Treatment of recurrent Clostridium difficile infection: a systematic review

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.

Clostridioides difficile Infection in Children: Recent Updates on Epidemiology, Diagnosis, Therapy

Clostridioides (formerly Clostridium) difficile is the most important infectious cause of antibiotic-associated diarrhea worldwide and a leading cause of healthcare-associated infection in the United States. The incidence of C. difficile infection (CDI) in children has increased, with 20 000 cases now reported annually, also posing indirect educational and economic consequences. In contrast to infection in adults, CDI in children is more commonly community-associated, accounting for three-quarters of all cases. A wide spectrum of disease severity ranging from asymptomatic carriage to severe diarrhea can occur, varying by age. Fulminant disease, although rare in children, is associated with high morbidity and even fatality. Diagnosis of CDI can be challenging as currently available tests detect either the presence of organism or disease-causing toxin but cannot distinguish colonization from infection. Since colonization can be high in specific pediatric groups, such as infants and young children, biomarkers to aid in accurate diagnosis are urgently needed. Similar to disease in adults, recurrence of CDI in children is common, affecting 20% to 30% of incident cases. Metronidazole has long been considered the mainstay therapy for CDI in children. However, new evidence supports the safety and efficacy of oral vancomycin and fidaxomicin as additional treatment options, whereas fecal microbiota transplantation is gaining popularity for recurrent infection. Recent advancements in our understanding of emerging epidemiologic trends and management of CDI unique to children are highlighted in this review. Despite encouraging therapeutic advancements, there remains a pressing need to optimize CDI therapy in children, particularly as it pertains to severe and recurrent disease.

Biochemical Characterizations of the Putative Endolysin Ecd09610 Catalytic Domain from Clostridioides difficile

Clostridioides difficile is the major pathogen of pseudomembranous colitis, and novel antimicrobial agents are sought after for its treatment. Phage-derived endolysins with species-specific lytic activity have potential as novel antimicrobial agents. We surveyed the genome of C. difficile strain 630 and identified an endolysin gene, Ecd09610, which has an uncharacterized domain at the N-terminus and two catalytic domains that are homologous to glucosaminidase and endopeptidase at the C-terminus. Genes containing the two catalytic domains, the glucosaminidase domain and the endopeptidase domain, were cloned and expressed in Escherichia coli as N-terminal histidine-tagged proteins. The purified domain variants showed lytic activity almost specifically for C. difficile, which has a unique peptide bridge in its peptidoglycan. This species specificity is thought to depend on substrate cleavage activity rather than binding. The domain variants were thermostable, and, notably, the glucosaminidase domain remained active up to 100 °C. In addition, we determined the optimal pH and salt concentrations of these domain variants. Their properties are suitable for formulating a bacteriolytic enzyme as an antimicrobial agent. This lytic enzyme can serve as a scaffold for the construction of high lytic activity mutants with enhanced properties.

Characterization of an Endolysin Targeting Clostridioides difficile That Affects Spore Outgrowth

Clostridioides difficile is a spore-forming enteric pathogen causing life-threatening diarrhoea and colitis. Microbial disruption caused by antibiotics has been linked with susceptibility to, and transmission and relapse of, C. difficile infection. Therefore, there is an urgent need for novel therapeutics that are effective in preventing C. difficile growth, spore germination, and outgrowth. In recent years bacteriophage-derived endolysins and their derivatives show promise as a novel class of antibacterial agents. In this study, we recombinantly expressed and characterized a cell wall hydrolase (CWH) lysin from C. difficile phage, phiMMP01. The full-length CWH displayed lytic activity against selected C. difficile strains. However, removing the N-terminal cell wall binding domain, creating CWH_351—656, resulted in increased and/or an expanded lytic spectrum of activity. C. difficile specificity was retained versus commensal clostridia and other bacterial species. As expected, the putative cell wall binding domain, CWH_1—350, was completely inactive. We also observe the effect of CWH_351—656 on preventing C. difficile spore outgrowth. Our results suggest that CWH_351—656 has therapeutic potential as an antimicrobial agent against C. difficile infection.

Factors that influence clinical efficacy of live biotherapeutic products

Traditional probiotics are increasingly being used in a medical context. The use of these products as drugs is considerably different from the traditional use as food or food supplements, as, obviously, the target population is different (diseased versus healthy or at risk population). Besides the target population, also the regulatory context is different, mainly with respect to production, administration regime and type of clinical studies required. In this paper we will, besides the regulatory differences, focus on aspects that may impact the efficacy of a live biotherapeutic product (drug), especially in a clinical setting. The impact of the dosage seems to depend on the strain and the application and may follow some rationale. In contrast, information on the impact of the time of administration or diet, is often still lacking. The matrix and the use of protective measures may clearly have an impact on the survival and efficacy of the strain.

Effect of nitazoxanide on diarrhea: A systematic review and network meta-analysis of randomized controlled trials

We aimed to systematically review evidence pertaining to the safety and efficacy of nitazoxanide in treating infectious diarrhea. On September 21, 2017, we identified relevant studies using 12 databases. The estimates of the included studies were pooled as a risk ratio (RR). We conducted a network and pairwise random-effects meta-analysis for both direct and indirect comparisons of different organisms that are known to cause diarrhea. The primary and secondary analysis outcomes were clinical response until cessation of illness, parasitological response and adverse events. We included 18 studies in our analysis. In cryptosporidiosis, the overall estimate favored nitazoxanide in its clinical response in comparison with placebo RR 1.46 [95% CI 1.22-1.74; P-value <0.0001]. Network meta-analysis among patients with Giardia intestinalis showed an increase in the probability of diarrheal cessation and parasitological responses in comparison with placebo, RR 1.69 [95% CI 1.08-2.64, P-score 0.27] and RR 2.91 [95% CI 1.72-4.91, P-score 0.55] respectively. In Clostridium difficile infection, the network meta-analysis revealed a non-significantly superior clinical response effect of nitazoxanide to metronidazole 31 days after treatment RR 1.21 [95% CI 0.87-1.69, P-score 0.26]. In Entamoeba histolytica, the overall estimate significantly favored nitazoxanide in parasitological response with placebo RR 1.80 [95% CI 1.35-2.40, P-value < 0.001]. We highlighted the effectiveness of nitazoxanide in the cessation of diarrhea caused by Cryptosporidium, Giardia intestinalis and Entamoeba histolytica infection. We also found significant superiority of NTZ to metronidazole in improving the clinical response to G. intestinalis, thus it may be a suitable candidate for treating infection-induced diarrhea. To prove the superiority of NTZ during a C. difficile infection may warrant a larger-scale clinical trial since its superiority was deemed insignificant. We recommend nitazoxanide as an appropriate option for treating infectious diarrhea.

Follow-on RifAximin for the Prevention of recurrence following standard treatment of Infection with Clostridium Difficile (RAPID): a randomised placebo controlled trial

BACKGROUND

Clostridium difficile infection (CDI) recurs after initial treatment in approximately one in four patients. A single-centre pilot study suggested that this could be reduced using 'follow-on' rifaximin treatment. We aimed to assess the efficacy of rifaximin treatment in preventing recurrence.

METHODS

A multisite, parallel group, randomised, placebo controlled trial recruiting patients aged ≥18 years immediately after resolution of CDI through treatment with metronidazole or vancomycin. Participants received either rifaximin 400 mg three times a day for 2 weeks, reduced to 200 mg three times a day for a further 2 weeks or identical placebo. The primary endpoint was recurrence of CDI within 12 weeks of trial entry.

RESULTS

Between December 2012 and March 2016, 151 participants were randomised to either rifaximin or placebo. Primary outcome data were available on 130. Mean age was 71.9 years (SD 15.3). Recurrence within 12 weeks was 29.5% (18/61) among participants allocated to placebo compared with 15.9% (11/69) among those allocated to rifaximin, a difference between groups of 13.7% (95% CI -28.1% to 0.7%, p=0.06). The risk ratio was 0.54 (95% CI 0.28 to 1.05, p=0.07). During 6-month safety follow-up, nine participants died in each group (12%). Adverse event rates were similar between groups.

CONCLUSION

While 'follow-on' rifaximin after CDI appeared to halve recurrence rate, we failed to reach our recruitment target in this group of frail elderly patients, so the estimated effect of rifaximin lacks precision. A meta-analysis including a previous trial suggests that rifaximin may be effective; however, further, larger confirmatory studies are needed.

2019 update of the WSES guidelines for management of Clostridioides (Clostridium) difficile infection in surgical patients

In the last three decades, Clostridium difficile infection (CDI) has increased in incidence and severity in many countries worldwide. The increase in CDI incidence has been particularly apparent among surgical patients. Therefore, prevention of CDI and optimization of management in the surgical patient are paramount. An international multidisciplinary panel of experts from the World Society of Emergency Surgery (WSES) updated its guidelines for management of CDI in surgical patients according to the most recent available literature. The update includes recent changes introduced in the management of this infection.

2019 update of the WSES guidelines for management of Clostridioides (Clostridium) difficile infection in surgical patients

In the last three decades, Clostridium difficile infection (CDI) has increased in incidence and severity in many countries worldwide. The increase in CDI incidence has been particularly apparent among surgical patients. Therefore, prevention of CDI and optimization of management in the surgical patient are paramount. An international multidisciplinary panel of experts from the World Society of Emergency Surgery (WSES) updated its guidelines for management of CDI in surgical patients according to the most recent available literature. The update includes recent changes introduced in the management of this infection.

Guidelines for Antibiotic Prescription in Intensive Care Unit

How to cite this article: Khilnani GC, Zirpe K, Hadda V, Mehta Y, Madan K, Kulkarni A, Mohan A, Dixit S, Guleria R, Bhattacharya P. Guidelines for Antibiotic Prescription in Intensive Care Unit. Indian Journal of Critical Care Medicine 2019;23 (Suppl 1):1-63.

Pre-colonization with the commensal fungus Candida albicans reduces murine susceptibility to Clostridium difficile infection

Clostridium difficile is a major nosocomial pathogen responsible for close to half a million infections and 27,000 deaths annually in the U.S. Preceding antibiotic treatment is a major risk factor for C. difficile infection (CDI) leading to recognition that commensal microbes play a key role in resistance to CDI. Current antibiotic treatment of CDI is only partially successful due to a high rate of relapse. As a result, there is interest in understanding the effects of microbes on CDI susceptibility to support treatment of patients with probiotic microbes or entire microbial communities (e.g., fecal microbiota transplantation). The results reported here demonstrate that colonization with the human commensal fungus Candida albicans protects against lethal CDI in a murine model. Colonization with C. albicans did not increase the colonization resistance of the host. Rather, our findings showed that one effect of C. albicans colonization was to enhance a protective immune response. Mice pre-colonized with C. albicans expressed higher levels of IL-17A in infected tissue following C. difficile challenge compared to mice that were not colonized with C. albicans. Administration of cytokine IL-17A was demonstrated to be protective against lethal murine CDI in mice not colonized with C. albicans. C. albicans colonization was associated with changes in the abundance of some bacterial components of the gut microbiota. Therefore, C. albicans colonization altered the gut ecosystem, enhancing survival after C. difficile challenge. These findings demonstrate a new, beneficial role for C. albicans gut colonization.

Comparing fecal microbiota transplantation to standard-of-care treatment for recurrent Clostridium difficile infection: a systematic review and meta-analysis

BACKGROUND

The use of fecal microbiota transplantation (FMT) as a treatment option for recurrent Clostridium difficile infection (rCDI) is well established. Various studies have used different forms and administration routes for FMT. We performed a systemic review and meta-analysis to update the clinical knowledge about different FMT modalities for curing rCDI compared with medical treatment (MT).

PATIENTS AND METHODS

We searched PubMed and Medline from inception through 10 May 2018 for randomized control trials (RCTs) comparing FMT (fresh or frozen) versus MT. We used Cochrane Collaboration's Risk of Bias tool to assess bias in the RCTs. We estimated odds ratio (OR) with 95% confidence interval (CI) for each outcome using a random effects model. P values of less than 0.05 were considered significant.

RESULTS

We included seven RCTs comprising a total of 543 patients with recurrent CDI. There was a nonsignificant trend toward resolution of diarrhea following a single fresh FMT infusion compared with frozen FMT and MT (OR=2.45, 95% CI=0.78-7.71, P=0.12, I=69%). Subgroup analysis of fresh FMT vs. frozen FMT showed no difference between the two groups (OR=2.13, 95% CI=0.22-20.41, P=0.51, I=61%). Frozen FMT infusion through upper route versus lower route showed no difference (OR=0.62, 95% CI=0.15-2.54, P=0.51, I=0%). There was a nonsignificant trend favoring multiple treatments with FMT versus multiple courses of MT (OR=3.68, 95% CI=0.74-18.22, P=0.11, I=0%).

CONCLUSION

FMT is a promising treatment modality for rCDI compared with MT alone. Different forms and routes of FMT administration seem to be equally efficacious. In future, more well-designed RCTs directed at homogenous FMT preparation and delivery methods are required to validate these findings.

Extended duration vancomycin in recurrent Clostridium difficile infection: a systematic review

Clostridium difficile infections have a high recurrence rate following acute treatment. Extended duration vancomycin (EDV) is a mainstay for the treatment of recurrent Clostridium difficile infections (rCDI). Clinical disease guidelines recommend a variety of different vancomycin treatment regimens though based on weak, low-quality evidence. Patients typically receive an initial vancomycin treatment course of 7-14 days for the acute infection, followed by an extended duration vancomycin course. Multiple publications on the utility of EDV regimens have been published but few include reported effectiveness outcomes associated with a prescribed treatment regimen. The purpose of this review is to evaluate the safety and efficacy data on extended duration vancomycin regimens used in recurrent clostridium treatment. Five articles, three case series and two randomized open-label clinical trials, were identified which included both elements. Outcomes were evaluable in 174 patients, 31 from randomized trials, with prior average recurrent episodes ranging from 3 to 4. Vancomycin dose ranged from 3500 to >6800 mg with therapy durations extending from 21 days to over 60 days. Follow-up duration ranged from 10 weeks to 12 months. Case series reported success rates for EDV in rCDI from 61% to 100%, while randomized trials found lower success rates from 26% to 58%. Taper and pulse regimens reported superior outcomes compared to pulse-only regimens, 58-100% versus 26-81%, respectively. Comparative EDV data is limited. Current available data supports an EDV regimen which includes both a daily dosing taper followed by an every 48 or 72 h pulse.

Probiotic use in clinical practice: Results of a national survey of gastroenterologists and nutritionists

INTRODUCTION AND AIMS

Probiotics are effective in gastrointestinal disease management. In Mexico, there are no studies on the use and prescription of probiotics by healthcare professionals. Our aim was to evaluate probiotic use and prescription on the part of gastroenterologists and nutritionists.

MATERIALS AND METHODS

An online survey questionnaire was sent to members of the Asociación Mexicana de Gastroenterología (n = 1042), the Asociación Mexicana de Nutriología (n = 220), and healthcare professionals registered at the Fourth International Symposium: Intestinal Microbiota (n = 1328).

RESULTS

Response was 34% (997 questionnaires answered) and 570 (64%) of the respondents were women. Mean participant age was 36.2 years (range 18-83). Thirty-six percent of the participants were gastroenterologists, 46% were nutritionists, and 18% were chemists and microbiologists. Seventy-one percent of the respondents knew the Food and Agriculture Organization (FAO) definition of probiotics and recommended them «always» (64.9%), «rarely» (31.7%), and «never» (3.6%). Gastroenterologists indicated probiotics for the treatment of disease (56.5%) and nutritionists for health maintenance (39%). Ninety-seven percent of the gastroenterologists and 98% of the nutritionists evaluated probiotics as effective in gastrointestinal symptom management and considered them safe. The majority of the respondents did not know which probiotic strain was contained in the commercial probiotic product.

CONCLUSIONS

The survey results showed that the participating gastroenterologists and nutritionists understood the concept of probiotics, recommended them frequently, and considered them safe. The gastroenterologists prescribed probiotics as therapeutic agents and the nutritionists to maintain health. There was a lack of knowledge about the microbial composition of the products containing probiotics available in Mexico.

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 being 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 studied conducted to evaluate probiotic products, in combination with antibiotics, in order to select the best candidate for C. difficile infections.

Fecal calprotectin in management of Clostridium difficile infection: a longitudinal study

BACKGROUND

Clostridium difficile infection (CDI) is characterized by a relevant intestinal neutrophil infiltrate. So far, role of fecal calprotectin in CDI, has been investigated only in few studies, mainly focused on diagnosis of the disease.

AIM

By a longitudinal design, we assess fecal calprotectin concentrations (FCCs) in subjects with CDI, evaluating the correlation between fecal marker and response to therapy.

METHODS

Clinical (diarrhea scoring) and laboratory (FCCs and leucocytes count) evaluation was performed in 56 subjects with CDI at time of diagnosis (T₀) and after a week from starting of therapy (T₁). Clinical response to therapy at T₁ was related with both T₀ and T₁ FCC values. FCCs were also related to all-cause 30-day mortality, recurrence and death, both of them within 90 days.

RESULTS

FCCs at T₁ were significantly increased in subjects with persistence of diarrhea in respect to the other ones (285.5 ± 270 µg/g vs 150.7 ± 147 µg/g, respectively; p < .05). Patients who did not respond to therapy showed higher, but not significative, FCCs at T₀ than patients who responded. No correlation was found among FCCs, both at T₀ and T₁, and the other outcomes.

CONCLUSIONS

Longitudinal evaluation of FCCs in patients with CDI could support physicians in clinical management of disease, for example in term of duration (10 vs 14 days) or type (first vs second line therapy). Further and larger studies could confirm the eventual role of this marker in prognostic algorithms, mainly in prediction of recurrence.

Comparison of Different Strategies for Providing Fecal Microbiota Transplantation to Treat Patients with Recurrent Clostridium difficile Infection in Two English Hospitals: A Review

Fecal microbiota transplant (FMT) has emerged as a highly efficacious treatment for difficult cases of refractory and/or recurrent Clostridium difficile infection (CDI). There have been many well-conducted randomized controlled trials and thousands of patients reported in case series that describe success rates of approximately 90% following one or more FMT. Although the exact mechanisms of FMT have yet to be fully elucidated, replacement or restoration of a 'normal' microbiota (or at least a microbiota resembling those who have never had CDI) appears to have a positive effect on the gut dysbiosis that is thought to exist in these patients. Furthermore, despite being aesthetically unappealing, this 'ultimate probiotic' is a particularly attractive solution to a difficult problem that avoids repeated courses of antibiotics. The lack of clarity about the exact mechanism of action and the 'active ingredient' of FMT (e.g., individual or communities of bacteria, bacteriophage, or bioactive molecules such as bile acids) has hindered the ability to produce a standardized and well-characterized FMT product. There is no standard method to produce material for FMT, and there are a multitude of factors that can vary between institutions that offer this therapy. Only a few studies have directly compared clinical efficacy in groups of patients who have been treated with FMT prepared differently (e.g., fresh vs. frozen) or administered by different route (e.g., by nasojejunal tube, colonoscopy or by oral administration of encapsulated product). More of these studies should be undertaken to clarify the superiority or otherwise of these variables. This review describes the methods and protocols that two English NHS hospitals independently adopted over the same time period to provide FMT for patients with recurrent CDI. There are several fundamental differences in the methods used, including selection and testing of donors, procedures for preparation and storage of material, and route of administration. These methods are described in detail in this review highlighting differing practice. Despite these significant methodological variations, clinical outcomes in terms of cure rate appear to be remarkably similar for both FMT providers. Although both hospitals have treated only modest numbers of patients, these findings suggest that many of the described differences may not be critical factors in influencing the success of the procedure. As FMT is increasingly being proposed for a number of conditions other than CDI, harmonization of methods and techniques may be more critical to the success of FMT, and thus it will be important to standardize these as far as practically possible.

Treatment of recurrent Clostridium difficile colitis: a narrative review

Clostridium difficile is a gram-positive, spore-forming, obligate anaerobic bacillus that was originally isolated from the stool of a healthy neonate in 1935. In high-income countries, C. difficile is the most common cause of infectious diarrhoea in hospitalized patients. The incidence of C. difficile infection in the USA has increased markedly since 2000, with hospitalizations for C. difficile infections in non-pregnant adults doubling between 2000 and 2010. Between 20% and 35% of patients with C. difficile infection will fail initial antibiotic treatment and, of these, 40-60% will have a second recurrence. Recurrence of C. difficile infection after initial treatment causes substantial morbidity and is a major burden on health care systems. In this article, current treatments for recurrent C. difficile infection are reviewed and future directions explored. These include the use of antibiotics, probiotics, donor faecal transplants, anion resins, secondary bile acids or anti-toxin antibodies.

Faecal microbiota transplantation: a regulatory hurdle?

During faecal microbiota transplantation, stool from a healthy donor is transplanted to treat a variety of dysbiosis-associated gut diseases. Competent authorities are faced with the challenge to provide adequate regulation. Currently, regulatory harmonization is completely lacking and authorities apply non-existing to most stringent requirements. A regulatory approach for faecal microbiota transplantation could be inserting faecal microbiota transplantation in the gene-, cell- and tissue regulations, including the hospital exemption system in the European Advanced Therapy Medicinal Products regulation, providing a pragmatic and efficacy-risk balanced approach and granting all patients as a matter of principle access to this therapy.

Existing and investigational therapies for the treatment of Clostridium difficile infection: A focus on narrow spectrum, microbiota-sparing agents

Despite intense international attention and efforts to reduce its incidence, Clostridium difficile infection (CDI) remains a significant concern for patients, clinicians, and healthcare organizations. It is costly for payers and disabling for patients. Furthermore, recurrent CDI is particularly difficult to manage, resulting in excess mortality, hospital length of stay, and other healthcare resource use. A greater understanding of the role of the gut microbiome has emphasized the importance of this diverse community in providing colonization resistance against CDI. The introduction of fidaxomicin, which has limited effect on the microflora has improved clinical outcomes in relation to disease recurrence. There are a number of other new agents in development, which appear to have a narrow spectrum of activity whilst exerting minimal effect on the microflora. Whilst the role of these emerging agents in the treatment of CDI is presently unclear, they appear to be promising candidates.

Systematic review with meta-analysis: the efficacy of faecal microbiota transplantation for the treatment of recurrent and refractory Clostridium difficile infection

BACKGROUND

Clostridium difficile infection (CDI) is the commonest nosocomial cause of diarrhoea. Faecal microbiota transplantation (FMT) is an approved treatment for recurrent or refractory CDI but there is uncertainty about its use.

AIM

To evaluate the efficacy of FMT in treating recurrent and refractory CDI and investigate outcomes from modes of delivery and preparation.

METHODS

A systematic review and meta-analysis was performed. MEDLINE, EMBASE, CINAHL, Cochrane Library, trial registers and conference proceedings were searched. Studies on FMT in recurrent and refractory CDI were included. The primary outcome was clinical resolution with subgroup analyses of modes of delivery and preparation. Random effects meta-analyses were used to combine data.

RESULTS

Thirty seven studies were included; seven randomised controlled trials and 30 case series. FMT was more effective than vancomycin (RR: 0.23 95%CI 0.07-0.80) in resolving recurrent and refractory CDI. Clinical resolution across all studies was 92% (95%CI 89%-94%). A significant difference was observed between lower GI and upper GI delivery of FMT 95% (95%CI 92%-97%) vs 88% (95%CI 82%-94%) respectively (P=.02). There was no difference between fresh and frozen FMT 92% (95%CI 89%-95%) vs 93% (95%CI 87%-97%) respectively (P=.84). Administering consecutive courses of FMT following failure of first FMT resulted in an incremental effect. Donor screening was consistent but variability existed in recipient preparation and volume of FMT. Serious adverse events were uncommon.

CONCLUSION

Faecal microbiota transplantation is an effective treatment for recurrent and refractory Clostridium difficile infection, independent of preparation and route of delivery.

Cost-Effectiveness of Fecal Microbiota Transplantation in the Treatment of Recurrent Clostridium Difficile Infection: A Literature Review

Clostridium difficile (C. difficile) is a common cause of antibiotic-­associated diarrhea (AAD), being responsible for 15­-25% of all AAD cases. The purpose of this literature review is to determine the cost-effectiveness of fecal microbiota transplantation (FMT) and how it compares in this regard to the standard treatments of choice for recurrent C. difficile infection (CDI). The review of the literature along with the evaluation of three comparative cost effective analyses yielded findings consistent with the view that FMT is the most cost-effective option in treating recurrent CDI. There are some (but considerably less) data indicating that FMT may be a cost effective strategy in treating initial CDI, as well. The superior cost-effectiveness of FMT as compared to the preferred standards of treatment for recurrent CDI suggest FMT use should become more integrated in routine clinical practice. Increased utilization of FMTs would allow for better control of this increasingly problematic disease as well as lower costs associated with its management.

The chemical disruption of human metabolism

BACKGROUND

Recent evidence highlights the reality of unprecedented human exposure to toxic chemical agents found throughout our environment - in our food and water supply, in the air we breathe, in the products we apply to our skin, in the medical and dental materials placed into our bodies, and even within the confines of the womb. With biomonitoring confirming the widespread bioaccumulation of myriad toxicants among population groups, expanding research continues to explore the pathobiological impact of these agents on human metabolism.

METHODS

This review was prepared by assessing available medical and scientific literature from Medline as well as by reviewing several books, toxicology journals, government publications, and conference proceedings. The format of a traditional integrated review was chosen.

RESULTS

Toxicant exposure and accrual has been linked to numerous biochemical and pathophysiological mechanisms of harm. Some toxicants effect metabolic disruption via multiple mechanisms.

CONCLUSIONS

As a primary causative determinant of chronic disease, toxicant exposures induce metabolic disruption in myriad ways, which consequently result in varied clinical manifestations, which are then categorized by health providers into innumerable diagnoses. Chemical disruption of human metabolism has become an etiological determinant of much illness throughout the lifecycle, from neurodevelopmental abnormalities in-utero to dementia in the elderly.

The Mexican consensus on probiotics in gastroenterology

INTRODUCTION

Probiotics are frequently prescribed in clinical practice. Their efficacy in treating gastrointestinal disorders is supported by a significant number of clinical trials. However, the correct prescription of these agents is hampered due to a lack of knowledge of the scientific evidence and to the different presentations and microbial compositions of the probiotics that are currently available.

AIM

To provide the clinician with a consensus review of probiotics and recommendations for their use in gastroenterology.

MATERIALS AND METHODS

Controlled clinical trials, meta-analyses, and systematic reviews published up to 2015 were selected, using the MESH terms: probiotics, gastrointestinal diseases, humans, adults, AND children. The Delphi method was employed. Eighteen gastroenterologists treating adult patients and 14 pediatric gastroenterologists formulated statements that were voted on until agreement>70% was reached. The level of evidence based on the GRADE system was evaluated for each statement.

RESULTS AND CONCLUSIONS

Eleven statements on the general concepts of probiotics and 27 statements on the use of probiotics in gastrointestinal diseases in both adults and children were formulated. The consensus group recommends the use of probiotics under the following clinical conditions: the prevention of diarrhea associated with antibiotics, the treatment of acute infectious diarrhea, the prevention of Clostridium difficile infection and necrotizing enterocolitis, the reduction of adverse events from Helicobacter pylori eradication therapy, relief from irritable bowel syndrome symptoms, the treatment of functional constipation in the adult, and the induction and maintenance of remission in patients with ulcerative colitis and pouchitis, and the treatment of covert and overt hepatic encephalopathy.

Australasian Society of Infectious Diseases updated guidelines for the management of Clostridium difficile infection in adults and children in Australia and New Zealand

The incidence of Clostridium difficile infection (CDI) continues to rise, whilst treatment remains problematic due to recurrent, refractory and potentially severe nature of disease. The treatment of C. difficile is a challenge for community and hospital-based clinicians. With the advent of an expanding therapeutic arsenal against C. difficile since the last published Australasian guidelines, an update on CDI treatment recommendations for Australasian clinicians was required. On behalf of the Australasian Society of Infectious Diseases, we present the updated guidelines for the management of CDI in adults and children.

A review of dose-responses of probiotics in human studies

The probiotic definition requires the administration of an 'adequate amount' in order to obtain a health benefit. What that amount should be is not indicated. Here, an overview is given of studies that investigated the dose-response relation of probiotics in human interventions. Studies were divided in; meta-analyses, meta-analyses on specific probiotic strains, and studies testing two or more doses of a probiotic (combination) in the same study. Meta-analyses on the effect of probiotics on antibiotic associated diarrhoea (AAD) suggest a dose-response effect; for Clostridium difficile-associated diarrhoea on the other hand no dose-response was observed. For other end-points; such as necrotising enterocolitis, prevention of atopic dermatitis and slow intestinal transit, no dose-response relation was identified in meta-analyses. For prophylaxis in colorectal cancer and relief of irritable bowel syndrome, no dose-response relation was determined. However, for blood pressure, a meta-analysis observed that higher doses (greater than 10¹¹ cfu) were more effective than lower doses. Meta-analyses of specific strains suggest a break-point for effectiveness of Lactobacillus rhamnosus GG in the treatment of acute gastroenteritis in children; no dose-response was observed for two other probiotics assessed. Studies comparing two or more doses indicate that faecal recovery and risk reduction of AAD follow a positive dose-response relationship. Other end-points such as immune markers, general health, and bowel function did not exhibit clear dose-response relations. For AAD, the findings are very compelling; both meta-analyses and dedicated dose-response studies observe a positive correlation between dose and AAD risk. These findings do not allow for extrapolation, but suggest that studying higher doses for this end-point would be worthwhile. The lack of a clear dose-response for other end-points, does not mean it does not exist; present data does just not allow drawing any conclusions.

Cellular and molecular effects of yeast probiotics on cancer

The cancer is one of the main causes of human deaths worldwide. The exact mechanisms of initiation and progression of malignancies are not clear yet, but there is a common agreement about the role of colonic microbiota in the etiology of different cancers. Probiotics have been examined for their anti-cancer effects, and different mechanisms have been suggested about their antitumor functions. Nonpathogenic yeasts, as members of probiotics family, can be effective on gut microbiota dysbiosis. Generally safe yeasts have shown so many beneficial effects on human health. Probiotic yeasts influence physiology, metabolism, and immune homeostasis in the colon and contribute to cancer treatment due to possessing anti-inflammatory, anti-proliferative and anti-cancer properties. This study reviews some of the health-beneficial effects of probiotic yeasts and their biological substances like folic acid and β-glucan on cancer and focuses on the possible cellular and molecular mechanisms of probiotic yeasts such as influencing pathogenic bacteria, inactivation of carcinogenic compounds, especially those derived from food, improvement of intestinal barrier function, modulation of immune responses, antitoxic function, apoptosis, and anti-proliferative effects.

A case of multiple recurrence of Clostridium difficile infection with severe hematochezia in an immunocompromised host

Clostridium difficile infection (CDI) is increasing in incidence and severity. Clinically, diarrhea frequently occurs, but severe hematochezia is rarely seen with CDI. We describe here a hematopoietic stem cell transplantation (HSCT) recipient who experienced life-threatening gastrointestinal bleeding due to severe CDI. Subsequent stool surveillance and molecular typing observed the patient who had two episodes of recurrence with a new strain of C. difficile distinct from the initial infection. We analyze C. difficile strains obtained from the patient, and also discuss the diagnosis and treatment of this case.

Fecal Microbiota Therapy for Clostridium difficile Infection: A Health Technology Assessment

BACKGROUND

Fecal microbiota therapy is increasingly being used to treat patients with Clostridium difficile infection. This health technology assessment primarily evaluated the effectiveness and cost-effectiveness of fecal microbiota therapy compared with the usual treatment (antibiotic therapy).

METHODS

We performed a literature search using Ovid MEDLINE, Embase, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, CRD Health Technology Assessment Database, Cochrane Central Register of Controlled Trials, and NHS Economic Evaluation Database. For the economic review, we applied economic filters to these search results. We also searched the websites of agencies for other health technology assessments. We conducted a meta-analysis to analyze effectiveness. The quality of the body of evidence for each outcome was examined according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. Using a step-wise, structural methodology, we determined the overall quality to be high, moderate, low, or very low. We used a survey to examine physicians' perception of patients' lived experience, and a modified grounded theory method to analyze information from the survey.

RESULTS

For the review of clinical effectiveness, 16 of 1,173 citations met the inclusion criteria. A meta-analysis of two randomized controlled trials found that fecal microbiota therapy significantly improved diarrhea associated with recurrent C. difficile infection versus treatment with vancomycin (relative risk 3.24, 95% confidence interval [CI] 1.85-5.68) (GRADE: moderate). While fecal microbiota therapy is not associated with a significant decrease in mortality compared with antibiotic therapy (relative risk 0.69, 95% CI 0.14-3.39) (GRADE: low), it is associated with a significant increase in adverse events (e.g., short-term diarrhea, relative risk 30.76, 95% CI 4.46-212.44; abdominal cramping, relative risk 14.81, 95% CI 2.07-105.97) (GRADE: low). For the value-for-money component, two of 151 economic evaluations met the inclusion criteria. One reported that fecal microbiota therapy was dominant (more effective and less expensive) compared with vancomycin; the other reported an incremental cost-effectiveness ratio of $17,016 USD per quality-adjusted life-year for fecal microbiota therapy compared with vancomycin. This ratio for the second study indicated that there would be additional cost associated with each recurrent C. difficile infection resolved. In Ontario, if fecal microbiota therapy were adopted to treat recurrent C. difficile infection, considering it from the perspective of the Ministry of Health and Long-Term Care as the payer, an estimated $1.5 million would be saved after the first year of adoption and $2.9 million after 3 years. The contradiction between the second economic evaluation and the savings we estimated may be a result of the lower cost of fecal microbiota therapy and hospitalization in Ontario compared with the cost of therapy used in the US model. Physicians reported that C. difficile infection significantly reduced patients' quality of life. Physicians saw fecal microbiota therapy as improving patients' quality of life because patients could resume daily activities. Physicians reported that their patients were happy with the procedures required to receive fecal microbiota therapy.

CONCLUSIONS

In patients with recurrent C. difficile infection, fecal microbiota therapy improves outcomes that are important to patients and provides good value for money.

Cost-effectiveness analysis of fecal microbiota transplantation for recurrent Clostridium difficile infection

OBJECTIVE

Clostridium difficile infection (CDI) places a high burden on the US healthcare system. Recurrent CDI (RCDI) occurs frequently. Recently proposed guidelines from the American College of Gastroenterology (ACG) and the American Gastroenterology Association (AGA) include fecal microbiota transplantation (FMT) as a therapeutic option for RCDI. The purpose of this study was to estimate the cost-effectiveness of FMT compared with vancomycin for the treatment of RCDI in adults, specifically following guidelines proposed by the ACG and AGA.

DESIGN

We constructed a decision-analytic computer simulation using inputs from the published literature to compare the standard approach using tapered vancomycin to FMT for RCDI from the third-party payer perspective. Our effectiveness measure was quality-adjusted life years (QALYs). Because simulated patients were followed for 90 days, discounting was not necessary. One-way and probabilistic sensitivity analyses were performed.

RESULTS

Base-case analysis showed that FMT was less costly ($1,669 vs $3,788) and more effective (0.242 QALYs vs 0.235 QALYs) than vancomycin for RCDI. One-way sensitivity analyses showed that FMT was the dominant strategy (both less expensive and more effective) if cure rates for FMT and vancomycin were ≥70% and <91%, respectively, and if the cost of FMT was <$3,206. Probabilistic sensitivity analysis, varying all parameters simultaneously, showed that FMT was the dominant strategy over 10, 000 second-order Monte Carlo simulations.

CONCLUSIONS

Our results suggest that FMT may be a cost-saving intervention in managing RCDI. Implementation of FMT for RCDI may help decrease the economic burden to the healthcare system.

Long-term changes of bacterial and viral compositions in the intestine of a recovered Clostridium difficile patient after fecal microbiota transplantation

Fecal microbiota transplantation (FMT) is an effective treatment for recurrent Clostridium difficile infections (RCDIs). However, long-term effects on the patients' gut microbiota and the role of viruses remain to be elucidated. Here, we characterized bacterial and viral microbiota in the feces of a cured RCDI patient at various time points until 4.5 yr post-FMT compared with the stool donor. Feces were subjected to DNA sequencing to characterize bacteria and double-stranded DNA (dsDNA) viruses including phages. The patient's microbial communities varied over time and showed little overall similarity to the donor until 7 mo post-FMT, indicating ongoing gut microbiota adaption in this time period. After 4.5 yr, the patient's bacteria attained donor-like compositions at phylum, class, and order levels with similar bacterial diversity. Differences in the bacterial communities between donor and patient after 4.5 yr were seen at lower taxonomic levels. C. difficile remained undetectable throughout the entire timespan. This demonstrated sustainable donor feces engraftment and verified long-term therapeutic success of FMT on the molecular level. Full engraftment apparently required longer than previously acknowledged, suggesting the implementation of year-long patient follow-up periods into clinical practice. The identified dsDNA viruses were mainly Caudovirales phages. Unexpectedly, sequences related to giant algae-infecting Chlorella viruses were also detected. Our findings indicate that intestinal viruses may be implicated in the establishment of gut microbiota. Therefore, virome analyses should be included in gut microbiota studies to determine the roles of phages and other viruses-such as Chlorella viruses-in human health and disease, particularly during RCDI.

The Monoclonal Antitoxin Antibodies (Actoxumab-Bezlotoxumab) Treatment Facilitates Normalization of the Gut Microbiota of Mice with Clostridium difficile Infection

Antibiotics have significant and long-lasting impacts on the intestinal microbiota and consequently reduce colonization resistance against Clostridium difficile infection (CDI). Standard therapy using antibiotics is associated with a high rate of disease recurrence, highlighting the need for novel treatment strategies that target toxins, the major virulence factors, rather than the organism itself. Human monoclonal antibodies MK-3415A (actoxumab-bezlotoxumab) to C. difficile toxin A and toxin B, as an emerging non-antibiotic approach, significantly reduced the recurrence of CDI in animal models and human clinical trials. Although the main mechanism of protection is through direct neutralization of the toxins, the impact of MK-3415A on gut microbiota and its restoration has not been examined. Using a CDI murine model, we compared the bacterial diversity of the gut microbiome of mice under different treatments including MK-3415A, vancomycin, or vancomycin combined with MK-3415A, sampled longitudinally. Here, we showed that C. difficile infection resulted in the prevalence of Enterobacter species. Sixty percent of mice in the vehicle group died after 2 days and their microbiome was almost exclusively formed by Enterobacter. MK-3415A treatment resulted in lower Enterobacter levels and restoration of Blautia, Akkermansia, and Lactobacillus which were the core components of the original microbiota. Vancomycin treatment led to significantly lower survival rate than the combo treatment of MK-3415A and vancomycin. Vancomycin treatment decreased bacterial diversity with predominant Enterobacter and Akkermansia, while Staphylococcus expanded after vancomycin treatment was terminated. In contrast, mice treated by vancomycin combined with MK-3415A also experienced decreased bacterial diversity during vancomycin treatment. However, these animals were able to recover their initial Blautia and Lactobacillus proportions, even though episodes of Staphylococcus overgrowth were detected by the end of the experiments. In conclusion, MK-3415A (actoxumab-bezlotoxumab) treatment facilitates normalization of the gut microbiota in CDI mice. It remains to be examined whether or not the prevention of recurrent CDI by the antitoxin antibodies observed in clinical trials occurs through modulation of microbiota.

Adverse events in faecal microbiota transplant: a review of the literature

BACKGROUND

Faecal microbiota transplant (FMT) is the infusion of donor faeces into the gut with the aim of improving microbial diversity. The procedure has gained significant interest recently in the treatment of recurrent Clostridium difficile infection (CDI). The literature is currently dominated by small case series and isolated case reports. There is no standardization of methods and recording of outcomes.

AIM

To present the adverse events that have been associated with the use of FMT, as reported in the English literature to date.

METHODS

A database search of Medline and Embase identified publications where FMT has been administered. Review articles were excluded. In total, 109 publications were identified that described the use of FMT in 1555 individuals.

FINDINGS

Other than three small randomized controlled studies, the data consisted of small series and case reports. CDI was the most common indication for FMT (N = 1190), with the majority of the remaining cases receiving FMT for inflammatory bowel disease. FMT had also been applied for irritable bowel syndrome, metabolic syndrome and constipation in small numbers. Adverse events appear to be uncommon, often mild and self-limiting; however, serious adverse events including bacteraemia, perforations and death have been reported.

CONCLUSION

The vast majority of adverse events of FMT appear to be mild, self-limiting and gastrointestinal in nature. In some cases, a credible association was not established due to the lack of controlled data. There is a need for standardized, randomized controlled trials to qualify and quantify the risks associated with FMT.

Immune-based treatment and prevention of Clostridium difficile infection

Clostridium difficile (C. difficile) causes over 500,000 infections per year in the US, with an estimated 15,000 deaths and an estimated cost of $1-3 billion. Moreover, a continual rise in the incidence of severe C. difficile infection (CDI) has been observed worldwide. Currently, standard treatment for CDI is the administration of antibiotics. While effective, these treatments do not prevent and may contribute to a disease recurrence rate of 15-35%. Prevention of recurrence is one of the most challenging aspects in the field. A better knowledge of the molecular mechanisms of the disease, the host immune response and identification of key virulence factors of C. difficilenow permits the development of immune-based therapies. Antibodies specific for C. difficile toxins have been shown to effectively treat CDI and prevent disease relapse in animal models and in humans. Vaccination has been recognized as the most cost-effective treatment/prevention for CDI. This review will summarize CDI transmission, epidemiology, major virulent factors and highlights the rational and the development of immune-based approaches against this remerging threat.

Using a Novel Lysin To Help Control Clostridium difficile Infections

As a consequence of excessive antibiotic therapies in hospitalized patients, Clostridium difficile, a Gram-positive anaerobic spore-forming intestinal pathogen, is the leading cause of hospital-acquired diarrhea and colitis. Drug treatments for these diseases are often complicated by antibiotic-resistant strains and a high frequency of treatment failures and relapse; therefore, novel nonantibiotic approaches may prove to be more effective. In this study, we recombinantly expressed a prophage lysin identified from a C. difficile strain, CD630, which we named PlyCD. PlyCD was found to have lytic activity against specific C. difficile strains. However, the recombinantly expressed catalytic domain of this protein, PlyCD1-174, displayed significantly greater lytic activity (>4-log kill) and a broader lytic spectrum against C. difficile strains while still retaining a high degree of specificity toward C. difficile versus commensal clostridia and other bacterial species. Our data also indicated that noneffective doses of vancomycin and PlyCD1-174 when combined in vitro could be significantly more bactericidal against C. difficile. In an ex vivo treatment model of mouse colon infection, we found that PlyCD1-174 functioned in the presence of intestinal contents, significantly decreasing colonizing C. difficile compared to controls. Together, these data suggest that PlyCD1-174 has potential as a novel therapeutic for clinical application against C. difficile infection, either alone or in combination with other preexisting treatments to improve their efficacy.

WSES guidelines for management of Clostridium difficile infection in surgical patients

In the last two decades there have been dramatic changes in the epidemiology of Clostridium difficile infection (CDI), with increases in incidence and severity of disease in many countries worldwide. The incidence of CDI has also increased in surgical patients. Optimization of management of C difficile, has therefore become increasingly urgent. An international multidisciplinary panel of experts prepared evidenced-based World Society of Emergency Surgery (WSES) guidelines for management of CDI in surgical patients.

Cost-effectiveness analysis of treatment strategies for initial Clostridium difficile infection

Clostridium difficile infection (CDI) is costly. Current guidelines recommend metronidazole as first-line therapy and vancomycin as an alternative. Recurrence is common. Faecal microbiota transplantation (FMT) is an effective therapy for recurrent CDI (RCDI). This study explores the cost-effectiveness of FMT, vancomycin and metronidazole for initial CDI. We constructed a decision-analytic computer simulation using inputs from published literature to compare FMT with a 10-14-day course of oral metronidazole or vancomycin for initial CDI. Parameters included cure rates (baseline value (range)) for metronidazole (80% (65-85%)), vancomycin (90% (88-92%)) and FMT(91% (83-100%)). Direct costs of metronidazole, vancomycin and FMT, adjusted to 2011 dollars, were $57 ($43-72), $1347 ($1195-1499) and $1086 ($815-1358), respectively. Our effectiveness measure was quality-adjusted life years (QALYs). One-way and probabilistic sensitivity analyses were conducted from the third-party payer perspective. Analysis using baseline values showed that FMT($1669, 0.242 QALYs) dominated (i.e. was less costly and more effective) vancomycin ($1890, 0.241 QALYs). FMT was more costly and more effective than metronidazole ($1167, 0.238 QALYs), yielding an incremental cost-effectiveness ratio (ICER) of $124 964/QALY. One-way sensitivity analyses showed that metronidazole dominated both strategies if its probability of cure were >90%; FMT dominated if it cost <$584. In a probabilistic sensitivity analysis at a willingness-to-pay threshold of $100 000/QALY, metronidazole was favoured in 55% of model iterations; FMT was favoured in 38%. Metronidazole, as the first-line treatment for CDIs, is less costly. FMT and vancomycin are more effective. However, FMT is less likely to be economically favourable, and vancomycin is unlikely to be favourable as first-line therapy when compared with FMT.

Recurrent Clostridium difficile infection: From colonization to cure

Clostridium difficile infection (CDI) is increasingly prevalent, dangerous and challenging to prevent and manage. Despite intense national and international attention the incidence of primary and of recurrent CDI (PCDI and RCDI, respectively) have risen rapidly throughout the past decade. Of major concern is the increase in cases of RCDI resulting in substantial morbidity, morality and economic burden. RCDI management remains challenging as there is no uniformly effective therapy, no firm consensus on optimal treatment, and reliable data regarding RCDI-specific treatment options is scant. Novel therapeutic strategies are critically needed to rapidly, accurately, and effectively identify and treat patients with, or at-risk for, RCDI. In this review we consider the factors implicated in the epidemiology, pathogenesis and clinical presentation of RCDI, evaluate current management options for RCDI and explore novel and emerging therapies.

Dietary Supplement Use in Patients With Celiac Disease in the United States

BACKGROUND

There has been increasing interest in the use of complementary and alternative medicine (CAM) in the general population. Little is known about CAM use in patients with celiac disease (CD).

GOALS

We aimed to determine the demographics and clinical characteristics of patients with biopsy-proven CD who use dietary supplements to treat their symptoms.

STUDY

CD patients completed a questionnaire on demographics, types of dietary supplement use, attitudes toward CAM, and 3 validated scales: CD-related Quality Of Life (CD-QOL), the CD Symptoms Index (CSI), and the CD Adherence Test (CDAT).

RESULTS

Of 423 patients, 100 (23.6%) used dietary supplements to treat CD symptoms. The most frequently used supplement was probiotics (n=59). Supplement users had a higher CD-QOL score (75.06 vs. 71.43, P=0.04) but had more symptoms based on CSI (35.64 vs. 32.05, P=0.0032). On multivariable analysis, adjusting for age, sex, education, symptom improvement following a gluten-free diet, and where the survey was completed, patients presenting with classic symptoms (OR, 2.56; 95% CI, 1.01-6.44) or nonclassic symptoms (OR, 2.75; 95% CI, 1.04-7.24) were significantly more likely to use supplements than those with asymptomatic/screen-detected CD.

CONCLUSIONS

Patients with biopsy-proven CD who have symptoms at diagnosis tend to use dietary supplements more than those that are screen detected. Those using supplements report persistent symptoms, but a higher quality of life. The contribution of the gluten-free diet and supplement use to quality of life in the symptomatic CD patient needs to be determined.

Probiotic Saccharomyces cerevisiae strains as biotherapeutic tools: is there room for improvement?

The probiotic yeast Saccharomyces cerevisiae var boulardii is widely used as a low cost and efficient adjuvant against gastrointestinal tract disorders such as inflammatory bowel disease and treatment of several types of diarrhea, both in humans and animals. S. boulardii exerts its protective mechanisms by binding and neutralizing enteric pathogens or their toxins, by reducing inflammation and by inducing the secretion of sIgA. Although several S. cerevisiae strains have proven probiotic potential in both humans and animals, only S. boulardii is currently licensed for use in humans. Recently, some researchers started using S. boulardii as heterologous protein expression systems. Combined with their probiotic activity, the use of these strains as prophylactic and therapeutic proteins carriers might result in a positive combined effort to fight specific diseases. Here, we provide an overview of the current use of S. cerevisiae strains as probiotics and their mechanisms of action. We also discuss their potential to produce molecules with biotherapeutic application and the advantages and hurdles of this approach. Finally, we suggest future directions and alternatives for which the combined effort of specific immunomodulatory effects of probiotic S. cerevisiae strains and ability to express desired foreign genes would find a practical application.

Clostridium difficile infection: current, forgotten and emerging treatment options

Clostridium difficile infection (CDI) has increased in incidence and severity, and is now among the most common nosocomial infections. Several agents are available for the initial treatment of CDI, some of which are rarely used, and none of which is clearly superior for initial clinical cure. Fidaxomicin appears to offer a benefit in terms of preventing recurrent disease, although the cost-benefit ratio is debated. Recurrent CDI is a major challenge, occurring after 15-30% of initial episodes. The treatment of recurrent CDI is difficult, with sparse evidence available to support any particular agent. Fecal microbiota therapy, also known as 'stool transplantation', appears to be highly effective, although availability is currently limited, and the regulatory environment is in flux. Synthetic stool products and an orally available fecal microbiota therapy product are both under investigation, which may address the problem of availability. As with most infectious diseases, an effective vaccine would be a welcome addition to our armamentarium, but none is currently available.

Fecal microbiota transplantation (FMT) for Clostridium difficile infection: focus on immunocompromised patients

Clostridium difficile infection (CDI) is an emerging problem worldwide associated with significant morbidity, mortality, recurrence rates and healthcare costs. Immunosuppressed patients, including HIV-seropositive individuals, solid organ transplant recipients, patients with malignancies, hematopoietic stem cell transplant recipients, and patients with inflammatory bowel disease are increasingly recognized as being at higher risk of developing CDI where it may be associated with significant complications, recurrence, and mortality. Fecal microbiota transplantation (FMT) has proven to be an effective and safe procedure for the treatment of recurrent or refractory CDI in immunocompetent patients by restoring the gut microbiota and resistance to further recurrences. During the last two years the first data on FMT in immunocompromised patients began to appear in the medical literature. Herein we summarize the use of FMT for the treatment of CDI with a focus on immunocompromised patients.

Diagnosis and treatment of Clostridium difficile in adults: a systematic review

IMPORTANCE

Since 2000, the incidence and severity of Clostridium difficile infection (CDI) have increased.

OBJECTIVE

To review current evidence regarding best practices for the diagnosis and treatment of CDI in adults (age ≥ 18 years).

EVIDENCE REVIEW

Ovid MEDLINE and Cochrane databases were searched using keywords relevant to the diagnosis and treatment of CDI in adults. Articles published between January 1978 and October 31, 2014, were selected for inclusion based on targeted keyword searches, manual review of bibliographies, and whether the article was a guideline, systematic review, or meta-analysis published within the past 10 years. Of 4682 articles initially identified, 196 were selected for full review. Of these, the most pertinent 116 articles were included. Clinical trials, large observational studies, and more recently published articles were prioritized in the selection process.

FINDINGS

Laboratory testing cannot distinguish between asymptomatic colonization and symptomatic infection with C difficile. Diagnostic approaches are complex due to the availability of multiple testing strategies. Multistep algorithms using polymerase chain reaction (PCR) for the toxin gene(s) or single-step PCR on liquid stool samples have the best test performance characteristics (for multistep: sensitivity was 0.68-1.00 and specificity was 0.92-1.00; and for single step: sensitivity was 0.86-0.92 and specificity was 0.94-0.97). Vancomycin and metronidazole are first-line therapies for most patients, although treatment failures have been associated with metronidazole in severe or complicated cases of CDI. Recent data demonstrate clinical success rates of 66.3% for metronidazole vs 78.5% for vancomycin for severe CDI. Newer therapies show promising results, including fidaxomicin (similar clinical cure rates to vancomycin, with lower recurrence rates for fidaxomicin, 15.4% vs vancomycin, 25.3%; P = .005) and fecal microbiota transplantation (response rates of 83%-94% for recurrent CDI).

CONCLUSIONS AND RELEVANCE

Diagnostic testing for CDI should be performed only in symptomatic patients. Treatment strategies should be based on disease severity, history of prior CDI, and the individual patient's risk of recurrence. Vancomycin is the treatment of choice for severe or complicated CDI, with or without adjunctive therapies. Metronidazole is appropriate for mild disease. Fidaxomicin is a therapeutic option for patients with recurrent CDI or a high risk of recurrence. Fecal microbiota transplantation is associated with symptom resolution of recurrent CDI but its role in primary and severe CDI is not established.