective therapeutics is yet available for these disorders. Mounting evidence suggests that gut dysbiosis is closely related to human health and disease, and pancreatic diseases are no exception. Now much effort is under way to explore the correlation and eventually potential causation between the gut microbiome and the course of pancreatic diseases, as well as to develop novel preventive and/or therapeutic strategies of targeted microbiome modulation by probiotics, prebiotics, synbiotics, postbiotics, and fecal microbiota transplantation (FMT) for these multifactorial disorders. Attempts to dissect the intestinal microbial landscape and its metabolic profile might enable deep insight into a holistic picture of these complex conditions. This article aims to review the subtle yet intimate nexus loop between the gut microbiome and pancreatic diseases, with a particular focus on current evidence supporting the feasibility of preventing and controlling pancreatic diseases via microbiome-based therapeutics and therapies.