Fecal microbiota transplantation for treatment of patients with recurrent Clostridioides difficile infection

Bacillus coagulans restores pathogen-induced intestinal dysfunction via acetate-FFAR2-NF-κB-MLCK-MLC axis in Apostichopus japonicus

Skin ulceration syndrome (SUS) is currently the main disease threatening Apostichopus japonicus aquaculture due to its higher mortality rate and infectivity, which is caused by Vibrio splendidus. Our previous studies have demonstrated that SUS is accompanied by intestinal microbiota (IM) dysbiosis, alteration of short-chain fatty acids (SCFAs) content and the damage to the intestinal barrier. However, the mediating effect of IM on intestine dysfunction is largely unknown. Herein, we conducted comprehensive intestinal microbiota transplantation (IMT) to explore the link between IM and SUS development. Furthermore, we isolated and identified a Bacillus coagulans strain with an ability to produce acetic acid from both healthy individual and SUS individual with IM from healthy donors. We found that dysbiotic IM and intestinal barrier function in SUS recipients A. japonicus could be restored by IM from healthy donors. The B. coagulans strain could restore IM community and intestinal barrier function. Consistently, acetate supply also restores intestinal homeostasis of SUS-diseased and V. splendidus-infected A. japonicus. Mechanically, acetate was found to specifically bind to its receptor-free fatty acid receptor 2 (FFAR2) to mediate IM structure community and intestinal barrier function. Knockdown of FFAR2 by transfection of specific FFAR2 siRNA could hamper acetate-mediated intestinal homeostasis in vivo. Furthermore, we confirmed that acetate/FFAR2 could inhibit V. splendidus-activated NF-κB-MLCK-MLC signaling pathway to restore intestinal epithelium integrity and upregulated the expression of ZO-1 and Occludin. Our findings provide the first evidence that B. coagulans restores pathogen-induced intestinal barrier dysfunction via acetate/FFAR2-NF-κB-MLCK-MLC axis, which provides new insights into the control and prevention of SUS outbreak from an ecological perspective.IMPORTANCESkin ulceration syndrome (SUS) as a main disease in Apostichopus japonicus aquaculture has severely restricted the developmental A. japonicus aquaculture industry. Intestinal microbiota (IM) has been studied extensively due to its immunomodulatory properties. Short-chain fatty acids (SCFAs) as an essential signal molecule for microbial regulation of host health also have attracted wide attention. Therefore, it is beneficial to explore the link between IM and SUS for prevention and control of SUS. In the study, the contribution of IM to SUS development has been examined. Additionally, our research further validated the restoration of SCFAs on intestinal barrier dysfunction caused by SUS via isolating SCFAs-producing bacteria. Notably, this restoration might be achieved by inhibition of NF-κB-MLCK-MLC signal pathway, which could be activated by V. splendidus. These findings may have important implications for exploration of the role of IM in SUS occurrence and provide insight into the SUS treatment.

Fighting against Clostridioides difficile infection: Current medications

Clostridioides difficile (formerly Clostridium difficile) has been regarded as an 'urgent threat' and a significant global health problem, as life-threatening diarrhoea and refractory recurrence are common in patients with C. difficile infection (CDI). Unfortunately, the available anti-CDI drugs are limited. Recent guidelines recommend fidaxomicin and vancomycin as first-line drugs to treat CDI, bezlotoxumab to prevent recurrence, and faecal microbiota transplantation for rescue treatment. Currently, researchers are investigating therapeutic antibacterial drugs (e.g. teicoplanin, ridinilazole, ibezapolstat, surotomycin, cadazolid, and LFF571), preventive medications against recurrence (e.g. Rebyota, Vowst, VP20621, VE303, RBX7455, and MET-2), primary prevention strategies (e.g. vaccine, ribaxamase, and DAV132) and other anti-CDI medications in the preclinical stage (e.g. Raja 42, Myxopyronin B, and bacteriophage). This narrative review summarises current medications, including newly marketed drugs and products in development against CDI, to help clinicians treat CDI appropriately and to call for more research on innovation.

Rise to the Challenge: Master the Management of Clostridioides difficile Infection

Clostridioides difficile infection (CDI) is a significant public health challenge in the developed world. Although previously CDI was primarily a health care-acquired infection, there are now rising numbers of community-acquired cases in patients without traditional risk factors, such as antibiotic exposure. The landscape for the treatment of CDI has changed significantly during the past decade, including newer diagnostic tests, novel antibiotic regimens, and strategies for microbiome restoration in the form of traditional fecal microbiota transplant and approved live biotherapeutics in an effort to address the underlying pathophysiologic process of gut microbial dysbiosis. We present a concise review for clinicians on the diagnosis and management of both primary and recurrent CDI.

Corticosteroid-resistant immune-related adverse events: a systematic review

Immune checkpoint inhibitor (ICI) treatment has become an important therapeutic option for various cancer types. Although the treatment is effective, ICI can overstimulate the patient's immune system, leading to potentially severe immune-related adverse events (irAEs), including hepatitis, colitis, pneumonitis and myocarditis. The initial mainstay of treatments includes the administration of corticosteroids. There is little evidence how to treat steroid-resistant (sr) irAEs. It is mainly based on small case series or single case reports. This systematic review summarizes available evidence about sr-irAEs. We conducted a systematic literature search in PubMed. Additionally, we included European Society for Medical Oncology, Society for Immunotherapy of Cancer, National Comprehensive Cancer Network and American Society of Clinical Oncology Guidelines for irAEs in our assessment. The study population of all selected publications had to include patients with cancer who developed hepatitis, colitis, pneumonitis or myocarditis during or after an immunotherapy treatment and for whom corticosteroid therapy was not sufficient. Our literature search was not restricted to any specific cancer diagnosis. Case reports were also included. There is limited data regarding life-threatening sr-irAEs of colon/liver/lung/heart and the majority of publications are single case reports. Most publications investigated sr colitis (n=26), followed by hepatitis (n=21), pneumonitis (n=17) and myocarditis (n=15). There is most data for mycophenolate mofetil (MMF) to treat sr hepatitis and for infliximab, followed by vedolizumab, to treat sr colitis. Regarding sr pneumonitis there is most data for MMF and intravenous immunoglobulins (IVIG) while data regarding infliximab are conflicting. In sr myocarditis, most evidence is available for the use of abatacept or anti-thymocyte globulin (ATG) (both with or without MMF) or ruxolitinib with abatacept. This review highlights the need for prompt recognition and treatment of sr hepatitis, colitis, pneumonitis and myocarditis. Guideline recommendations for sr situations are not defined precisely. Based on our search, we recommend-as first line treatment-(1) MMF for sr hepatitis, (2) infliximab for sr colitis, followed by vedolizumab, (3) MMF and IVIG for sr pneumonitis and (4) abatacept or ATG (both with or without MMF) or ruxolitinib with abatacept for sr myocarditis. These additional immunosuppressive agents should be initiated promptly if there is no sufficient response to corticosteroids within 3 days.

Therapeutics for Clostridioides difficile infection: molecules and microbes

INTRODUCTION

Clostridioides difficile infection (CDI) is a major healthcare problem in the developed world, and effective management of recurrent infection remains one of the biggest challenges. Several advances have occurred in the management of CDI, and in the last 15 years, multiple new agents have been tested. Since 2011, four new products have been approved by the US FDA for treatment of CDI or prevention of recurrent CDI.

AREAS COVERED

This review focuses on therapeutics of CDI and includes sections on primary prevention, management of active infection, and prevention of recurrent CDI. Specifically, data are included on fecal microbiota transplantation and live biotherapeutics. A comprehensive search of several databases including Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, and Daily, Ovid EMBASE, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus from inception to 1 May 2023 was conducted.

EXPERT OPINION

Metronidazole is no longer advised for management of outpatient CDI. The preferred medication of choice for a first episode is oral vancomycin or fidaxomicin. For those patients who recur after the first episode, vancomycin taper pulse or fidaxomicin can be used. Intravenous bezlotoxumab, a monoclonal antibody, is available to prevent recurrences. There are now two FDA-approved microbiome-based therapies or live biotherapeutics for prevention of recurrent CDI, for any recurrent CDI and not necessarily multiply recurrent C difficile. Fecal microbiota transplantation remains available in limited settings for recurrent CDI.

Fecal Microbiota Transplantation

Fecal microbiota transplantation (FMT) is the process of transplanting stool from a healthy donor into the gut of a patient for therapeutic purposes. Current guidelines recommend FMT for the prevention of multiply recurrent Clostridioides difficile infection (CDI) after two recurrences, with cure rates approaching 90%. Emerging evidence also supports the use of FMT in the management of severe and fulminant CDI, resulting in decreased mortality and colectomy rates compared with standard of care approach. FMT shows promise as salvage therapy for critically-ill, refractory CDI patients who are poor surgical candidates. FMT should be considered early in the clinical course of severe CDI, preferably within 48 hours of failing to respond to antibiotic therapy and volume resuscitation. Besides CDI, ulcerative colitis was more recently identified as a potential treatment target for FMT. Several live biotherapeutics for microbiome restoration are on the horizon.

The evaluation of different types fecal bacteria products for the treatment of recurrent Clostridium difficile associated diarrhea: A systematic review and network meta-analysis

Purpose

To determine the efficacy of different types of fecal microbiota transplantation for the treatment of recurrent clostridium difficile associated diarrhea (RCDAD).

Methods

We searched PubMed, Embase, The Cochrane Library, Web of Science, China Biomedical Medicine (CBM), China National Knowledge Infrastructure (CNKI) and WanFang database. We also tracked the references found in systematic reviews of RCDAD treated with fecal microbiota transplantation. We included randomized controlled trials (RCTs) comparing different types of fecal microbiota transplantation with other methods for the treatment of RCDAD. The search period was from the date of inception of this treatment method to January 16, 2022. Two reviewers independently screened the published literature, extracted the data and assessed the risk of bias. Systematic review and network meta-analysis were conducted using RevMan 5.4, Stata 16.0 and R 4.1.2 software.

Results

Ten RCTs involving 765 patients were included in this network meta-analysis. The results showed that treatment with fresh fecal bacteria and frozen fecal bacteria were better than vancomycin, fresh vs. vancomycin [odds ratio, (OR) = 8.98, 95% confidence interval (95% CI) (1.84, 43.92)], frozen vs. vancomycin [OR = 7.44, 95% CI (1.39, 39.75)]. However, there were no statistically significant differences in cure rate [fresh vs. frozen: OR = 1.21, 95% CI (0.22, 6.77); fresh vs. lyophilized, OR = 1.95, 95% CI (0.20, 19.44); frozen vs. lyophilized, OR = 1.62, 95% CI (0.30, 8.85)]. The Surface Under the Cumulative Ranking (SUCRA) indicated that fresh fecal bacteria were the best treatment for RCDAD.

Conclusions

Fresh fecal bacteria are the best treatment of RCDAD, frozen fecal bacteria and lyophilized fecal bacteria can achieve the same effect. Fecal microbiota transplantation is worthy of clinical and commercial application.

Mechanisms of Immune Checkpoint Inhibitor-Mediated Colitis

Immune checkpoint inhibitors (ICIs) have provided tremendous clinical benefit in several cancer types. However, systemic activation of the immune system also leads to several immune-related adverse events. Of these, ICI-mediated colitis (IMC) occurs frequently and is the one with the highest absolute fatality. To improve current treatment strategies, it is important to understand the cellular mechanisms that induce this form of colitis. In this review, we discuss important pathways that are altered in IMC in mouse models and in human colon biopsy samples. This reveals a complex interplay between several types of immune cells and the gut microbiome. In addition to a mechanistic understanding, patients at risk should be identifiable before ICI therapy. Here we propose to focus on T-cell subsets that interact with bacteria after inducing epithelial damage. Especially, intestinal resident immune cells are of interest. This may lead to a better understanding of IMC and provides opportunities for prevention and management.

Safety and efficacy of fecal microbiota transplantation to treat and prevent recurrent Clostridioides difficile in cancer patients

Background: Cancer patients are at increased risk of recurrent Clostridioides difficile infection (rCDI) due to malignancy itself, cancer therapy, and frequent antibiotic use and have a lower response rate to standard oral antibiotics. There are limited data on the safety and efficacy of fecal microbiota transplantation (FMT) for treating rCDI in cancer patients. We aim to describe our experience of using FMT to treat rCDI at a tertiary cancer center.

Methods: We conducted a retrospective study of cancer patients who underwent FMT for rCDI at The University of Texas MD Anderson Cancer Center from June 2017 through January 2020. Baseline clinical data and risk factors related to rCDI and FMT were evaluated and compared between cancer types and between cases with remission and recurrence.

Results: A total of 19 patients were studied: 12 with solid malignancies and 7 with hematologic malignancies. Most patients had stage IV cancer, and 21% of patients were in cancer remission. On average, patients had 2 episodes of CDI and received 3 courses of antibiotics within 1 year before FMT. 84% of patients with rCDI responded to FMT. Compared with patients who had CDI remission following FMT, non-remission cases were more likely to have received antibiotics following FMT. There were no serious adverse events or mortality within 30 days associated with FMT.

Conclusions: FMT is safe, well-tolerated, and efficacious in treating rCDI in selected cancer patients. However, additional antibiotic use for complications from chemotherapy or immunosuppression negatively affected the efficacy of FMT in this population with advanced cancer.

Microbiota restoration for recurrent Clostridioides difficile: Getting one step closer every day!

Clostridioides difficile infection (CDI) is an urgent health threat being the most common healthcare-associated infection, and its management is a clinical conundrum. Over 450 000 infections are seen in the United States with similar incidence seen in the rest of the developed world. The majority of infections seen are mild-moderate with fulminant disease and mortality being rare complications seen in the elderly and in those with comorbidities. The most common complication of CDI is recurrent infection with rates as high as 60% after three or more infections. A dilemma in the management of primary and recurrent CDI is testing due to the high sensitivity of the nucleic acid amplification tests such as the polymerase chain reaction, which leads to clinical false positives if patients are not chosen carefully (with symptoms) before testing. A newer testing regimen involving a 2-step strategy is emerging using glutamate dehydrogenase as a screening strategy followed by enzyme immunoassay for the C. difficile toxin. Microbiota restoration therapies are the cornerstone of management of recurrent CDI to prevent future recurrences. The most common modality of microbiota restoration is faecal microbiota transplantation, which has been tainted with heterogeneity and adverse events such as serious infectious transmission. The success rates for recurrence prevention from microbiota restoration therapies are over 90% compared with less than 50% of recurrence prevention with courses of antibiotics. This has led to development and emergence of standardized microbiota restoration therapies in capsule and enema forms. Capsule-based therapies include CP101 (positive phase II results), RBX7455 (positive phase I results), SER-109 (positive phase III results) and VE303 (ongoing phase II trial). Enema-based therapy includes RBX2660 (positive phase III data). This review summarizes the principles of management and diagnosis of CDI and focuses on emerging and existing data on faecal microbiota transplantation and standardized microbiota restoration therapies.

My Treatment Approach to Clostridioides difficile Infection

Clostridioides difficile infection is the most common cause of infectious diarrhea in hospitals with an increasing incidence in the community. Clinical presentation of C difficile infection ranges from diarrhea manageable in the outpatient setting to fulminant infection requiring intensive care admission. There have been significant advances in the management of primary and recurrent C difficile infection including diagnostics, newer antibiotics, antibody treatments, and microbiome restoration therapies. Because of the risk of clinical false-positive results with the polymerase chain reaction test, a two-step assay combining an enzyme immune assay for glutamate dehydrogenase and the C difficile toxin is being used. Cost permitting, I treat a first episode of C difficile infection preferably with fidaxomicin over vancomycin but not metronidazole. The most common complication after C difficile infection is recurrence. I manage a first recurrence with a vancomycin taper and pulse or fidaxomicin and recommend a single dose of intravenous bezlotoxumab (a monoclonal antibody against the toxin B) to reduce recurrence rates for those patients at high risk. Patients with multiply recurrent C difficile infection are managed with a course of antibiotics such as vancomycin or fidaxomicin followed by microbiota restoration. The success of fecal microbiota transplantation is greater than 85%, compared with the 40% to 50% success rate of antibiotics in this situation. Fecal microbiota transplantation is heterogeneous and has rare but serious risks such as transmission of infections. Standardized microbiota restoration therapies are in clinical development and have completed phase III clinical trials. This review answers common clinical questions in the management of C difficile infection.

The Keystone commensal bacterium Christensenella minuta DSM 22607 displays anti-inflammatory properties both in vitro and in vivo

Christensenellaceae is a family of subdominant commensal bacteria found in humans. It is thought to play an important role in gut health by maintaining microbial symbiosis. Indeed, these bacteria occur at significantly lower levels or are absent in individuals suffering from inflammatory bowel diseases (IBDs). Here, we explored if type species Christensenella minuta (strain: DSM 22607) could have the potential to help treat IBDs. We assessed key properties displayed by the bacterium using a combination of in vitro and in vivo assays. We found that while C. minuta is a strict anaerobe, it is also oxygen tolerant. Additionally, we observed that the species produces high levels of acetate and moderate levels of butyrate. We performed deep phenotyping using Biolog microarrays. Using human intestinal cell lines, we discovered that C. minuta demonstrated strong anti-inflammatory activity, resulting in reduced levels of proinflammatory IL-8 cytokines via the inhibition of the NF-κB signaling pathway. Furthermore, C. minuta protected intestinal epithelial integrity in vitro. Finally, in two distinct animal models of acute colitis, C. minuta prevented intestinal damage, reduced colonic inflammation, and promoted mucosal healing. Together, these results indicate that C. minuta has potent immunomodulatory properties, underscoring its potential use in innovative microbiome-based IBD biotherapies.

The link among microbiota, epigenetics, and disease development

The microbiome is a community of various microorganisms that inhabit or live on the skin of humans/animals, sharing the body space with their hosts. It is a sort of complex ecosystem of trillions of commensals, symbiotic, and pathogenic microorganisms, including trillions of bacteria, archaea, protozoa, fungi, and viruses. The microbiota plays a role in the health and disease status of the host. Their number, species dominance, and viability are dynamic. Their long-term disturbance is usually accompanied by serious diseases such as metabolic disorders, cardiovascular diseases, or even cancer. While epigenetics is a term that refers to different stimuli that induce modifications in gene expression patterns without structural changes in the inherited DNA sequence, these changes can be reversible or even persist for several generations. Epigenetics can be described as cell memory that stores experience against internal and external factors. Results from multiple institutions have contributed to the role and close interaction of both microbiota and epigenetics in disease induction. Understanding the mechanisms of both players enables a better understanding of disease induction and development and also opens the horizon to revolutionary therapeutic approaches. The present review illustrates the roles of diet, microbiome, and epigenetics in the induction of several chronic diseases. In addition, it discusses the application of epigenetic data to develop diagnostic biomarkers and therapeutics and evaluate their safety for patients. Understanding the interaction among all these elements enables the development of innovative preventive/therapeutic approaches for disease control.

The interplay of SARS-CoV-2 and Clostridioides difficile infection

The COVID-19 pandemic has changed the way we practice medicine and lead our lives. In addition to pulmonary symptoms; COVID-19 as a syndrome has multisystemic involvement including frequent gastrointestinal symptoms such as diarrhea. Due to microbiome alterations with COVID-19 and frequent antibiotic exposure, COVID-19 can be complicated by Clostridioides difficile infection. Co-infection with these two can be associated with a high risk of complications. Infection control measures in hospitals is enhanced due to the COVID-19 pandemic which in turn appears to reduce the incidence of hospital-acquired infections such as C. difficile infection. Another implication of COVID-19 and its potential transmissibility by stool is microbiome-based therapies. Potential stool donors should be screened COVID-19 symptoms and be tested for COVID-19.

Alzheimer's Disease and Diabetes: Role of Diet, Microbiota and Inflammation in Preclinical Models

Alzheimer's disease (AD) is the most common cause of dementia. Epidemiological studies show the association between AD and type 2 diabetes (T2DM), although the mechanisms are not fully understood. Dietary habits and lifestyle, that are risk factors in both diseases, strongly modulate gut microbiota composition. Also, the brain-gut axis plays a relevant role in AD, diabetes and inflammation, through products of bacterial metabolism, like short-chain fatty acids. We provide a comprehensive review of current literature on the relation between dysbiosis, altered inflammatory cytokines profile and microglia in preclinical models of AD, T2DM and models that reproduce both diseases as commonly observed in the clinic. Increased proinflammatory cytokines, such as IL-1β and TNF-α, are widely detected. Microbiome analysis shows alterations in Actinobacteria, Bacteroidetes or Firmicutes phyla, among others. Altered α- and β-diversity is observed in mice depending on genotype, gender and age; therefore, alterations in bacteria taxa highly depend on the models and approaches. We also review the use of pre- and probiotic supplements, that by favoring a healthy microbiome ameliorate AD and T2DM pathologies. Whereas extensive studies have been carried out, further research would be necessary to fully understand the relation between diet, microbiome and inflammation in AD and T2DM.