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Annals of Nutrition & Metabolism 2012Probiotics are live microorganisms that provide health benefits to the host when ingested in adequate amounts. The strains most frequently used as probiotics include... (Review)
Review
Probiotics are live microorganisms that provide health benefits to the host when ingested in adequate amounts. The strains most frequently used as probiotics include lactic acid bacteria and bifidobacteria. Probiotics have demonstrated significant potential as therapeutic options for a variety of diseases, but the mechanisms responsible for these effects have not been fully elucidated yet. Several important mechanisms underlying the antagonistic effects of probiotics on various microorganisms include the following: modification of the gut microbiota, competitive adherence to the mucosa and epithelium, strengthening of the gut epithelial barrier and modulation of the immune system to convey an advantage to the host. Accumulating evidence demonstrates that probiotics communicate with the host by pattern recognition receptors, such as toll-like receptors and nucleotide-binding oligomerization domain-containing protein-like receptors, which modulate key signaling pathways, such as nuclear factor-ĸB and mitogen-activated protein kinase, to enhance or suppress activation and influence downstream pathways. This recognition is crucial for eliciting measured antimicrobial responses with minimal inflammatory tissue damage. A clear understanding of these mechanisms will allow for appropriate probiotic strain selection for specific applications and may uncover novel probiotic functions. The goal of this systematic review was to explore probiotic modes of action focusing on how gut microbes influence the host.
Topics: Animals; Anti-Infective Agents; Bacterial Adhesion; Bifidobacterium; Gastrointestinal Tract; Humans; Immune System; Intestinal Mucosa; Lactobacillaceae; Metagenome; Mitogen-Activated Protein Kinases; Models, Animal; NF-kappa B; Probiotics; Signal Transduction
PubMed: 23037511
DOI: 10.1159/000342079 -
BMJ Open Aug 2021To evaluate existing evidence for the use of probiotics in preventing antibiotic-associated diarrhoea (AAD) in adults. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To evaluate existing evidence for the use of probiotics in preventing antibiotic-associated diarrhoea (AAD) in adults.
DESIGN
Systematic review and meta-analysis of randomised controlled trials (RCTs).
DATA SOURCES
We performed a literature search of the electronic databases CINAHL Plus, EMBASE, MEDLINE (Ovid) and Web of Science from database inception to May 2021 as well as hand searching of trial registries and reference lists of related reviews.
STUDY SELECTION
Two reviewers identified whether RCTs met the following inclusion criteria: adult population to whom antibiotics were administered; a probiotic intervention; a placebo, alternative dose, alternative probiotic strain or no treatment control; and incidence of AAD as the outcome.
DATA EXTRACTION AND SYNTHESIS
Two reviewers independently collected data and assessed risk of bias using preconstructed data extraction forms. We used a random effects model for all analyses. Subgroup analyses were performed to evaluate species-specific and dose-specific response.
RESULTS
Forty-two studies (11,305 participants) were included in this review. The pooled analysis suggests that co-administration of probiotics with antibiotics reduces the risk of AAD in adults by 37% (risk ratio (RR)=0.63 (95% CI 0.54 to 0.73), p<0.00001). The overall quality of the evidence using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) criteria was found to be moderate. In subgroup analyses, high dose compared with low dose of the same probiotic demonstrated a positive protective effect (RR 0.54 (95% CI 0.38 to 0.76), p<0.01), and only certain species, mainly of the lactobacillus and bifidobacteria genera, were found to be effective. Studies with a low baseline AAD risk did not show any difference in risk but studies with moderate or high baseline AAD risk demonstrated a significant risk reduction.
CONCLUSIONS
Probiotics are effective for preventing AAD. Secondary analyses of higher dosages and certain species have shown increased effectiveness. Our results may not be applicable in clinical scenarios of lower baseline AAD risk.
Topics: Adult; Anti-Bacterial Agents; Diarrhea; Humans; Incidence; Lactobacillus; Probiotics
PubMed: 34385227
DOI: 10.1136/bmjopen-2020-043054 -
The vaginal microbiome and the risk of preterm birth: a systematic review and network meta-analysis.Scientific Reports May 2022Preterm birth is a major cause of neonatal morbidity and mortality worldwide. Increasing evidence links the vaginal microbiome to the risk of spontaneous preterm labour... (Meta-Analysis)
Meta-Analysis
Preterm birth is a major cause of neonatal morbidity and mortality worldwide. Increasing evidence links the vaginal microbiome to the risk of spontaneous preterm labour that leads to preterm birth. The aim of this systematic review and network meta-analysis was to investigate the association between the vaginal microbiome, defined as community state types (CSTs, i.e. dominance of specific lactobacilli spp, or not (low-lactobacilli)), and the risk of preterm birth. Systematic review using PubMed, Web of Science, Embase and Cochrane library was performed. Longitudinal studies using culture-independent methods categorizing the vaginal microbiome in at least three different CSTs to assess the risk of preterm birth were included. A (network) meta-analysis was conducted, presenting pooled odds ratios (OR) and 95% confidence intervals (CI); and weighted proportions and 95% CI. All 17 studies were published between 2014 and 2021 and included 38-539 pregnancies and 8-107 preterm births. Women presenting with "low-lactobacilli" vaginal microbiome were at increased risk (OR 1.69, 95% CI 1.15-2.49) for delivering preterm compared to Lactobacillus crispatus dominant women. Our network meta-analysis supports the microbiome being predictive of preterm birth, where low abundance of lactobacilli is associated with the highest risk, and L. crispatus dominance the lowest.
Topics: Female; Humans; Infant, Newborn; Lactobacillus; Lactobacillus crispatus; Microbiota; Network Meta-Analysis; Pregnancy; Premature Birth; Vagina
PubMed: 35562576
DOI: 10.1038/s41598-022-12007-9 -
The Cochrane Database of Systematic... Mar 2019Infantile colic is typically defined as full-force crying for at least three hours per day, on at least three days per week, for at least three weeks. Infantile colic... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Infantile colic is typically defined as full-force crying for at least three hours per day, on at least three days per week, for at least three weeks. Infantile colic affects a large number of infants and their families worldwide. Its symptoms are broad and general, and while not indicative of disease, may represent a serious underlying condition in a small percentage of infants who may need a medical assessment. Probiotics are live microorganisms that alter the microflora of the host and provide beneficial health effects. The most common probiotics used are of Lactobacillus, Bifidobacterium and Streptococcus. There is growing evidence to suggest that intestinal flora in colicky infants differ from those in healthy infants, and it is suggested that probiotics can redress this balance and provide a healthier intestinal microbiota landscape. The low cost and easy availability of probiotics makes them a potential prophylactic solution to reduce the incidence and prevalence of infantile colic.
OBJECTIVES
To evaluate the efficacy and safety of prophylactic probiotics in preventing or reducing severity of infantile colic.
SEARCH METHODS
In January 2018 we searched CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, 10 other databases and two trials registers. In addition, we handsearched the abstracts of relevant meetings, searched reference lists, ran citation searches of included studies, and contacted authors and experts in the field, including the manufacturers of probiotics, to identify unpublished trials.
SELECTION CRITERIA
Randomised control trials (RCTs) of newborn infants less than one month of age without the diagnosis of infantile colic at recruitment. We included any probiotic, alone or in combination with a prebiotic (also known as synbiotics), versus no intervention, another intervention(s) or placebo, where the focus of the study was the effect of the intervention on infantile colic.
DATA COLLECTION AND ANALYSIS
We used standard methodological procedures of Cochrane.
MAIN RESULTS
Our search yielded 3284 records, and of these, we selected 21 reports for full-text review. Six studies with 1886 participants met our inclusion criteria, comparing probiotics with placebo. Two studies examined Lactobacillus reuteri DSM, two examined multi-strain probiotics, one examined Lactobacillus rhamnosus, and one examined Lactobacillus paracasei and Bifidobacterium animalis. Two studies began probiotics during pregnancy and continued administering them to the baby after birth.We considered the risk of bias for randomisation as low for all six trials; for allocation concealment as low in two studies and unclear in four others. All studies were blinded, and at low risk of attrition and reporting bias.A random-effects meta-analysis of three studies (1148 participants) found no difference between the groups in relation to occurrence of new cases of colic: risk ratio (RR) 0.46, 95% confidence interval (CI) 0.18 to 1.19; low-certainty evidence; I = 72%.A random-effects meta-analysis of all six studies (1851 participants) found no difference between the groups in relation to serious adverse effects (RR 1.02, 95% CI 0.14 to 7.21; low-certainty evidence; I not calculable (only four serious events for one comparison, two in each group: meconium plug obstruction, patent ductus arteriosus and neonatal hepatitis).A random-effects meta-analysis of three studies (707 participants) found a mean difference (MD) of -32.57 minutes per day (95% CI -55.60 to -9.54; low-certainty evidence; I = 93%) in crying time at study end in favour of probiotics.A subgroup analysis of the most studied agent, Lactobacillus reuteri, showed a reduction of 44.26 minutes in daily crying with a random-effects model (95% CI -66.6 to -21.9; I = 92%), in favour of probiotics.
AUTHORS' CONCLUSIONS
There is no clear evidence that probiotics are more effective than placebo at preventing infantile colic; however, daily crying time appeared to reduce with probiotic use compared to placebo. There were no clear differences in adverse effects.We are limited in our ability to draw conclusions by the certainty of the evidence, which we assessed as being low across all three outcomes, meaning that we are not confident that these results would not change with the addition of further research.
Topics: Bifidobacterium; Breast Feeding; Colic; Crying; Female; Gastrointestinal Microbiome; Humans; Infant; Infant, Newborn; Limosilactobacillus reuteri; Prebiotics; Pregnancy; Probiotics; Randomized Controlled Trials as Topic; Time Factors
PubMed: 30865287
DOI: 10.1002/14651858.CD012473.pub2 -
Nutrients Jun 2022To perform a systematic review and meta-analysis to evaluate the effectiveness and safety of probiotics in the treatment of constipation-predominant irritable bowel... (Meta-Analysis)
Meta-Analysis Review
Effectiveness and Safety of Probiotics for Patients with Constipation-Predominant Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of 10 Randomized Controlled Trials.
To perform a systematic review and meta-analysis to evaluate the effectiveness and safety of probiotics in the treatment of constipation-predominant irritable bowel syndrome (IBS-C), we searched for randomized controlled trials (RCTs) comparing probiotic care versus placebos for patients with IBS-C in five comprehensive databases (March 2022). The risk of bias was assessed using the Cochrane Collaboration Risk of Bias Tool. RevMan 5.3 was used to perform a meta-analysis on stool consistency, abdominal pain, bloating, quality of life (QoL), fecal Bifidobacterium and Lactobacillus counts, and adverse events. The GRADE approach was used to evaluate the certainty of the evidence. Ten RCTs involving 757 patients were included. Only three studies were rated as having a low risk of bias. The meta-analysis results show that, compared to the placebo, probiotics significantly improved stool consistency (MD = 0.72, 95% CI (0.18, 1.26), p < 0.05, low quality) and increased the number of fecal Bifidobacteria (MD = 1.75, 95% CI (1.51, 2.00), p < 0.05, low quality) and Lactobacillus (MD = 1.69, 95% CI (1.48, 1.89), p < 0.05, low quality), while no significant differences were found in abdominal pain scores, bloating scores, QoL scores, or the incidence of adverse events (p > 0.05). The low-to-very low certainty evidence suggests that probiotics might improve the stool consistency of patients with IBS-C and increase the number of Bifidobacteria and Lactobacilli in feces with good safety. However, more high-quality studies with large samples are needed to verify the findings.
Topics: Abdominal Pain; Bifidobacterium; Constipation; Flatulence; Humans; Irritable Bowel Syndrome; Lactobacillus; Probiotics; Randomized Controlled Trials as Topic; Treatment Outcome
PubMed: 35745212
DOI: 10.3390/nu14122482 -
Frontiers in Cellular and Infection... 2021, first described in 1999, is a prevalent bacterial species of the vaginal microbiome. As does not easily grow on de Man-Rogosa-Sharpe agar, but can grow anaerobically... (Review)
Review
, first described in 1999, is a prevalent bacterial species of the vaginal microbiome. As does not easily grow on de Man-Rogosa-Sharpe agar, but can grow anaerobically on blood agar, it has been initially overlooked by traditional culture methods. It was not until the wide application of molecular biology techniques that the function of in the vaginal microbiome was carefully explored. has the smallest genome among known and it has many probiotic characteristics, but is partly different from other major vaginal species, such as , in contributing to the maintenance of a healthy vaginal microbiome. It is not only commonly present in the healthy vagina but quite often recovered in high numbers in bacterial vaginosis (BV). Increasing evidence suggests that is a transitional species that colonizes after the vaginal environment is disturbed and offers overall less protection against vaginal dysbiosis and, subsequently, leads to BV, sexually transmitted infections, and adverse pregnancy outcomes. Accordingly, under certain conditions, is a genuine vaginal symbiont, but it also seems to be an opportunistic pathogen. Further studies are necessary to identify the exact role of this intriguing species in vaginal health and diseases.
Topics: Dysbiosis; Female; Humans; Lactobacillus; Pregnancy; Vagina; Vaginosis, Bacterial
PubMed: 34881196
DOI: 10.3389/fcimb.2021.792787 -
Frontiers in Psychiatry 2020Cumulative evidence shows a linkage between gut microbiota pattern and depression through the brain-gut microbiome axis. The aim of this systematic review was to...
Cumulative evidence shows a linkage between gut microbiota pattern and depression through the brain-gut microbiome axis. The aim of this systematic review was to identify the alterations of the gut microbiota patterns in people with depression compared to healthy controls. A comprehensive literature search of human studies, published between January 2000 and June 2019, was reviewed. The key words included gastrointestinal microbiome, gut microbiome, microbiota, depression, depressive symptoms, and depressive disorder. The systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Nine articles met the eligibility criteria. Disparities in α-diversity and β-diversity of the microbiota existed in people with depression compared to healthy controls. At the phylum level, there were inconsistencies in the abundance of , , . However, high abundance in and phyla were observed in people with depression. On the family level, high abundance of , , , , , , , , , , , , , low abundance of , , , , , , and were observed in people with depression. On the genus level, high abundance of , , , , , , , , , , , , , , , , , , , , , , , and low abundance of , , , , , , , and were found in people with depression. Alteration of gut microbiome patterns was evident in people with depression. Further evidence is warranted to allow for the translation of microbiome findings toward innovative clinical strategies that may improve treatment outcomes in people with depression.
PubMed: 32587537
DOI: 10.3389/fpsyt.2020.00541 -
Nutrients Jan 2021Recent evidence supports a role of probiotics in preventing necrotizing enterocolitis (NEC) in preterm infants. (Meta-Analysis)
Meta-Analysis
BACKGROUND
Recent evidence supports a role of probiotics in preventing necrotizing enterocolitis (NEC) in preterm infants.
METHODS
A systematic review and network meta-analysis of randomized controlled trials (RCTs) on the role of probiotics in preventing NEC in preterm infants, focusing on the differential effect of type of feeding, was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A random-effects model was used; a subgroup analysis on exclusively human milk (HM)-fed infants vs. infants receiving formula (alone or with HM) was performed.
RESULTS
Fifty-one trials were included (10,664 infants, 29 probiotic interventions); 31 studies (19 different probiotic regimens) were suitable for subgroup analysis according to feeding. In the overall analysis, LB revealed the most promising effect for reducing NEC risk (odds ratio (OR), 0.03; 95% credible intervals (CrIs), 0.00-0.21). The subgroup analysis showed that Bb-12/B94 was associated with a reduced risk of NEC stage ≥2 in both feeding type populations, with a discrepancy in the relative effect size in favour of exclusively HM-fed infants (OR 0.04; 95% CrIs <0.01-0.49 vs. OR 0.32; 95% CrIs 0.10-0.36).
CONCLUSIONS
Bb-12/B94 could reduce NEC risk with a different size effect according to feeding type. Of note, most probiotic strains are evaluated in few trials and relatively small populations, and outcome data according to feeding type are not available for all RCTs. Further trials are needed to confirm the present findings.
Topics: Databases, Factual; Enterocolitis, Necrotizing; Female; Humans; Infant, Newborn; Infant, Newborn, Diseases; Infant, Premature; Lactobacillus acidophilus; Male; Middle Aged; Network Meta-Analysis; Probiotics
PubMed: 33435456
DOI: 10.3390/nu13010192 -
The Cochrane Database of Systematic... Jul 2020Crohn's disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract, in which the pathogenesis is believed to be partly influenced by the gut... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Crohn's disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract, in which the pathogenesis is believed to be partly influenced by the gut microbiome. Probiotics can be used to manipulate the microbiome and have therefore been considered as a potential therapy for CD. There is some evidence that probiotics benefit other gastrointestinal conditions, such as irritable bowel syndrome and ulcerative colitis, but their efficacy in CD is unclear. This is the first update of a Cochrane Review previously published in 2008.
OBJECTIVES
To assess the efficacy and safety of probiotics for the induction of remission in CD.
SEARCH METHODS
The following electronic databases were searched: MEDLINE (from inception to 6 July 2020), Embase (from inception to 6 July 2020), the Cochrane Central Register of Controlled Trials (CENTRAL), The Cochrane IBD Review Group Specialised Trials Register, World Health Organization (WHO) International Clinical Trials Registry, and ClinicalTrials.gov.
SELECTION CRITERIA
Randomised controlled trials (RCTs) that compared probiotics with placebo or any other non-probiotic intervention for the induction of remission in CD were eligible for inclusion.
DATA COLLECTION AND ANALYSIS
Two review authors independently extracted data and assessed the methodological quality of included studies. The primary outcome was clinical remission. Risk ratios (RRs) and 95% confidence intervals (CIs) were calculated for dichotomous outcomes.
MAIN RESULTS
There were two studies that met criteria for inclusion. One study from Germany had 11 adult participants with mild-to-moderate CD, who were treated with a one-week course of corticosteroids and antibiotics (ciprofloxacin 500 mg twice daily and metronidazole 250 mg three times a day), followed by randomised assignment to Lactobacillus rhamnosus strain GG (two billion colony-forming units per day) or corn starch placebo. The other study from the United Kingdom (UK) had 35 adult participants with active CD (CDAI score of 150 to 450) randomised to receive a synbiotic treatment (comprised of freeze-dried Bifidobacterium longum and a commercial product) or placebo. The overall risk of bias was low in one study, whereas the other study had unclear risk of bias in relation to random sequence generation, allocation concealment, and blinding. There was no evidence of a difference between the use of probiotics and placebo for the induction of remission in CD (RR 1.06; 95% CI 0.65 to 1.71; 2 studies, 46 participants) after six months. There was no difference in adverse events between probiotics and placebo (RR 2.55; 95% CI 0.11 to 58.60; 2 studies, 46 participants). The evidence for both outcomes was of very low certainty due to risk of bias and imprecision.
AUTHORS' CONCLUSIONS
The available evidence is very uncertain about the efficacy or safety of probiotics, when compared with placebo, for induction of remission in Crohn's disease. There is a lack of well-designed RCTs in this area and further research is needed.
Topics: Adult; Anti-Bacterial Agents; Bifidobacterium longum; Ciprofloxacin; Crohn Disease; Gastrointestinal Microbiome; Humans; Lacticaseibacillus rhamnosus; Metronidazole; Placebos; Probiotics; Randomized Controlled Trials as Topic; Remission Induction
PubMed: 32678465
DOI: 10.1002/14651858.CD006634.pub3 -
International Journal of Molecular... Dec 2021The human microbiome plays a crucial role in determining the health status of every human being, and the microbiome of the genital tract can affect the fertility...
The human microbiome plays a crucial role in determining the health status of every human being, and the microbiome of the genital tract can affect the fertility potential before and during assisted reproductive treatments (ARTs). This review aims to identify and appraise studies investigating the correlation of genital microbiome to infertility. Publications up to February 2021 were identified by searching the electronic databases PubMed/MEDLINE, Scopus and Embase and bibliographies. Only full-text original research articles written in English were considered eligible for analysis, whereas reviews, editorials, opinions or letters, case studies, conference papers, and abstracts were excluded. Twenty-six articles were identified. The oldest studies adopted the exclusive culture-based technique, while in recent years PCR and RNA sequencing based on 16S rRNA were the most used technique. Regardless of the anatomical site under investigation, the -dominated flora seems to play a pivotal role in determining fertility, and in particular showed a central role. Nonetheless, the presence of pathogens in the genital tract, such as , , species, and Gram-negative stains microorganism, affected fertility also in case of asymptomatic bacterial vaginosis (BV). We failed to identify descriptive or comparative studies regarding tubal microbiome. The microbiome of the genital tract plays a pivotal role in fertility, also in case of ARTs. The standardization of the sampling methods and investigations approaches is warranted to stratify the fertility potential and its subsequent treatment. Prospective tubal microbiome studies are warranted.
Topics: Cervix Uteri; Endometrium; Female; Genitalia, Female; Humans; Infertility, Female; Lactobacillus; Microbiota; Vagina
PubMed: 35008605
DOI: 10.3390/ijms23010180