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Neuroscience and Biobehavioral Reviews Mar 2024The use of probiotics, prebiotics, synbiotics or fermented foods can modulate the gut-brain axis and constitute a potentially therapeutic intervention in psychiatric... (Review)
Review
The use of probiotics, prebiotics, synbiotics or fermented foods can modulate the gut-brain axis and constitute a potentially therapeutic intervention in psychiatric disorders. This systematic review aims to identify current evidence regarding these interventions in the treatment of patients with DSM/ICD psychiatric diagnoses. Forty-seven articles from 42 studies met the inclusion criteria. Risk of bias was assessed in all included studies. Major depression was the most studied disorder (n = 19 studies). Studies frequently focused on schizophrenia (n = 11) and bipolar disorder (n = 5) and there were limited studies in anorexia nervosa (n = 4), ADHD (n = 3), Tourette (n = 1), insomnia (n = 1), PTSD (n = 1) and generalized anxiety disorder (n = 1). Except in MDD, current evidence does not clarify the role of probiotics and prebiotics in the treatment of mental illness. Several studies point to an improvement in the immune and inflammatory profile (e.g. CRP, IL6), which may be a relevant mechanism of action of the therapeutic response identified in these studies. Future research should consider lifestyle and dietary habits of patients as possible confounders that may influence inter-individual treatment response.
Topics: Humans; Prebiotics; Synbiotics; Probiotics; Mental Disorders
PubMed: 38280441
DOI: 10.1016/j.neubiorev.2024.105561 -
Medicina (Kaunas, Lithuania) May 2019: Autism spectrum disorder (ASD) is a complex developmental condition typically characterized by deficits in social and communicative behaviors as well as repetitive...
: Autism spectrum disorder (ASD) is a complex developmental condition typically characterized by deficits in social and communicative behaviors as well as repetitive patterns of behaviors. Despite its prevalence (affecting 0.1% to 1.8% of the global population), the pathogenesis of ASD remains incompletely understood. Patients with ASD are reported to have more frequent gastrointestinal (GI) complaints. There is some anecdotal evidence that probiotics are able to alleviate GI symptoms as well as improve behavioral issues in children with ASD. However, systematic reviews of the effect of prebiotics/probiotics on ASD and its associated symptoms are lacking. : Using the keywords (prebiotics OR probiotics OR microbiota OR gut) AND (autism OR social OR ASD), a systematic literature search was conducted on PubMed, EMBASE, Medline, Clinicaltrials.gov and Google Scholar databases. The inclusion criteria were original clinical trials, published in English between the period 1st January 1988 and 1st February 2019. : A total of eight clinical trials were systematically reviewed. Two clinical trials examined the use of prebiotic and/or diet exclusion while six involved the use of probiotic supplementation in children with ASD. Most of these were prospective, open-label studies. Prebiotics only improved certain GI symptoms; however, when combined with an exclusion diet (gluten and casein free) showed a significant reduction in anti-sociability scores. As for probiotics, there is limited evidence to support the role of probiotics in alleviating the GI or behavioral symptoms in children with ASD. The two available double-blind, randomized, placebo-controlled trials found no significant difference in GI symptoms and behavior. : Despite promising preclinical findings, prebiotics and probiotics have demonstrated an overall limited efficacy in the management of GI or behavioral symptoms in children with ASD. In addition, there was no standardized probiotics regimen, with multiple different strains and concentrations of probiotics, and variable duration of treatments.
Topics: Autism Spectrum Disorder; Gastrointestinal Microbiome; Humans; Prebiotics; Probiotics
PubMed: 31083360
DOI: 10.3390/medicina55050129 -
Sultan Qaboos University Medical Journal Feb 2020Treatments that target alterations in gut microbiota may be beneficial for patients with irritable bowel syndrome (IBS). A systematic review and meta-analysis was... (Meta-Analysis)
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; <0.001), with significant heterogeneity between studies ( = 72%; <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.
Topics: Adult; Female; Gastrointestinal Microbiome; Humans; Irritable Bowel Syndrome; Male; Middle Aged; Prebiotics; Probiotics; Prospective Studies; Randomized Controlled Trials as Topic; Synbiotics; Treatment Outcome
PubMed: 32190365
DOI: 10.18295/squmj.2020.20.01.003 -
The Cochrane Database of Systematic... Feb 2019Inflammatory bowel disease (IBD), comprised of Crohn's disease (CD) and ulcerative colitis (UC), is characterized by chronic mucosal inflammation, frequent... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Inflammatory bowel disease (IBD), comprised of Crohn's disease (CD) and ulcerative colitis (UC), is characterized by chronic mucosal inflammation, frequent hospitalizations, adverse health economics, and compromised quality of life. Diet has been hypothesised to influence IBD activity.
OBJECTIVES
To evaluate the efficacy and safety of dietary interventions on IBD outcomes.
SEARCH METHODS
We searched the Cochrane IBD Group Specialized Register, CENTRAL, MEDLINE, Embase, Web of Science, Clinicaltrials.gov and the WHO ICTRP from inception to 31 January 2019. We also scanned reference lists of included studies, relevant reviews and guidelines.
SELECTION CRITERIA
We included randomized controlled trials (RCTs) that compared the effects of dietary manipulations to other diets in participants with IBD. Studies that exclusively focused on enteral nutrition, oral nutrient supplementation, medical foods, probiotics, and parenteral nutrition were excluded.
DATA COLLECTION AND ANALYSIS
Two review authors independently performed study selection, extracted data and assessed bias using the risk of bias tool. We conducted meta-analyses where possible using a random-effects model and calculated the risk ratio (RR) and corresponding 95% confidence interval (CI) for dichotomous outcomes. We assessed the certainty of evidence using GRADE.
MAIN RESULTS
The review included 18 RCTs with 1878 participants. The studies assessed different dietary interventions for active CD (six studies), inactive CD (seven studies), active UC (one study) and inactive UC (four studies). Dietary interventions involved either the consumption of low amounts or complete exclusion of one or more food groups known to trigger IBD symptoms. There was limited scope for data pooling as the interventions and control diets were diverse. The studies were mostly inadequately powered. Fourteen studies were rated as high risk of bias. The other studies were rated as unclear risk of bias.The effect of high fiber, low refined carbohydrates, low microparticle diet, low calcium diet, symptoms-guided diet and highly restricted organic diet on clinical remission in active CD is uncertain. At 4 weeks, remission was induced in: 100% (4/4) of participants in the low refined carbohydrates diet group compared to 0% (0/3) of participants in the control group (RR 7.20, 95% CI 0.53 to 97.83; 7 participants; 1 study; very low certainty evidence). At 16 weeks, 44% (23/52) of participants in the low microparticle diet achieved clinical remission compared to 25% (13/51) of control-group participants (RR 3.13, 95% CI 0.22 to 43.84; 103 participants; 2 studies; I² = 73%; very low certainty evidence). Fifty per cent (16/32) of participants in the symptoms-guided diet group achieved clinical remission compared to 0% (0/19) of control group participants (RR 20.00, 95% CI 1.27 to 315.40; 51 participants ; 1 study; very low certainty evidence) (follow-up unclear). At 24 weeks, 50% (4/8) of participants in the highly restricted organic diet achieved clinical remission compared to 50% (5/10) of participants in the control group (RR 1.00, 95% CI 0.39 to 2.53; 18 participants; 1 study; very low certainty evidence). At 16 weeks, 37% (16/43) participants following a low calcium diet achieved clinical remission compared to 30% (12/40) in the control group (RR 1.24, 95% CI 0.67 to 2.29; 83 participants; 1 study; very low certainty evidence).The effect of low refined carbohydrate diets, symptoms-guided diets and low red processed meat diets on relapse in inactive CD is uncertain. At 12 to 24 months, 67% (176/264) of participants in low refined carbohydrate diet relapsed compared to 64% (193/303) in the control group (RR 1.04, 95% CI 0.87 to 1.25; 567 participants; 3 studies; I² = 35%; low certainty evidence). At 6 to 24 months, 48% (24/50) of participants in the symptoms-guided diet group relapsed compared to 83% (40/48) participants in the control diet (RR 0.53, 95% CI 0.28 to 1.01; 98 participants ; 2 studies; I² = 54%; low certainty evidence). At 48 weeks, 66% (63/96) of participants in the low red and processed meat diet group relapsed compared to 63% (75/118) of the control group (RR 1.03, 95% CI 0.85 to 1.26; 214 participants; 1 study; low certainty evidence). At 12 months, 0% (0/16) of participants on an exclusion diet comprised of low disaccharides / grains / saturated fats / red and processed meat experienced clinical relapse compared to 26% (10/38) of participants on a control group (RR 0.11, 95% CI 0.01 to 1.76; 54 participants; 1 study; very low certainty evidence).The effect of a symptoms-guided diet on clinical remission in active UC is uncertain. At six weeks, 36% (4/11) of symptoms-guided diet participants achieved remission compared to 0% (0/10) of usual diet participants (RR 8.25, 95% CI 0.50 to 136.33; 21 participants; 1 study; very low certainty evidence).The effect of the Alberta-based anti-inflammatory diet, the Carrageenan-free diet or milk-free diet on relapse rates in inactive UC is uncertain. At 6 months, 36% (5/14) of participants in the Alberta-based anti-inflammatory diet group relapsed compared to 29% (4/14) of participants in the control group (RR 1.25, 95% CI 0.42 to 3.70; 28 participants; 1 study; very low certainty evidence). Thirty per cent (3/10) of participants following the carrageenan-free diet for 12 months relapsed compared to 60% (3/5) of the participants in the control group (RR 0.50, 95% CI 0.15 to 1.64; 15 participants; 1 study; very low certainty evidence). At 12 months, 59% (23/39) of milk free diet participants relapsed compared to 68% (26/38) of control diet participants (RR 0.83, 95% CI 0.60 to 1.15; 77 participants; 2 studies; I² = 0%; low certainty evidence).None of the included studies reported on diet-related adverse events.
AUTHORS' CONCLUSIONS
The effects of dietary interventions on CD and UC are uncertain. Thus no firm conclusions regarding the benefits and harms of dietary interventions in CD and UC can be drawn. There is need for consensus on the composition of dietary interventions in IBD and more RCTs are required to evaluate these interventions. Currently, there are at least five ongoing studies (estimated enrollment of 498 participants). This review will be updated when the results of these studies are available.
Topics: Animals; Calcium, Dietary; Cattle; Colitis, Ulcerative; Crohn Disease; Dietary Carbohydrates; Dietary Fiber; Food, Organic; Humans; Meat; Quality of Life; Randomized Controlled Trials as Topic; Recurrence; Remission Induction
PubMed: 30736095
DOI: 10.1002/14651858.CD012839.pub2 -
BMJ Clinical Evidence Nov 2014Anal fissures are a common cause of anal pain during, and for 1 to 2 hours after, defecation. The cause is not fully understood, but low intake of dietary fibre may be a... (Review)
Review
INTRODUCTION
Anal fissures are a common cause of anal pain during, and for 1 to 2 hours after, defecation. The cause is not fully understood, but low intake of dietary fibre may be a risk factor.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical question: What are the effects of surgical treatments for chronic anal fissure? We searched: Medline, Embase, The Cochrane Library, and other important databases up to January 2014 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
RESULTS
We found nine studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
CONCLUSIONS
In this systematic review, we present information relating to the effectiveness and safety of the following interventions: anal advancement flap, anal stretch/dilation, and internal anal sphincterotomy.
Topics: Anal Canal; Fissure in Ano; Humans; Risk Factors; United States
PubMed: 25391392
DOI: No ID Found -
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 -
Autism Research : Official Journal of... Sep 2021The emerging role of a microbiota-gut-brain axis in autism spectrum disorder (ASD) suggests that modulating gut microbial composition may offer a tractable approach to... (Review)
Review
The emerging role of a microbiota-gut-brain axis in autism spectrum disorder (ASD) suggests that modulating gut microbial composition may offer a tractable approach to addressing the lifelong challenges of ASD. The aim of this systematic review was to provide an overview and critically evaluate the current evidence on the efficacy and safety of probiotic, prebiotic, synbiotic, and fecal microbiota transplantation therapies for core and co-occurring behavioral symptoms in individuals with ASD. Comprehensive searches of MEDLINE, EMBASE, Scopus, Web of Science Core Collection, Cochrane Library, and Google Scholar were performed from inception to March 5, 2020, and two update searches were completed on October 25, 2020, and April 22, 2021, respectively. A total of 4306 publications were identified, of which 14 articles met the inclusion criteria. Data were extracted independently by two reviewers using a preconstructed form. Results of probiotic studies do not confirm the supposed beneficial effect of probiotics on ASD, whereas prebiotics and synbiotic combinations appear to be efficacious in selective behavioral symptoms. Evidence of the efficacy of fecal microbiota transplantation in ASD is still scarce but supports further research. Overall, the current evidence base to suggest beneficial effects of these modalities in ASD is limited and inconclusive. More clinical trials are currently looking at the use of microbial-based therapies in ASD. With a robust double-blind randomized controlled protocol to investigate the efficacy, these trials should provide significant and definitive results. LAY SUMMARY: There is a link between altered gut bacteria and autism spectrum disorder. Some people believe that modulating bacterial composition in the gut may help reduce autism symptoms, but evidence from human studies suggesting beneficial effects of probiotic, prebiotic, and combination thereof as well as fecal transplants in autism spectrum disorder is limited and inconclusive. Current data should not encourage use of these modalities. Further clinical studies are needed.
Topics: Autism Spectrum Disorder; Behavioral Symptoms; Fecal Microbiota Transplantation; Gastrointestinal Microbiome; Humans; Prebiotics; Probiotics; Randomized Controlled Trials as Topic; Synbiotics
PubMed: 34173726
DOI: 10.1002/aur.2560 -
Nutrients Aug 2020Nutritional guidelines suggest specific energy and protein requirements for patients with cancer. However, cancer patients, often malnourished, use self-made or...
Nutritional guidelines suggest specific energy and protein requirements for patients with cancer. However, cancer patients, often malnourished, use self-made or web-based diets to ameliorate the prognosis of their disease. This review aimed to investigate the associations between post-diagnostic diet and prognostic outcomes in cancer patients. A systematic literature search was performed in Pubmed and Web of Science databases from inception to 30 October 2019, based on fixed inclusion and exclusion criteria. The risk of bias was assessed. A total of 29 prospective studies was identified. Breast ( = 11), colorectal ( = 9), prostate ( = 8) cancers are the most studied. Low- fat diet, healthy quality diet, regular consumption of fiber such as vegetables and high-quality protein intake are beneficial while Western diet (WD) and high consumption of saturated fats could be associated with a higher risk of mortality. Bladder ( = 1), gynecological ( = 1), lung, stomach, and pancreatic cancers still remain almost unexplored. This systematic review suggested that detrimental dietary patterns such as WD should be avoided but none of the food categories (meat, dairy products) should be eliminated in cancer patients' diet. Further large prospective studies are needed to assess the role of post-diagnostic diet in patients with cancer.
Topics: Cohort Studies; Dairy Products; Diet; Diet, Fat-Restricted; Diet, Western; Dietary Fats; Dietary Fiber; Disease Progression; Feeding Behavior; Female; Gastrointestinal Microbiome; Humans; Male; Meat; Neoplasms; Prognosis; Prospective Studies; Vegetables
PubMed: 32764484
DOI: 10.3390/nu12082345 -
Epidemiology and Health 2023Cancer is a major health burden in Korea, and dietary factors have been suggested as putative risk factors for cancer development at various sites. This study... (Meta-Analysis)
Meta-Analysis
Cancer is a major health burden in Korea, and dietary factors have been suggested as putative risk factors for cancer development at various sites. This study systematically reviewed the published literature investigating the associations between dietary factors and cancer incidence among Korean adults, following the Preferred Reporting Items for Systematic Reviews and Meta- Analyses guidelines. We focused on the 5 most studied cancer sites (stomach, colorectum, breast, thyroid, and cervix) as outcomes and dietary exposures with evidence levels greater than limited-suggestive according to the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) panel's judgment for any of the cancer sites. This resulted in the inclusion of 72 studies. Pooled estimates of the impact of dietary factors on cancer risk suggested protective associations of fruits and vegetables with risks for gastric cancer (GC), colorectal cancer (CRC), and breast cancer (BC) and dietary vitamin C with the risk of GC, as well as a harmful association between fermented soy products and the risk of GC. Despite the limited number of studies, we observed consistent protective associations of dietary fiber with GC and dietary fiber, coffee, and calcium with CRC. These findings are largely consistent with the WCRF/AICR expert report. However, pooled estimates for the associations of other salt-preserved foods with GC, meat with CRC, and dietary carotenoids and dairy products with BC did not reach statistical significance. Further studies with prospective designs, larger sample sizes, and diverse types of dietary factors and cancer sites are necessary.
Topics: Adult; Humans; Diet; Dietary Fiber; Eating; Incidence; Neoplasms; Republic of Korea; Risk Factors; Observational Studies as Topic
PubMed: 38037322
DOI: 10.4178/epih.e2023102 -
The Lancet. Gastroenterology &... Feb 2020Although novel therapies for irritable bowel syndrome (IBS) continue to be developed, many doctors rely on more established, traditional therapies as first-line or...
BACKGROUND
Although novel therapies for irritable bowel syndrome (IBS) continue to be developed, many doctors rely on more established, traditional therapies as first-line or second-line treatment options. These therapies include soluble fibre (eg, ispaghula husk), antispasmodic drugs, peppermint oil, and gut-brain neuromodulators (including tricyclic antidepressants, selective serotonin reuptake inhibitors, or α-2-δ calcium channel subunit ligands). However, the relative efficacy of traditional treatments in patients with IBS is unclear because there have been few head-to-head randomised controlled trials (RCTs). We aimed to compare and rank the efficacy of traditional therapies in patients with IBS to help inform clinical decisions.
METHODS
For this systematic review and network meta-analysis, we searched MEDLINE, Embase, Embase Classic, and the Cochrane Central Register of Controlled Trials from inception to week 2 of August 2019; ClinicalTrials.gov for unpublished trials or supplementary data published up to Aug 18, 2019; and gastroenterology conference proceedings for study abstracts published between 2001 and Aug 18, 2019. We included RCTs that compared any of these treatments with each other (head-to-head trials) or with placebo, in which the efficacy of soluble fibre, antispasmodic drugs, peppermint oil, or gut-brain neuromodulators was assessed in adults (aged at least 18 years) with IBS of any subtype after 4-12 weeks of treatment. Only RCTs reporting a dichotomous assessment of overall response to therapy, in terms of either improvement in global IBS symptoms or improvement in abdominal pain, were included. The efficacy and safety of all treatments were reported as a pooled relative risk (RR) with 95% CIs to summarise the effect of each comparison tested, and treatments were ranked according to their P-score.
FINDINGS
Our search identified 5863 references, of which 81 were screened for eligibility. 51 RCTs with data from 4644 patients were eligible for inclusion in our analysis, but only 13 of these trials were at low risk of bias. Based on an endpoint of failure to achieve improvement in global IBS symptoms at 4-12 weeks, peppermint oil capsules were ranked first for efficacy (RR 0·63, 95% CI 0·48-0·83, P-score 0·84) and tricyclic antidepressants were ranked second (0·66, 0·53-0·83, P-score 0·77). For failure to achieve an improvement in global IBS symptoms at 4-12 weeks, there were no significant differences between active treatments after direct or indirect comparisons. For failure to achieve improvement in abdominal pain at 4-12 weeks, tricyclic antidepressants were ranked first for efficacy (0·53, 0·34-0·83, P-score 0·87); however, this result was based on data from only four RCTs involving 92 patients. For failure to achieve an improvement in abdominal pain, none of the active treatments showed superior efficacy upon indirect comparison. Tricyclic antidepressants were more likely than placebo to lead to adverse events (1·59, 1·26-2·06, P-score 0·16).
INTERPRETATION
In this network meta-analysis of RCTs of soluble fibre, antispasmodic drugs, peppermint oil, and gut-brain neuromodulators for IBS, few of which were judged as being at a low risk of bias, peppermint oil was ranked first for efficacy when global symptoms were used as the outcome measure, and tricyclic antidepressants were ranked first for efficacy when abdominal pain was used as the outcome measure. However, because of the lack of methodological rigour of some RCTs analysed in our study, there is likely to be considerable uncertainty around these findings. In addition, because treatment duration in most included trials was 4-12 weeks, the long-term relative efficacy of these treatments is unknown.
FUNDING
None.
Topics: Brain; Dietary Fiber; Humans; Intestinal Mucosa; Irritable Bowel Syndrome; Network Meta-Analysis; Neurotransmitter Agents; Parasympatholytics; Treatment Outcome
PubMed: 31859183
DOI: 10.1016/S2468-1253(19)30324-3