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Frontiers in Nutrition 2023Dietary factors may affect the incidence of colorectal serrated polyps (SP). However, its effects on SP are unclear as epidemiological studies on this topic have showed...
BACKGROUND
Dietary factors may affect the incidence of colorectal serrated polyps (SP). However, its effects on SP are unclear as epidemiological studies on this topic have showed inconsistent results. The present systematic review and meta-analysis sought to evaluate the effects of dietary factors on SPs.
METHODS
Studies regarding the association between dietary factors and SPs were identified by searching PubMed, Cochrane library, Embase and Chinese Biomedical Literature database from inception until 27 February 2023. Search terms include serrated, hyperplastic, adenoma, polyps, colorectal, rectal, rectum and risk. Heterogeneity was assessed using statistics. The meta-analysis was conducted by using a random-effects model, and the pooled effects were expressed with odds ratios (OR) and 95% confidence intervals (95% CI). Probable sources of heterogeneity were identified through meta-regression. Subgroup analysis were based on lesion types, study designs, countries, and so on.
RESULTS
28 studies were ultimately eligible after scanning, and five dietary factors including vitamin D, calcium, folate, fiber and red or processed meat were excerpted. Higher intakes of vitamin D (OR = 0.95, 95%CI:0.90-1.02), calcium (OR = 0.97, 95%CI: 0.91-1.03) and folate (OR = 0.82, 95% CI: 0.6-1.13) were not significantly associated with SP. Fiber intake (OR = 0.90, 95% CI: 0.82-0.99) was a protective factor against SPs. Red meat intake increased the risk of SPs by 30% for the highest versus lowest intakes (OR = 1.30, 95% CI: 1.13-1.51). For different lesion types, higher folate intake was associated with a decreased risk of HPs (OR = 0.59, 95%CI: 0.44-0.79), and higher vitamin D intake decreased the risk of SPs including SSA/P (OR = 0.93, 95%CI: 0.88-0.98).
CONCLUSIONS
Higher dietary fiber intake plays an effective role in preventing SP, while red meat intake is associated with an increased risk of SP. This evidence provides guidance for us to prevent SP from a dietary perspective.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/prospero/display_record.php?, RecordID=340750.
PubMed: 37575321
DOI: 10.3389/fnut.2023.1187539 -
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 -
Medicine Sep 2018The purpose of this study was to conduct a systematic review and meta-analysis of studies investigating the relationship between dietary fiber intake and... (Meta-Analysis)
Meta-Analysis Review
The purpose of this study was to conduct a systematic review and meta-analysis of studies investigating the relationship between dietary fiber intake and subsite-specific colon cancer.The PubMed database was searched to identify relevant cohort studies published from inception to August 2016 in order to examine individually the association between dietary fiber intake and the risk of proximal colon cancer (PCC), and that between dietary fiber intake and the risk of distal colon cancer (DCC). We searched the reference lists of the studies included in our analysis as well as those listed in the published meta-analyses. A random-effects model was used to compute summary risk estimates. Heterogeneity was assessed using I and Q statistics. Publication bias was assessed with the Egger's and Begg's tests, with a P value of P < .10 indicating publication bias. All statistical tests were 2-sided.We identified and included 11 prospective cohort studies in the final meta-analysis. The risks of PCC and DCC among individuals in the highest dietary fiber intake quartile/quintile were 14% (relative risk [RR] = 0.86, 95% confidence interval [CI] = 0.78-0.95) and 21% (RR = 0.79, 95% CI = 0.71-0.87) lower, respectively, than those among individuals with the lowest dietary fiber intake. In a subgroup analysis, the inverse association observed in the sex-based subgroup was apparent only for men with PCC. Dietary fiber intake was inversely associated with DCC for both men and women. In addition, dietary fiber intake appeared to be inversely associated with PCC only in European countries, whereas this association was observed for DCC in both European countries and the United States.Our findings reveal that dietary fiber intake is associated inversely with the risk of both PCC and DCCs.
Topics: Colonic Neoplasms; Diet; Dietary Fiber; Humans; Observational Studies as Topic; Risk Factors
PubMed: 30200062
DOI: 10.1097/MD.0000000000011678 -
World Journal of Gastroenterology May 2015To investigate fiber and prebiotic supplementation of enteral nutrition (EN) for diarrhea, fecal microbiota and short-chain fatty acids (SCFAs). (Meta-Analysis)
Meta-Analysis Review
AIM
To investigate fiber and prebiotic supplementation of enteral nutrition (EN) for diarrhea, fecal microbiota and short-chain fatty acids (SCFAs).
METHODS
MEDLINE, EMBASE, Cochrane Library, CINAHL, Academic Search Premier, and Web of Science databases were searched for human experimental and observational cohort studies conducted between January 1990 and June 2014. The keywords used for the literature search were fiber, prebiotics and enteral nutrition. English language studies with adult patient populations on exclusive EN were selected. Abstracts and/or full texts of selected studies were reviewed and agreed upon by two independent researchers for inclusion in the meta-analysis. Tools used for the quality assessment were Jadad Scale and the Scottish Intercollegiate Guidelines Network Critical Appraisal of the Medical Literature.
RESULTS
A total of 456 possible articles were retrieved, and 430 were excluded due to lack of appropriate data. Of the 26 remaining studies, only eight investigated the effects of prebiotics. Results of the meta-analysis indicated that overall, fiber reduces diarrhea in patients receiving EN (OR = 0.47; 95%CI: 0.29-0.77; P = 0.02). Subgroup analysis revealed a positive effect of fiber supplementation in EN towards diarrhea in stable patients (OR = 0.31; 95%CI: 0.19-0.51; P < 0.01), but not in critically ill patients (OR = 0.89; 95%CI: 0.41-1.92; P = 0.77). Prebiotic supplementation in EN does not improve the incidence of diarrhea despite its manipulative effect on bifidobacteria concentrations and SCFA in healthy humans. In addition, the effect of fiber and/or prebiotic supplementation towards fecal microbiota and SCFA remain disputable.
CONCLUSION
Fiber helps minimize diarrhea in patients receiving EN, particularly in non-critically ill patients. However, the effect of prebiotics in moderating diarrhea is inconclusive.
Topics: Chi-Square Distribution; Critical Illness; Diarrhea; Dietary Fiber; Enteral Nutrition; Fatty Acids; Feces; Humans; Incidence; Intestinal Mucosa; Intestines; Microbiota; Odds Ratio; Prebiotics; Risk Factors; Treatment Outcome
PubMed: 25954112
DOI: 10.3748/wjg.v21.i17.5372 -
Nutrients Nov 2022The efficacy of different types and doses of dietary fiber supplementation in the treatment of gestational diabetes (GDM) remains controversial. The purpose of this... (Meta-Analysis)
Meta-Analysis Review
The efficacy of different types and doses of dietary fiber supplementation in the treatment of gestational diabetes (GDM) remains controversial. The purpose of this study is to investigate the effect of dietary fiber on blood glucose control in pregnant women with gestational diabetes mellitus, and further observe the effect on their blood lipids and pregnancy outcomes. We searched on Web of Science, PubMed, Embase, Scopus, and Cochrane, and included several articles on additional fortification with dietary fiber for gestational diabetes interventions. This meta-analysis included 8 trials. We found that additional dietary fiber supplements significantly reduced fasting glucose (Hedges’g = −0.3; 95% CI [−0.49, −0.1]), two-hour postprandial glucose (Hedges’g = −0.69; 95% CI [−0.88, −0.51]), glycated hemoglobin (Hedges’g = −0.5; 95% CI [−0.68, −0.31]), TC (Hedges’g = −0.44; 95% CI [−0.69, −0.19]), TG (Hedges’g = −0.3; 95% CI [−0.4, −0.2]) and LDL-C (Hedges’g = −0.48; 95% CI [−0.63, −0.33]). It also significantly reduced preterm delivery (Hedges’g = 0.4, 95% CI [0.19~0.84]), cesarean delivery (Hedges’g = 0.6; 95% CI [0.37~0.97]), fetal distress (Hedges’g = 0.51; 95% CI [0.22~1.19]), and neonatal weight (Hedges’g = −0.17; 95% CI [−0.27~−0.07]). In a subgroup analysis comparing dietary fiber type and dose, insoluble dietary fiber was more effective than soluble dietary fiber in reducing fasting glucose (Hedges’g = −0.44; 95% CI [−0.52, −0.35]). ≥12 g fiber per day may be more effective in improving glycemic lipid and pregnancy outcomes than <12 g/day, but the difference was not statistically significant. In conclusion, our meta-analysis showed that dietary fiber supplementation significantly improved glycolipid metabolism and pregnancy outcomes in gestational diabetes. Dietary fiber may be considered adjunctive therapy for gestational diabetes, and an additional supplement with insoluble dietary fiber is more recommended for those with poor fasting glucose. However, more high-quality studies are needed on the further effect of fiber type and the dose-effect relationship.
Topics: Infant, Newborn; Female; Pregnancy; Humans; Diabetes, Gestational; Pregnant Women; Dietary Supplements; Blood Glucose; Dietary Fiber
PubMed: 36364883
DOI: 10.3390/nu14214626 -
Nutrition Reviews Nov 2017Pancreatic cancer has the highest case fatality rate of all major cancers. (Meta-Analysis)
Meta-Analysis Review
CONTEXT
Pancreatic cancer has the highest case fatality rate of all major cancers.
OBJECTIVE
A systematic review using PRISMA guidelines was conducted to summarize the associations between dietary patterns and risk of pancreatic cancer.
DATA SOURCES
PubMed and Web of Science databases were searched for case-control and cohort studies published up to June 15, 2016.
STUDY SELECTION
Eligible studies included a dietary pattern as exposure and pancreatic cancer incidence or mortality as outcome and reported odds ratios, hazard ratios, or relative risks, along with corresponding 95%CIs.
DATA EXTRACTION
Important characteristics of each study, along with the dietary assessment instrument, the component foods or nutrients included in each dietary pattern or the scoring algorithm of a priori dietary patterns, were presented. For each dietary pattern identified, the estimate of association and the 95%CI comparing the highest versus the lowest category from the model with the most covariate adjustment were reported.
RESULTS
A total of 16 studies were identified. Among the 8 studies that examined data-driven dietary patterns, significant positive associations were found between pancreatic cancer risk and the Animal Products, Starch Rich, and Western dietary patterns, with effect estimates ranging from 1.69 to 2.40. Significant inverse relationships were found between risk of pancreatic cancer and dietary patterns designated as Fruits and Vegetables, Vitamins and Fiber, and Prudent, with effect estimates ranging from 0.51 to 0.55. Eight studies of a priori dietary patterns consistently suggested that improved dietary quality was associated with reduced risk of pancreatic cancer.
CONCLUSIONS
Better diet quality is associated with reduced risk of pancreatic cancer. The associations between dietary patterns and pancreatic cancer were stronger in case-control studies than in cohort studies and were stronger among men than among women.
Topics: Diet; Diet, Western; Dietary Fiber; Female; Fruit; Humans; Incidence; Male; Meat; Pancreatic Neoplasms; Risk; Starch; Vegetables; Vitamins
PubMed: 29025004
DOI: 10.1093/nutrit/nux038 -
BMJ Clinical Evidence Mar 2011Diverticula (mucosal outpouching through the wall of the colon) are rare before the age of 40 years, after which prevalence increases steadily and reaches over 25% by 60... (Review)
Review
INTRODUCTION
Diverticula (mucosal outpouching through the wall of the colon) are rare before the age of 40 years, after which prevalence increases steadily and reaches over 25% by 60 years. However, only 10% to 25% of affected people will develop symptoms such as lower abdominal pain. Recurrent symptoms are common, and 5% of people with diverticula eventually develop complications such as perforation, obstruction, haemorrhage, fistulae, or abscesses.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of: treatments for uncomplicated diverticular disease; treatments to prevent complications; and treatments for acute diverticulitis? We searched: Medline, Embase, The Cochrane Library, and other important databases up to May 2010 (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 16 systematic reviews, RCTs, or observational 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: antispasmodics, elective surgery, increasing fibre intake with bran or ispaghula husk, lactulose, medical treatment, mesalazine, methylcellulose, rifaximin, and surgery.
Topics: Abdominal Pain; Acute Disease; Dietary Fiber; Diverticulitis; Diverticulosis, Colonic; Diverticulum; Humans
PubMed: 21401970
DOI: No ID Found -
Frontiers in Nutrition 2023Periodontitis is a chronic inflammatory condition affecting the supporting structures of a tooth in the oral cavity. The relationship between dietary fiber and... (Review)
Review
BACKGROUND
Periodontitis is a chronic inflammatory condition affecting the supporting structures of a tooth in the oral cavity. The relationship between dietary fiber and periodontitis is poorly understood. The objective of this systematic review is to investigate if an intake of dietary fiber modulates periodontal disease in animal models and any concomitant effects on systemic inflammation, microbiota and their metabolites.
METHODS
Animal studies using periodontitis models with any form of fiber intervention were included. Studies with comorbidities that were mutually inclusive with periodontitis and animals with physiological conditions were excluded. Search strategy with MeSH and free-text search terms were finalized and performed on the 22nd of September 2021.CINAHL Complete, EMBASE, MEDLINE, SciVerse Scopus® and Web of Science Core Collection databases were used to identify studies. SYRCLE's risk of bias tool and CAMARADES were used for quality assessment. Results were synthesized utilizing Covidence© web-based platform software to remove duplicates, and the remaining studies were manually filtered.
RESULTS
A total of 7,141 articles were retrieved from all databases. Out of 24 full-text articles assessed for eligibility, four studies ( = 4) were included. Four studies involved the use of -(1,3/1,6)-glucan ( = 3) and mannan oligosaccharide ( = 1) at differing dosages for different study durations. All studies utilized a ligature-induced model of periodontitis in rats, either Wistar ( = 3) or Sprague-Dawley ( = 1). A dose-dependent relationship between the increased fiber intake and decrease in alveolar bone loss and pro-inflammatory markers was observed.
CONCLUSION
The number of included studies is limited and narrow in scope. They highlight the importance of pre-clinical trials in this field with broader dietary fiber intervention groups before proceeding to clinical trials. The use of dietary fiber as an intervention shows promise in the reduction of inflammatory conditions like periodontitis. However, further research is required to delineate the relationship between diet and its effects on microbiota and their metabolites such as short chain fatty acids in animal models of periodontitis.
PubMed: 36998913
DOI: 10.3389/fnut.2023.1130153