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Nutrients Dec 2021Alzheimer's disease (AD) is the most common form of neurodegenerative disorders affecting mostly the elderly. It is characterized by the presence of Aβ and...
Alzheimer's disease (AD) is the most common form of neurodegenerative disorders affecting mostly the elderly. It is characterized by the presence of Aβ and neurofibrillary tangles (NFT), resulting in cognitive and memory impairment. Research shows that alteration in gut microbial diversity and defects in gut brain axis are linked to AD. Probiotics are known to be one of the best preventative measures against cognitive decline in AD. Numerous in vivo trials and recent clinical trials have proven the effectiveness of selected bacterial strains in slowing down the progression of AD. It is proven that probiotics modulate the inflammatory process, counteract with oxidative stress, and modify gut microbiota. Thus, this review summarizes the current evidence, diversity of bacterial strains, defects of gut brain axis in AD, harmful bacterial for AD, and the mechanism of action of probiotics in preventing AD. A literature search on selected databases such as PubMed, Semantic Scholar, Nature, and Springer link have identified potentially relevant articles to this topic. However, upon consideration of inclusion criteria and the limitation of publication year, only 22 articles have been selected to be further reviewed. The search query includes few sets of keywords as follows. (1) Probiotics OR gut microbiome OR microbes AND (2) Alzheimer OR cognitive OR aging OR dementia AND (3) clinical trial OR in vivo OR animal study. The results evidenced in this study help to clearly illustrate the relationship between probiotic supplementation and AD. Thus, this systematic review will help identify novel therapeutic strategies in the future as probiotics are free from triggering any adverse effects in human body.
Topics: Alzheimer Disease; Brain-Gut Axis; Gastrointestinal Microbiome; Humans; Probiotics
PubMed: 35010895
DOI: 10.3390/nu14010020 -
Frontiers in Immunology 2022Probiotics have proven beneficial in a number of immune-mediated and allergic diseases. Several human studies have evaluated the efficacy and safety of probiotics in... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Probiotics have proven beneficial in a number of immune-mediated and allergic diseases. Several human studies have evaluated the efficacy and safety of probiotics in allergic rhinitis; however, evidence for their use has yet to be firmly established.
OBJECTIVE
We undertook a systematic review and meta-analysis aiming to address the effect and safety of probiotics on allergic rhinitis.
METHODS
We systematically searched databases [MEDLINE (PubMed), Embase, and the Cochrane Central Register of Controlled Trials] from inception until June 1, 2021. Qualified literature was selected according to inclusion and exclusion criteria, the data were extracted, and a systematic review and meta-analysis was conducted.
RESULTS
Twenty-eight studies were included. The results showed that probiotics significantly relieved allergic rhinitis symptoms (standardized mean difference [SMD], -0.29, 95% confidence interval (CI) [-0.44, -0.13]; = 0.0003, = 89%), decreased Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scores compared with the control group (SMD, -0.64, 95% CI [-0.79, -0.49], < 0.00001, = 97%), and increased T helper cell 1(Th1)/Th2 ratio (mean difference [MD], -2.47, 95% CI [-3.27, -1.68], < 0.00001, = 72%). There was no significant change in overall or specific IgE levels between probiotic-treated and placebo-treated subjects (SMD, 0.09, 95% CI [-0.16, 0.34], = 0%, and SMD, -0.03, 95% CI [-0.18, 0.13], = 0.72, = 0%, respectively).
CONCLUSIONS
To sum up, probiotic supplement seems to be effective in ameliorating allergic rhinitis symptoms and improving the quality of life, but there is high heterogeneity in some results after subgroup analysis and clinicians should be cautious when recommending probiotics in treating allergic rhinitis.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/PROSPERO/, PROSPERO (CRD42021242645).
Topics: Humans; Probiotics; Quality of Life; Rhinitis; Rhinitis, Allergic; Surveys and Questionnaires
PubMed: 35663980
DOI: 10.3389/fimmu.2022.848279 -
The Cochrane Database of Systematic... Dec 2020Probiotics may be effective in reducing the duration of acute infectious diarrhoea. (Meta-Analysis)
Meta-Analysis
BACKGROUND
Probiotics may be effective in reducing the duration of acute infectious diarrhoea.
OBJECTIVES
To assess the effects of probiotics in proven or presumed acute infectious diarrhoea.
SEARCH METHODS
We searched the trials register of the Cochrane Infectious Diseases Group, MEDLINE, and Embase from inception to 17 December 2019, as well as the Cochrane Controlled Trials Register (Issue 12, 2019), in the Cochrane Library, and reference lists from studies and reviews. We included additional studies identified during external review.
SELECTION CRITERIA
Randomized controlled trials comparing a specified probiotic agent with a placebo or no probiotic in people with acute diarrhoea that is proven or presumed to be caused by an infectious agent.
DATA COLLECTION AND ANALYSIS
Two review authors independently applied inclusion criteria, assessed risk of bias, and extracted data. Primary outcomes were measures of diarrhoea duration (diarrhoea lasting ≥ 48 hours; duration of diarrhoea). Secondary outcomes were number of people hospitalized in community studies, duration of hospitalization in inpatient studies, diarrhoea lasting ≥ 14 days, and adverse events.
MAIN RESULTS
We included 82 studies with a total of 12,127 participants. These studies included 11,526 children (age < 18 years) and 412 adults (three studies recruited 189 adults and children but did not specify numbers in each age group). No cluster-randomized trials were included. Studies varied in the definitions used for "acute diarrhoea" and "end of the diarrhoeal illness" and in the probiotic(s) tested. A total of 53 trials were undertaken in countries where both child and adult mortality was low or very low, and 26 where either child or adult mortality was high. Risk of bias was high or unclear in many studies, and there was marked statistical heterogeneity when findings for the primary outcomes were pooled in meta-analysis. Effect size was similar in the sensitivity analysis and marked heterogeneity persisted. Publication bias was demonstrated from funnel plots for the main outcomes. In our main analysis of the primary outcomes in studies at low risk for all indices of risk of bias, no difference was detected between probiotic and control groups for the risk of diarrhoea lasting ≥ 48 hours (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.91 to 1.09; 2 trials, 1770 participants; moderate-certainty evidence); or for duration of diarrhoea (mean difference (MD) 8.64 hours shorter, 95% CI 29.4 hours shorter to 12.1 hours longer; 6 trials, 3058 participants; very low-certainty evidence). Effect size was similar and marked heterogeneity persisted in pre-specified subgroup analyses of the primary outcomes that included all studies. These included analyses limited to the probiotics Lactobacillus rhamnosus GG and Saccharomyces boulardii. In six trials (433 participants) of Lactobacillus reuteri, there was consistency amongst findings (I² = 0%), but risk of bias was present in all included studies. Heterogeneity also was not explained by types of participants (age, nutritional/socioeconomic status captured by mortality stratum, region of the world where studies were undertaken), diarrhoea in children caused by rotavirus, exposure to antibiotics, and the few studies of children who were also treated with zinc. In addition, there were no clear differences in effect size for the primary outcomes in post hoc analyses according to decade of publication of studies and whether or not trials had been registered. For other outcomes, the duration of hospitalization in inpatient studies on average was shorter in probiotic groups than in control groups but there was marked heterogeneity between studies (I² = 96%; MD -18.03 hours, 95% CI -27.28 to -8.78, random-effects model: 24 trials, 4056 participants). No differences were detected between probiotic and control groups in the number of people with diarrhoea lasting ≥ 14 days (RR 0.49, 95% CI 0.16 to 1.53; 9 studies, 2928 participants) or in risk of hospitalization in community studies (RR 1.26, 95% CI 0.84 to 1.89; 6 studies, 2283 participants). No serious adverse events were attributed to probiotics.
AUTHORS' CONCLUSIONS
Probiotics probably make little or no difference to the number of people who have diarrhoea lasting 48 hours or longer, and we are uncertain whether probiotics reduce the duration of diarrhoea. This analysis is based on large trials with low risk of bias.
Topics: Acute Disease; Adolescent; Adult; Bias; Child; Child, Preschool; Diarrhea; Humans; Infant; Probiotics; Randomized Controlled Trials as Topic
PubMed: 33295643
DOI: 10.1002/14651858.CD003048.pub4 -
Nutrients Jul 2021Probiotic and prebiotic products have shown potential health benefits, including for the prevention of adverse pregnancy outcomes. The incidence of adverse effects in... (Meta-Analysis)
Meta-Analysis
Probiotic and prebiotic products have shown potential health benefits, including for the prevention of adverse pregnancy outcomes. The incidence of adverse effects in pregnant people and their infants associated with probiotic/prebiotic/synbiotic intake, however, remains unclear. The objectives of this study were to evaluate the evidence on adverse effects of maternal probiotic, prebiotic, and/or synbiotic supplementation during pregnancy and lactation and interpret the findings to help inform clinical decision-making and care of this population. A systematic review was conducted following PRISMA guidelines. Scientific databases were searched using pre-determined terms, and risk of bias assessments were conducted to determine study quality. Inclusion criteria were English language studies, human studies, access to full-text, and probiotic/prebiotic/synbiotic supplementation to the mother and not the infant. In total, 11/100 eligible studies reported adverse effects and were eligible for inclusion in quantitative analysis, and data were visualised in a GOfER diagram. Probiotic and prebiotic products are safe for use during pregnancy and lactation. One study reported increased risk of vaginal discharge and changes in stool consistency (relative risk [95% CI]: 3.67 [1.04, 13.0]) when administering and Adverse effects associated with probiotic and prebiotic use do not pose any serious health concerns to mother or infant. Our findings and knowledge translation visualisations provide healthcare professionals and consumers with information to make evidence-informed decisions about the use of pre- and probiotics.
Topics: Female; Humans; Infant; Infant, Newborn; Lactation; Prebiotics; Pregnancy; Prenatal Exposure Delayed Effects; Probiotics; Risk Assessment; Risk Factors; Synbiotics
PubMed: 34371892
DOI: 10.3390/nu13072382 -
Clinical Nutrition (Edinburgh, Scotland) Dec 2022Probiotics and synbiotics have been increasingly investigated for the management of chronic constipation. We aimed to investigate the effect of probiotics and synbiotics... (Meta-Analysis)
Meta-Analysis
BACKGROUND & AIMS
Probiotics and synbiotics have been increasingly investigated for the management of chronic constipation. We aimed to investigate the effect of probiotics and synbiotics on stool output, gut transit time, symptoms and quality of life in adults with chronic constipation via a systematic review and meta-analysis of randomized controlled trials (RCTs).
METHODS
Studies were identified using electronic databases, backward citation and hand-searching abstracts. The search date was 10 July 2022. RCTs reporting administration of probiotics or synbiotics in adults with chronic constipation were included. Risk of bias (RoB) was assessed with the Cochrane RoB 2.0 tool. Meta-analysis was conducted separately for probiotics and synbiotics. Results were synthesized using risk ratios (RRs), mean differences or standardized mean differences (SMDs) and 95% confidence intervals (CIs) using a random-effects model.
RESULTS
Thirty RCTs investigating probiotics and four RCTs investigating synbiotics were included. Overall, 369/647 (57%) responded to probiotic treatment and 252/567 (44%) to control (RR 1.28, 95% CI 1.07, 1.52, p = 0.007). Probiotics increased stool frequency (SMD 0.71, 95% CI 0.37, 1.04, p < 0.00001), with Bifidobacterium lactis having a significant effect, but not mixtures of probiotics, Bacillus coagulans Unique IS2 or Lactobacillus casei Shirota. Probiotics did not impact stool consistency (SMD 0.26, 95% CI -0.03, 0.54, p = 0.08). Probiotics improved integrative symptom scores compared to control (SMD -0.46, 95% CI -0.89, -0.04). Synbiotics did not impact stool output or integrative symptom scores compared to control.
CONCLUSIONS
Certain probiotics may improve response to treatment, stool frequency and integrative constipation symptoms, providing cautious optimism for their use as a dietary management option. There is currently insufficient evidence to recommend synbiotics in the management of chronic constipation. Caution is needed when interpreting these results due to high heterogeneity and risk of bias amongst the studies.
Topics: Adult; Humans; Synbiotics; Randomized Controlled Trials as Topic; Probiotics; Constipation; Bifidobacterium animalis
PubMed: 36372047
DOI: 10.1016/j.clnu.2022.10.015 -
Journal of Cachexia, Sarcopenia and... Feb 2023Probiotics have shown potential to counteract sarcopenia, although the extent to which they can influence domains of sarcopenia such as muscle mass and strength in... (Meta-Analysis)
Meta-Analysis Review
Probiotics have shown potential to counteract sarcopenia, although the extent to which they can influence domains of sarcopenia such as muscle mass and strength in humans is unclear. The aim of this systematic review and meta-analysis was to explore the impact of probiotic supplementation on muscle mass, total lean mass and muscle strength in human adults. A literature search of randomized controlled trials (RCTs) was conducted through PubMed, Scopus, Web of Science and Cochrane Library from inception until June 2022. Eligible RCTs compared the effect of probiotic supplementation versus placebo on muscle and total lean mass and global muscle strength (composite score of all muscle strength outcomes) in adults (>18 years). To evaluate the differences between groups, a meta-analysis was conducted using the random effects inverse-variance model by utilizing standardized mean differences. Twenty-four studies were included in the systematic review and meta-analysis exploring the effects of probiotics on muscle mass, total lean mass and global muscle strength. Our main analysis (k = 10) revealed that muscle mass was improved following probiotics compared with placebo (SMD: 0.42, 95% CI: 0.10-0.74, I = 57%, P = 0.009), although no changes were revealed in relation to total lean mass (k = 12; SMD: -0.03, 95% CI: -0.19 - 0.13, I = 0%, P = 0.69). Interestingly, a significant increase in global muscle strength was also observed among six RCTs (SMD: 0.69, 95% CI: 0.33-1.06, I = 64%, P = 0.0002). Probiotic supplementation enhances both muscle mass and global muscle strength; however, no beneficial effects were observed in total lean mass. Investigating the physiological mechanisms underpinning different ageing groups and elucidating appropriate probiotic strains for optimal gains in muscle mass and strength are warranted.
Topics: Adult; Humans; Sarcopenia; Randomized Controlled Trials as Topic; Probiotics; Muscle Strength; Muscles
PubMed: 36414567
DOI: 10.1002/jcsm.13132 -
Beneficial Microbes Dec 2020This review aims to present a comprehensive state-of-the-art analysis of the bidirectional crosstalk between gut microbiota and the central nervous system (CNS). The... (Meta-Analysis)
Meta-Analysis
This review aims to present a comprehensive state-of-the-art analysis of the bidirectional crosstalk between gut microbiota and the central nervous system (CNS). The literature concerning the potential effects of gut microbiota on psychiatric disorders through neural pathways comprising the 'gut-brain axis' were gathered. In addition, the influence of probiotics and prebiotics and dairy-rich diets combined with the intake of probiotics and prebiotics on gut microbiota and the subsequent relationship with brain function was reviewed. However, a meta-analysis on the effectiveness of probiotic supplementation in psychiatric disorders is lacking. Therefore, a systematic search of PubMed, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases from January 1969 to December 2019 was conducted. It led to the identification of a total of 844 research articles. Of these, a total of 23 studies met the meta-analysis criteria. Statistical analysis revealed that there was no significant difference in the symptoms of schizophrenia, stress, and anxiety between probiotic and placebo groups, post-intervention. Probiotic administration reduced depressive symptoms among patients with depression in a statistically significant manner (standardised mean difference (SMD) = -0.87; 95% confidence interval (95% confidence interval): -1.66, -0.99; =0.03). Further evidence from larger and more rigorous studies with longer duration of probiotic administration, as well as well-defined populations, homogenous probiotic intervention and outcome measures, are needed to clarify the potential therapeutic effects of probiotics on psychiatric symptoms. Based on the current literature, it seems that not all probiotic-/prebiotic-/dairy-rich diet-based treatments exhibited a psychobiotic effect on the CNS. Among the parameters determining the success of the given treatment, the most significant were probiotic composition (multi-strain formulation), the quantity of ingested psychobiotics and the duration of the study.
Topics: Anxiety Disorders; Brain; Diet; Diet Therapy; Gastrointestinal Microbiome; Humans; Prebiotics; Probiotics; Schizophrenia; Stress, Psychological
PubMed: 33191776
DOI: 10.3920/BM2020.0063 -
Nutrients Sep 2023Irritable bowel syndrome (IBS) is a common gastrointestinal disease. The efficacy of different probiotics in treating IBS remains controversial. This network... (Meta-Analysis)
Meta-Analysis Review
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 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. MTCC 5856 (SUCRA, 96.9%) and 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). MTCC 5856 (SUCRA, 99.6%) and 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.
Topics: Adult; Humans; Irritable Bowel Syndrome; Network Meta-Analysis; Abdominal Pain; Bacillus coagulans; Probiotics; Saccharomyces cerevisiae
PubMed: 37686889
DOI: 10.3390/nu15173856 -
Nutrients Jan 2022The gut microbiota impacts on central nervous system (CNS) function via the microbiota-gut-brain axis. Thus, therapeutics targeting the gut microbiota such as probiotics... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The gut microbiota impacts on central nervous system (CNS) function via the microbiota-gut-brain axis. Thus, therapeutics targeting the gut microbiota such as probiotics have the potential for improving mental health. This meta-analysis synthesizes the evidence regarding the impacts of probiotics on psychological well-being, psychiatric symptoms and CNS functioning.
METHODS
The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were applied for executing this review using the databases PubMed, Web of Science and Cochrane Library. The data were summarized at qualitative and quantitative level.
RESULTS
Fifty-four randomized placebo-controlled studies were included, of which 30 were eligible for meta-analysis. If investigated, the probiotics mostly exerted effects on CNS function. Most probiotics did not affect mood, stress, anxiety, depression and psychiatric distress when compared to placebo at the qualitative level. At quantitative level, depression and psychiatric distress improved slightly in the probiotic condition (depression: mean difference -0.37 (95% CI: -0.55, -0.20); ≤ 0.0001; psychiatric distress: mean difference -0.33 (95% CI: -0.53, -0.13); = 0.001).
CONCLUSIONS
To date it is unclear to which extent and in which specific areas next generation probiotics selected and developed for their ability to improve psychiatric condition and potentially other CNS functions are promising.
Topics: Anxiety Disorders; Central Nervous System; Depression; Gastrointestinal Microbiome; Humans; Probiotics
PubMed: 35276981
DOI: 10.3390/nu14030621 -
PloS One 2018Clinicians and patients face a daunting task when choosing the most appropriate probiotic for their specific needs. Available preparations encompass a diverse and...
INTRODUCTION
Clinicians and patients face a daunting task when choosing the most appropriate probiotic for their specific needs. Available preparations encompass a diverse and continuously expanding product base, with most available products lacking evidence-based trials that support their use. Even when evidence exists, not all probiotic products are equally effective for all disease prevention or treatment indications. At this point in time, drug regulatory agencies offer limited assistance with regard to guidance and oversight in most countries, including the U.S.
METHODS
We reviewed the current medical literature and sources on the internet to survey the types of available probiotic products and to determine which probiotics had evidence-based efficacy data. Standard medical databases from inception to June 2018 were searched and discussions with experts in the field were conducted. We graded the strength of the evidence for probiotics having multiple, randomized controlled trials and developed a guide for the practical selection of current probiotic products for specific uses.
RESULTS
We found the efficacy of probiotic products is both strain-specific and disease-specific. Important factors involved in choosing the appropriate probiotic include matching the strain(s) with the targeted disease or condition, type of formulation, dose used and the source (manufacturing quality control and shelf-life). While we found many probiotic products lacked confirmatory trials, we found sufficient evidence for 22 different types of probiotics from 249 trials to be included. For example, several types of probiotics had strong evidence for the prevention of antibiotic-associated diarrhea [Saccharomyces boulardii I-745, a three-strain mixture (Lactobacillus acidophilus CL1285, L. casei Lbc80r, L. rhamnosus CLR2) and L. casei DN114001]. Strong evidence was also found for four types of probiotics for the prevention of a variety of other diseases/conditions (enteral-feed associated diarrhea, travellers' diarrhea, necrotizing enterocolits and side-effects associated with H. pylori treatments. The evidence was most robust for the treatment of pediatric acute diarrhea based on 59 trials (7 types of probiotics have strong efficacy), while an eight-strain multi-strain mixture showed strong efficacy for inflammatory bowel disease and two types of probiotics had strong efficacy for irritable bowel disease. Of the 22 types of probiotics reviewed, 15 (68%) had strong-moderate evidence for efficacy for at least one type of disease.
CONCLUSION
The choice of an appropriate probiotic is multi-factored, based on the mode and type of disease indication and the specific efficacy of probiotic strain(s), as well as product quality and formulation.
TRIAL REGISTRATION
This review was registered with PROSPERO: CRD42018103979.
Topics: Evidence-Based Medicine; Humans; Probiotics; Randomized Controlled Trials as Topic
PubMed: 30586435
DOI: 10.1371/journal.pone.0209205