Fecal Transplant in Children With Clostridioides difficile Gives Sustained Reduction in Antimicrobial Resistance and Potential Pathogen Burden

Rational Design of Live Biotherapeutic Products for the Prevention of Clostridioides difficile Infection

Clostridioides difficile infection (CDI) is one of the leading causes of healthcare- and antibiotic-associated diarrhea. While fecal microbiota transplantation (FMT) has emerged as a promising therapy for recurrent CDI, its exact mechanisms of action and long-term safety are not fully understood. Defined consortia of clonal bacterial isolates, known as live biotherapeutic products (LBPs), have been proposed as an alternative therapeutic option. However, the rational design of LBPs remains challenging. Here, we employ a computational pipeline and three independent metagenomic datasets to systematically identify microbial strains that have the potential to inhibit CDI. We first constructed the CDI-related microbial genome catalog, comprising 3,741 non-redundant metagenome-assembled genomes (nrMAGs) at the strain level. We then identified multiple potential protective nrMAGs that can be candidates for the design of microbial consortia targeting CDI, including strains from Dorea formicigenerans, Oscillibacter welbionis, and Faecalibacterium prausnitzii. Importantly, some of these potential protective nrMAGs were found to play an important role in the success of FMT, and the majority of the top protective nrMAGs can be validated by various previously reported findings. Our results demonstrate a computational framework for the rational selection of microbial strains targeting CDI, paving the way for the computational design of microbial consortia against other enteric infections.

Donor-recipient intermicrobial interactions impact transfer of subspecies and fecal microbiota transplantation outcome

Studies on fecal microbiota transplantation (FMT) have reported inconsistent connections between clinical outcomes and donor strain engraftment. Analyses of subspecies-level crosstalk and its influences on lineage transfer in metagenomic FMT datasets have proved challenging, as single-nucleotide polymorphisms (SNPs) are generally not linked and are often absent. Here, we utilized species genome bin (SGB), which employs co-abundance binning, to investigate subspecies-level microbiome dynamics in patients with autism spectrum disorder (ASD) who had gastrointestinal comorbidities and underwent encapsulated FMT (Chinese Clinical Trial: 2100043906). We found that interactions between donor and recipient microbes, which were overwhelmingly phylogenetically divergent, were important for subspecies transfer and positive clinical outcomes. Additionally, a donor-recipient SGB match was indicative of a high likelihood of strain transfer. Importantly, these ecodynamics were shared across FMT datasets encompassing multiple diseases. Collectively, these findings provide detailed insight into specific microbial interactions and dynamics that determine FMT success.

Faecal microbiota transplantation in children: A systematic review

AIM

Novel technologies offer insights into the potential role of the intestinal microbiota in human health and disease. Dysbiosis has been associated with several diseases, and it is thought to play a role in the pathogenesis of different gastrointestinal diseases. Faecal microbiota transplantation (FMT) is emerging as a method to modulate the gastrointestinal microbial ecosystem. While recurrent Clostridioides difficile infection is the recognised FMT indication, exploration of other therapeutic uses is ongoing.

METHODS

Following PRISMA guidelines, we conducted a systematic review, extracting 583 articles from Embase and PubMed (index date to October 2022).

RESULTS

The search yielded 58 studies for full review, with 50 included in the systematic review. Articles were categorised by FMT indication, study design, efficacy, adverse events, donor selection and administration route. FMT appears safe and effective for recurrent Clostridioides difficile infection, although severe adverse events are reported in children. However, there are currently insufficient data to support the use of FMT for other potential therapeutic indications (such as irritable or inflammatory bowel disease or obesity), beside the potential to decolonise multi-drug resistant organisms.

CONCLUSION

This underscores the need for randomised, controlled, prospective cohort studies in children to assess FMT effectiveness in diverse conditions and counteract publication bias.

Vaccination to Reduce Antimicrobial Resistance Burden-Data Gaps and Future Research

Antimicrobial resistance (AMR) poses an immediate danger to global health. If unaddressed, the current upsurge in AMR threatens to reverse the achievements in reducing the infectious disease-associated mortality and morbidity associated with antimicrobial treatment. Consequently, there is an urgent need for strategies to prevent or slow the progress of AMR. Vaccines potentially contribute both directly and indirectly to combating AMR. Modeling studies have indicated significant gains from vaccination in reducing AMR burdens for specific pathogens, reducing mortality/morbidity, and economic loss. However, quantifying the real impact of vaccines in these reductions is challenging because many of the study designs used to evaluate the contribution of vaccination programs are affected by significant background confounding, and potential selection and information bias. Here, we discuss challenges in assessing vaccine impact to reduce AMR burdens and suggest potential approaches for vaccine impact evaluation nested in vaccine trials.

Fecal microbiota transplantation in childhood: past, present, and future

BACKGROUND

Fecal microbiota transplantation (FMT) has been well described in the treatment of pediatric diseases; however, the latest updates regarding its use in children are unclear and the concepts involved need to be revisited.

DATA SOURCES

We performed advanced searches in the MEDLINE, EMBASE, and Cochrane databases using the keywords "Fecal microbiota transplantation OR Fecal microbiota transfer" in the [Title/Abstract] to identify relevant articles published in English within the last five years. To identify additional studies, reference lists of review articles and included studies were manually searched. Retrieved manuscripts (case reports, reviews, and abstracts) were assessed by the authors.

RESULTS

Among the articles, studies were based on the mechanism (n = 28), sample preparation (n = 9), delivery approaches (n = 23), safety (n = 26), and indications (n = 67), including Clostridium difficile infection (CDI) and recurrent C. difficile infection (rCDI; n = 21), non-alcoholic fatty liver disease (NAFLD; n = 10), irritable bowel syndrome (IBS; n = 5), inflammatory bowel disease (IBD; n = 15), diabetes (n = 5), functional constipation (FC; n = 4), and autism spectrum disorder (ASD; n = 7).

CONCLUSIONS

Concepts of FMT in pediatric diseases have been updated with respect to underlying mechanisms, methodology, indications, and safety. Evidence-based clinical trials for the use of FMT in pediatric diseases should be introduced to resolve the challenges of dosage, duration, initiation, and the end point of treatment.

Identification of donor Bacteroides vulgatus genes encoding proteins that correlate with early colonization following fecal transplant of patients with recurrent Clostridium difficile

Due to suppressive antibiotics, patients with recurrent Clostridium difficile have gut microbial communities that are devoid of most commensal microbes. Studies have shown that most of the failures using fecal microbe transplantation (FMT) for recurrent C. difficile occur during the first 4 weeks following transplantation. To identify features of donor Bacteroides vulgatus that lead to early colonization, we used two data sets that collected fecal samples from recipients at early times points post FMT. The first analysis used the shotgun metagenomic DNA sequencing data set from Aggarwala et al. consisting of 7 FMT donors and 13 patients with recurrent C. difficile with fecal samples taken as early as 24 h post FMT. We identified 2 FMT donors in which colonization of recipients by donor B. vulgatus was detected as early as 24 h post FMT. We examined a second data set from Hourigan et al. that collected fecal samples from C. difficile infected children and identified 1 of 3 FMT that also had early colonization of the donor B. vulgatus. We found 19 genes out of 4911 encoding proteins were unique to the 3 donors that had early colonization. A gene encoding a putative chitobiase was identified that was in a gene complex that had been previously identified to enhance colonization in mice. A gene encoding a unique fimbrillin (i.e., pili) family protein and 17 genes encoding hypothetical proteins were also specific for early colonizing donors. Most of the genes encoding hypothetical proteins had neighboring genes that encoded proteins involved in mobilization or transposition. Finally, analysis of 42 paired fecal samples from the human microbiome project (HMP) found no individuals had all 19 genes while 2 individuals had none of the 19 genes. Based on the results from our study, consideration should be given to the screening of FMT donors for these B. vulgatus genes found to enhance early colonization that would be of benefit to promote colonization following FMT.

Fecal Microbiota Transplantation for Clostridioides difficile Infection in Immunocompromised Pediatric Patients

OBJECTIVES

We sought to evaluate the safety and effectiveness of fecal microbiota transplantation (FMT) for recurrent Clostridioides difficile infection (CDI) in pediatric immunocompromised (IC) patients.

METHODS

This is a multicenter retrospective cohort study of pediatric participants who underwent FMT between March 2013 and April 2020 with 12-week follow-up. Pediatric patients were included if they met the definition of IC and were treated with FMT for an indication of recurrent CDI. We excluded patients over 18 years of age, those with incomplete records, insufficient follow-up, or not meeting study definition of IC. We also excluded those treated for Clostridioides difficile recurrence without meeting the study definition and those with inflammatory bowel disease without another immunocompromising condition.

RESULTS

Of 59 pediatric patients identified at 9 centers, there were 42 who met inclusion and no exclusion criteria. Included patients had a median age of 6.7 years. Etiology of IC included: solid organ transplantation (18, 43%), malignancy (12, 28%), primary immunodeficiency (10, 24%), or other chronic conditions (2, 5%). Success rate was 79% after first FMT and 86% after 1 or more FMT. There were no statistically significant differences in patient characteristics or procedural components when patients with a failed FMT were compared to those with a successful FMT. There were 15 total serious adverse events (SAEs) in 13 out of 42 (31%) patients that occurred during the follow-up period; 4 (9.5%) of which were likely treatment-related. There were no deaths or infections with multidrug resistant organisms during follow-up and all patients with a SAE fully recovered.

CONCLUSIONS

The success rate of FMT for recurrent CDI in this pediatric IC cohort is high and mirrors data for IC adults and immunocompetent children. FMT-related SAEs do occur (9.5%) and highlight the need for careful consideration of risk and benefit.

Fecal Microbiota Transplantation Across the Lifespan: Balancing Efficacy, Safety, and Innovation

Fecal microbiota transplantation (FMT) is a rapidly growing therapy aimed at reconstituting the dysbiotic microbiota of a patient with the beneficial stool microbiota of a healthy individual. The efficacy rates of FMT are very robust for recurrent Clostridioides difficile infection in both children and adults. Although complications of FMT have been reported, it is generally believed to be a safe procedure. Novel indications for FMT are being studied, with the hope that ultimately it may be useful for a variety of disorders. As this field continues to grow, however, it is necessary to consider efficacy, safety, and innovation across the lifespan. There are unique concerns regarding FMT as it pertains to children, adults, and the elderly. In this review, we seek to update clinicians, researchers, and regulators on how these factors must be balanced across the lifespan as we move forward with this innovative therapy.

The person-to-person transmission landscape of the gut and oral microbiomes

The human microbiome is an integral component of the human body and a co-determinant of several health conditions1,2. However, the extent to which interpersonal relations shape the individual genetic makeup of the microbiome and its transmission within and across populations remains largely unknown3,4. Here, capitalizing on more than 9,700 human metagenomes and computational strain-level profiling, we detected extensive bacterial strain sharing across individuals (more than 10 million instances) with distinct mother-to-infant, intra-household and intra-population transmission patterns. Mother-to-infant gut microbiome transmission was considerable and stable during infancy (around 50% of the same strains among shared species (strain-sharing rate)) and remained detectable at older ages. By contrast, the transmission of the oral microbiome occurred largely horizontally and was enhanced by the duration of cohabitation. There was substantial strain sharing among cohabiting individuals, with 12% and 32% median strain-sharing rates for the gut and oral microbiomes, and time since cohabitation affected strain sharing more than age or genetics did. Bacterial strain sharing additionally recapitulated host population structures better than species-level profiles did. Finally, distinct taxa appeared as efficient spreaders across transmission modes and were associated with different predicted bacterial phenotypes linked with out-of-host survival capabilities. The extent of microorganism transmission that we describe underscores its relevance in human microbiome studies5, especially those on non-infectious, microbiome-associated diseases.

Antimicrobial Resistance and Recent Alternatives to Antibiotics for the Control of Bacterial Pathogens with an Emphasis on Foodborne Pathogens

Antimicrobial resistance (AMR) is one of the most important global public health problems. The imprudent use of antibiotics in humans and animals has resulted in the emergence of antibiotic-resistant bacteria. The dissemination of these strains and their resistant determinants could endanger antibiotic efficacy. Therefore, there is an urgent need to identify and develop novel strategies to combat antibiotic resistance. This review provides insights into the evolution and the mechanisms of AMR. Additionally, it discusses alternative approaches that might be used to control AMR, including probiotics, prebiotics, antimicrobial peptides, small molecules, organic acids, essential oils, bacteriophage, fecal transplants, and nanoparticles.

Efficacy and Safety of Fecal Microbiota Transplantation in Treatment of Clostridioides difficile Infection among Pediatric Patients: A Systematic Review and Meta-Analysis

Background and Aims: Cases of Clostridioides difficile infection have been rising among the pediatric and adolescent population. Fecal microbiota transplantation (FMT) has emerged as an alternative therapy for recurrent C. difficile infection. We aim to perform the first systematic review and meta-analysis investigating the safety and efficacy of fecal microbiota transplantation for C. difficile infection in children and adolescents. Methods: A literature search was performed using variations of the keywords “pediatrics”, “C. difficile infection”, and “fecal microbiota transplantation” in PubMed, EMBASE, CINAHL, Cochrane, and Google Scholar from inception to 30 June 2022. The resulting 575 articles were independently screened by three authors. Fourteen studies that satisfied the eligibility criteria were included in the meta-analysis. Results: The pooled success rate of FMT in the overall cohort was 86% (95% confidence interval: 77−95%; p < 0.001; I2 = 70%). There were 38 serious adverse events in 36 patients with a pooled rate of 2.0% (95% confidence interval: 0.0−3.0%; p = 0.1; I2 = 0.0%) and 47 adverse events in 45 patients with a pooled rate of 15% (95% confidence interval: 5.0−25.0%; p = 0.02; I2 = 54.0%). There was no death associated with FMT. Conclusions: FMT was concluded to be an effective and safe therapy in pediatric and adolescent patients with C. difficile infection. Underlying comorbidities may impede the efficacy. A rigorous screening process of the donors is recommended prior to embarking on FMT. There is no universal and cost-effective way to monitor the long-term outcomes of FMT. While promising, metagenomic sequencing may not be available in settings with limited resources. Robust data from randomized clinical trials is warranted.

Impact of Fecal Microbiota Transplantation on Gut Bacterial Bile Acid Metabolism in Humans

Fecal microbiota transplantation (FMT) is a promising therapeutic modality for the treatment and prevention of metabolic disease. We previously conducted a double-blind, randomized, placebo-controlled pilot trial of FMT in obese metabolically healthy patients in which we found that FMT enhanced gut bacterial bile acid metabolism and delayed the development of impaired glucose tolerance relative to the placebo control group. Therefore, we conducted a secondary analysis of fecal samples collected from these patients to assess the potential gut microbial species contributing to the effect of FMT to improve metabolic health and increase gut bacterial bile acid metabolism. Fecal samples collected at baseline and after 4 weeks of FMT or placebo treatment underwent shotgun metagenomic analysis. Ultra-high-performance liquid chromatography-mass spectrometry was used to profile fecal bile acids. FMT-enriched bacteria that have been implicated in gut bile acid metabolism included Desulfovibrio fairfieldensis and Clostridium hylemonae. To identify candidate bacteria involved in gut microbial bile acid metabolism, we assessed correlations between bacterial species abundance and bile acid profile, with a focus on bile acid products of gut bacterial metabolism. Bacteroides ovatus and Phocaeicola dorei were positively correlated with unconjugated bile acids. Bifidobacterium adolescentis, Collinsella aerofaciens, and Faecalibacterium prausnitzii were positively correlated with secondary bile acids. Together, these data identify several candidate bacteria that may contribute to the metabolic benefits of FMT and gut bacterial bile acid metabolism that requires further functional validation.

The global incidence of adverse events associated with fecal microbiota transplantation in children over the past 20 years: A systematic review and meta-analysis

OBJECTIVES

To understand the global incidence of the adverse events associated with fecal microbiota transplantation (FMT) in children over the past 20 years.

METHODS

We searched PubMed, Web of Science, Embase, and three Chinese databases (CNKI, Wanfang, and Chongqing Weipu) for high-quality articles written over the past 20 years and made selections based on the quality standard score. The study characteristics and incidences of adverse events were extracted from each article, meta-analysis was performed using the R.3.6.3 software, and randomized-effect or fixed-effect meta-analyses were used to determine the incidence of adverse events. Subgroup analysis was performed to determine heterogeneity.

RESULTS

A total of 18 articles involving 681 children were included in the analysis. The total effective rate of FMT in children was 85.75% (95% CI: 76.23-93.15%), of which the overall efficacy of FMT for the treatment of Clostridium difficile infection was 91.22% (95% CI: 83.49-96.68%) and the overall adverse event rate was 28.86% (95% CI: 19.56-39.15%), with a mild to moderate adverse event rate of 27.72% (95% CI: 17.86-38.83%) and a severe adverse event rate of 0.90% (95% CI: 0.33-1.76%). The most common mild to moderate adverse events were as follows: bellyache, 14.02% (95% CI: 5.43-25.77%); diarrhea, 7.75% (95% CI: 2.69-15.11%); and bloating, 7.36% (95% CI: 1.79-16.28%). Other adverse events included fever, 2.34%; vomiting, 3.12%; nausea, 1.50%; hematochezia, 2.30%; anorexia, 1.94%; and fatigue, 0.03%. The only death reported was in a study from China, in which the patient died of sepsis and liver failure 4 weeks after FMT. The other serious adverse event was an immunodeficiency patient with severe hematochezia. Another study in the United States described seven serious adverse events including one death that was not considered to be related to FMT; however, they did not describe the events in detail. There was no difference in the incidence of adverse events between the upper and lower gastrointestinal tracts (OR = 0.61, 95% CI: 0.02-15.42, P = 0.76).

CONCLUSION

Adverse events related to FMT in children are mostly mild to moderate, of short duration, and self-limiting. Therefore, the use of FMT in children is safe and worthy of widespread promotion.

Variability of strain engraftment and predictability of microbiome composition after fecal microbiota transplantation across different diseases

Fecal microbiota transplantation (FMT) is highly effective against recurrent Clostridioides difficile infection and is considered a promising treatment for other microbiome-related disorders, but a comprehensive understanding of microbial engraftment dynamics is lacking, which prevents informed applications of this therapeutic approach. Here, we performed an integrated shotgun metagenomic systematic meta-analysis of new and publicly available stool microbiomes collected from 226 triads of donors, pre-FMT recipients and post-FMT recipients across eight different disease types. By leveraging improved metagenomic strain-profiling to infer strain sharing, we found that recipients with higher donor strain engraftment were more likely to experience clinical success after FMT (P = 0.017) when evaluated across studies. Considering all cohorts, increased engraftment was noted in individuals receiving FMT from multiple routes (for example, both via capsules and colonoscopy during the same treatment) as well as in antibiotic-treated recipients with infectious diseases compared with antibiotic-naïve patients with noncommunicable diseases. Bacteroidetes and Actinobacteria species (including Bifidobacteria) displayed higher engraftment than Firmicutes except for six under-characterized Firmicutes species. Cross-dataset machine learning predicted the presence or absence of species in the post-FMT recipient at 0.77 average AUROC in leave-one-dataset-out evaluation, and highlighted the relevance of microbial abundance, prevalence and taxonomy to infer post-FMT species presence. By exploring the dynamics of microbiome engraftment after FMT and their association with clinical variables, our study uncovered species-specific engraftment patterns and presented machine learning models able to predict donors that might optimize post-FMT specific microbiome characteristics for disease-targeted FMT protocols.

Characteristics and management of children with Clostridioides difficile infection at a tertiary pediatric hospital in China

Background

Clostridiodes difficile infection (CDI) is one of the most common causes of antibiotic-associated diarrhea in children. Conventional antibiotics and emerging fecal microbiota transplantation (FMT) are used to treat CDI.

Methods

Children with CDI admitted to the Shanghai Children's Hospital, from September 2014 to September 2020, were retrospectively included to this observational study. Pediatric patients were assigned as initial CDI and recurrent CDI (RCDI), and symptoms, comorbidities, imaging findings, laboratory tests, and treatments were systematically recorded and analyzed.

Results

Of 109 pediatric patients with CDI, 58 were boys (53.2%), and the median age was 5 years (range, 2-9 years). The main clinical symptoms of CDI children were diarrhea (109/109, 100%), hematochezia (55/109, 50.46%), abdominal pain (40/109, 36.70%); fever, pseudomembrane, vomit, and bloating were observed in 39 (35.78%), 33 (30.28%), and 24 (22.02%) patients, respectively. For the primary therapy with conventional antibiotics, 68 patients received metronidazole, and 41 patients received vancomycin. RCDI occurred in 48.53% (33/68) of those initially treated with metronidazole compared with 46.33% (19/41) of those initially treated with vancomycin (p=0.825). The total resolution rate of FMT for RCDI children was significantly higher than with vancomycin treatment (28/29, 96.55% vs 11/23, 47.83%, p < 0.001). There were no serious adverse events (SAEs) reported after two months of FMT.

Conclusions

The major manifestations of children with CDI were diarrhea, hematochezia, and abdominal pain. The cure rate of FMT for pediatric RCDI is superior to vancomycin treatment.

Intestinal Microbial Composition of Children in a Randomized Controlled Trial of Probiotics to Treat Acute Gastroenteritis

Compositional analysis of the intestinal microbiome in pre-schoolers is understudied. Effects of probiotics on the gut microbiota were evaluated in children under 4-years-old presenting to an emergency department with acute gastroenteritis. Included were 70 study participants (n=32 placebo, n=38 probiotics) with stool specimens at baseline (day 0), day 5, and after a washout period (day 28). Microbiota composition and deduced functions were profiled using 16S ribosomal RNA sequencing and predictive metagenomics, respectively. Probiotics were detected at day 5 of administration but otherwise had no discernable effects, whereas detection of bacterial infection (P<0.001) and participant age (P<0.001) had the largest effects on microbiota composition, microbial diversity, and deduced bacterial functions. Participants under 1 year had lower bacterial diversity than older aged pre-schoolers; compositional changes of individual bacterial taxa were associated with maturation of the gut microbiota. Advances in age were associated with differences in gut microbiota composition and deduced microbial functions, which have the potential to impact health later in life.

Antimicrobial Resistance in Rivers: A Review of the Genes Detected and New Challenges

River ecosystems are very important parts of the water cycle and an excellent habitat, food, and drinking water source for many organisms, including humans. Antibiotics are emerging contaminants which can enter rivers from various sources. Several antibiotics and their related antibiotic resistance genes (ARGs) have been detected in these ecosystems by various research programs and could constitute a substantial problem. The presence of antibiotics and other resistance cofactors can boost the development of ARGs in the chromosomes or mobile genetic elements of natural bacteria in rivers. The ARGs in environmental bacteria can also be transferred to clinically important pathogens. However, antibiotics and their resistance genes are both not currently monitored by national or international authorities responsible for controlling the quality of water bodies. For example, they are not included in the contaminant list in the European Water Framework Directive or in the US list of Water-Quality Benchmarks for Contaminants. Although ARGs are naturally present in the environment, very few studies have focused on non-impacted rivers to assess the background ARG levels in rivers, which could provide some useful indications for future environmental regulation and legislation. The present study reviews the antibiotics and associated ARGs most commonly measured and detected in rivers, including the primary analysis tools used for their assessment. In addition, other factors that could enhance antibiotic resistance, such as the effects of chemical mixtures, the effects of climate change, and the potential effects of the coronavirus disease 2019 pandemic, are discussed. Environ Toxicol Chem 2022;41:687-714. © 2022 SETAC.

An update on fecal microbiota transplantation for the treatment of gastrointestinal diseases

Our understanding of the microbiome and its implications for human health and disease continues to develop. Fecal microbiota transplantation (FMT) is now an established treatment for recurrent Clostridioides difficile infection. There is also increasing evidence for the efficacy of FMT in inducing remission for mild-moderate ulcerative colitis. However, for other indications, data for FMT are limited, with randomized controlled trials rare, typically small and often conflicting. Studies are continuing to explore the role of FMT for many other conditions, including Crohn's disease, functional gut disorders, metabolic syndrome, modulating responses to chemotherapy, eradication of multidrug resistant organisms, and the gut-brain axis. In light of safety, logistical, and regulatory challenges, there is a move to standardized products including narrow spectrum consortia. However, the mechanisms underpinning FMT remain incompletely understood, including the role of non-bacterial components, which may limit success of novel microbial approaches.

Fecal Microbiota Transplantation and Microbial Therapeutics for the Treatment of Clostridioides difficile Infection in Pediatric Patients

Clostridioides difficile infection (CDI) is the most common cause of antibiotic-associated diarrhea and has high rates of recurrent disease. As a disease associated with intestinal dysbiosis, gastrointestinal microbiome manipulation and fecal microbiota transplantation (FMT) have evolved as effective, although relatively unregulated therapeutics and not without safety concerns. FMT for the treatment of CDI has been well studied in adults with increasing data reported in children. In this review, we discuss the current body of literature on the use of FMT in children including effectiveness, safety, risk factors for a failed FMT, and the role of FMT in children with comorbidities. We also review emerging microbial therapeutics for the treatment of rCDI.

Updates and Challenges in Fecal Microbiota Transplantation for Clostridioides difficile Infection in Children

Fecal microbiota transplantation (FMT) is currently the most effective but loosely regulated therapy, for recurrent Clostridioides difficile infection (rCDI) in pediatrics. Over the last 2 years, there have been mounting challenges in the ability to provide FMT to pediatric patients. Firstly, an Food and Drug Administration (FDA) safety alert in 2019 reported transmission of a multidrug resistant organism from FMT donor to recipient resulting in the death of 1 patient. Secondly, the coronavirus disease 2019 (COVID-19) pandemic induced further safety and regulatory challenges. Biotherapeutics are promising and more readily regulated treatment options for rCDI, which may replace FMT in the near future for adults upon regulatory agency approvals. Such approvals, however, are expected to be significantly delayed for children, raising concerns for limited access to effective treatment for children with rCDI. In this commentary, we discuss the recent challenges and future directions of FMT and microbial therapeutics in children with rCDI.

Clostridioides difficile Infection in Pediatric Inflammatory Bowel Disease: A Clinician's Dilemma

Clostridioides difficile infection (CDI) in children with inflammatory bowel disease (IBD) can present and manifest differently from the general population with CDI, and it can worsen the underlying disease course. Furthermore, current clinical assays used to test for CDI do not accurately distinguish between true CDI or colonization. This uncertainty leads to difficulty in identifying the etiology and therapy for symptomatic patients with IBD. Improved diagnostic tests, biomarkers, and safe and effective treatment options are greatly needed for this vulnerable population.

Tandem fecal microbiota transplantation cycles in an allogeneic hematopoietic stem cell transplant recipient targeting carbapenem-resistant Enterobacteriaceae colonization: a case report and literature review

BACKGROUND

Due to limited antibiotic options, carbapenem-resistant Enterobacteriaceae (CRE) infections are associated with high non-relapse mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Also, intestinal CRE colonization is a risk factor for subsequent CRE infection. Several clinical studies have reported successful fecal microbiota transplantation (FMT) for the gut decontamination of a variety of multidrug-resistant bacteria (MDRB), even in immunosuppressed patients. Similarly, other studies have also indicated that multiple FMTs may increase or lead to successful therapeutic outcomes.

CASE PRESENTATION

We report CRE colonization in an allo-HSCT patient with recurrent CRE infections, and its successful eradication using tandem FMT cycles at 488 days after allo-HSCT. We also performed a comprehensive microbiota analysis. No acute or delayed adverse events (AEs) were observed. The patient remained clinically stable with CRE-negative stool culture at 26-month follow-up. Our analyses also showed some gut microbiota reconstruction. We also reviewed the current literature on decolonization strategies for CRE.

CONCLUSIONS

CRE colonization led to a high no-relapse mortality after allo-HSCT; however, well-established decolonization strategies are currently lacking. The successful decolonization of this patient suggests that multiple FMT cycles may be potential options for CRE decolonization.

Faecalibacterium prausnitzii increases following fecal microbiota transplantation in recurrent Clostridioides difficile infection

OBJECTIVE

Fecal microbiota transplantation (FMT) is a highly effective treatment for Clostridioides difficile infection (CDI). However, the fecal transplant's causal components translating into clearance of the CDI are yet to be identified. The commensal bacteria Faecalibacterium prausnitzii may be of great interest in this context, since it is one of the most common species of the healthy gut microbiota and produces metabolites with anti-inflammatory properties. Although there is mounting evidence that F. prausnitzii is an important regulator of intestinal homeostasis, data about its role in CDI and FMT are relatively scarce.

METHODS

Stool samples from patients with recurrent CDI were collected to investigate the relative abundance of F. prausnitzii before and after FMT. Twenty-one patients provided fecal samples before the FMT procedure, at 2 weeks post-FMT, and at 2-4 months post-FMT. The relative abundance of F. prausnitzii was determined using quantitative polymerase chain reaction.

RESULTS

The abundance of F. prausnitzii was elevated in samples (N = 9) from donors compared to pre-FMT samples (N = 15) from patients (adjusted P<0.001). No significant difference in the abundance of F. prausnitzii between responders (N = 11) and non-responders (N = 4) was found before FMT (P = 0.85). In patients with CDI, the abundance of F. prausnitzii significantly increased in the 2 weeks post-FMT samples (N = 14) compared to the pre-FMT samples (N = 15, adjusted P<0.001). The increase persisted 2-4 months post-FMT (N = 15) compared to pre-FMT samples (N = 15) (adjusted P<0.001).

CONCLUSIONS

FMT increases the relative abundance of F. prausnitzii in patients with recurrent CDI, and this microbial shift remains several months later. The baseline abundance of F. prausnitzii in donors or recipients was not associated with future treatment response, although a true predictive capacity cannot be excluded because of the limited sample size. Further studies are needed to discern whether F. prausnitzii plays an active role in the resolution of CDI.

Periodic screening of donor faeces with a quarantine period to prevent transmission of multidrug-resistant organisms during faecal microbiota transplantation: a retrospective cohort study

BACKGROUND

On June 13, 2019, the US Food and Drug Administration issued a warning after transfer of faeces containing an extended-spectrum β-lactamase (ESBL)-producing Escherichia coli by faecal microbiota transplantation led to bacteraemia in two immunocompromised patients. Consequently, we evaluated the effectiveness of the faeces donor-screening protocol of the Netherlands Donor Faeces Bank, which consists of screening of donors for multidrug-resistant organisms every 3 months, combined with additional screening on indication (eg, after travelling abroad) and application of a quarantine period for all faecal suspensions delivered within those 3 months.

METHODS

We did a retrospective cohort study of data collected between Jan 1, 2015, and Oct 14, 2019, on the multidrug-resistant organism testing results of donor faeces. Additionally, we tested previously quarantined faecal suspensions approved for faecal microbiota transplantation between Dec 12, 2016, and May 1, 2019, for the presence of multidrug-resistant organisms using both aselective and selective broth enrichment media. Whole-genome sequencing with core-genome multilocus sequence typing (cgMLST) was done on all multidrug-resistant isolates.

FINDINGS

Among initial screenings, six (9%) of 66 tested individuals were positive for multidrug-resistant organisms and 11 (17%) of 66 tested individuals were positive for multidrug-resistant organisms at any timepoint. Multidrug-resistant organisms were detected in four (25%) of 16 active donors, who had a median donation duration of 268 days (IQR 92 to 366). Among all screening results, 14 (74%) of 19 detected multidrug-resistant organisms were ESBL-producing E coli. 170 (49%) of 344 approved faecal suspensions had corresponding research faeces aliquots available and were tested (from 11 active donors with a median of eight [IQR five to 26] suspensions per donor). No multidrug-resistant organisms were detected in the 170 approved faecal suspensions (one-sided 95% CI 0 to 1·7). cgMLST revealed that all multidrug-resistant organisms were genetically different.

INTERPRETATION

Healthy faeces donors can become colonised with multidrug-resistant organisms during donation activities. Our screening protocol did not result in approval of multidrug-resistant organism-positive faecal suspensions for microbiota transplantation.

FUNDING

None.

Overview: The Ongoing Threat of Antimicrobial Resistance

The effectiveness of antibiotics continues to erode because of the relentless spread of antimicrobial resistance (AMR). Public and private foundations, professional organizations, and international health agencies recognize the threat posed by AMR and have issued calls for action. One of the main drivers of AMR is overprescription of antibiotics, both in human and in veterinary medicine. The One Health concept is a response from a broad group of stakeholders to counter the global health threat posed by AMR. In this article, we discuss current trends in AMR and suggest strategies to mitigate its ongoing dissemination.

Understanding the impact of antibiotic perturbation on the human microbiome

The human gut microbiome is a dynamic collection of bacteria, archaea, fungi, and viruses that performs essential functions for immune development, pathogen colonization resistance, and food metabolism. Perturbation of the gut microbiome's ecological balance, commonly by antibiotics, can cause and exacerbate diseases. To predict and successfully rescue such perturbations, first, we must understand the underlying taxonomic and functional dynamics of the microbiome as it changes throughout infancy, childhood, and adulthood. We offer an overview of the healthy gut bacterial architecture over these life stages and comment on vulnerability to short and long courses of antibiotics. Second, the resilience of the microbiome after antibiotic perturbation depends on key characteristics, such as the nature, timing, duration, and spectrum of a course of antibiotics, as well as microbiome modulatory factors such as age, travel, underlying illness, antibiotic resistance pattern, and diet. In this review, we discuss acute and chronic antibiotic perturbations to the microbiome and resistome in the context of microbiome stability and dynamics. We specifically discuss key taxonomic and resistance gene changes that accompany antibiotic treatment of neonates, children, and adults. Restoration of a healthy gut microbial ecosystem after routine antibiotics will require rationally managed exposure to specific antibiotics and microbes. To that end, we review the use of fecal microbiota transplantation and probiotics to direct recolonization of the gut ecosystem. We conclude with our perspectives on how best to assess, predict, and aid recovery of the microbiome after antibiotic perturbation.

Updated Management Guidelines for Clostridioides difficile in Paediatrics

Clostridioides difficile, formerly known as Clostridium difficile, causes infections (CDI) varying from self-limited diarrhoea to severe conditions, including toxic megacolon and bowel perforation. For this reason, a prompt diagnosis is fundamental to early treatment and the prevention of transmission. The aim of this article is to review diagnostic laboratory methods that are now available to detect C. difficile and to discuss the most recent recommendations on CDI treatment in children. Currently, there is no consensus on the best method for detecting C. difficile. Indeed, none of the available diagnostics possess at the same time high sensitivity and specificity, low cost and rapid turnaround times. Appropriate therapy is targeted according to age, severity and recurrence of the episode of infection, and the recent availability of new antibiotics opens new opportunities. De-escalation of antibiotics that are directly associated with CDI remains a priority and the cautious use of probiotics is recommended. Vancomycin represents the first-line therapy for CDI, although in children metronidazole can still be used as a first-line drug. Fidaxomicin is a new treatment option with equivalent initial response rates as vancomycin but lower relapse rates of CDI. Faecal microbiota transplantation should be considered for patients with multiple recurrences of CDI. Monoclonal antibodies and vaccines seem to represent a future perspective against CDI. However, only further studies will permit us to understand whether these new approaches could be effective in therapy and prevention of CDI in paediatric populations.

Fecal microbiota transplantation ameliorates active ulcerative colitis

Ulcerative colitis (UC) is a complex chronic pathological condition of the gut in which microbiota targeted treatment, such as fecal microbiota transplantation (FMT), has shown an encouraging effect. The aim of the present study was to investigate the efficacy and safety of FMT in patients with mild or moderate UC. A single-center, open-label study was designed, including 47 patients with mild or moderate active UC who received three treatments of fresh FMT via colonic transendoscopic enteral tubing within 1 week. The inflammatory bowel disease questionnaire, partial Mayo scores, colonoscopy, erythrocyte sedimentation rate, C-reactive protein level and procalcitoin values were used to assess the efficacy of FMT and alteration in gut microbiota was detected by 16S ribosomal RNA-sequencing. Before FMT, microbiota Faecalibacterium prausnitzii (F. prausnitzii) levels were significantly decreased in patients with UC compared with healthy donors (P<0.01). At 4 weeks post-FMT, F. prausnitzii levels were significantly increased (P<0.05), and the Mayo score was significantly decreased (1.91±1.07 at baseline vs. 4.02±1.47 at week 4; P<0.001) in patients with UC compared with healthy donors. Steroid-free clinical responses were reported in 37 patients (84.1%), and steroid-free clinical remission was achieved in 31 patients (70.5%) at week 4 post-FMT, however, steroid-free remission was not achieved in any patient. No adverse events were reported in 41 (93.2%) patients after FMT or during the 12-week follow-up. Shannon's diversity index and Chao1 estimator were also improved in patients with UC receiving FMT. In conclusion, the results of the present study suggested that FMT resulted in clinical remission in patients with mild to moderate UC, and that the remission may be associated with significant alterations to the intestinal microbiota of patients with UC. Furthermore, F. prausnitzii may serve as a diagnostic and therapeutic biomarker for the use of FMT in UC.

The Cancer Microbiome: Distinguishing Direct and Indirect Effects Requires a Systemic View

The collection of microbes that live in and on the human body - the human microbiome - can impact on cancer initiation, progression, and response to therapy, including cancer immunotherapy. The mechanisms by which microbiomes impact on cancers can yield new diagnostics and treatments, but much remains unknown. The interactions between microbes, diet, host factors, drugs, and cell-cell interactions within the cancer itself likely involve intricate feedbacks, and no single component can explain all the behavior of the system. Understanding the role of host-associated microbial communities in cancer systems will require a multidisciplinary approach combining microbial ecology, immunology, cancer cell biology, and computational biology - a systems biology approach.