Clinical trial: a multistrain probiotic preparation significantly reduces symptoms of irritable bowel syndrome in a double-blind placebo-controlled study

Efficacy and safety of probiotics in irritable bowel syndrome: A systematic review and meta-analysis

BACKGROUND

Irritable bowel syndrome (IBS) is a common gastrointestinal disease characterized by abdominal pain, distension, and altered bowel habits. Probiotics may alleviate IBS symptoms, but clinical trials remain conflicting.

AIMS

To conduct a systematic review and meta-analysis of clinical trials to evaluate the efficacy and safety of probiotics for IBS patients.

METHODS

We searched relevant trials in PubMed, Web of Science, Embase, Cochrane Library, and Google Scholar from 2000 to June 2023. Standardized mean difference (SMD) and 95% confidence interval (CI) were calculated for continuous outcomes. A risk ratio (RR) and a 95% CI were calculated for dichotomous outcomes.

RESULTS

A total of 20 studies involving 3011 patients were obtained. The results demonstrated that probiotics are more effective than placebo in reducing global IBS symptoms improvement rate (RR = 1.401, 95% CI 1.182-1.662, P < 0.001) and quality of life scores (SMD = 0.286, 95% CI = 0.154-0.418, P < 0.001). Subgroup analyses showed that a shorter treatment time (less than eight weeks) could reduce distension scores (SMD = 0.197, 95% CI = 0.038-0.356, P = 0.015). High doses (daily dose of probiotics ≥ 10ˆ10) or multiple strains of probiotics exhibit beneficial effects on abdominal pain (SMD = 0.412, 95% CI = 0.112-0.711, P = 0.007; SMD = 0.590, 95% CI = 0.050-1.129, P = 0.032; respectively). However, there was no significant benefit on global symptom scores (SMD = 0.387, 95% CI 0.122 to 0.653, P = 0.004) with statistically high inter-study heterogeneity (I2 = 91.9%, P < 0.001). Furthermore, there was no significant inter-group difference in terms of adverse events frequency (RR = 0.997, 95% CI 0.845-1.177, P = 0.973).

CONCLUSION

Probiotics are effective and safe for IBS patients. High doses or multiple probiotic strains seem preferable, but definite conclusions are challenging due to the high heterogeneity. Large-scale, well-designed, and rigorous trials are needed to confirm their effectiveness.

A double-blind, randomized, placebo-controlled study assessing the impact of probiotic supplementation on the symptoms of irritable bowel syndrome in females

BACKGROUND

A previous exploratory study demonstrated the ability of the Lab4 probiotic to alleviate the symptoms of IBS, and post hoc data analysis indicated greatest improvements in the female subgroup. The aim of this study is to confirm the impact of this multistrain probiotic on IBS symptom severity in females.

METHODS

An 8-week, single-center, randomized, double-blinded, placebo-controlled, superiority study in 70 females with Rome IV-diagnosed irritable bowel syndrome (IBS) receiving the Lab4 probiotic (25 billion colony-forming units) daily or a matched placebo. Changes from baseline in the IBS-symptom severity score (IBS-SSS), daily bowel habits, anxiety, depression, IBS-related control, and avoidance behavior, executive function, and the fecal microbiota composition were assessed. The study was prospectively registered: ISRCTN 14866272 (registration date 20/07/22).

KEY RESULTS

At the end of the study, there were significant between-group reductions in IBS-SSS (-85.0, p < 0.0001), anxiety and depression scores (-1.9, p = 0.0002 and -2.4, p < 0.0001, respectively), and the IBS-related control and avoidance behavior score (-7.5, p = 0.0002), all favoring the probiotic group. A higher proportion of the participants in the probiotic group had normal stool form (p = 0.0106) and/or fewer defecations with loose stool form (p = 0.0311). There was little impact on the overall diversity of the fecal microbiota but there were significant differences in Roseburia, Holdemanella, Blautia, Agathobacter, Ruminococcus, Prevotella, Bacteroides, and Anaerostipes between the probiotic and placebo groups at the end of the study.

CONCLUSIONS & INFERENCES

Daily supplementation with this probiotic may represent an option to be considered in the management of IBS.

Intestinal microbiota regulates the gut-thyroid axis: the new dawn of improving Hashimoto thyroiditis

Intestinal microbiota plays an indispensable role in the host's innate immune system, which may be related to the occurrence of many autoimmune diseases. Hashimoto thyroiditis (HT) is one of the most common autoimmune diseases, and there is plenty of evidence indicating that HT may be related to genetics and environmental triggers, but the specific mechanism has not been proven clearly. Significantly, the composition and abundance of intestinal microbiota in patients with HT have an obvious difference. This phenomenon led us to think about whether intestinal microbiota can affect the progress of HT through some mechanisms. By summarizing the potential mechanism of intestinal microflora in regulating Hashimoto thyroiditis, this article explores the possibility of improving HT by regulating intestinal microbiota and summarizes relevant biomarkers as therapeutic targets, which provide new ideas for the clinical diagnosis and treatment of Hashimoto thyroiditis.

The impact of probiotics and vitamin C on the prevention of upper respiratory tract symptoms in two preschool children cohorts

BACKGROUND/OBJECTIVES

The efficacy of Lab4 probiotic and vitamin C combination on the prevention of upper respiratory tract infections (URTIs) was investigated in two studies with children. Our objective was to pool dataset of 57 preschool children from the PROCHILD study (ISRCTN28722693) and the dataset of 50 preschool matched cohort from the PROCHILD-2 study (ISRCTN26587549) to evaluate the impact of probiotic/vitamin C combination on the prevention of upper respiratory tract symptoms and provide a more robust assessment of effect using detailed individual level data.

SUBJECTS/METHODS

The children were supplemented daily for 6 months with either the multistrain probiotic (1.25×1010 cfu/tablet consisting of two strains of Lactobacillus acidophilus CUL21 and CUL60, Bifidobacterium bifidum CUL20 and Bifidobacterium animalis subsp. lactis CUL34) plus 50 mg vitamin C or a placebo.

RESULTS

In the pooled analysis of the individual participant data (per protocol population), significant reductions were observed for the incidence (-25%; 95% confidence interval [CI], 0.66, 0.85; P < 0.0001) and duration (-14.9 days; 95% CI, -24.8, -5.1; P = 0.0030) of typical URTI symptoms in the active group compared with the placebo. The incidence rates of absenteeism from preschool (IR ratio, 0.75; 95% CI, 0.66, 0.86; P < 0.0001), paediatric visits (IR ratio, 0.56; 95% CI, 0.47; 0.68; P < 0.0001) and antibiotic usage (IR ratio, 0.53; 95% CI, 0.39, 0.71; P < 0.0001) were also significantly reduced.

CONCLUSION

The pooled analysis findings of comparable preschool cohorts from two studies indicate that the supplementation with probiotic and vitamin C combination is beneficial in the prevention and management of URTI symptoms.

Role of Baseline Gut Microbiota on Response to Fiber Intervention in Individuals with Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is one of the most prevalent functional gut disorders in the world. Partially hydrolyzed guar gum, a low-viscosity soluble fiber, has shown promise in the management of IBS-related symptoms. In this study, we aimed to determine if an individual's baseline gut microbiota impacted their response to a partially hydrolyzed guar gum intervention. Patients diagnosed with IBS undertook a 90-day intervention and follow-up. IBS symptom severity, tolerability, quality-of-life, and fecal microbiome composition were recorded during this study. Patients with normal microbiota diversity (Shannon index ≥ 3) showed significant improvements to IBS symptom scores, quality-of-life, and better tolerated the intervention compared to patients with low microbiota diversity (Shannon index < 3). Our findings suggest that an individual's baseline microbiome composition exerts a substantial influence on their response to fiber intervention. Future investigations should explore a symbiotic approach to the treatment of IBS.

Controlling Intestinal Infections and Digestive Disorders Using Probiotics

After consumption, probiotics provide health benefits to the host. Probiotics and their metabolites have therapeutic and nutritional properties that help to alleviate gastrointestinal, neurological, and cardiovascular problems. Probiotics strengthen host immunity through various mechanisms, including improved gut barrier function, receptor site blocking, competitive exclusion of pathogens, and the production of bioactive molecules. Emerging evidence suggests that intestinal bowel diseases can be fatal, but regular probiotic consumption can alleviate disease symptoms. The use and detailed description of the health benefits of probiotics to consumers in terms of reducing intestinal infection, inflammation, and digestive disorders are discussed in this review. The well-designed and controlled studies that examined the use of probiotics to reduce life-threatening activities caused by intestinal bowel diseases are also covered. This review discussed the active principles and potency of probiotics as evidenced by the known effects on host health, in addition to providing information on the mechanism of action.

Outcome-Specific Efficacy of Different Probiotic Strains and Mixtures in Irritable Bowel Syndrome: A Systematic Review and Network Meta-Analysis

Irritable bowel syndrome (IBS) is a common gastrointestinal disease. The efficacy of different probiotics in treating IBS remains controversial. This network meta-analysis aimed to compare and rank the outcome-specific efficacy of different probiotic strains or combinations in adults with IBS. We searched the literature up to June 2023. Randomized controlled trials (RCTs) that evaluated the efficacy of probiotics in IBS were included. A frequentist framework was used to perform this study. In total, 9253 participants from 81 RCTs were included in the study. Four probiotic strains and five mixtures were significantly superior to placebo in improving IBS Symptom Severity Scale, among which Lactobacillus acidophilus DDS-1 ranked first (surface under the cumulative ranking, SUCRA, 92.9%). A mixture containing five probiotics (SUCRA, 100%) ranked first in improving the IBS-Quality of life. Bacillus coagulans MTCC 5856 (SUCRA, 96.9%) and Bacillus coagulans Unique IS2 (SUCRA, 92.6%) were among the most effective probiotics for improving abdominal pain. Three probiotic strains and two mixtures were effective in alleviating abdominal bloating. Four probiotic strains and a mixture were significantly superior to placebo in reducing the bowel movement frequency in diarrhea-predominant IBS (IBS-D). Bacillus coagulans MTCC 5856 (SUCRA, 99.6%) and Saccharomyces cerevisiae CNCM I-3856 (SUCRA, 89.7%) were among the most effective probiotics for improving the Bristol stool form scale of IBS-D. Only some probiotics are effective for particular outcomes in IBS patients. This study provided the first ranking of outcome-specific efficacy of different probiotic strains and combinations in IBS. Further studies are needed to confirm these results.

Gastroparesis: The Complex Interplay with Microbiota and the Role of Exogenous Infections in the Pathogenesis of the Disease

Gastroparesis (GP) is a disorder of gastric functions that is defined by objective delayed gastric emptying in the absence of mechanical obstruction. This disease is characterized by symptoms such as nausea, post-prandial fullness, and early satiety. GP significantly impacts patients' quality of life and contributes to substantial healthcare expenses for families and society. However, the epidemiological burden of GP is difficult to evaluate, mainly due its significant overlap with functional dyspepsia (FD). GP and FD represent two similar diseases. The pathophysiology of both disorders involves abnormal gastric motility, visceral hypersensitivity, and mucosal inflammation. Moreover, both conditions share similar symptoms, such as epigastric pain, bloating, and early satiety. The latest evidence reveals that dysbiosis is directly or indirectly connected to gut-brain axis alterations, which are the basis of pathogenesis in both FD and GP. Furthermore, the role of microbiota in the development of gastroparesis was demonstrated by some clinical studies, which found that the use of probiotics is correlated with improvements in the gastric emptying time (GET). Infections (with viruses, bacteria, and protozoa) represent a proven etiology for GP but have not been sufficiently considered in current clinical practice. Previous viral infections can be found in about 20% of idiopathic GP cases. Moreover, delayed gastric emptying during systemic protozoal infections represents a huge concern for compromised patients, and few data exist on the topic. This comprehensive narrative review analyzes the relationship between microorganisms and GP. We explore, on the one hand, the correlation between gut microbiota dysbiosis and GP pathogenesis, including treatment implications, and, on the other hand, the association between exogenous infections and the etiology of the disease.

Development of a microecologic product from Lactobacillus rhamnosus based on silica

BACKGROUND

Probiotics are primarily made into microecologic products for use in the food and feed industries. The freeze-drying technique is widely used in their preparation to maintain their high level of bioactivity. This causes high costs in terms of the energy and time needed. In this study, we developed a method to produce a highly active microecologic product from Lactobacillus rhamnosus using heating and silica.

RESULTS

A microecologic product was made successfully from L. rhamnosus using the whole bacterial culture broth, without waste, and using food-grade silica (4.5 mL g^-1 ) to absorb water before drying at 37 °C for 8 h. The activity of L. rhamnosus cells was increased significantly by adding water extracts of green tea to the culture medium. The viable amount of L. rhamnosus in the obtained microecologic product was 9.80 × 10¹⁰  cfu g^-1 with a survival rate of 224.67% in simulated gastric juice for 3 h and 68.2% in simulated intestinal juice for 3 h. The microecologic product treated an intestinal infection by multi-drug-resistant Staphylococcus aureus in mice very efficiently.

CONCLUSION

The study developed an economic, eco-friendly, and efficient method for preparing highly active microecologic agents using heating and without waste. © 2022 Society of Chemical Industry.

Low FODMAP Diet and Probiotics in Irritable Bowel Syndrome: A Systematic Review With Network Meta-analysis

Background: Probiotic and low fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) diet are two commonly used management approaches for patients with irritable bowel syndrome (IBS). We aimed to evaluate the most effective combinations and components among different probiotics or low FODMAP diet through component network meta-analysis (NMA).

Methods: We searched Embase, Ovid Medline, and Web of Science from inception to 21 January 2021. Randomized controlled trials (RCTs) examining the efficacy of probiotics and low FODMAP diet for IBS were included, with placebo, sham diet, or conventional treatments as controls. Binary outcomes were compared among treatments using the relative ratio (RR). A minimally contextualized framework recommended by the GRADE group was used to evaluate the certainty of evidence. The primary efficacy outcome was the relief of global IBS symptoms, and the secondary efficacy outcome was the reduction in IBS symptom scores or abdominal pain scores.

Key Results: We included 76 RCTs (n = 8058) after screening 1940 articles. Eight RCTs were classified as low risk of bias. Standard network meta-analysis (NMA) showed that Lactobacillus (RR 1.74, 95% CI 1.22–2.48) and Bifidobacterium (RR 1.76, 95% CI 1.01–3.07) were the most effective for the primary efficacy outcome (high certainty evidence); component NMA showed that Bacillus (RR 5.67, 95% CI 1.88 to 17.08, p = 0.002) and Lactobacillus (RR 1.42, 95% CI 1.07 to 1.91, p = 0.017) were among the most effective components. The results of standard NMA and CNMA analysis of the improvement of overall IBS symptom scores or abdominal pain scores were consistent with this finding.

Conclusion:Lactobacillus was the most effective component for the relief of IBS symptoms; Bifidobacterium and Bacillus were possibly effective and need further verification.

Systematic Review Registration: website, identifier registration number.

Probiotic therapy in patients with irritable bowel syndrome: does it have a real role?

Background

Irritable bowel syndrome (IBS) is one of the most prevalent functional gastrointestinal disorders (FGIDs). There is good evidence that microbiota plays a predominant role in the IBS pathophysiology. The aim of the study is to evaluate the role of probiotics in improvement of IBS symptoms via IBS-symptom severity scale (IBS-SSS Arabic version) and improvement of quality of life via irritable bowel syndrome-quality of life survey (IBS-QOL).

Results

This double-armed comparative trial was conducted on IBS patients, who fulfill ROME IV criteria and the IBS diagnostic questionnaire between August and December 2019. Ninety patients were followed up for 4 weeks from the first visit. The first group was prescribed probiotics (10 billion colony of Lactobacillus delbruekii and Lactobacillus fermentum) and itopride hcl 50 mg three times daily, while the second group received only itopride hcl 50 mg by the same dose for 4 weeks. There was a highly significant improvement in the IBS-SSS score in group 1 after 4 weeks of treatment than in group 2 (137.56±67.53 vs 258.44±34.18) (p=0.001). Also, there was a highly significant improvement in the overall QOL terms in group 1 in comparison with baseline QOL score [with overall mean score (60.64±7.77) at baseline vs (81.54±7.87) at 4 weeks (p value <0.001)].

Conclusion

Probiotics are useful for the improvement of IBS symptoms and quality of life of the studied patients. Larger multicenter studies are needed in the future.

A genome guided evaluation of the Lab4 probiotic consortium

In this study, we present the draft genome sequences of the Lab4 probiotic consortium using whole genome sequencing. Draft genome sequences were retrieved and deposited for each of the organisms; PRJNA559984 for B. bifidum CUL20, PRJNA482335 for Lactobacillus acidophilus CUL60, PRJNA482434 for Lactobacillus acid. Probiogenomic in silico analyses confirmed existing taxonomies and identified the presence putative gene sequences that were functionally related to the performance of each organism during in vitro assessments of bile and acid tolerability, adherence to enterocytes and susceptibility to antibiotics. Predictions of genomic stability identified no significant risk of horizontal gene transfer in any of the Lab4 strains and the absence of both antibiotic resistance and virulence genes. These observations were supported by the outcomes of acute phase and repeat dose tolerability studies in Wistar rats where challenge with high doses of Lab4 did not result in any mortalities, clinical/histopathological abnormalities nor indications of systemic toxicity. Detection of increased numbers of lactobacilli and bifidobacteria in the faeces of supplemented rats implied an ability to survive transit through the gastrointestinal tract and/or impact upon the intestinal microbiota composition. In summary, this study provides in silico, in vitro and in vivo support for probiotic functionality and the safety of the Lab4 consortium.

The Effect of Probiotics on Quality of Life, Depression and Anxiety in Patients with Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis

Background: Functional gastrointestinal disorders such as irritable bowel syndrome (IBS) report clinical improvement following probiotic therapy, but whether psychiatric comorbidity and quality-of-life in IBS improves directly or in directly is unknown. This meta-analysis synthesized the evidence regarding the effects of probiotics on quality of life (QoL), anxiety and depression in IBS. Methods: The review was executed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the databases PubMed, Web of Science and Cochrane Library. For QoL, the data were meta-analyzed, and for anxiety and depression a qualitative analysis was performed. Results: Thirty-five placebo-controlled studies were included of which 11 were eligible for meta-analysis. QoL improved with probiotic and placebo similarly, with the probiotic interventions slightly superior (mean QoL difference—0.36 (95% CI: 0.07, 0.64); p = 0.01). Anxiety and depression were similar between placebo and probiotic groups following therapy. Conclusion: For IBS, probiotic therapy improved QoL, but had no effects on anxiety and depression. However, the applied probiotics were not developed for selective effects on psyche and the brain. Therefore, it remains to be shown whether or not patients with IBS would benefit from second generation probiotics developed for these central effects (psychobiotics).

Microbiome and Graves' Orbitopathy

BACKGROUND

Studies from animal models of autoimmunity have highlighted the potential importance of microorganisms and their metabolic products in shaping the immune system.

SUMMARY

This review provides an introduction to the current state-of-the-art in microbiome research both from the perspective of "what is known" and of methodologies for its investigation. It then summarises the evidence for a role for the microbiome in the pathogenesis of Graves' disease and Graves' orbitopathy with reference to animal models and studies in human cohorts, from both published and ongoing sources.

KEY MESSAGE

Microbiome research is in its infancy but has already provided novel insights into disease pathogenesis across the spectrum from cancer to mental health and autoimmunity.

Effects of Probiotics on Depressive or Anxiety Variables in Healthy Participants Under Stress Conditions or With a Depressive or Anxiety Diagnosis: A Meta-Analysis of Randomized Controlled Trials

Background: Probiotics have been associated with the treatment of depression and anxiety. However, the results reported in the literature have been inconsistent, and no meta-analysis specifically reported probiotics used on participants with varying levels of emotional state. Methods: This meta-analysis aimed to study the effectiveness of probiotics on anxious or depressive symptomatology for participants under stress conditions or with a depressive or anxiety disorder diagnosis. Medline, PubMed, EMBASE, and the Cochrane Library were searched through December 2019 for randomized controlled trials (RCTs). The primary outcomes were depression and anxiety scores. Main inclusion criteria: RCTs of probiotics for participants with a mood or emotional disorder diagnosis or under stress situations; and all participants were adults (age ≥16 years); Assessed by the modified Jadad assessment scale found seven high-quality studies and three low-quality studies. Results: Ten clinical trials (n = 685 total participants) were included based on the inclusion and exclusion criteria. All studies were assessed as low or moderate risk of bias. The meta-analysis showed that probiotics could significantly reduce the depression scale for patients with anxiety and depression, and healthy participants under stress. However, there was no significant difference between the probiotics and placebo groups in the reduction of patient anxiety scores, even if they are depressive or anxious patients or healthy participants under stress. Subgroup analysis revealed that probiotics had significant effect on depressive symptoms just in patients with depression, and no significant change in anxiety in patients, and no improvement in participant performance under stress. Conclusions: Probiotics could alleviate depressive symptoms in patients with a depression diagnosis or depression scores also in anxiety disorder diagnosis, and suggesting that probiotics may be adjunct therapies for mood or emotional disorders. Therefore, it is essential that probiotics could be more involved in the treatment of patients with depression in the future. The evidence of probiotics successfully treating depression is still insufficient, and more high-quality studies on patients with depression are still needed.

Efficacy of Lactobacillus paracasei HA-196 and Bifidobacterium longum R0175 in Alleviating Symptoms of Irritable Bowel Syndrome (IBS): A Randomized, Placebo-Controlled Study

Specific probiotic strains can alleviate the gastrointestinal (GI) symptoms and psychiatric comorbidities of irritable bowel syndrome (IBS). In this randomized, double-blind, placebo-controlled study, the efficacy of Lactobacillus paracasei HA-196 (L. paracasei) and Bifidobacterium longum R0175 (B. longum) in reducing the GI and psychological symptoms of IBS was evaluated in 251 adults with either constipation (IBS-C), diarrhea (IBS-D), or mixed-pattern (IBS-M). Following a 2-week run-in period, participants were randomized to one of three interventions: L. paracasei (n = 84), B. longum (n = 83) or placebo (n = 81). IBS symptoms, stool frequency and consistency and quality of life were assessed by questionnaires. The differences from baseline in the severity of IBS symptoms at 4 and 8 weeks were similar between groups. Participants in this study were classified, after randomization, into subtypes according to Rome III. Within the L. paracasei group, complete spontaneous and spontaneous bowel movement frequency increased in participants with IBS-C (n = 10) after 8 weeks of supplementation (both p < 0.05) and decreased in participants with IBS-D (n = 10, p = 0.013). Both L. paracasei and B. longum supplementation improved the quality of life in emotional well-being and social functioning compared with baseline (all p < 0.05). In conclusion, L. paracasei and B. longum may reduce GI symptom severity and improve the psychological well-being of individuals with certain IBS subtypes.

Efficacy and Safety of Probiotics in Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis

Background

Irritable bowel syndrome is a functional gastrointestinal disease. Evidence has suggested that probiotics may benefit IBS symptoms. However, clinical trials remain conflicting.

Aims

To implement a systematic review and meta-analysis of clinical trials regarding the efficacy and safety of probiotics for IBS patients.

Methods

We searched for relevant trials in Medline(1966 to Jan 2019), Embase(1974 to Jan 2019), the Cochrane Central Register of Controlled Trials(up to Jan 2019), the ClinicalTrials.gov trials register(up to Jan 2019), and Chinese Biomedical Literature Database(1978 to Jan 2019). Risk ratio (RR) and a 95% confidence interval (CI) were calculated for dichotomous outcomes. Standardized mean difference (SMD) and 95% CI were calculated for continuous outcomes.

Results

A total of 59 studies, including 6,761 patients, were obtained. The RR of the improvement or response with probiotics versus placebo was 1.52 (95% CI 1.32-1.76), with significant heterogeneity (I² = 71%, P < 0.001). The SMD of Probiotics in improving global IBS symptoms vs. Placebo was -1.8(95% CI -0.30 to -0.06), with significant heterogeneity (I² = 65%, P < 0.001). It was impossible to draw a determinate conclusion. However, there were differences in subgroup analyses of probiotics type, dose, treatment duration, and geographic position. Probiotics seem to be safe by the analysis of adverse events(RR = 1.07; 95% CI 0.92-1.24; I² = 0, P = 0.83).

Conclusion

Probiotics are effective and safe for IBS patients. Single probiotics with a higher dose (daily dose of probiotics ≥10¹⁰) and shorter duration (< 8 weeks) seem to be a better choice, but it still needs more trials to prove it.

Efficacy and Safety of Probiotics, Prebiotics and Synbiotics in the Treatment of Irritable Bowel Syndrome: A systematic review and meta-analysis

Treatments that target alterations in gut microbiota may be beneficial for patients with irritable bowel syndrome (IBS). A systematic review and meta-analysis was conducted of randomised clinical trials (RCTs) evaluating the efficacy and safety of probiotics, prebiotics and synbiotics. Factors considered in the analysis included global IBS symptoms and/or abdominal pain, secondary symptoms and the frequency of adverse events. A total of 33 RCTs involving 4,321 patients were identified. Overall, probiotics significantly improved global IBS symptoms compared to placebos (standardised mean difference = −0.32, 95% confidence interval: −0.48 to −0.15; P <0.001), with significant heterogeneity between studies (I² = 72%; P <0.001). This remained apparent in both single- and multi-strain probiotic interventions as well as synbiotic formulations. However, evidence regarding prebiotics was scarce. There were no significant inter-group differences in terms of the frequency of adverse events. Future RCTs should address methodological limitations, including short follow-up periods and patient adherence.

Efficacy and safety of probiotics in irritable bowel syndrome: A systematic review and meta-analysis

BACKGROUND/AIM

Irritable Bowel Syndrome (IBS) is a common chronic functional bowel disorder and the evidence shows most drug therapies in the treatment of IBS are weak. Recently, some studies showed probiotics may have a positive effect in IBS and they are widely used to improve the symptom of IBS, which indicate probiotics may play an important role in the treatment of IBS. However, the exact effectiveness and safety of probiotics are largely unknown. This systematic review focuses on identifying the efficacy and safety of probiotics in the treatment of IBS.

MATERIALS AND METHODS

Data sources were searched up to February 2019. Databases included MEDLINE, CENTRAL, CINAHL, and Embase. Randomized controlled trials (RCTs) comparing probiotics including complex or individual probiotics with placebo or no therapy were screened, extracted, and appraised by two independent reviewers. The data were pooled using a random-effects model. The methodological quality of all RCTs was assessed using the Cochrane risk of bias and Jadad scale. Outcomes included symptom-relevant and patient-relevant characteristics, such as symptom relief, abdominal pain, bloating, flatulence, quality of life, and adverse event.

RESULTS

This review includes 28 studies with a total of 3606 participants. Particular combinations of probiotics, or specific species and strains, showed probiotics have beneficial effect on overall IBS symptoms (22 studies, n = 3144, RR of improvement in overall IBS symptoms = 1.5, CI 1.23 to 1.83) or overall IBS symptom and abdominal pain scores (18 studies, n = 2766, SMD = -0.31, CI -0.45 to -0.17). In addition, adverse events were not significantly higher with probiotics (8 studies, n = 923, RR = 1.05; 95% CI 0.85-1.31). However, there was no significant benefit on individual IBS symptom scores and quality of life.

CONCLUSION

Current evidence shows particular combinations, species or strains of probiotics are effective for overall IBS symptoms. However, it is hard to derive a definite conclusion due to high heterogeneity and unclear risk of bias of some trials. Large well-designed and rigorous trials are warranted.

Randomized clinical trial: the effect of probiotic Bacillus coagulans Unique IS2 vs. placebo on the symptoms management of irritable bowel syndrome in adults

The therapeutic effects of B. coagulans Unique IS2 have been well established in children with irritable bowel syndrome (IBS), but its efficacy in adults remain under reported. Thus, in this study the efficacy of B. coagulans Unique IS2 in the management of IBS symptoms in adults was investigated. Patients (n = 153) fulfilling Rome III criteria were provided placebo capsules for a 2 weeks run-in period. Only patients satisfying compliance criteria (n = 136) were randomized (double blind) to receive either B. coagulans Unique IS2 (2 billion CFU) or placebo capsules daily for 8 weeks. Reduction of abdominal discomfort/pain intensity and increase in complete spontaneous bowel movements were analyzed as primary end points. Other clinical symptoms of IBS and serum cytokines were also evaluated. B. coagulans Unique IS2 showed significant improvement in primary and secondary endpoints, as compared to placebo. Haematology of both the arms remained normal. No significant changes in pro- (IL-6, IL-12, TNF-α, INF- γ) and anti-inflammatory cytokine (IL-10) levels were detected at the end of B. coagulans treatment (8 weeks) as compared to placebo. B. coagulans was well tolerated with no severe adverse events to report. Overall, the results demonstrate that B. coagulans Unique IS2 is efficacious in the management of IBS symptoms in adults (18–60 years).

Adhesive Bifidobacterium Induced Changes in Cecal Microbiome Alleviated Constipation in Mice

Constipation, which seriously affects living quality of people, is a common gastrointestinal disease. The engagement of the intestinal flora in the development of symptoms of constipation has been frequently hypothesized. In this study, constipated mice induced by loperamide were used to investige the alleviation of constipation by Bifidobacteria. Bifidobacteria was sorted out according to their adhesive properties into two groups. One group combined multiple strains of Bifidobacterium with adhesion property (CMB1), the other combined multiple strains of Bifidobacterium without adhesion property (CMB2). It was found that CMB1 can alleviate constipation more efficiently by improving the water, propionate and butyrate content in feces, and overall gastrointestinal transit time. Meanwhile, from the perspective of fecal microbiota, CMB1 alleviated constipation mainly by increasing the relative abundances of genera (Bifidobacterium, Lactobacillus, and Prevotella) associated with rapid bowel movement. From the perspective of cecal microbiota, CMB1 alleviated constipation mainly by increasing the relative abundances of genera Lactobacillus, Bacteroides, unclassified S24-7, Dorea, Ruminococcus, Coprococcus, and Rikenella, and decreasing the relative abundances of genera Oscillospira, Odoribacter and Unclassified F16, which are associated with methane production and colonic transit. Overall, changes of microbiota in caecum by CMB1 reflect the stage of constipation in mice more comprehensively than that in feces.

Systematic review with meta-analysis: the efficacy of prebiotics, probiotics, synbiotics and antibiotics in irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a chronic functional bowel disorder. Disturbances in the gastrointestinal microbiome may be involved in its aetiology.

AIM

To perform a systematic review and meta-analysis to examine the efficacy of prebiotics, probiotics, synbiotics and antibiotics in IBS.

METHODS

MEDLINE, EMBASE, and the Cochrane Controlled Trials Register were searched (up to July 2017). Randomised controlled trials (RCTs) recruiting adults with IBS, comparing prebiotics, probiotics, synbiotics or antibiotics with placebo or no therapy were eligible. Dichotomous symptom data were pooled to obtain a relative risk (RR) of remaining symptomatic after therapy, with a 95% confidence interval (CI). Continuous data were pooled using a standardised mean difference with a 95% CI.

RESULTS

The search identified 4017 citations. Data for prebiotics and synbiotics were sparse. Fifty-three RCTs of probiotics, involving 5545 patients, were eligible. Particular combinations of probiotics, or specific species and strains, appeared to have beneficial effects on global IBS symptoms and abdominal pain, but it was not possible to draw definitive conclusions about their efficacy. There were five trials of similar design that used rifaximin in non-constipated IBS patients, which was more effective than placebo (RR of symptoms persisting = 0.84; 95% CI 0.79-0.90). Adverse events were no more common with probiotics or antibiotics.

CONCLUSIONS

Which particular combination, species or strains of probiotics are effective for IBS remains, for the most part, unclear. Rifaximin has modest efficacy in improving symptoms in non-constipated IBS.

Efficacy of probiotics on anxiety-A meta-analysis of randomized controlled trials

BACKGROUND

The concept "psychobiotics" claims potential beneficial effect of probiotics on anxiety, whereas findings from clinical trials are inconsistent. Thus, a meta-analysis is needed to clarify the effect of probiotics on anxiety.

METHODS

Randomized controlled trials (RCTs) assessing the effect of probiotics on anxiety were systematically retrieved from online databases and manually screened for references of relevant published literature through September 1, 2017. Standardized mean difference in change from baseline of anxiety rating scales between probiotics groups and placebo groups was selected as the main effect index. Subgroup analyses were conducted with respect to overall health status of the sample, existence of gastrointestinal symptoms, strains of flora, trial duration, and risk of bias assessment. Publication bias was evaluated by funnel plot and Egger's test. The reliability of the result was assessed by leave-one-out sensitivity analysis.

RESULTS

Twelve studies with 1,551 subjects (871 in probiotics group and 680 in control group) were included. All the studies were rated as low or moderate risk of bias. The meta-analysis and subgroup analyses all showed no significant difference between probiotics and placebo in alleviating anxiety symptoms. The Egger's test revealed no evidence of significant publication bias. Sensitivity analysis showed that leaving out one study would result in marginal significance.

CONCLUSIONS

The evidence for the efficacy of probiotics in alleviating anxiety, as presented in currently published RCTs, is insufficient. More reliable evidence from clinical trials is needed before a case can be made for promoting the use of probiotics for alleviating anxiety.

Probiotics Ameliorate Stool Consistency in Patients with Chronic Constipation: A Randomized, Double-Blind, Placebo-Controlled Study

BACKGROUND/AIMS

The efficacy of probiotics for improving clinical symptoms, altering the fecal microbiota, and regulating serum immune cytokine levels was investigated in patients with irritable bowel syndrome-constipation (IBS-C) or functional constipation (FC).

METHODS

A randomized, double-blind, placebo-controlled trial was conducted at Kyung Hee University Hospital between October 2016 and February 2017. Consecutive 18-75-year-old patients with diagnosis of IBS-C or FC (based on Rome IV criteria) consumed probiotics (3.0 × 10⁸ CFU/g Streptococcus thermophilus MG510 and 1.0 × 10⁸ CFU/g Lactobacillus plantarum LRCC5193) or a placebo daily for 4 weeks (weeks 1-4) and were followed up for a 4-week washout period without intervention (weeks 5-8). The primary outcomes of the study were Bristol Stool Form Scale and Complete Spontaneous Bowel Movements (CSBM). Efficacy was assessed by per protocol.

RESULTS

Stool consistency measured by the Bristol Stool Form Scale was significantly better in the probiotic group (n = 88) than in the placebo group (n = 83) at 4 and 8 weeks (3.7 ± 1.1 vs. 3.1 ± 1.1 at 8 weeks, P = 0.002). No significant difference was found in CSBM. The quality of life was significantly better in the probiotic group than in the placebo group at 4 weeks (P = 0.044) and 8 weeks (P = 0.049). The relative abundance of L. plantarum among the fecal microbiomes was significantly greater in the probiotic group than in the placebo group at 4 weeks (P = 0.029). However, the levels of other microbiomes and of serum cytokines (IL-10/IL-12 ratio and TNF-α) did not differ significantly between the two groups.

CONCLUSIONS

Probiotics significantly ameliorated stool consistency in patients with chronic constipation. In addition, the beneficial effect of L. plantarum on stool consistency remained after the probiotic supplementation was discontinued. The mechanism whereby probiotics benefit patients with chronic constipation should be clarified in further studies.

Guidelines on the management of irritable bowel syndrome: In memory of Professor Witold Bartnik

These guidelines constitute an update of the previous "Recommendations on the management of irritable bowel syndrome" issued in 2008. They have been developed by a Task Force organized by the Governing Board of the Polish Society of Gastroenterology. They discuss, with particular emphasis on new scientific data covering papers published since 2008, the aetiology, epidemiology, clinical presentation, diagnostic principles and criteria for the diagnosis, and recommendations for the treatment of irritable bowel syndrome (IBS). The English-language acronym for the syndrome (IBS) has become popular in medical and popular scientific language. It is also widely recognized by patients who identify with this diagnosis. Therefore, in the discussed guidelines, this is what we will use.

Systematic review: probiotics in the management of lower gastrointestinal symptoms - an updated evidence-based international consensus

BACKGROUND

In 2013, a systematic review and Delphi consensus reported that specific probiotics can benefit adult patients with irritable bowel syndrome (IBS) and other gastrointestinal (GI) problems.

AIM

To update the consensus with new evidence.

METHODS

A systematic review identified randomised, placebo-controlled trials published between January 2012 and June 2017. Evidence was graded, previously developed statements were reassessed by an 8-expert panel, and agreement was reached via Delphi consensus.

RESULTS

A total of 70 studies were included (IBS, 34; diarrhoea associated with antibiotics, 13; diarrhoea associated with Helicobacter pylori eradication therapy, 7; other conditions, 16). Of 15 studies that examined global IBS symptoms as a primary endpoint, 8 reported significant benefits of probiotics vs placebo. Consensus statements with 100% agreement and "high" evidence level indicated that specific probiotics help reduce overall symptom burden and abdominal pain in some patients with IBS and duration/intensity of diarrhoea in patients prescribed antibiotics or H. pylori eradication therapy, and have favourable safety. Statements with 70%-100% agreement and "moderate" evidence indicated that, in some patients with IBS, specific probiotics help reduce bloating/distension and improve bowel movement frequency/consistency.

CONCLUSIONS

This updated review indicates that specific probiotics are beneficial in certain lower GI problems, although many of the new publications did not report benefits of probiotics, possibly due to inclusion of new, less efficacious preparations. Specific probiotics can relieve lower GI symptoms in IBS, prevent diarrhoea associated with antibiotics and H. pylori eradication therapy, and show favourable safety. This study will help clinicians recommend/prescribe probiotics for specific symptoms.

The Role of Bacteria, Probiotics and Diet in Irritable Bowel Syndrome

Irritable bowel syndrome is a highly prevalent gastrointestinal disorder that threatens the quality of life of millions and poses a substantial financial burden on healthcare systems around the world. Intense research into the human microbiome has led to fascinating discoveries which directly and indirectly implicate the diversity and function of this occult organ in irritable bowel syndrome (IBS) pathophysiology. The benefit of manipulating the gastrointestinal microbiota with diet and probiotics to improve symptoms has been demonstrated in a wealth of both animal and human studies. The positive and negative mechanistic roles bacteria play in IBS will be explored and practical probiotic and dietary choices offered.

Modulation of the gut microbiota: a focus on treatments for irritable bowel syndrome

Irritable bowel syndrome (IBS), which is characterized by recurrent abdominal pain and disordered bowel habits, is one of the most common functional bowel disorders. IBS is a substantial burden on both patient health-related quality of life and healthcare costs. Several pathophysiologic mechanisms have been postulated for the occurrence of IBS, including altered gastrointestinal motility, visceral hypersensitivity, changes in gut permeability, immune activation, gut-brain dysregulation, central nervous system dysfunction, and changes in the gut microbiota. Of note, both qualitative and quantitative differences have been observed in the gut microbiota of a population with IBS versus a healthy population. Because of the substantial interest in the gut microbiota and its role as a therapeutic target in IBS, this article provides an overview of specific interventions with the potential to modulate the gut microbiota in IBS, including elimination diets, prebiotics, probiotics, synbiotics, and nonsystemic antibiotics. Although probiotics and synbiotics are generally well tolerated, differences in the composition and concentration of different bacterial species and inclusion or exclusion of prebiotic components varies widely across studies and has prevented strong recommendations on their use in IBS. For nonsystemic antibiotics, rifaximin is indicated in the United States for the treatment of IBS with diarrhea in adults and has been shown to be efficacious and well tolerated in well-designed clinical trials. Overall, more consistent evidence is needed regarding the efficacy and safety of elimination diets, prebiotics, probiotics, and synbiotics for the treatment of patients with IBS. Furthermore, additional well-designed studies are needed that examine alterations in the gut microbiota that occur with these interventions and their potential associations with clinical symptoms of IBS.

The anti-cholesterolaemic effect of a consortium of probiotics: An acute study in C57BL/6J mice

Hypercholesterolaemia is a major risk factor for cardiovascular disease and it has been found that some probiotic bacteria possess cholesterol-lowering capabilities. In this study, the ability of the Lab4 probiotic consortium to hydrolyse bile salts, assimilate cholesterol and regulate cholesterol transport by polarised Caco-2 enterocytes was demonstrated. Furthermore, in wild-type C57BL/6J mice fed a high fat diet, 2-weeks supplementation with Lab4 probiotic consortium plus Lactobacillusplantarum CUL66 resulted in significant reductions in plasma total cholesterol levels and suppression of diet-induced weight gain. No changes in plasma levels of very low-density lipoprotein/low-density lipoprotein, high-density lipoprotein, triglycerides, cytokines or bile acids were observed. Increased amounts of total and unconjugated bile acids in the faeces of the probiotic-fed mice, together with modulation of hepatic small heterodimer partner and cholesterol-7α-hydroxylase mRNA expression, implicates bile salt hydrolase activity as a potential mechanism of action. In summary, this study demonstrates the cholesterol-lowering efficacy of short-term feeding of the Lab4 probiotic consortium plus L. plantarum CUL66 in wild-type mice and supports further assessment in human trials.

Bifidobacteria exert species-specific effects on constipation in BALB/c mice

Edible bifidobacteria exerted species-specific effects in relieving constipation.

Irritable bowel syndrome symptom severity improves equally with probiotic and placebo

AIM

To determine the effects of Lactobacillus acidophilus NCFM on irritable bowel syndrome (IBS) symptoms and quality of life (QoL).

METHODS

In this randomized triple-blind trial, adult IBS volunteers who were recruited according to Rome III criteria received 10⁹ or 10¹⁰ colony-forming units of NCFM or placebo daily for 12 wk. IBS Symptom Severity Score (IBS-SSS), which constituted the primary outcome, and secondary outcomes, including individual IBS symptoms, IBS-related QoL questionnaire, anxiety and depression, defecation frequency, and stool consistency, were assessed at baseline at the end of the 8-wk run-in period, after 4 and 12 wk of intervention, and after a 4-wk washout.

RESULTS

A total of 340 of 391 randomized volunteers completed the trial. IBS-SSS improved over 12 wk of treatment in all treatment groups, decreasing by a mean ± SD of 44.0 ± 80.2, 50.8 ± 82.4, and 48.3 ± 72.2 in the placebo, active low-dose, and active high-dose groups, respectively. Similarly, secondary outcomes did not differ between treatment groups. However, in a post hoc analysis of volunteers with moderate to severe abdominal pain at baseline (VAS > 35/100), the treatment significantly reduced the sensation of abdominal pain. Pain scores fell by 20.8 ± 22.8, 29.4 ± 17.9, and 31.2 ± 21.9 in the placebo, active low-dose, and active high-dose groups, respectively (P value for placebo vs combined active doses = 0.0460).

CONCLUSION

NCFM alleviates moderate to severe abdominal pain, consistent with earlier observations of this strain mitigating visceral pain through increased analgesic receptor expression.

An Exploratory Investigation of Endotoxin Levels in Novice Long Distance Triathletes, and the Effects of a Multi-Strain Probiotic/Prebiotic, Antioxidant Intervention

Gastrointestinal (GI) ischemia during exercise is associated with luminal permeability and increased systemic lipopolysaccharides (LPS). This study aimed to assess the impact of a multistrain pro/prebiotic/antioxidant intervention on endotoxin unit levels and GI permeability in recreational athletes. Thirty healthy participants (25 males, 5 females) were randomly assigned either a multistrain pro/prebiotic/antioxidant (LAB⁴_ANTI; 30 billion CFU·day⁻¹ containing 10 billion CFU·day⁻¹Lactobacillus acidophilus CUL-60 (NCIMB 30157), 10 billion CFU·day⁻¹Lactobacillus acidophillus CUL-21 (NCIMB 30156), 9.5 billion CFU·day⁻¹Bifidobacterium bifidum CUL-20 (NCIMB 30172) and 0.5 billion CFU·day⁻¹Bifidobacterium animalis subspecies lactis CUL-34 (NCIMB 30153)/55.8 mg·day⁻¹ fructooligosaccharides/ 400 mg·day⁻¹ α-lipoic acid, 600 mg·day⁻¹N-acetyl-carnitine); matched pro/prebiotic (LAB⁴) or placebo (PL) for 12 weeks preceding a long-distance triathlon. Plasma endotoxin units (via Limulus amebocyte lysate chromogenic quantification) and GI permeability (via 5 h urinary lactulose (L): mannitol (M) recovery) were assessed at baseline, pre-race and six days post-race. Endotoxin unit levels were not significantly different between groups at baseline (LAB⁴_ANTI: 8.20 ± 1.60 pg·mL⁻¹; LAB⁴: 8.92 ± 1.20 pg·mL⁻¹; PL: 9.72 ± 2.42 pg·mL⁻¹). The use of a 12-week LAB⁴_ANTI intervention significantly reduced endotoxin units both pre-race (4.37 ± 0.51 pg·mL⁻¹) and six days post-race (5.18 ± 0.57 pg·mL⁻¹; p = 0.03, ηp² = 0.35), but only six days post-race with LAB⁴ (5.01 ± 0.28 pg·mL⁻¹; p = 0.01, ηp² = 0.43). In contrast, endotoxin units remained unchanged with PL. L:M significantly increased from 0.01 ± 0.01 at baseline to 0.06 ± 0.01 with PL only (p = 0.004, ηp² = 0.51). Mean race times (h:min:s) were not statistically different between groups despite faster times with both pro/prebiotoic groups (LAB⁴_ANTI: 13:17:07 ± 0:34:48; LAB⁴: 12:47:13 ± 0:25:06; PL: 14:12:51 ± 0:29:54; p > 0.05). Combined multistrain pro/prebiotic use may reduce endotoxin unit levels, with LAB⁴_ANTI potentially conferring an additive effect via combined GI modulation and antioxidant protection.

British Dietetic Association systematic review and evidence-based practice guidelines for the dietary management of irritable bowel syndrome in adults (2016 update)

BACKGROUND

The first British Dietetic Association (BDA) guidelines for the dietary management of irritable bowel syndrome (IBS) in adults were published in 2012. Subsequently, there has been a wealth of new research. The aim of this work was to systematically review the evidence for the role of diet in the management of IBS and to update the guidelines.

METHODS

Twelve questions relating to diet and IBS were defined based on review of the previous guideline questions, current evidence and clinical practice. Chosen topics were on healthy eating and lifestyle (alcohol, caffeine, spicy food, elimination diets, fat and fluid intakes and dietary habits), milk and dairy, dietary fibre, fermentable carbohydrates, gluten, probiotics and elimination diets/food hypersensitivity. Data sources were CINAHL, Cochrane Register of Controlled Trials, Embase, Medline, Scopus and Web of Science up to October 2015. Studies were assessed independently in duplicate using risk of bias tools specific to each included study based on inclusion and exclusion criteria for each question. National Health and Medical Research Council grading evidence levels were used to develop evidence statements and recommendations, in accordance with Practice-based Evidence in Nutrition Global protocol used by the BDA.

RESULTS

Eighty-six studies were critically appraised to generate 46 evidence statements, 15 clinical recommendations and four research recommendations. The IBS dietary algorithm was simplified to first-line (healthy eating, provided by any healthcare professional) and second-line [low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) to be provided by dietitian] dietary advice.

CONCLUSIONS

These guidelines provide updated comprehensive evidence-based details to achieve the successful dietary management of IBS in adults.

Efficacy of a Gluten-Free Diet in Subjects With Irritable Bowel Syndrome-Diarrhea Unaware of Their HLA-DQ2/8 Genotype

BACKGROUND & AIMS

A gluten-containing diet alters bowel barrier function in patients with irritable bowel syndrome with diarrhea (IBS-D), particularly those who are positive for HLA allele DQ2/8. We studied the effects of a gluten-free diet (GFD) in patients with IBS-D who have not previously considered the effects of gluten in their diet and were unaware of their HLA-DQ2/8 genotype.

METHODS

We performed a prospective study of 41 patients with IBS-D (20 HLA-DQ2/8-positive and 21 HLA-DQ2/8-negative) at the Royal Hallamshire Hospital in Sheffield, United Kingdom, from September 2012 through July 2015. All subjects were placed on a 6-week GFD following evaluation by a dietician. Subjects completed validated questionnaires at baseline and Week 6 of the GFD. The primary endpoint was mean change in IBS Symptom Severity Score; a 50-point reduction was considered to indicate a clinical response. Secondary endpoints were changes in hospital anxiety and depression score, fatigue impact score, and Short Form-36 results. Clinical responders who chose to continue a GFD after the study period were evaluated on average 18 months later to assess diet durability, symptom scores, and anthropometric and biochemical status.

RESULTS

A 6-week GFD reduced IBS Symptom Severity Score by ≥50 points in 29 patients overall (71%). The mean total IBS Symptom Severity Score decreased from 286 before the diet to 131 points after 6 weeks on the diet (P < .001); the reduction was similar in each HLA-DQ group. However, HLA-DQ2/8-negative subjects had a greater reduction in abdominal distention (P = .04). Both groups had marked mean improvements in hospital anxiety and depression scores, fatigue impact score, and Short Form-36 results, although HLA-DQ2/8-positive subjects had a greater reduction in depression score and increase in vitality score than HLA-DQ2/8-negative subjects (P = .02 and P = .03, respectively). Twenty-one of the 29 subjects with a clinical response (72%) planned to continue the GFD long term; 18 months after the study they were still on a GFD, with maintained symptom reductions, and demonstrated similar anthropometric and biochemical features compared with baseline.

CONCLUSIONS

A dietitian-led GFD provided sustained benefit to patients with IBS-D. The symptoms that improved differed in magnitude according to HLA-DQ status. Clinical trials.gov no: NCT02528929.

Probiotic Bacterial and Fungal Strains: Claims with Evidence

BACKGROUND

Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit for the host. This review summarizes current (i.e. published in the last 5 years) key evidence on probiotic efficacy and its safety in adults and children. To identify relevant data, searches of MEDLINE and the Cochrane Library databases were performed in August 2015 to locate randomized controlled trials (RCTs) or their meta-analyses. The focus was on commonly used, well-specified, bacterial and yeast probiotics for the treatment of gastrointestinal disorders. The MEDLINE database was also searched for evidence-based clinical practice guidelines, developed by scientific societies in the same timeframe. Data on safety of probiotics were obtained from a document developed by the US Agency for Healthcare Research and Quality.

KEY MESSAGES

A number of relevant RCTs and meta-analyses are available. Saccharomyces boulardii is the most studied yeast probiotic, and Lactobacillus rhamnosus GG is the most studied bacterial probiotic. For both, the best documented fact is their efficacy for the treatment of acute gastroenteritis, especially in children, and for the prevention of antibiotic-associated diarrhea, both in adults and children. There is some evidence to support the use of probiotics to prevent or treat other diseases, such as necrotizing enterocolitis, infantile colic, Helicobacter pylori infection, and irritable bowel syndrome, but further studies are needed to identify which strain(s) is/are the most effective. Data on safety, particularly long-term safety, are limited. The risk of side effects is greater in people who have severe underlying health conditions.

CONCLUSIONS

The evidence on bacterial and yeast probiotics has considerably expanded during recent years. Accumulated data allow one to make informed decisions about the effectiveness of probiotics and about how to reduce the use of those without proven efficacy.

Gut microbiota role in irritable bowel syndrome: New therapeutic strategies

In the last decade the impressive expansion of our knowledge of the vast microbial community that resides in the human intestine, the gut microbiota, has provided support to the concept that a disturbed intestinal ecology might promote development and maintenance of symptoms in irritable bowel syndrome (IBS). As a correlate, manipulation of gut microbiota represents a new strategy for the treatment of this multifactorial disease. A number of attempts have been made to modulate the gut bacterial composition, following the idea that expansion of bacterial species considered as beneficial (Lactobacilli and Bifidobacteria) associated with the reduction of those considered harmful (Clostridium, Escherichia coli, Salmonella, Shigella and Pseudomonas) should attenuate IBS symptoms. In this conceptual framework, probiotics appear an attractive option in terms of both efficacy and safety, while prebiotics, synbiotics and antibiotics still need confirmation. Fecal transplant is an old treatment translated from the cure of intestinal infective pathologies that has recently gained a new life as therapeutic option for those patients with a disturbed gut ecosystem, but data on IBS are scanty and randomized, placebo-controlled studies are required.

Bifidobacterium and irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common functional gastrointestinal (GI) disorder usually originated from gut dysfunction, and the mechanisms underlying IBS are not clear. IBS can seriously disrupt patient's normal routine, even though it is not life-threatening. With the development of high-throughput sequencing technology, a large number of studies have showed that intestinal flora imbalance does play an important role in the pathogenesis of IBS, especially Bifidobacterium. Bifidobacterium can resist the colonization and invasion of intestinal pathogenic bacteria, and enhance the intestinal epithelial barrier function. Besides, its metabolites also can improve the defense function of the intestinal tract. In the gut of patients with IBS, the number of Bifidobacteria is usually significantly reduced, suggesting that increasing the number of intestinal Bifidobacteria may play a positive role in the treatment of IBS. This paper summarizes the relationship between Bifidobacterium and IBS, and discusses the effect of Bifidobacterium in the adjuvant treatment of IBS.

Efficacy of Lactobacillus casei Shirota for patients with irritable bowel syndrome

BACKGROUND AND AIMS

Meta-analyses point to a modest but significant effect of probiotics on symptoms in irritable bowel syndrome (IBS). We aimed to assess the effect of the probiotic Lactobacillus casei Shirota (LcS) on symptoms and quality of life in IBS patients in a randomized, double-blind, placebo-controlled intervention study.

MATERIALS AND METHODS

IBS patients (Rome II) between 18 and 65 years of age were included. The study consisted of an 8-week intervention period in which the participants received probiotic (LcS) or placebo twice daily, followed by an 8-week follow-up period. Symptom diaries and quality of life were scored at weeks 0, 8 and 16. The primary outcome parameter was a decrease of at least 30% in a composite mean symptom score (MSS) at week 8 on the basis of an intention-to-treat analysis.

RESULTS

Thirty-nine individuals (67% women) were included in the probiotic group and 41 individuals (71% women) were included in the placebo group. After the intervention period, the mean relative improvement did not reach 30% for MSS or any individual symptom score. After follow-up (week 16), a mean improvement of at least 30% was achieved for MSS in the probiotic group, but no significant difference was found between both treatment groups (mean±SD: 34±7%; 13±8%, P=0.06).

CONCLUSION

After probiotic treatment with LcS, no improvement of 30% in MSS was observed after 8 weeks.