Meta-analysis: the effect and adverse events of Lactobacilli versus placebo in maintenance therapy for Crohn disease

Probiotics for inflammatory bowel disease: Is there sufficient evidence?

Inflammatory bowel disease (IBD) refers to chronic inflammatory disorders of the gut. Ulcerative colitis (UC) and Crohn's disease (CD) are two subtypes of IBD. Evidence suggests that the intestinal microbiota plays a role in the pathogenesis of IBD, so probiotics have garnered a lot of interest as a potential treatment or prevention for IBD. However, clinical evidence of the efficacy of probiotics is still debatable. We performed a literature review. An advanced search considered clinical studies on probiotic for IBD from inception to 2023 in PubMed, Embase, Cochrane Library, and Web of Science. In the treatment of UC with probiotics, only Escherichia coli Nissle 1917 for maintenance treatment of UC in remission, and Bifidobacterium and VSL#3 for induction of remission in patients with mild to moderately active UC have shown strong evidence. Currently, there are no definitive conclusions regarding the effectiveness of probiotics in CD. The mechanism of probiotic treatment for IBD may be related to reducing oxidative stress, repairing the intestinal barrier, regulating intestinal flora balance, and modulating intestinal immune response. Differences in the benefits of probiotics between CD and UC may be attributable to the different lesion extent and immune-mediated pathophysiology. More robust randomized clinical trials are required to validate the efficacy and safety of diverse probiotic strains in IBD.

Exploring the Benefits of Probiotics in Gut Inflammation and Diarrhea-From an Antioxidant Perspective

Inflammatory bowel disease (IBD), characterized by an abnormal immune response, includes two distinct types: Crohn's disease (CD) and ulcerative colitis (UC). Extensive research has revealed that the pathogeny of IBD encompasses genetic factors, environmental factors, immune dysfunction, dysbiosis, and lifestyle choices. Furthermore, patients with IBD exhibit both local and systemic oxidative damage caused by the excessive presence of reactive oxygen species. This oxidative damage exacerbates immune response imbalances, intestinal mucosal damage, and dysbiosis in IBD patients. Meanwhile, the weaning period represents a crucial phase for pigs, during which they experience pronounced intestinal immune and inflammatory responses, leading to severe diarrhea and increased mortality rates. Pigs are highly similar to humans in terms of physiology and anatomy, making them a potential choice for simulating human IBD. Although the exact mechanism behind IBD and post-weaning diarrhea remains unclear, the oxidative damage, in its progression and pathogenesis, is well acknowledged. Besides conventional anti-inflammatory drugs, certain probiotics, particularly Lactobacillus and Bifidobacteria strains, have been found to possess antioxidant properties. These include the scavenging of reactive oxygen species, chelating metal ions to inhibit the Fenton reaction, and the regulation of host antioxidant enzymes. Consequently, numerous studies in the last two decades have committed to exploring the role of probiotics in alleviating IBD. Here, we sequentially discuss the oxidative damage in IBD and post-weaning diarrhea pathogenesis, the negative consequences of oxidative stress on IBD, the effectiveness of probiotics in IBD treatment, the application of probiotics in weaned piglets, and the potential antioxidant mechanisms of probiotics.

Probiotics in Pediatrics. A Review and Practical Guide

The potential benefit of the administration of probiotics in children has been studied in many settings globally. Probiotics products contain viable micro-organisms that confer a health benefit on the host. Beneficial effects of selected probiotic strains for the management or prevention of selected pediatric conditions have been demonstrated. The purpose of this paper is to provide an overview of current available evidence on the efficacy of specific probiotics in selected conditions to guide pediatricians in decision-making on the therapeutic or prophylactic use of probiotic strains in children. Evidence to support the use of certain probiotics in selected pediatric conditions is often available. In addition, the administration of probiotics is associated with a low risk of adverse events and is generally well tolerated. The best documented efficacy of certain probiotics is for treatment of infectious gastroenteritis, and prevention of antibiotic-associated, Clostridioides difficile-associated and nosocomial diarrhea. Unfortunately, due to study heterogeneity and in some cases high risk of bias in published studies, a broad consensus is lacking for specific probiotic strains, doses and treatment regimens for some pediatric indications. The current available evidence thus limits the systematic administration of probiotics. The most recent meta-analyses and reviews highlight the need for more well-designed, properly powered, strain-specific and dedicated-dose response studies.

Anti-inflammatory diet and inflammatory bowel disease: what clinicians and patients should know?

Current treatment for inflammatory bowel disease (IBD) includes the application of anti-inflammatory agents for the induction and remission of IBD. However, prolonged use of anti-inflammatory agents can exert adverse effects on patients. Recently, formulated dietary approach in treating IBD patients is utilized to improve clinical activity scores. An alteration of gastrointestinal microbiota through dietary therapy was found to reduce IBD and is recognized as a promising therapeutic strategy for IBD. One of the recommended formulated diets is an anti-inflammatory diet (AID) that restricts the intake of carbohydrates with modified fatty acids. This diet also contains probiotics and prebiotics that can promote balanced intestinal microbiota composition. However, scientific evidences are limited to support this specific dietary regime in maintaining the remission and prevention relapse of IBD. Therefore, this review aimed to summarize available data from various studies to evaluate the AID diet effectiveness which will be useful for clinicians to manage their IBD patients by application of improved dietary therapy.

A randomised, double-blind, placebo-controlled trial of a multi-strain probiotic in patients with asymptomatic ulcerative colitis and Crohn's disease

Background

There is considerable interest in the possible importance of the gut microflora in the pathophysiology of the inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn’s disease (CD). Probiotics offer a potential adjuvant treatment in these patients by modifying the intestinal milieu, but reports of their efficacy are conflicting.

Aims

To assess the efficacy of a multi-strain probiotic (Symprove™, Symprove Ltd, Farnham, United Kingdom) in quality of life issues and intestinal inflammation in patients with asymptomatic UC and CD.

Methods

A single-centre, randomised, double-blind, placebo-controlled trial of adult patients with asymptomatic IBD. Patients received 4 weeks of treatment with the probiotic or placebo (1 ml/kg/day). The primary efficacy measure was the difference in change in the IBD Quality of Life Questionnaire results (QOL) between probiotic vs. placebo at week 4. Secondary outcome measures included analyses of the change in laboratory findings, including faecal calprotectin (FCAL).

Results

Over 500 patients were recruited to the study and 81 and 61 patients with UC and CD, respectively were randomised and completed the study. There were no significant differences in IBD-QOL scores between placebo and the probiotic groups. Similarly, there were no significant changes observed in the laboratory data. However, the differences in FCAL between patients with UC before and after probiotics versus placebo approached statistical significance with a p value of 0.076. Post-hoc analyses showed that the FCAL levels were significantly (p < 0.015) reduced in the UC patients receiving the probiotic as opposed to placebo. No significant changes were seen in CD. No serious adverse events were observed.

Conclusion

This multi-strain probiotic is associated with decreased intestinal inflammation in patients with UC, but not in CD and is well tolerated. Further research is required to see if the probiotic reduces the incidence of clinical relapses in asymptomatic IBD patients.

Induction and maintenance treatment of inflammatory bowel disease: A comprehensive review

Ulcerative colitis (UC) and Crohn's disease (CD) are the two major types of inflammatory bowel disease (IBD). We conducted a comprehensive review of meta-analyses to summarize the reported effectiveness of different drugs for IBD. We performed a literature search and a total of 110 meta-analyses from 66 articles were summarized and re-analyzed (62 in UC and 48 in CD). In summary, 5-ASA was more effective than placebo in both induction and maintenance treatment of UC, but there were conflicting results on the effect of 5-ASA on the induction treatment or relapse of CD. The use of immunomodulatory agents in the induction or maintenance phase of UC and CD using immunomodulators appeared to be more effective than placebo, but the results were impacted by small number of patients, discordant results with the largest study and risk of biases. Anti-TNF-α and anti-integrin therapeutic antibodies in both, induction and maintenance, showed a better efficacy than placebo in a large proportion of patients analyzed. Other agents, such as probiotics, antibiotics, omega-3, were shown to be more effective than placebo, but the same issues arose as stated above with the use of immunomodulatory agents. In conclusion, we performed a comprehensive review of meta-analysis on comparative efficacy of pharmacotherapy used in the management of IBD. Our review will augment our understanding of the treatment of UC and CD by providing a guideline for interpreting the statistically significant findings and discusses the optimal choice for IBD treatment.

Complementary and Alternative Medicine Use in Children With Inflammatory Bowel Disease

Complementary and alternative medicine (CAM) consists of products and practices that are not considered to be a part of conventional medicine. This article reviews pediatric studies on CAM in inflammatory bowel disease (IBD) along with relevant adult studies. Prevalence of CAM use ranges from 22% to 84% in children with IBD all over the world. CAM use in IBD includes diet changes, supplements, herbals, botanicals, and mind-body therapies. Common reasons for using CAM include severe disease and concern for adverse effects of conventional medicines. Despite widespread use, there are limited studies on efficacy and safety of CAM in children. Small studies suggest a favorable evidence for use of probiotics, fish oil, marijuana, and mind-body therapy in IBD. Adverse effects of CAM are reported but are rare. The article provides current state of knowledge on the topic and provides guidance to physicians to address CAM use in pediatric patients with IBD.

Nutrition in Pediatric Inflammatory Bowel Disease: A Position Paper on Behalf of the Porto Inflammatory Bowel Disease Group of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition

BACKGROUND AND AIMS

A growing body of evidence supports the need for detailed attention to nutrition and diet in children with inflammatory bowel disease (IBD). We aimed to define the steps in instituting dietary or nutritional management in light of the current evidence and to offer a useful and practical guide to physicians and dieticians involved in the care of pediatric IBD patients.

METHODS

A group of 20 experts in pediatric IBD participated in an iterative consensus process including 2 face-to-face meetings, following an open call to Nutrition Committee of the European Society of Pediatric Gastroenterology, Hepatology and Nutrition Porto, IBD Interest, and Nutrition Committee. A list of 41 predefined questions was addressed by working subgroups based on a systematic review of the literature.

RESULTS

A total of 53 formal recommendations and 47 practice points were endorsed with a consensus rate of at least 80% on the following topics: nutritional assessment; macronutrients needs; trace elements, minerals, and vitamins; nutrition as a primary therapy of pediatric IBD; probiotics and prebiotics; specific dietary restrictions; and dietary compounds and the risk of IBD.

CONCLUSIONS

This position paper represents a useful guide to help the clinicians in the management of nutrition issues in children with IBD.

Systematic review with meta-analysis: the efficacy of probiotics in inflammatory bowel disease

BACKGROUND

Ulcerative colitis (UC) and Crohn's disease (CD) are inflammatory bowel diseases (IBD). Evidence implicates disturbances of the gastrointestinal microbiota in their pathogenesis.

AIM

To perform a systematic review and meta-analysis to examine the efficacy of probiotics in IBD.

METHODS

MEDLINE, EMBASE, and the Cochrane Controlled Trials Register were searched (until November 2016). Eligible randomised controlled trials (RCTs) recruited adults with UC or CD, and compared probiotics with 5-aminosalicylates (5-ASAs) or placebo. Dichotomous symptom data were pooled to obtain a relative risk (RR) of failure to achieve remission in active IBD, or RR of relapse of disease activity in quiescent IBD, with 95% confidence intervals (CIs).

RESULTS

The search identified 12 253 citations. Twenty-two RCTs were eligible. There was no benefit of probiotics over placebo in inducing remission in active UC (RR of failure to achieve remission=0.86; 95% CI=0.68-1.08). However, when only trials of VSL#3 were considered there appeared to be a benefit (RR=0.74; 95% CI=0.63-0.87). Probiotics appeared equivalent to 5-ASAs in preventing UC relapse (RR=1.02; 95% CI=0.85-1.23). There was no benefit of probiotics in inducing remission of active CD, in preventing relapse of quiescent CD, or in preventing relapse of CD after surgically induced remission.

CONCLUSIONS

VSL#3 may be effective in inducing remission in active UC. Probiotics may be as effective as 5-ASAs in preventing relapse of quiescent UC. The efficacy of probiotics in CD remains uncertain, and more evidence from RCTs is required before their utility is known.

Probiotics: The scientific evidence in the context of inflammatory bowel disease

Inflammatory bowel disease (IBD) generally comprises Crohn's disease (CD) and ulcerative colitis (UC), and their main characteristic is the intestinal mucosa inflammation. Although its origin is not yet fully known, there is growing evidence related to genetics, intestinal microbiota composition, and the immune system factors such as precursors for the initiation and progression of intestinal conditions. The use of certain probiotic microorganisms has been touted as a possible and promising therapeutic approach in reducing the risk of inflammatory bowel disease, specifically ulcerative colitis. Several mechanisms have been proposed to explain the benefits of probiotics, indicating that some bacterial strains are able to positively modulate the intestinal microbiota and the immune system, and to produce metabolites with anti-inflammatory properties. The aim of this paper is to bring together the various results and information, based on scientific evidence, that are related to probiotics and inflammatory bowel disease, emphasizing the possible mechanisms involved in this action.

An Examination of Diet for the Maintenance of Remission in Inflammatory Bowel Disease

Diet has been speculated to be a factor in the pathogenesis of inflammatory bowel disease and may be an important factor in managing disease symptoms. Patients manipulate their diet in attempt to control symptoms, often leading to the adoption of inappropriately restrictive diets, which places them at risk for nutritional complications. Health professionals struggle to provide evidence-based nutrition guidance to patients due to an overall lack of uniformity or clarity amongst research studies. Well-designed diet studies are urgently needed to create an enhanced understanding of the role diet plays in the management of inflammatory bowel disease. The aim of this review is to summarize the current data available on dietary management of inflammatory bowel disease and to demonstrate that dietary modulation may be an important consideration in managing disease. By addressing the relevance of diet in inflammatory bowel disease, health professionals are able to better support patients and collaborate with dietitians to improve nutrition therapy.

Methodological Quality Assessment of Meta-Analyses and Systematic Reviews of Probiotics in Inflammatory Bowel Disease and Pouchitis

BACKGROUND

Probiotics are widely used for the induction and maintenance of remission in inflammatory bowel disease (IBD) and pouchitis. There are a large number of meta-analyses (MAs)/ systematic reviews (SRs) on this subject, the methodological quality of which has not been evaluated.

OBJECTIVES

This study aimed to evaluate the methodological quality of and summarize the evidence obtained from MAs/SRs of probiotic treatments for IBD and pouchitis patients.

METHODS

The PubMed, EMBASE, Cochrane Library and China National Knowledge Infrastructure (CNKI) databases were searched to identify Chinese and English language MAs/SRs of the use of probiotics for IBD and pouchitis. The Assessment of Multiple Systematic Reviews (AMSTAR) scale was used to assess the methodological quality of the studies.

RESULTS

A total of 36 MAs/SRs were evaluated. The AMSTAR scores of the included studies ranged from 1 to 10, and the average score was 5.81. According to the Canadian Agency for Drugs and Technologies in Health, 4 articles were classified as high quality, 24 articles were classified as moderate quality, and 8 articles were classified as low quality. Most of the MAs/SRs suggested that probiotics had potential benefits for patients with ulcerative colitis (UC), but failed to show effectiveness in the induction and maintenance of remission in Crohn's disease (CD). The probiotic preparation VSL#3 may play a beneficial role in pouchitis.

CONCLUSION

The overall methodological quality of the current MAs/SRs in the field of probiotics for IBD and pouchitis was found to be low to moderate. More MAs/SRs of high quality are required to support using probiotics to treat IBD and pouchitis.

Gut Microbiota and Lifestyle Interventions in NAFLD

The human digestive system harbors a diverse and complex community of microorganisms that work in a symbiotic fashion with the host, contributing to metabolism, immune response and intestinal architecture. However, disruption of a stable and diverse community, termed "dysbiosis", has been shown to have a profound impact upon health and disease. Emerging data demonstrate dysbiosis of the gut microbiota to be linked with non-alcoholic fatty liver disease (NAFLD). Although the exact mechanism(s) remain unknown, inflammation, damage to the intestinal membrane, and translocation of bacteria have all been suggested. Lifestyle intervention is undoubtedly effective at improving NAFLD, however, not all patients respond to these in the same manner. Furthermore, studies investigating the effects of lifestyle interventions on the gut microbiota in NAFLD patients are lacking. A deeper understanding of how different aspects of lifestyle (diet/nutrition/exercise) affect the host-microbiome interaction may allow for a more tailored approach to lifestyle intervention. With gut microbiota representing a key element of personalized medicine and nutrition, we review the effects of lifestyle interventions (diet and physical activity/exercise) on gut microbiota and how this impacts upon NAFLD prognosis.

Probiotics and prebiotics in Crohn's disease therapies

Therapeutic manipulation of gut microbiota has proven valuable in the management of ulcerative colitis and pouchitis. Despite some similarities among the various inflammatory bowel conditions, the probiotics investigated thus far seem to confer little benefit in Crohn's disease. In this review, we aim to bring together the evidence available on the clinical effect of probiotics and prebioltics in Crohn's disease patients, and to clarify the place of probiotic treatment in current Crohn's therapeutic regimens.

Samples and techniques highlighting the links between obesity and microbiota

The composition of gut microbiota and its relationship to human health, particularly its links with obesity remain an ongoing challenge for scientists. The current gold standard for exploring human gut microbiota consists of using stool samples and only applying next generations sequencing techniques, which sometimes generate contradictory results. Here, we comprehensively describe nutrient absorption, fat digestion, carbohydrate and protein absorption, demonstrating that absorption of these diverse nutrients occurs mainly in the stomach and small intestine. Indeed, bariatric surgery, including Roux-en-Y, removes part of the upper intestine, resulting in weight loss, while colonic surgery is associated with a stable weight. However, most studies only use stool samples rather than small intestine samples because of the easy with which this can be accessed. Metagenomics studies are associated with several biases such as extraction and primer biases and depth bias, including the more modern platforms. High-throughput culture-dependent techniques, such as culturomics, which uses rapid identification methods such as MALDI-TOF, remain time-consuming, but have demonstrated their complementarity with molecular techniques. In conclusion, we believe that a comprehensive analysis of the relationships between obesity and gut microbiota requires large-scale studies coupling metagenomics and culture-dependent research, in order to analyse both small intestine and stool samples.

Different treatment benefits were estimated by clinical trials performed in adults compared with those performed in children

OBJECTIVE

Our main objective was to see whether the therapeutic benefit observed in placebo controlled randomized controlled trials (RCTs) is different between adults and children.

STUDY DESIGN AND SETTING

We searched three electronic databases for meta-analyses that included double-blind, placebo-controlled RCTs with separate results for adults and children. The selected reviews were classified according to disease and drug used. The heterogeneity of treatment response between adults and children was measured using ratio of odds ratios (RORs).

RESULTS

We selected 89 meta-analyses and calculated RORs for 124 drugs. Heterogeneity in the direction of the treatment effect was observed in one drug and heterogeneity in the quantity of the treatment effect for 13 drugs, indicating significantly different treatment effect in adults when compared with children. RORs were not significantly different from 1 for 110 drugs. For 36 of these drugs, the treatment effect was confirmed in both populations.

CONCLUSION

We found different treatment benefits estimated by clinical trials performed in adults compared with those performed in children for 14 of 124 drugs. Data on dose adjustment and child age groups from RCTs were not adequately reported to investigate their influence on the treatment benefit dissimilarities.

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.

Intestinal microbiota pathogenesis and fecal microbiota transplantation for inflammatory bowel disease

The intestinal microbiota plays an important role in inflammatory bowel disease (IBD). The pathogenesis of IBD involves inappropriate ongoing activation of the mucosal immune system driven by abnormal intestinal microbiota in genetically predisposed individuals. However, there are still no definitive microbial pathogens linked to the onset of IBD. The composition and function of the intestinal microbiota and their metabolites are indeed disturbed in IBD patients. The special alterations of gut microbiota associated with IBD remain to be evaluated. The microbial interactions and host-microbe immune interactions are still not clarified. Limitations of present probiotic products in IBD are mainly due to modest clinical efficacy, few available strains and no standardized administration. Fecal microbiota transplantation (FMT) may restore intestinal microbial homeostasis, and preliminary data have shown the clinical efficacy of FMT on refractory IBD or IBD combined with Clostridium difficile infection. Additionally, synthetic microbiota transplantation with the defined composition of fecal microbiota is also a promising therapeutic approach for IBD. However, FMT-related barriers, including the mechanism of restoring gut microbiota, standardized donor screening, fecal material preparation and administration, and long-term safety should be resolved. The role of intestinal microbiota and FMT in IBD should be further investigated by metagenomic and metatranscriptomic analyses combined with germ-free/human flora-associated animals and chemostat gut models.

The microbiome in inflammatory bowel disease and its modulation as a therapeutic manoeuvre

Inflammatory bowel disease (IBD) is increasing in incidence in both the developed and the developing world. Genetic, immunological and environmental factors are known to be involved. Genome-wide studies have examined the contribution played by host genetics in the development of IBD and have estimated that genetic factors are responsible for about 25 % of the disease risk. Having an IBD-associated genotype does not always lead to development of the disease phenotype, and hence it seems likely that environmental factors are key to triggering development of the disease in genetically susceptible individuals. The gut microbiota contains more cells than its human host, and mounting evidence attests to the importance of the microbiota in the development of several diseases, including IBD, metabolic syndrome and CVD. The present paper reviews the interplay between the microbiota and the mucosal immune system in health and in IBD; and discusses the evidence base for the use of therapeutic modulation of the microbiota to prevent and treat IBD.

Intestinal microbiota, probiotics and prebiotics in inflammatory bowel disease

It has been presumed that aberrant immune response to intestinal microorganisms in genetically predisposed individuals may play a major role in the pathogenesis of the inflammatory bowel disease, and there is a good deal of evidence supporting this hypothesis. Commensal enteric bacteria probably play a central role in pathogenesis, providing continuous antigenic stimulation that causes chronic intestinal injury. A strong biologic rationale supports the use of probiotics and prebiotics for inflammatory bowel disease therapy. Many probiotic strains exhibit anti-inflammatory properties through their effects on different immune cells, pro-inflammatory cytokine secretion depression, and the induction of anti-inflammatory cytokines. There is very strong evidence supporting the use of multispecies probiotic VSL#3 for the prevention or recurrence of postoperative pouchitis in patients. For treatment of active ulcerative colitis, as well as for maintenance therapy, the clinical evidence of efficacy is strongest for VSL#3 and Escherichia coli Nissle 1917. Moreover, some prebiotics, such as germinated barley foodstuff, Psyllium or oligofructose-enriched inulin, might provide some benefit in patients with active ulcerative colitis or ulcerative colitis in remission. The results of clinical trials in the treatment of active Crohn’s disease or the maintenance of its remission with probiotics and prebiotics are disappointing and do not support their use in this disease. The only exception is weak evidence of advantageous use of Saccharomyces boulardii concomitantly with medical therapy in maintenance treatment.

Manipulation of the microbiota for treatment of IBS and IBD-challenges and controversies

There is compelling rationale for manipulating the microbiota to treat inflammatory bowel diseases (IBDs). Although studies of animal models of intestinal inflammation produced promising results, trials in humans have been disappointing. In contrast to IBD, the role of the microbiota in the development of irritable bowel syndrome (IBS) only recently has been considered, but early stage results have been encouraging. As pharmaceutical companies develop fewer truly novel agents for treatment of these disorders, consumers seek safer, long-term strategies to deal with chronic symptoms. We assess the rationale for modulating the microbiota for treatment of IBD and IBS, and discuss whether current concepts are simplistic and overstated or simply under-researched. Are claims exaggerated and expectations unrealistic? Difficulties with microbiota terminology and technologies, as well as differences among patients and the heterogeneity of these diseases, pose additional challenges in developing microbiota-based therapies for IBD and IBS.

The microbiome and probiotics in childhood

Infants, from the moment of birth, are colonized by large numbers of microbes. This colonization continues throughout childhood and from preliminary studies seems to be a highly dynamic process, even during the usual physiologic state we refer to as health. In this context, the persistence of bacterial and fungal species in and on the human body likely confers various benefits to the host. One specific approach to modulate such beneficial effects is the administration of probiotics, also known as beneficial microbes. Herein, we outline the highest level evidence in regard to the evolution of the microbiome during childhood and its manipulation by probiotics for genitourinary, enteric, and allergic and atopic disorders. Thus, probiotic approaches are promising alternatives and adjuvants to traditional vaccines and antibiotics. This may usher in a new age in which vaccine and antibiotic side effects and antibiotic resistance are minimal issues in the setting of maintaining children's health and prevention of disease.

Probiotic treatments for induction and maintenance of remission in inflammatory bowel diseases: a meta-analysis of randomized controlled trials

Probiotics have been used for the treatment of inflammatory bowel diseases (IBD). However, the effects of probiotics on the induction and maintenance of remission in ulcerative colitis (UC) or Crohn's disease (CD) still remain controversial. This systematic review verified the findings of high-quality randomized controlled trials (RCTs) which investigated the therapeutic effects of probiotics on IBD. After the quality assessment, 20 RCTs which investigated the effects of probiotics on the induction or maintenance of remission in IBD were identified. From the results of the validation of these RCTs, beneficial effects of probiotic treatments to improve the response rate and remission rate on the remission induction therapies [risk ratio (RR) 1.81; 95 % confidence interval (CI) 1.40-2.35 and RR 1.56; 95 % CI 0.95-2.56, respectively] were verified. Furthermore, probiotic treatments exhibited effects equal to mesalazine on the maintenance of remission in UC (RR 1.00; 95 % CI 0.79-1.26). In contrast, no significant effect of probiotic treatments was shown in either the induction or maintenance of remission in CD. Because there were many variations in the conditions among these studies, a further analysis evaluating the effects of probiotic treatments in IBD is needed to clarify the optimal probiotics and treatment regimens for each condition or population in IBD patients.

Related actions of probiotics and antibiotics on gut microbiota and weight modification

Antibiotics and probiotics are widely used as growth promoters in agriculture. Most antibiotics prescribed in clinical practice are natural products that originate from Streptomyces spp, which were first used as agricultural probiotics. Antibiotics and probiotics both modify the gut microbiota. The effect of a probiotic species on the digestive flora depends on the strain and is largely determined by bacteriocin production. In human beings, as in animals, specific probiotics are associated with weight gain or loss. Improved understanding of the ability of specific probiotics to harvest energy from the host diet might lead to development of new treatments for obesity and malnutrition. In this Review, we present the effects of probiotics and antibiotics on the gut microbiota of human beings and animals and discuss their potential therapeutic use as interventions for weight gain and loss in human beings.

Saccharomyces boulardii does not prevent relapse of Crohn's disease

BACKGROUND & AIMS

Saccharomyces boulardii is a probiotic yeast that has been shown to have beneficial effects on the intestinal epithelial barrier and digestive immune system. There is preliminary evidence that S boulardii could be used to treat patients with Crohn's disease (CD). We performed a randomized, placebo-controlled trial to evaluate the effects of S boulardii in patients with CD who underwent remission during therapy with steroids or aminosalicylates.

METHODS

We performed a prospective study of 165 patients who achieved remission after treatment with steroids or salicylates; they were randomly assigned to groups given S boulardii (1 g/day) or placebo for 52 weeks. The primary end point was the percentage of patients in remission at week 52. Time to relapse, Crohn's disease activity index scores, and changes in parameters of inflammation were secondary end points.

RESULTS

CD relapsed in 80 patients, 38 in the S boulardii group (47.5%) and 42 in the placebo group (53.2%, a nonsignificant difference). The median time to relapse did not differ significantly between patients given S boulardii (40.7 weeks) vs placebo (39.0 weeks). There were no significant differences between groups in mean Crohn's disease activity index scores or erythrocyte sedimentation rates or in median levels of C-reactive protein. In a post hoc analysis, nonsmokers given S boulardii were less likely to experience a relapse of CD than nonsmokers given placebo, but this finding requires confirmation.

CONCLUSIONS

Although the probiotic yeast S boulardii is safe and well tolerated, it does not appear to have any beneficial effects for patients with CD in remission after steroid or salicylate therapies.

[Probiotics in gastroenterology -- from a different angle]

After a short overview of the history of probiotics, the author presents the development of human intestinal microflora based on the newest genetic data and the microbiological features of main probiotics. The indications of probiotic administration have been defined and extended in recent years. The author reviews significant results of probiotic treatment in some gastrointestinal diseases based on meta-analytical data. Probiotics are useful in preventing and treating diarrhoea caused by antibiotics and Clostridium difficile caused diarrhoea. In the treatment of Helicobacter pylori infection, preparations containing certain Lactobacillus,Bifidobacterium strains or Saccaromyces boulardii could enhance by 5-10% the rate of successful eradication and reduce the incidence and severity of the side effects. Some symptoms of irritable bowel syndrome and thus the quality of life can be improved by probiotics. Their beneficial effect in ulcerative colitis was proven, while in Crohn's disease has not yet been defined. The use of probiotics is not included in guidelines, with the exception of the Maastricht IV/Florence consensus. For each disease it is advisable to use probiotics containing strains only with proven beneficial effect. The efficiency of preparations containing mixed strains has not yet been properly investigated. The author reviews the rare but potentially serious side effects of probiotics. In Hungary, there are many probiotic preparations available which can be purchased in pharmacies without prescription: their use is more empirical than evidence-based. The European Food Safety Authority has recently rejected claims for probiotics to be classed as medicines given the lack of convincing evidence on the effects of probiotics on human health and well-being. Clearly, further research is needed to collect evidence which could be incorporated into the international guidelines.

Probiotic bacteria in the prevention and the treatment of inflammatory bowel disease

Definitive curative strategies for inflammatory bowel disease remain challenging for physicians and patients. For decades, probiotic organisms have been used in various gastrointestinal diseases. Only recently has comprehension of the pathophysiology of inflammatory bowel disease developed to the point where the significance of the host gastrointestinal microbial population is seen to have marked influence on the initiation and ongoing inflammatory processes of Crohn disease and ulcerative colitis. Well-designed, large randomized controlled trials using probiotics in patients with inflammatory bowel disease are required for probiotics to become mainstream therapy.

Lessons from probiotic-host interaction studies in murine models of experimental colitis

In inflammatory bowel diseases (IBD), it is known that besides genetic and environmental factors (e.g. diet, drugs, stress), the microbiota play an important role in the pathogenesis. Patients with IBD have an altered microbiota (dysbiosis) and therefore, probiotics, defined as 'live micro-organisms that when administered in adequate amounts can confer a health benefit on the host', have been suggested as nutritional supplements to restore these imbalances. The best response on probiotics among the different types of IBD appears to be in the case of ulcerative colitis. Although probiotics show promise in IBD in both clinical and animal studies, further mechanistic studies are necessary to optimize the use of probiotics as supporting therapy in IBD. Murine models of experimental colitis have been used for decades to study this pathology, and these models have been proven useful to search for new therapeutic approaches. The purpose of this review is to summarize probiotic-host interaction studies in murine models of experimental colitis and to evaluate how these models can further help in understanding these complex interactions. Unraveling the molecular mechanisms behind the beneficial effects will assist in better and possibly more efficient probiotic formulations.

Microbiota restoration: natural and supplemented recovery of human microbial communities

In a healthy host, a balance exists between members of the microbiota, such that potential pathogenic and non-pathogenic organisms can be found in apparent harmony. During infection, this balance can become disturbed, leading to often dramatic changes in the composition of the microbiota. For most bacterial infections, nonspecific antibiotics are used, killing the non-pathogenic members of the microbiota as well as the pathogens and leading to a substantial delay in the restoration of a healthy microbiota. However, in some cases, infections can self-resolve without the intervention of antibiotics. In this Review, we explore the mechanisms underlying microbiota restoration following insult (antibiotic or otherwise) to the skin, oral cavity, and gastrointestinal and urogenital tracts, highlighting recovery by natural processes and after probiotic administration.

Impact of lipoteichoic acid modification on the performance of the probiotic Lactobacillus rhamnosus GG in experimental colitis

While some probiotic strains might have adjuvant effects in the therapy for inflammatory bowel diseases (IBD), these effects remain controversial and cannot be generalized. In this study, a dltD mutant of the model probiotic Lactobacillus rhamnosus GG (LGG), having a drastic modification in its lipoteichoic acid (LTA) molecules, was analysed for its effects in an experimental colitis model. Dextran sulphate sodium (DSS) was used to induce either moderate to severe or mild chronic colitis in mice. Mice received either phosphate-buffered saline (PBS), LGG wild-type or the dltD mutant via the drinking water. Macroscopic parameters, histological abnormalities, cytokine and Toll-like receptor (TLR) expression were analysed to assess disease activity. LGG wild-type did not show efficacy in the different experimental colitis set-ups. This wild-type strain even seemed to exacerbate the severity of colitic parameters in the moderate to severe colitis model compared to untreated mice. In contrast, mice treated with the dltD mutant showed an improvement of some colitic parameters compared to LGG wild-type-treated mice in both experimental models. In addition, treatment with the dltD mutant correlated with a significant down-regulation of Toll-like receptor-2 expression and of downstream proinflammatory cytokine expression in the colitic mice. These results show that molecular cell surface characteristics of probiotics are crucial when probiotics are considered for use as supporting therapy in IBD.