Microbiota-Based Therapeutics as New Standard-of-Care Treatment for Recurrent Clostridioides difficile Infection.

Background: Clostridioides difficile (C. difficile) is a spore-forming bacterial species that ubiquitously exists in the environment. Colonization by C. difficile is highly prevalent in infants, while fewer than 5% of adults are asymptomatic carriers. Disruption of the microbiome, such as through antibiotic treatment, triggers the germination of bacterial spores into numerous vegetative cells. These cells then produce enterotoxins that result in watery diarrhea and colonic inflammation. If left untreated, C. difficile infection (CDI) can lead to pseudomembranous colitis with the potentially life-threatening complication of toxic megacolon. Summary: Over the past few decades, the incidence, morbidity, and mortality associated with CDIs have increased. They have emerged as the primary cause of nosocomial gastrointestinal infections in industrialized countries, posing a significant burden on healthcare systems. Despite antibiotics often being the cause of CDIs, they remain the standard treatment. However, a considerable number of patients treated with antibiotics will experience recurrent CDI (rCDI). Microbiota-based therapies targeting the core issue of CDI - antibiotic-induced dysbiosis - hold promise for rCDI treatment. While data for probiotics are insufficient, numerous studies have highlighted the effectiveness of fecal microbiota transplantation (FMT) as a safe and viable therapeutic option for rCDI. This approach is now endorsed by multiple guidelines. Nonetheless, regulatory prerequisites, such as comprehensive stool donor screening, restrict the widespread adoption of FMT beyond specialized centers. Recently, the US Food and Drug Administration has approved two commercial microbiota-based therapeutics to prevent CDI recurrence. These therapeutics are available by prescription in the USA. RBX2660 (REBYOTA™) comprises a diverse consortium of live microbes derived from human stool and is administered via enema. On the other hand, SER-109 (VOWST™) is an orally administered spore-based medication. In this review, we discuss the potential of microbiota-based treatments for rCDI against the background of medico-legal challenges associated with classical FMT. Key Messages: FMT has emerged as a highly effective cure for rCDI. Nonetheless, regulatory prerequisites and laborious preparation procedures impede its widespread use. The establishment of ready-to-use microbiota-based therapeutics in clinical practice is necessary. In the USA, the recent approval of the first two commercial medications, including a spore-based oral preparation, marks a significant step forward.

Engraftment of essential functions through multiple fecal microbiota transplants in chronic antibiotic-resistant pouchitis-a case study using metatranscriptomics.

BACKGROUND: Ileal pouch-anal anastomosis (IPAA) is the standard of care after total proctocolectomy for ulcerative colitis (UC). Around 50% of patients will experience pouchitis, an idiopathic inflammatory condition. Antibiotics are the backbone of treatment of pouchitis; however, antibiotic-resistant pouchitis develops in 5-10% of those patients. It has been shown that fecal microbiota transplantation (FMT) is an effective treatment for UC, but results for FMT antibiotic-resistant pouchitis are inconsistent. METHODS: To uncover which metabolic activities were transferred to the recipients during FMT and helped the remission, we performed a longitudinal case study of the gut metatranscriptomes from three patients and their donors. The patients were treated by two to three FMTs, and stool samples were analyzed for up to 140 days. RESULTS: Reduced expression in pouchitis patients compared to healthy donors was observed for genes involved in biosynthesis of amino acids, cofactors, and B vitamins. An independent metatranscriptome dataset of UC patients showed a similar result. Other functions including biosynthesis of butyrate, metabolism of bile acids, and tryptophan were also much lower expressed in pouchitis. After FMT, these activities transiently increased, and the overall metatranscriptome profiles closely mirrored those of the respective donors with notable fluctuations during the subsequent weeks. The levels of the clinical marker fecal calprotectin were concordant with the metatranscriptome data. Faecalibacterium prausnitzii represented the most active species contributing to butyrate synthesis via the acetyl-CoA pathway. Remission occurred after the last FMT in all patients and was characterized by a microbiota activity profile distinct from donors in two of the patients. CONCLUSIONS: Our study demonstrates the clear but short-lived activity engraftment of donor microbiota, particularly the butyrate biosynthesis after each FMT. The data suggest that FMT triggers shifts in the activity of patient microbiota towards health which need to be repeated to reach critical thresholds. As a case study, these insights warrant cautious interpretation, and validation in larger cohorts is necessary for generalized applications. In the long run, probiotics with high taxonomic diversity consisting of well characterized strains could replace FMT to avoid the costly screening of donors and the risk of transferring unwanted genetic material. Video Abstract.

[Fecal microbiota transplantation: indications, risks and opportunities]. / Fäkaler Mikrobiomtransfer ­ Indikationen, Risiken und Chancen.

Fecal microbiome transfer (FMT) involving the transfer of the microbiome of healthy stool donors to patients with various diseases has been performed in Germany in clinical studies and individual treatment attempts. There is no doubt that FMT is an effective therapeutic principle for recurrent Clostridium difficile infection and ulcerative colitis. From a medico-legal point of view, it should be stressed that, in Germany, the microbiome to be transferred is regarded as a drug, the manufacture of which is subject to the Medicines Act and the risk information from the Federal Institute for Drugs and Medical Devices. The background of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and the potential risk of transmitting pathogens must also be considered. There is an obligation to notify the competent state authorities to perform FMTs in the context of individual treatment attempts. In the context of the limited availability and the fundamental problem of infection, future studies aim to identify the therapeutically active components in the microbiome. Recombinant production is the aim. Initial results represent preliminary steps, as these concepts are not yet established in clinical practice.

Transfer of FRozen Encapsulated multi-donor Stool filtrate for active ulcerative Colitis (FRESCO): study protocol for a prospective, multicenter, double-blind, randomized, controlled trial.

BACKGROUND: Ulcerative colitis (UC) is a chronic inflammatory bowel disease with significant morbidity and mortality. Although the precise cause remains unknown, disturbances in the intestinal microbial community have been linked to its pathogenesis. Randomized controlled trials in UC and relapsing Clostridioides difficile infection (CDI) have established fecal microbiota (FM) transfer (FMT) as an effective therapy. In this context, preliminary results indicated that the transfer of sterile fecal microbiota filtrates (<0.2 µm; FMF, FMFT) of donor stool also drives gastrointestinal microbiota changes and eliminates symptoms in CDI patients. However, along with the success of FMT, regulatory agencies issued safety alerts following reports of serious adverse events due to transmission of enteric pathogens through FMT. To reduce this risk, we established an extensive test protocol for our donors and quarantine regulations for the produced capsules, but alternative concepts are desirable. METHODS: Our project is a randomized, controlled, longitudinal, prospective, three-arm, multicenter, double-blind study to determine the safety and efficacy of repeated long-term, multi-donor FM or FMF transfers compared to placebo using oral, frozen capsules in 174 randomized patients with mild to moderate active UC. The primary outcome will be clinical remission at week 12. DISCUSSION: This proposal aims to examine (a) the efficacy of encapsulated transfer of FM and FMF as a therapy for mild to moderate UC, (b) the short- and long-term safety of FMT and FMFT in patients with UC, and (c) the microbial and immunologic changes that occur after FMT and FMFT to help understand how and why it affects inflammatory bowel disease. TRIAL REGISTRATION: ClinicalTrials.gov NCT03843385 . DRKS (Deutsches Register für Klinische Studien) DRKS00020471.

Fecal Microbiota Transfer.

BACKGROUND: Fecal microbiota transfer (FMT) is increasingly being used in Ger- many, as in other countries, for the treatment of recurrent Clostridioides difficile infection (rCDI). FMT is now being performed both for research and in individual patients outside of clinical trials. No compulsory standards have been established to date for donor screening or for the method of fecal transfer. Given the potential dangers of FMT, this would seem to be urgently necessary. METHODS: This review is based on pertinent literature retrieved by a selective search, including the reports of consensus conferences from Germany and abroad. RESULTS: Because of its high efficacy, FMT is the treatment of choice for rCDI. It is largely free of adverse side effects, even in immune-deficient patients, as long as comprehensive and repeated donor screening has been carried out, with extensive clinical and microbiological testing and with the use of structured questionnaires. The ingestion of frozen, encapsulated microbiota is just as effective as other modes of delivery for the treatment of rCDI. CONCLUSION: Encapsulation of the fecal microbiome (FM) and storage at -20°C is the method of choice, because it can be standardized with the necessary quality controls and it is readily available. Patients with rCDI should undergo FMT by orally ingesting the capsules. There are ongoing research efforts to identify the active e FM. It is not yet clear when the ultimate goal of recombinant production can be achieved.

Peritoneal Level of CD206 Associates With Mortality and an Inflammatory Macrophage Phenotype in Patients With Decompensated Cirrhosis and Spontaneous Bacterial Peritonitis.

BACKGROUND & AIMS: Peritoneal macrophages (PMs) regulate inflammation and control bacterial infections in patients with decompensated cirrhosis. We aimed to characterize PMs and associate their activation with outcomes of patients with spontaneous bacterial peritonitis (SBP). METHODS: We isolated PMs from ascites samples of 66 patients with decompensated cirrhosis (19 with SBP) and analyzed them by flow cytometry, quantitative real-time polymerase chain reaction, functional analysis, and RNA microarrays. We used ascites samples of a separate cohort of 111 patients with decompensated cirrhosis (67 with SBP) and quantified the soluble form of the mannose receptor (CD206) and tumor necrosis factor by enzyme-linked immunosorbent assay (test cohort). We performed logistic regression analysis to identify factors associated with 90-day mortality. We validated our findings using data from 71 patients with cirrhosis and SBP. Data from 14 patients undergoing peritoneal dialysis for end-stage renal disease but without cirrhosis were included as controls. RESULTS: We used surface levels of CD206 to identify subsets of large PMs (LPM) and small PMs (SPM), which differed in granularity and maturation markers, in ascites samples from patients with cirrhosis. LPMs vs SPMs from patients with cirrhosis had different transcriptomes; we identified more than 4000 genes that were differentially regulated in LPMs vs SPMs, including those that regulate the cycle, metabolism, self-renewal, and immune cell signaling. LPMs had an inflammatory phenotype, were less susceptible to tolerance induction, and released more tumor necrosis factor than SPMs. LPMs from patients with cirrhosis produced more inflammatory cytokines than LPMs from controls. Activation of PMs by Toll-like receptor agonists and live bacteria altered levels of CD206 on the surface of LPMs and release of soluble CD206. Analysis of serial ascites fluid from patients with SBP revealed loss of LPMs in the early phase of SBP, but levels increased after treatment. In the test and validation cohorts, patients with SBP and higher concentrations of soluble CD206 in ascites fluid (>0.53 mg/L) were less likely to survive for 90 days than those with lower levels. CONCLUSIONS: Surface level of CD206 can be used to identify mature, resident, inflammatory PMs in patients with cirrhosis. Soluble CD206 is released from activated LPMs and increased concentrations in patients with cirrhosis and SBP indicate reduced odds of surviving for 90 days.

[Ulcerative colitis: Does the modulation of gut microbiota induce long-lasting remission?] / Colitis ulcerosa: Kann eine Modulation der intestinalen Mikrobiota eine langfristige Remission bedingen?

Although the pathogenesis of ulcerative colitis (UC) remains elusive, substantial progress in understanding its development and progression has been achieved in the past decades, and novel effective treatment strategies have been developed. Changes in gut microbiota, environmental triggers, deregulation of immunological responses, and genetic predisposition have been identified as pathogenic key factors. There are several lines of clinical observations, which support a close connection of altered gut microbiota with the development and course of UC. Despite a plethora of microbiota alterations in UC, it is currently unclear whether the observed changes in inflammation are cause or effect of the altered microbiota state.Fecal microbiota transplantation (FMT) provides a novel, perhaps complementary, strategy to restore gut microbial diversity, bacterial richness, and microbial homeostasis in UC. FMT is an already established treatment option for recurrent Clostridioides difficile infection, and several case series and randomized controlled trials have described its use in UC. In this review, we evaluate recent efficacy and safety data on FMT for UC, discuss possible pitfalls and show possible areas of future development. Although FMT could become a promising treatment modality for UC, based on currently available data, FMT should be only performed in clinical trials as controlled studies focusing on long-term outcomes and safety are warranted.

High-intensity UV laser ChIP-seq for the study of protein-DNA interactions in living cells.

Genome-wide mapping of transcription factor binding is generally performed by chemical protein-DNA crosslinking, followed by chromatin immunoprecipitation and deep sequencing (ChIP-seq). Here we present the ChIP-seq technique based on photochemical crosslinking of protein-DNA interactions by high-intensity ultraviolet (UV) laser irradiation in living mammalian cells (UV-ChIP-seq). UV laser irradiation induces an efficient and instant formation of covalent "zero-length" crosslinks exclusively between nucleic acids and proteins that are in immediate contact, thus resulting in a "snapshot" of direct protein-DNA interactions in their natural environment. Here we show that UV-ChIP-seq, applied for genome-wide profiling of the sequence-specific transcriptional repressor B-cell lymphoma 6 (BCL6) in human diffuse large B-cell lymphoma (DLBCL) cells, produces sensitive and precise protein-DNA binding profiles, highly enriched with canonical BCL6 DNA sequence motifs. Using this technique, we also found numerous previously undetectable direct BCL6 binding sites, particularly in condensed, inaccessible areas of chromatin.

[Microbiota and Cancer: a "pas de deux"?] / Gastrointestinale Mikrobiota und Tumorerkrankungen ­ ein "pas de deux"?

Malignant diseases pose an enormous challenge to today's health care system. Advanced pathophysiological understanding of gastrointestinal microbiota and a viable, causal relation to the development of malignant tumors is increasingly becoming the focus of medical research. The following article presents key pathomechanisms of reciprocal interaction between microbiota and malignancy and illustrates the associated role of diet.