Regulatory oversight and safety of probiotic use

Prebiotics and Probiotics in Digestive Health

As the importance of the gut microbiota in health and disease is increasingly recognized interest in interventions that can modulate the microbiota and its interactions with its host has soared. Apart from diet, prebiotics and probiotics represent the most commonly used substances taken in an effort to sustain a healthy microbiome or restore balance when it is believed bacterial homeostasis has been disturbed in disease. While a considerable volume of basic science attests to the ability of various prebiotic molecules and probiotic strains to beneficially influence host immune responses, metabolic processes and neuro-endocrine pathways, the evidence base from human studies leaves much to be desired. This translational gap owes much to the manner in which this sector is regulated but also speaks to the challenges that confront the investigator who seeks to explore microbiota modulation in either healthy populations or those who suffer from common digestive ailments. For many products marketed as probiotics, some of the most fundamental issues relating to quality control, such as characterization, formulation, viability safety are scarcely addressed.

Necrotizing Enterocolitis and the Preterm Infant Microbiome

Bacterial colonization patterns in preterm infants differ from those of their term counterparts due to maternal microbial diversity, delivery mode, feeding methods, antibiotic use, and exposure to commensal microbiota and pathogens in the neonatal intensive care unit (NICU). Early gut microbiome dysbiosis predisposes neonates to necrotizing enterocolitis (NEC), a devastating intestinal disease with high morbidity and mortality. Though mechanisms of NEC pathogenesis are not fully understood, the microbiome is a promising therapy target for prevention and treatment. Direct administration of probiotics to preterm infants has been shown to reduce the incidence of NEC, but is not without risk. The immature immune systems of preterm infants leave them vulnerable to even beneficial bacteria. Further research is required to investigate both short-term and long-term effects of probiotic administration to preterm infants. Other methods of altering the preterm infant microbiome must also be considered, including breastfeeding, prebiotics, and targeting the maternal microbiome.

Probiotic supplements might not be universally-effective and safe: A review

Last few decades have witnessed the unprecedented growth in the application of probiotics for promoting the general gut health as well as their inception as biotherapeutics to alleviate certain clinical disorders related to dysbiosis. While numerous studies have substantiated the health-restoring potentials for a restricted group of microbial species, the marketed extrapolation of a similar probiotic label to a large number of partially characterized microbial formulations seems biased. In particular, the individuals under neonatal stages and/or those with some clinical conditions including malignancies, leaky gut, diabetes mellitus, and post-organ transplant convalescence likely fail to reap the benefits of probiotics. Further exacerbating the conditions, some probiotic strains might take advantage of the weak immunity in these vulnerable groups and turn into opportunistic pathogens engendering life-threatening pneumonia, endocarditis, and sepsis. Moreover, the unregulated and rampant use of probiotics potentially carry the risk of plasmid-mediated antibiotic resistance transfer to the gut infectious pathogens. In this review, we discuss the safety perspectives of probiotics and their therapeutic interventions in certain at-risk population groups. The embodied arguments and hypotheses certainly will shed light on the fact why probiotic usage should be treated with caution.

Application of Saccharomyces cerevisiae var. boulardii in food processing: a review

Probiotics are increasingly being added to food in order to develop products with health-promoting properties. Particularly, Saccharomyces cereviceae var. boulardii yeast is recently being investigated like a starting-culture for development of functional and probiotic foods. Although the literature is abundant on the beneficial effects of S. boulardii on health, slight information is available on the effects of supplementing this probiotic to food systems. The aim of this paper is to examine the applications of S. boulardii to different food matrices and its implication in food processing (stability, sensorial properties and other technological implications) and the concomitant effects on nutrition and health.

The Genus Enterococcus: Between Probiotic Potential and Safety Concerns-An Update

A considerable number of strains belonging to different species of Enterococcus are highly competitive due to their resistance to wide range of pH and temperature. Their competitiveness is also owed to their ability to produce bacteriocins recognized for their wide-range effectiveness on pathogenic and spoilage bacteria. Enterococcal bacteriocins have attracted great research interest as natural antimicrobial agents in the food industry, and as a potential drug candidate for replacing antibiotics in order to treat multiple drugs resistance pathogens. However, the prevalence of virulence factors and antibiotic-resistance genes and the ability to cause disease could compromise their application in food, human and animal health. From the current regulatory point of view, the genus Enterococcus is neither recommended for the QPS list nor have GRAS status. Although recent advances in molecular biology and the recommended methods for the safety evaluation of Enterococcus strains allowed the distinction between commensal and clinical clades, development of highly adapted methods and legislations are still required. In the present review, we evaluate some aspects of Enterococcus spp. related to their probiotic properties and safety concerns as well as the current and potential application in food systems and treatment of infections. The regulatory status of commensal Enterococcus candidates for food, feed, probiotic use, and recommended methods to assess and ensure their safety are also discussed.

Clinical translation of microbe-based therapies: Current clinical landscape and preclinical outlook

Next generation microbe-based therapeutics, inspired by the success of fecal microbiota transplants, are being actively investigated in clinical trials to displace or eliminate pathogenic microbes to treat various diseases in the gastrointestinal tract, skin, and vagina. Genetically engineered microbes are also being investigated in the clinic as drug producing factories for biologic delivery, which can provide a constant local source of drugs. In either case, microbe-therapeutics have the opportunity to address unmet clinical needs and open new areas of research by reducing clinical side effects associated with current treatment modalities or by facilitating the delivery of biologics. This review will discuss examples of past and current clinical trials that are investigating microbe-therapeutics, both microbiome-modulating and drug-producing, for the treatment of a range of diseases. We then offer a perspective on how preclinical approaches, both those focused on developing advanced delivery systems and those that use in vitro microbiome model systems to inform formulation design, will lead to the realization of next-generation microbe-therapeutics.

The microbiome in cancer immunotherapy: Diagnostic tools and therapeutic strategies

The fine line between human health and disease can be driven by the interplay between host and microbial factors. This "metagenome" regulates cancer initiation, progression, and response to therapies. Besides the capacity of distinct microbial species to modulate the pharmacodynamics of chemotherapeutic drugs, symbiosis between epithelial barriers and their microbial ecosystems has a major impact on the local and distant immune system, markedly influencing clinical outcome in cancer patients. Efficacy of cancer immunotherapy with immune checkpoint antibodies can be diminished with administration of antibiotics, and superior efficacy is observed with the presence of specific gut microbes. Future strategies of precision medicine will likely rely on novel diagnostic and therapeutic tools with which to identify and correct defects in the microbiome that compromise therapeutic efficacy.

Probiotics and Disease: A Comprehensive Summary-Part 9, Cancer

This article provides a literature review of the disease-specific probiotic strains associated with cancer. The literature review was restricted to research in both humans and animals. This is not an exhaustive review. The table design allows for quick access to supportive data and will be helpful as a guide for both researchers and clinicians. The goal of the probiotics and disease series is to provide clinically useful tools. The first article part 1 focused on mental health and neurological conditions; the second article part 2 explored cultured and fermented foods that are commonly available in the United States; part 3 explored the relationship between bacterial strains and 2 of the most prevalent diseases we have in modern society: cardiometabolic disease and fatigue syndromes; part 4 elucidated the role of the microbiome in infectious diseases; part 5 explored respiratory conditions of the ears, nose, and throat; part 6 explored the relationship between microbiota and skin disorders; part 7 reviewed allergy and autoimmune disease; and part 8 examined gastrointestinal and genitourinary conditions. This ninth article reviews the relationship between microbiota and cancer development and prognosis. This literature review is specific to disease condition, probiotic classification, and individual strain.

Probiotics and Disease: A Comprehensive Summary-Part 8, Gastrointestinal and Genitourinary Disorders

This article series provides a literature review of the disease-specific probiotic strains associated with gastrointestinal and genitourinary disorders studied in published clinical trials in humans and animals. This is not an exhaustive review. The table design allows for quick access to supportive data and will be helpful as a guide for both researchers and clinicians. The goal of the probiotics and disease series is to provide clinically useful tools. The first article (part 1) focused on mental health and neurological conditions; the second article (part 2) explored cultured and fermented foods that are commonly available in the United States; the third article (part 3) explored the relationship between bacterial strains and 2 of the most prevalent diseases we have in modern society: cardiometabolic disease and fatigue syndromes; the fourth article (part 4) elucidated the role of the microbiome in infectious diseases; the fifth article (part 5) explored respiratory conditions of the ears, nose, and throat; and the sixth article (part 6) explored the relationship between beneficial microbiota and skin disorders. The seventh article (part 7) reviewed the relationship between beneficial microbiota and autoimmune diseases, allergies, asthma, and other immunity-related disorders. This article (part 8) will explore the unique relationship between bacterial strains and gastrointestinal and genitourinary diseases associated with dysbiosis. Future articles will review the influence of the microbiome on cancer development and prognosis, followed by an article focused on probiotic supplements. This literature review is specific to disease condition, probiotic classification, and individual strain.

Probiotics and Disease: A Comprehensive Summary-Part 7, Immune Disorders

This article series provides a literature review of the disease-specific probiotic strains associated with immune and autoimmune conditions that have been studied in published clinical trials in humans and animals. This is not an exhaustive review. The table design allows for quick access to supportive data and will be helpful as a guide for both researchers and clinicians. The goal of the probiotics and disease series is to provide clinically useful tools. The first article (part 1) focused on mental health and neurological conditions, and the second article (part 2) explored cultured and fermented foods that are commonly available in the United States. The third article (part 3) explored the relationship between bacterial strains and 2 of the most prevalent diseases we have in modern society: cardiometabolic disease and fatigue syndromes. The fourth article (part 4) elucidated the role of the microbiome in infectious diseases, and the fifth article (part 5) examined respiratory conditions of the ears, nose, and throat. The sixth article (part 6) explored the relationship between beneficial microbiota and skin disorders. This seventh article (part 7) reviews the relationship between beneficial microbiota and autoimmune diseases, allergies, asthma, and other immunity-related disorders. Future articles will review the relationship between probiotics and skin disorders, the influence of the microbiome on cancer development and prognosis, and gastrointestinal and genitourinary diseases associated with dysbiosis, followed by an article focused on probiotic supplements. This literature review is specific to disease condition, probiotic classification, and individual strain.

Randomised controlled trial of Lactobacillus rhamnosus (LGG) versus placebo in children presenting to the emergency department with acute gastroenteritis: the PECARN probiotic study protocol

INTRODUCTION

Acute gastroenteritis (AGE) is a common and burdensome condition that affects millions of children worldwide each year. Currently available strategies are limited to symptomatic management, treatment and prevention of dehydration and infection control; no disease-modifying interventions exist. Probiotics, defined as live microorganisms beneficial to the host, have shown promise in improving AGE outcomes, but existing studies have sufficient limitations such that the use of probiotics cannot currently be recommended with confidence. Here we present the methods of a large, rigorous, randomised, double-blind placebo-controlled study to assess the effectiveness and side effect profile of Lactobacillus rhamnosus GG (LGG) (ATCC 53103) in children with AGE.

METHODS AND ANALYSIS

The study is being conducted in 10 US paediatric emergency departments (EDs) within the federally funded Pediatric Emergency Care Applied Research Network, in accordance with current SPIRIT and CONSORT statement recommendations. We will randomise 970 children presenting to participating EDs with AGE to either 5 days of treatment with LGG (10¹⁰colony-forming unit twice a day) or placebo between July 2014 to December 2017. The main outcome is the occurrence of moderate-to-severe disease over time, as defined by the Modified Vesikari Scale. We also record adverse events and side effects related to the intervention. We will conduct intention-to-treat analyses and use an enrichment design to restore the statistical power in case the presence of a subpopulation with a substantially low treatment effect is identified.

ETHICS AND DISSEMINATION

Institutional review board approval has been obtained at all sites, and data and material use agreements have been established between the participating sites. The results of the trial will be published in peer-reviewed journals. A deidentified public data set will be made available after the completion of all study procedures.

TRIAL REGISTRATION NUMBER

NCT01773967.

Implementation of Global Strategies to Prevent Hospital-Onset Clostridium difficile Infection: Targeting Proton Pump Inhibitors and Probiotics

Background: Proton pump inhibitors (PPIs) have been identified as a significant risk factor for the development of Clostridium difficile infection (CDI). Probiotics given concurrently with antibiotics have been shown to have a moderate impact on preventing CDI. Objective: To evaluate the effectiveness of hospital-wide interventions designed to reduce PPI use and increase probiotics and whether these interventions were associated with a change in the incidence of hospital onset (HO)-CDI. Methods: This retrospective cohort study compared 2 fiscal years: July 2013 to June 2014 (FY14) and July 2014 to June 2015 (FY15). In July of FY15, global educational initiatives were launched targeting PPIs. Additionally, a HO-CDI prevention bundle was added to antibiotic-containing order sets targeting probiotics. Overall PPI use, probiotic use, and incidence of HO-CDI were recorded and compared for each cohort. Charts were also reviewed for patients who developed HO-CDI for the presence and appropriateness of a PPI and presence of probiotics. Results: The interventions resulted in a decrease in PPI use by 14% or 96 doses/1000 patient days (TPD; P = 0.0002) and a reduction in IV PPI use by 31% or 71 doses/TPD ( P = 0.0008). Probiotic use increased by 130% or 126 doses/TPD ( P = 0.0006). The incidence of HO-CDI decreased by 20% or 0.1 cases/TPD ( P = 0.04). Conclusions: A collaborative, multifaceted educational initiative directed at highlighting the risks associated with PPI use was effective in reducing PPI prescribing. The implementation of a probiotic bundle added to antibiotic order sets was effective in increasing probiotic use. These interventions were associated with a decrease in incidence of HO-CDI.

Probiotics and Disease: A Comprehensive Summary-Part 6, Skin Health

This article series provides a literature review of the disease-specific probiotic strains associated with dermatological disorders and conditions that have been studied in published clinical trials in humans and animals. This is not an exhaustive review. The table design allows for quick access to supportive data and will be helpful as a guide for both researchers and clinicians. The goal of the probiotics and disease series is to provide clinically useful tools. The first article (part 1) focused on mental health and neurological conditions, and the second article (part 2) explored cultured and fermented foods that are commonly available in the United States. The third article (part 3) explored the relationship between bacterial strains and 2 of the most prevalent diseases we have in modern society: cardiometabolic disease and fatigue syndromes. The fourth article (part 4) elucidated the role of the microbiome in infectious diseases, and the fifth article (part 5) examined respiratory conditions and conditions of the ears, nose, and throat. This sixth article (part 6) article explores the relationship between the microbiome and skin disorders. Future articles will review conditions related to autoimmunity and dermatological conditions; the influence of the microbiome on cancer development and prognosis, gastrointestinal and genitourinary diseases associated with dysbiosis conditions; followed by an article focused on probiotic supplements. This literature review is specific to disease condition, probiotic classification, and individual strain.

Shaping functional gut microbiota using dietary bioactives to reduce colon cancer risk

Colon cancer is a multifactorial disease associated with a variety of lifestyle factors. Alterations in the gut microbiota and the intestinal metabolome are noted during colon carcinogenesis, implicating them as critical contributors or results of the disease process. Diet is a known determinant of health, and as a modifier of the gut microbiota and its metabolism, a critical element in maintenance of intestinal health. This review summarizes recent evidence demonstrating the role and responses of the intestinal microbiota during colon tumorigenesis and the ability of dietary bioactive compounds and probiotics to impact colon health from the intestinal lumen to the epithelium and systemically. We first describe changes to the intestinal microbiome, metabolome, and epithelium associated with colon carcinogenesis. This is followed by a discussion of recent evidence indicating how specific classes of dietary bioactives, prebiotics, or probiotics affect colon carcinogenesis. Lastly, we briefly address the prospects of using multiple 'omics' techniques to integrate the effects of diet, host, and microbiota on colon tumorigenesis with the goal of more fully appreciating the interconnectedness of these systems and thus, how these approaches can be used to advance personalized nutrition strategies and nutrition research.

Probiotics and Disease: A Comprehensive Summary-Part 5, Respiratory Conditions of the Ears, Nose, and Throat

This article series provides a literature review of the disease-specific probiotic strains studied in published clinical trials in humans and animals. The goal of the series is to provide clinically useful tools. The table design allows for quick access to supportive data and will be helpful as a guide for both researchers and clinicians. The first article (part 1) focused on mental health and neurological conditions and the second article (part 2) explored cultured and fermented foods that are commonly available in the United States. The third article (part 3) explored the relationship between bacterial strains and 2 of the most prevalent diseases we have in modern society, cardiometabolic disease and fatigue syndromes. The fourth article (part 4) elucidated the role of the microbiome in infectious diseases, and this fifth article (part 5) investigates probiotic strains on respiratory conditions that affect the ears, nose, and throat. Future articles will review conditions related to autoimmunity and dermatological conditions; the influence of the microbiome on cancer development and prognosis; gastrointestinal and genitourinary diseases associated with dysbiosis conditions; followed by an article focused on probiotic supplements. This literature review is specific to disease condition, probiotic classification, and individual strain.

Probiotics, fibre and herbal medicinal products for functional and inflammatory bowel disorders

Functional bowel disorders (FBD), mainly irritable bowel syndrome (IBS) and functional constipation (FC, also called chronic idiopathic constipation), are very common worldwide. Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, although less common, has a strong impact on patients' quality of life, as well as being highly expensive for our healthcare. A definite cure for those disorders is still yet to come. Over the years, several therapeutic approaches complementary or alternative to traditional pharmacological treatments, including probiotics, prebiotics, synbiotics, fibre and herbal medicinal products, have been investigated for the management of both groups of diseases. However, most available studies are biased by several drawbacks, including small samples and poor methodological quality. Probiotics, in particular Saccharomyces boulardii and Lactobacilli (among which Lactobacillus rhamnosus), synbiotics, psyllium, and some herbal medicinal products, primarily peppermint oil, seem to be effective in ameliorating IBS symptoms. Synbiotics and fibre seem to be beneficial in FC patients. The probiotic combination VSL#3 may be effective in inducing remission in patients with mild-to-moderate ulcerative colitis, in whom Escherichia coli Nissle 1917 seems to be as effective as mesalamine in maintaining remission. No definite conclusions can be drawn as to the efficacy of fibre and herbal medicinal products in IBD patients due to the low number of studies and the lack of randomized controlled trials that replicate the results obtained in the individual studies conducted so far. Thus, further, well-designed studies are needed to address the real role of these therapeutic options in the management of both FBD and IBD.

LINKED ARTICLES

This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.

Probiotics and Disease: A Comprehensive Summary-Part 4, Infectious Diseases

This article series provides a literature review of the disease-specific probiotic strains studied in published clinical trials in humans and animals. The goal of the series is to provide clinically useful tools. The table design allows for quick access to supportive data and will be helpful as a guide for both researchers and clinicians. The first article (part 1) focused on mental health and neurological conditions and the second article (part 2) explored cultured and fermented foods that are commonly available in the United States. The third article (part 3) explored the relationship between bacterial strains and 2 of the most prevalent diseases we have in modern society, cardiometabolic disease and fatigue syndromes. This fourth article (part 4) elucidates the role of the microbiome in infectious diseases. Future articles will review conditions related to infections of the upper respiratory system and ear, nose, and throat; autoimmunity and dermatological conditions; cancer; and gastrointestinal and genitourinary, followed by an article focused on probiotic supplements. This literature review is specific to disease condition, probiotic classification, and individual strain.

Enhanced Probiotic Potential of Lactobacillus reuteri When Delivered as a Biofilm on Dextranomer Microspheres That Contain Beneficial Cargo

As with all orally consumed probiotics, the Gram-positive bacterium Lactobacillus reuteri encounters numerous challenges as it transits through the gastrointestinal tract of the host, including low pH, effectors of the host immune system, as well as competition with commensal and pathogenic bacteria, all of which can greatly reduce the availability of live bacteria for therapeutic purposes. Recently we showed that L. reuteri, when adhered in the form of a biofilm to a semi-permeable biocompatible dextranomer microsphere, reduces the incidence of necrotizing enterocolitis by 50% in a well-defined animal model following delivery of a single prophylactic dose. Herein, using the same semi-permeable microspheres, we showed that providing compounds beneficial to L. reuteri as diffusible cargo within the microsphere lumen resulted in further advantageous effects including glucosyltransferase-dependent bacterial adherence to the microsphere surface, resistance of bound bacteria against acidic conditions, enhanced adherence of L. reuteri to human intestinal epithelial cells in vitro, and facilitated production of the antimicrobial compound reuterin and the anti-inflammatory molecule histamine. These data support continued development of this novel probiotic formulation as an adaptable and effective means for targeted delivery of cargo beneficial to the probiotic bacterium.

Probiotics and Disease: A Comprehensive Summary-Part 3, Cardiometabolic Disease and Fatigue Syndromes

This article series provides a literature review of the disease-specific probiotic strains, associated with cardiometabolic diseases and fatigue syndromes, studied in published clinical trials in humans and animals. This is not an exhaustive review. The table design allows for quick access to supportive data and will be helpful as a guide for both researchers and clinicians. The goal of the probiotics and disease series is to provide clinically useful tools. The first article (part 1) focused on mental health and neurological conditions and the second article (part 2) explored cultured and fermented foods that are commonly available in the United States. This third article (part 3) explores the relationship between bacterial strains and 2 of the most prevalent diseases we have in modern society: cardiometabolic disease and fatigue syndromes. Future articles will review conditions related to respiratory, ear, nose, and throat infections and infectious diseases; autoimmunity and dermatological conditions; cancer; and gastrointestinal and genitourinary, followed by an article focused on probiotic supplements. This literature review is specific to disease condition, probiotic classification, and individual strain.

Probiotic and enterohemorrhagic Escherichia coli: An effective strategy against a deadly enemy?

Enterohemorrhagic Escherichia coli (EHEC) are major food-borne pathogens that constitute a serious public health threat. Currently, there is no specific treatment available for EHEC infections in human creating an urgent need for the development of alternative therapeutic strategies. Among them, one of the most promising approaches is the use of probiotic microorganisms. Even if many studies have shown the antagonistic effects of probiotic bacteria or yeast on EHEC survival, virulence, adhesion on intestinal epithelium or pathogen-induced inflammatory responses, mechanisms mediating their beneficial effects remain unclear. This review describes EHEC pathogenesis and novel therapeutic strategies, with a particular emphasis on probiotics. The interests and limits of a probiotic-based approach and the way it might be incorporated into global health strategies against EHEC infections will be discussed.

An assessment of the future impact of alternative technologies on antibiotics markets

BACKGROUND

The increasing threat of antimicrobial resistance combined with the paucity of new classes of antibiotics represents a serious public health challenge. New treatment technologies could, in theory, have a significant impact on the future use of traditional antibiotics, be it by facilitating rational and responsible use or by product substitution in the existing antibiotics markets, including by reducing the incidence of bacterial infections through preventative approaches. The aim of this paper is to assess the potential of alternative technologies in reducing clinical use of and demand for antibiotics, and to briefly indicate which segments of the antibiotics market that might be impacted by these technologies.

METHODS

An initial mapping exercise to identify the alternative technologies was followed by a review of relevant published and grey literature (n = 52). We also carried out stakeholder engagement activities by a round-table discussion with infectious disease specialists and a multi-criteria decision analysis exercise with pharmaceutical industry experts.

RESULTS

Ten alternative technologies were identified and analyzed for their potential impact on the antibiotics market. Of these, rapid point-of-care diagnostics, vaccines, fecal microbiota transplantation, and probiotics were considered to have a "high" or "medium" potential impact over a 10-20 year horizon. Therapeutic antibodies, antibiotic biomaterials, bacteriophages, antimicrobial nanoparticles, antimicrobial peptides, and anti-virulence materials were rated as having "low" potential impact.

CONCLUSION

Despite the apparent potential of the most promising alternative technologies to reduce demand, that reduction will likely only happen in limited segments of the antibiotics market or, in the case of preventing community acquired streptococcal infections by vaccination, in a low-price generics market segment. Thus, alternative technologies are not expected to represent any disincentive to antibiotics developers. Finally, it is unlikely that alternative technologies will displace the need for new classes, and sub-classes, of antibiotics in the short and medium terms.

Prevention of necrotizing enterocolitis with probiotics: a systematic review and meta-analysis

CONTEXT

Necrotizing enterocolitis (NEC) is the most frequent gastrointestinal emergency in neonates. The microbiome of the preterm gut may regulate the integrity of the intestinal mucosa. Probiotics may positively contribute to mucosal integrity, potentially reducing the risk of NEC in neonates.

OBJECTIVE

To perform an updated systematic review and meta-analysis on the efficacy and safety of probiotics for the prevention of NEC in premature infants.

DATA SOURCES

Structured searches were performed in: Medline, Embase, and the Cochrane Central Register of Controlled Trials (all via Ovid, from 2013 to January 2015). Clinical trial registries and electronically available conference materials were also searched. An updated search was conducted June 3, 2016.

STUDY SELECTION

Randomized trials including infants less than 37 weeks gestational age or less than 2,500 g on probiotic vs. standard therapy.

DATA EXTRACTION

Data extraction of the newly-identified trials with a double check of the previously-identified trials was performed using a standardized data collection tool.

RESULTS

Thirteen additional trials (n = 5,033) were found. The incidence of severe NEC (RR 0.53 95% CI [0.42-0.66]) and all-cause mortality (RR 0.79 95% CI [0.68-0.93]) were reduced. No difference was shown in culture-proven sepsis RR 0.88 95% CI [0.77-1.00].

LIMITATIONS

Heterogeneity of organisms and dosing regimens studied prevent a species-specific treatment recommendation from being made.

CONCLUSIONS

Preterm infants benefit from probiotics to prevent severe NEC and death.

Probiotics and Disease: A Comprehensive Summary-Part 1, Mental and Neurological Health

This article series provides a literature review of the disease-specific probiotic strains studied in published clinical trials in humans and animals. The goal of the series is to provide clinically useful tools. The table designs allow for quick access to supportive data related to disease states and will be helpful as a guide for both researchers and clinicians. This first article (part 1) focuses on mental health and neurological conditions. Future articles in this series will review conditions related to cardiometabolic and fatigue syndromes; ear, nose, throat, respiratory, and infectious diseases; immune and dermatological conditions; cancer, gastrointestinal and genitourinary; followed by an article focused on food-based probiotic strains and nutritional supplements. This literature review is specific to condition, probiotic, and strain and also lists currently available products and foods in which these probiotics can be found. In part 1, we explore the role of probiotics in balancing mental health and neurological issues. Conditions in mental health include anxiety, depression, attention-deficit/hyperactivity disorder, and autism. Neurological conditions include age-related cognitive decline, hepatic encephalopathy, cerebral ischemia and reperfusion, traumatic brain injury, and multiple sclerosis.

Microbiological and molecular characterization of commercially available probiotics containing Bacillus clausii from India and Pakistan

Probiotics are actively used for treatment of diarrhoea, respiratory infections, and prevention of infectious gastrointestinal diseases. The efficacy of probiotics is due to strain-specific features and the number of viable cells; however, several reports of deviations from the label in the actual content of strains in probiotic products are a matter of concern. Most of the available data on quality focuses on probiotic products containing lactobacilli and/or bifidobacteria, while very few data are available on spore-forming probiotics. The present study evaluates the label claims for spore count and species identification in five commercial probiotic products marketed in India and Pakistan that claim to contain Bacillus clausii: Tufpro, Ecogro, Enterogermina, Entromax, and Ospor. Bacterial enumeration from three batches was done by microbiological plating methods by two independent operators. Species identification was done using PCR amplification and sequence analysis of the 16S rRNA gene, and determination of the total amount of species present in the products was done using PCR-denaturing gradient gel electrophoresis (PCR-DGGE) analysis followed by DNA sequencing of the excised bands. Plate count methods demonstrated poor correlations between quantitative label indications and bacteria recovered from plates for Tufpro, Ecogro, and Ospor. The 16S rRNA analysis performed on bacteria isolated from plate counts showed that only Enterogermina and Ospor contained homogenous B. clausii. PCR-DGGE analysis revealed that only Enterogermina had a homogenous B. clausii population while other products had mixed bacterial populations. In conclusion, the current analysis clearly demonstrates that of the five analysed commercial probiotics, only Enterogermina followed the label claims.

Probiotics are helpful in hepatic encephalopathy: a meta-analysis of randomized trials

BACKGROUND

Hepatic encephalopathy (HE) is a major complication of cirrhosis and is associated with decreased survival and increased health care utilization.

AIM

The aim of this study was to evaluate the efficacy of probiotics in the management minimal hepatic encephalopathy HE (MHE) and overt HE (OHE) in comparison to no treatment/placebo and lactulose.

METHODS

The main outcomes measured were mortality, improvement in MHE, progression to OHE in patients with MHE and hospitalization. We calculated odds ratios (OR) with 95% confidence intervals (CI). Study heterogeneity was assessed using the I(2) statistic.

RESULTS

Fourteen studies totalling 1152 patients were included in the analysis. The use of probiotics had no impact on the overall mortality when compared to either lactulose (OR: 1.07, 95% CI: 0.47-2.44, P = 0.88) or no treatment/placebo (OR: 0.69, 95% CI: 0.42-1.14, P = 0.15). When probiotics was compared to no treatment/placebo, it was associated with a significant improvement in MHE (OR: 3.91, 95% CI: 2.25-6.80, P < 0.00001), decreased hospitalization rates (OR: 0.53, 95% CI: 0.33-0.86, P = 0.01) and decreased progression to overt hepatic encephalopathy (OR: 0.40, 95% CI: 0.26-0.60, P < 0.0001). However when compared to lactulose, probiotics did not show a significant difference in improvement of MHE (OR: 0.81, 95% CI: 0.52-1.27, P = 0.35), hospitalization rates (OR: 1.02, 95% CI: 0.52-1.99, P = 0.96) or progression to overt hepatic encephalopathy (OR: 1.24, 95% CI 0.73-2.10, P = 0.42).

CONCLUSIONS

Overall the use of probiotics was more effective in decreasing hospitalization rates, improving MHE and preventing progression to OHE in patients with underlying MHE than placebo, but similar to that seen with lactulose. The use of probiotics did not affect mortality rates.

Prevalence of probiotic use among inpatients: A descriptive study of 145 U.S. hospitals

BACKGROUND

To inform clinical guidance, public health efforts, and research directions, probiotic use in U.S. health care needs to be better understood. This work aimed to assess the prevalence of inpatient probiotic use in a sample of U.S. hospitals.

METHODS

Probiotic use among patients discharged in 2012 was estimated using the MarketScan Hospital Drug Database. In addition, the annual trend in probiotic use (2006-2012) was assessed among a subset of hospitals.

RESULTS

Among 145 hospitals with 1,976,167 discharges in 2012, probiotics were used in 51,723 (2.6%) of hospitalizations occurring in 139 (96%) hospitals. Patients receiving probiotics were 9 times more likely to receive antimicrobials (P < .0001) and 21 times more likely to have a Clostridium difficile infection diagnosis (P < .0001). The most common probiotic formulations were Saccharomyces boulardii (32% of patients receiving probiotics), Lactobacillus acidophilus and Lactobacillus bulgaricus (30%), L acidophilus (28%), and Lactobacillus rhamnosus (11%). Probiotic use increased from 1.0% of 1,090,373 discharges in 2006 to 2.9% of 1,006,051 discharges in 2012 (P < .0001).

CONCLUSIONS

In this sample of U.S. hospitals, a sizable and growing number of inpatients received probiotics as part of their care despite inadequate evidence to support their use in this population. Additional research is needed to guide probiotic use in the hospital setting.

Invasive Fungal Infections Acquired from Contaminated Food or Nutritional Supplements: A Review of the Literature

Fungi are an integral part of the natural environment and, therefore, play many roles in relation to food: some fungi are used in food production, some are food sources themselves, and some are agents of food spoilage. Some fungi that contaminate food can also be harmful to human health. The harmful but noninfectious health consequences of mycotoxins have been well-characterized, but the extent to which fungi in food pose a risk for invasive infections is unknown. We conducted a literature review to identify cases of invasive fungal infections (IFIs) believed to have resulted from ingestion or inhalation of food, beverages, or dietary supplements (excluding Saccharomyces infections). We identified 11 publications describing cases or small outbreaks of IFIs related to foods or beverages and three describing IFIs related to dietary supplements. These food-associated IFIs were predominantly mold infections, and the few yeast infections were associated with dairy products. Suspected foodborne IFIs appear to be rare, but are increasingly described in the electronically searchable literature. They are associated with a variety of foods, are due to a variety of fungal pathogens, and primarily occur in persons with immunosuppressive conditions or other predisposing factors. Various guidelines for high-risk patients recommend avoidance of certain food products that may contain high levels of fungi, but further work is needed to evaluate the effectiveness of these restrictive diets in preventing fungal infections. The relationships between food spoilage, food insecurity, and IFI risk are another area that may warrant further exploration.

Impact of probiotic supplements on microbiome diversity following antibiotic treatment of mice

Shifts in microbial populations of the intestinal tract have been associated with a multitude of nutritional, autoimmune, and infectious diseases. The limited diversity following antibiotic treatments creates a window for opportunistic pathogens, diarrhea, and inflammation as the microbiome repopulates. Depending on the antibiotics used, microbial diversity can take weeks to months to recover. To alleviate this loss of diversity in the intestinal microbiota, supplementation with probiotics has become increasingly popular. However, our understanding of the purported health benefits of these probiotic bacteria and their ability to shape the microbiome is significantly lacking. This study examined the impact of probiotics concurrent with antibiotic treatment or during the recovery phase following antibiotic treatment of mice. We found that probiotics did not appear to colonize the intestine themselves or shift the overall diversity of the intestinal microbiota. However, the probiotic supplementation did significantly change the types of bacteria which were present. In particular, during the recovery phase the probiotic caused a suppression of Enterobacteriaceae outgrowth (Shigella and Escherichia) while promoting a blooming of Firmicutes, particularly from the Anaerotruncus genus. These results indicate that probiotics have a significant capacity to remodel the microbiome of an individual recovering from antibiotic therapy.

Engineering Human Microbiota: Influencing Cellular and Community Dynamics for Therapeutic Applications

The complex relationship between microbiota, human physiology, and environmental perturbations has become a major research focus, particularly with the arrival of culture-free and high-throughput approaches for studying the microbiome. Early enthusiasm has come from results that are largely correlative, but the correlative phase of microbiome research has assisted in defining the key questions of how these microbiota interact with their host. An emerging repertoire for engineering the microbiome places current research on a more experimentally grounded footing. We present a detailed look at the interplay between microbiota and host and how these interactions can be exploited. A particular emphasis is placed on unstable microbial communities, or dysbiosis, and strategies to reestablish stability in these microbial ecosystems. These include manipulation of intermicrobial communication, development of designer probiotics, fecal microbiota transplantation, and synthetic biology.

Assessing worldwide research activity on probiotics in pediatrics using Scopus database: 1994-2014

BACKGROUND

A wide variety of probiotic products has been introduced into the market in the past decade. Research trends and activity on probiotics help understand how these products were evolved and their potential future role in medicine. The objective of this study was to assess the research activity on probiotics in pediatrics using bibliometric indicators and network visualization.

METHODS

Original and review articles on probiotics in pediatrics published worldwide were retrieved from SciVerse, Scopus (1994-2014) and analyzed. VOSviewer was used for network visualization.

RESULTS

The total number of documents published on probiotics in pediatrics was 2817. Research activity on probiotics in pediatrics showed approximately 90- fold increase during the study period. Approximately 22 % of published articles originated from USA and has the greatest share, however, Finland ranked first when data were stratified by population or income. The most productive institution in this field was Turku University in Finland with 82 (2.91 %) articles. Half of the prolific authors were also from Finland. Most of the published research activity appeared in Journal of Pediatric Gastroenterology and Nutrition. Most frequently encountered title terms include nutrition, infant formula, necrotizing enetrocolitis, allergy, and diarrhea. The total number of citations for the retreived documents documents was 70991, and the average citation per article was 25.20.

CONCLUSIONS

Interest in probiotic research and its potential benefits in pediatric ailments is relatively recent but significantly increasing. Bibliometric analysis can be used as an indicator of the importance and growth of probiotic use in pediatrics.

Probiotics and Fecal Microbiota Transplant for Primary and Secondary Prevention of Clostridium difficile Infection

Clostridium difficile infection (CDI) is the most common cause of nosocomial diarrhea and is associated with an increased risk of mortality. The use of probiotics and fecal microbiota transplantation (FMT) has been studied to reduce the incidence and severity of this infection, but variable efficacy and safety data have been reported. Probiotics are hypothesized to be effective in the management of CDI through a number of mechanisms that include maintenance of normal gastrointestinal flora, antimicrobial and antitoxin properties, and immunomodulatory effects. Despite promising results in small trials and meta-analyses, prospective, randomized, controlled trials have not demonstrated probiotics to be effective in the primary prevention of C. difficile-associated diarrhea (CDAD). Probiotics may be effective for secondary prevention in patients with recurrent CDI, but guidelines acknowledge the lack of compelling evidence. Trials are limited by the use of varying types of strains, numbers of strains, and doses of probiotics, as well the definitions of CDI and CDAD. FMT has been proposed as a method for restoring gut microbiota and has been shown to significantly increase the rate of cure in patients with recurrent CDI. Current studies have demonstrated minimal adverse effects, with no reports of transmission of infectious diseases; however, the optimal delivery method, sample preparation, and donor selection remain unclear. In this review, findings from recent literature are highlighted, and guideline recommendations for the use of these agents in the primary and secondary prevention of CDI are summarized.

Probiotics for Antibiotic-Associated Diarrhoea (PAAD): a prospective observational study of antibiotic-associated diarrhoea (including Clostridium difficile-associated diarrhoea) in care homes

BACKGROUND

Antibiotic prescribing rates in care homes are higher than in the general population. Antibiotics disrupt the normal gut flora, sometimes causing antibiotic-associated diarrhoea (AAD). Clostridium difficile (Hall and O'Toole 1935) Prévot 1938 is the most commonly identified cause of AAD. Little is known either about the frequency or type of antibiotics prescribed in care homes or about the incidence and aetiology of AAD in this setting.

OBJECTIVES

The Probiotics for Antibiotic-Associated Diarrhoea (PAAD) study was designed as a two-stage study. PAAD stage 1 aimed to (1) prospectively describe antibiotic prescribing in care homes; (2) determine the incidence of C. difficile carriage and AAD (including C. difficile-associated diarrhoea); and (3) to consider implementation challenges and establish the basis for a sample size estimation for a randomised controlled trial (RCT) of probiotic administration with antibiotics to prevent AAD in care homes. If justified by PAAD stage 1, the RCT would be implemented in PAAD stage 2. However, as a result of new evidence regarding the clinical effectiveness of probiotics on the incidence of AAD, a decision was taken not to proceed with PAAD stage 2.

DESIGN

PAAD stage 1 was a prospective observational cohort study in care homes in South Wales with up to 12 months' follow-up for each resident.

SETTING

Recruited care homes had management and owner's agreement to participate and three or more staff willing to take responsibility for implementing the study.

PARTICIPANTS

Eleven care homes were recruited, but one withdrew before any residents were recruited. A total of 279 care home residents were recruited to the observational study and 19 withdrew, 16 (84%) because of moving to a non-participating care home.

MAIN OUTCOME MEASURES

The primary outcomes were the rate of antibiotic prescribing, incidence of AAD, defined as three or more loose stools (type 5-7 on the Bristol Stool Chart) in a 24-hour period, and C. difficile carriage confirmed on stool culture.

RESULTS

Stool samples were obtained at study entry from 81% of participating residents. Over half of the samples contained antibiotic-resistant isolates, with Enterobacteriaceae resistant to ciprofloxacin in 47%. Residents were prescribed an average of 2.16 antibiotic prescriptions per year [95% confidence interval (CI) 1.90 to 2.46]. Antibiotics were less likely to be prescribed to residents from dual-registered homes. The incidence of AAD was 0.57 (95% CI 0.41 to 0.81) episodes per year among those residents who were prescribed antibiotics. AAD was more likely in residents who were prescribed co-amoxiclav than other antibiotics and in those residents who routinely used incontinence pads. AAD was less common in residents from residential homes.

CONCLUSIONS

Care home residents, particularly in nursing homes, are frequently prescribed antibiotics and often experience AAD. Antibiotic resistance, including ciprofloxacin resistance, is common in Enterobacteriaceae isolated from the stool of care home residents. Co-amoxiclav is associated with greater risk of AAD than other commonly prescribed antibiotics.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN 7954844.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 18, No. 63. See the NIHR Journals Library website for further project information.

Progress and challenges in developing metabolic footprints from diet in human gut microbial cometabolism

Homo sapiens harbor trillions of microbes, whose microbial metagenome (collective genome of a microbial community) using omic validation interrogation tools is estimated to be at least 100-fold that of human cells, which comprise 23,000 genes. This article highlights some of the current progress and open questions in nutrition-related areas of microbiome research. It also underscores the metabolic capabilities of microbial fermentation on nutritional substrates that require further mechanistic understanding and systems biology approaches of studying functional interactions between diet composition, gut microbiota, and host metabolism. Questions surrounding bacterial fermentation and degradation of dietary constituents (particularly by Firmicutes and Bacteroidetes) and deciphering how microbial encoding of enzymes and derived metabolites affect recovery of dietary energy by the host are more complex than previously thought. Moreover, it is essential to understand to what extent the intestinal microbiota is subject to dietary control and to integrate these data with functional metabolic signatures and biomarkers. Many lines of research have demonstrated the significant role of the gut microbiota in human physiology and disease. Probiotic and prebiotic products are proliferating in the market in response to consumer demand, and the science and technology around these products are progressing rapidly. With high-throughput molecular technologies driving the science, studying the bidirectional interactions of host-microbial cometabolism, epithelial cell maturation, shaping of innate immune development, normal vs. dysfunctional nutrient absorption and processing, and the complex signaling pathways involved is now possible. Substantiating the safety and mechanisms of action of probiotic/prebiotic formulations is critical. Beneficial modulation of the human microbiota by using these nutritional and biotherapeutic strategies holds considerable promise as next-generation drugs, vaccinomics, and metabolic agents and in novel food discovery.

The involvement of gut microbiota in inflammatory bowel disease pathogenesis: potential for therapy

Over the past recent years, a great number of studies have been directed toward the evaluation of the human host-gut microbiota interaction, with the goal to progress the understanding of the etiology of several complex diseases. Alterations in the intestinal microbiota associated with inflammatory bowel disease are well supported by literature data and have been widely accepted by the research community. The concomitant implementation of high-throughput sequencing techniques to analyze and characterize the composition of the intestinal microbiota has reinforced the view that inflammatory bowel disease results from altered interactions between gut microbes and the mucosal immune system and has raised the possibility that some form of modulation of the intestinal microbiota may constitute a potential therapeutic basis for the disease. The aim of this review is to describe the changes of gut microbiota in inflammatory bowel disease, focusing the attention on its involvement in the pathogenesis of the disease, and to review and discuss the therapeutic potential to modify the intestinal microbial population with antibiotics, probiotics, prebiotics, synbiotics and fecal microbiota transplantation.

Probiotic guideline for necrotizing enterocolitis prevention in very low-birth-weight neonates

Necrotizing enterocolitis (NEC) is a gastrointestinal emergency that leads to inflammation and intestinal necrosis. Although probiotics can decrease the incidence of NEC, consistent recommendations for probiotic administration to very low-birth-weight (VLBW) neonates are lacking. Here, the best available evidence is reviewed and a practice guideline for probiotic administrations to VLBW neonates is described. A systematic review was conducted using MEDLINE and EMBASE, and the strength of evidence was classified using the Centre for Evidence-Based Medicine classification schema. Probiotics for VLBW neonates may decrease the incidence of NEC. Providers may choose to give probiotics to VLBW neonates at risk of acquiring NEC in facilities with a high NEC incidence. Clinicians must monitor infants for possible adverse effects. Contraindications for probiotic use include extremely low birth weight, clinical instability, abnormal abdominal examination, the presence of congenital abnormalities, post-NEC, stage III asphyxia, and umbilical catheters.

Clostridium difficile: biological therapies

PURPOSE OF REVIEW

Biological therapies for Clostridium difficile infection (CDI) include probiotics and faecal microbiota transplant (FMT). There is significant interest in their use in treating refractory/recurrent CDI. This review summarizes the latest evidence for these approaches.

RECENT FINDINGS

The small number of randomized controlled trials (RCTs) using probiotics in CDI have produced variable results; the most recent showed no benefit in preventing disease. However, several meta-analyses published in the last year have suggested benefit in their use, but these conclusions are limited by the poor quality of many of the primary studies, and lack of standardization of the probiotic administered. In contrast, FMT appears highly effective for the treatment of CDI. In the only published RCT, the cure rate was 81%, which is close to the rate shown by meta-analyses of previous case series. The use of artificially produced bacterial mixtures in place of faecal samples is now under investigation.

SUMMARY

Biological therapies for CDI, especially FMT, will continue to attract attention. Further, large-scale RCTs are required to identify which patients are most likely to benefit from these therapies in the future.

Bugs or drugs: are probiotics safe for use in the critically ill?

Probiotics are living microorganisms which have demonstrated many benefits in prevention, mitigation, and treatment of various disease states in critically ill populations. These diseases include antibiotic-associated diarrhea, Clostridium difficile diarrhea, ventilator-associated pneumonia, clearance of vancomycin-resistant enterococci from the GI tract, pancreatitis, liver transplant, major abdominal surgery, and trauma. However, their use has been severely limited due to a variety of factors including a general naïveté within the physician community, lack of regulation, and safety concerns. This article focuses on uses for probiotics in prevention and treatment, addresses current concerns regarding their use as well as proposing a protocol for safe use of probiotics in the critically ill patient.

Gleaning evolutionary insights from the genome sequence of a probiotic yeast Saccharomyces boulardii

Background

The yeast Saccharomyces boulardii is used worldwide as a probiotic to alleviate the effects of several gastrointestinal diseases and control antibiotics-associated diarrhea. While many studies report the probiotic effects of S. boulardii, no genome information for this yeast is currently available in the public domain.

Results

We report the 11.4 Mbp draft genome of this probiotic yeast. The draft genome was obtained by assembling Roche 454 FLX + shotgun data into 194 contigs with an N50 of 251 Kbp. We compare our draft genome with all other Saccharomyces cerevisiae genomes.

Conclusions

Our analysis confirms the close similarity of S. boulardii to S. cerevisiae strains and provides a framework to understand the probiotic effects of this yeast, which exhibits unique physiological and metabolic properties.

Microbial characterization of probiotics--advisory report of the Working Group "8651 Probiotics" of the Belgian Superior Health Council (SHC)

When ingested in sufficient numbers, probiotics are expected to confer one or more proven health benefits on the consumer. Theoretically, the effectiveness of a probiotic food product is the sum of its microbial quality and its functional potential. Whereas the latter may vary much with the body (target) site, delivery mode, human target population, and health benefit envisaged microbial assessment of the probiotic product quality is more straightforward. The range of stakeholders that need to be informed on probiotic quality assessments is extremely broad, including academics, food and biotherapeutic industries, healthcare professionals, competent authorities, consumers, and professional press. In view of the rapidly expanding knowledge on this subject, the Belgian Superior Health Council installed Working Group "8651 Probiotics" to review the state of knowledge regarding the methodologies that make it possible to characterize strains and products with purported probiotic activity. This advisory report covers three main steps in the microbial quality assessment process, i.e. (i) correct species identification and strain-specific typing of bacterial and yeast strains used in probiotic applications, (ii) safety assessment of probiotic strains used for human consumption, and (iii) quality of the final probiotic product in terms of its microbial composition, concentration, stability, authenticity, and labeling.

Probiotics: a new frontier for infection control

Probiotics are live micro-organisms administered to provide health benefits. Probiotics are being increasingly used in healthcare contexts both in research studies and routine practice, for example in neonatal intensive care. Currently there is a paucity of guidelines or regulations governing the mitigation of infection risks associated with the use of probiotics in clinical practice. We propose a number of recommendations to mitigate risks. These include the communication of probiotic use to appropriate stakeholders, ensuring that routine laboratories can identify and test the susceptibility of probiotic strains, assuring standards for preparation and administration, and ensuring surveillance designed to capture adverse events.

Investigation of inpatient probiotic use at an academic medical center

OBJECTIVES

Despite the widespread use of probiotics, there are limited data regarding their safety. The aims of this study were to characterize inpatient probiotic use and to determine the incidence of probiotic-related bloodstream infections due to Lactobacillus acidophilus/Lactobacillus bulgaricus.

METHODS

This study was a two-part retrospective study conducted at a large academic medical center. The first part was the characterization of probiotic use during 2007-2008, which included the type of prescribing provider, choice of probiotic prescribed, indications for use, and presence of potential risk factors for probiotic infection among recipients; the second part was the determination of the incidence of probiotic-related bloodstream infections due to L. acidophilus/L. bulgaricus for September 2000-August 2008.

RESULTS

Probiotic use was uncommon (0.4%). Ninety-six percent of patients received Lactobacillus-based compounds. Use was common in patients at theoretical risk for probiotic infection. The maximum estimated incidence of probiotic-related bacteremia due to L. acidophilus/L. bulgaricus during the 8-year period was 0.2%.

CONCLUSIONS

L. acidophilus/L. bulgaricus probiotic use at our institution appeared to be associated with a minimal risk of probiotic-related infection, even though it was used at a high frequency among inpatients who could be considered at high theoretical risk for probiotic-related bloodstream infection.

Prebiotics, probiotics and digestive health

PURPOSE OF REVIEW

The human gastrointestinal lumen is inhabited by a wide variety of microbiota. Our understanding of the intestinal microbiota and its full consequences on gastrointestinal health is still evolving. However, it is well accepted that altered colonic flora drives the pathogenesis of many disorders and diseases as seen in antibiotic-associated diarrhea and Clostridium difficile infection. Recent works published in the area of probiotics are reviewed here.

RECENT FINDINGS

Alterations in colonic microbiota, or dysbiosis, are now implicated in irritable bowel syndrome and inflammatory bowel diseases. Probiotics and prebiotics are evolving treatment options that are targeted at restoring nonpathogenic digestive flora. There has been great interest in the role of these therapies in treatment of many diseases including childhood diarrhea, antibiotic-associated diarrhea, Clostridium difficile infection, irritable bowel syndrome, and inflammatory bowel disease.

SUMMARY

Trials of probiotics have been shown to be helpful in some of these, not in others, and more work is needed in others. We review recent work done in these areas.

Is primary prevention of Clostridium difficile infection possible with specific probiotics?

BACKGROUND

The efficacy of probiotics for the prevention of Clostridium difficile infection (CDI) is highly controversial, particularly with regard to the prevention of recurrent CDI. We hypothesize that primary prevention of CDI among patients receiving antibiotics might be a more achievable goal for probiotics than prevention in patients with previous CDI where the host flora is markedly altered.

METHODS

We conducted a literature search for randomized, placebo-controlled efficacy studies of probiotic use among adults receiving antibiotics, in which CDI was one of the outcomes measured. In addition, we conducted meta-analyses of probiotics that were included in more than one randomized trial.

RESULTS

Eleven studies were identified; most were seriously underpowered to determine the efficacy of probiotics in the prevention of CDI. Two showed significantly lower rates of CDI among the probiotic recipients. A meta-analysis of three studies that used the probiotic combination Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R and a combined analysis of those studies with four studies that used Saccharomyces boulardii, showed lower CDI rates in recipients of probiotics compared with recipients of placebo (risk ratio=0.39; 95% confidence interval 0.19-0.79).

CONCLUSIONS

While potential flaws in study design were identified, a review of the available literature suggests that the primary prevention of CDI with specific probiotic agents may be achievable. Additional studies of sufficient size and with rigorous design are needed to confirm these findings.

The role of prebiotics and probiotics in prevention and treatment of childhood infectious diseases

Infant formulae and food products marketed for children have been increasingly supplemented with probiotics and/or prebiotics. A vast number of studies have accounted for the transit of probiotic use from alternative to more evidence-based medicine. Data support the use of certain probiotics for the adjunct treatment of acute viral gastroenteritis, and for prevention of gastrointestinal diseases. Further roles of prebiotics and probiotics are seen in the prevention of overall infectious diseases and respiratory infections. Data from well-conducted randomized-controlled trials support the therapeutic role for probiotics toward necrotizing enterocolitis in preterm infants. However, it is difficult to translate heterogeneous-based study results, which are mainly due to varying genera, strains, doses, study settings and measured outcomes, into evidence-based recommendations. This article focuses on the evidence of clinical benefits of prebiotics, probiotics and synbiotics toward prevention and treatment of pediatric infectious diseases.