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Food Science & Nutrition Nov 2023This systematic review and dose-response meta-analysis examined the risk of chronic obstructive pulmonary disease (COPD) following dietary fiber intake. Relevant... (Review)
Review
This systematic review and dose-response meta-analysis examined the risk of chronic obstructive pulmonary disease (COPD) following dietary fiber intake. Relevant articles were retrieved from a variety of databases, including Scopus, Embase, and Medline, until March 2023. Spirometry was the most frequently used method for determining the presence of COPD. Based on the search, there were a total of 213,912 participants across five separate studies. Random effects model was used to combine the data and a dose-response analysis was further conducted. Five distinct cohort studies were identified. Based on highest versus lowest analysis, there was an inverse correlation between the intake of total fiber (RR, 0.72; 95%, CI: 0.64-0.80), cereal fiber (RR: 0.76, 95% CI 0.68, 0.86), and fruit fiber (RR: 0.75, 95% CI: 0.68, 0.83). Although this result was not significant for vegetable fiber (RR, 0.95; 95% CI, 0.84-1.07). Dose-response analysis revealed that daily increase of 10 g of total dietary fiber, cereal fiber, or fruit fiber reduced the risk of COPD by 26%, 21%, and 37%, respectively. The ROBINS-E tool classified all cohort studies as having a moderate risk of bias. Total fiber, cereal fiber, and fruit fiber intake were found to have low credibility using the NutriGrade tool. Additionally, there is a lack of scientific evidence supporting the use of vegetable fiber. Larger, more comprehensive studies are required to confirm these findings.
PubMed: 37970426
DOI: 10.1002/fsn3.3640 -
Nutrients Mar 2020New knowledge about the gut microbiota and its interaction with the host's metabolic regulation has emerged during the last few decades. Several factors may affect the...
New knowledge about the gut microbiota and its interaction with the host's metabolic regulation has emerged during the last few decades. Several factors may affect the composition of the gut microbiota, including dietary fiber. Dietary fiber is not hydrolyzed by human digestive enzymes, but it is acted upon by gut microbes, and metabolites like short-chain fatty acids are produced. The short-chain fatty acids may be absorbed into the circulation and affect metabolic regulation in the host or be a substrate for other microbes. Some studies have shown improved insulin sensitivity, weight regulation, and reduced inflammation with increases in gut-derived short-chain fatty acids, all of which may reduce the risk of developing metabolic diseases. To what extent a dietary intervention with fiber may affect the human gut microbiota and hence metabolic regulation, is however, currently not well described. The aim of the present review is to summarize recent research on human randomized, controlled intervention studies investigating the effect of dietary fiber on gut microbiota and metabolic regulation. Metabolic regulation is discussed with respect to markers relating to glycemic regulation and lipid metabolism. Taken together, the papers on which the current review is based, suggest that dietary fiber has the potential to change the gut microbiota and alter metabolic regulation. However, due to the heterogeneity of the studies, a firm conclusion describing the causal relationship between gut microbiota and metabolic regulation remains elusive.
Topics: Body Weight; Diet Therapy; Dietary Fiber; Fatty Acids, Volatile; Female; Gastrointestinal Microbiome; Gastrointestinal Tract; Glucose; Host Microbial Interactions; Humans; Inflammation; Insulin Resistance; Intestinal Absorption; Lipid Metabolism; Male; Metabolic Diseases; Randomized Controlled Trials as Topic; Risk
PubMed: 32210176
DOI: 10.3390/nu12030859 -
Advances in Nutrition (Bethesda, Md.) Jun 2021No previous investigation has summarized findings from prospective cohort studies on the association between dietary intake of fiber, fruit, and vegetables and risk of... (Meta-Analysis)
Meta-Analysis
No previous investigation has summarized findings from prospective cohort studies on the association between dietary intake of fiber, fruit, and vegetables and risk of inflammatory bowel disease (IBD). Dietary fiber and its major sources can influence the risk of IBD by modulation of the gut microbiota. This study summarizes findings from published cohort studies on the association between dietary fiber, fruit, and vegetable consumption and risk of IBD. Relevant articles published up to January 2019 were searched via PubMed, MEDLINE, Scopus, Embase, Cochrane Library, and Google Scholar. All prospective cohort studies investigating the association between dietary fiber, fruit, and vegetable intake and risk of IBD were included. Combining 7 effect sizes from 6 studies, no significant association was found between dietary intake of fiber and risk of ulcerative colitis (UC) (RR: 1.09; 95% CI: 0.88, 1.34). However, a significant inverse association was found between dietary fiber intake and risk of Crohn disease (CD) (RR: 0.59; 95% CI: 0.46, 0.74), based on 5 studies with 6 effect sizes. Pooling information from 4 studies, we found a significant protective association between dietary intake of fruit and risk of UC (RR: 0.69; 95% CI: 0.55, 0.86) and CD (RR: 0.47; 95% CI: 0.38, 0.58). We also found a significant inverse association between vegetable consumption and risk of UC (RR: 0.56; 95% CI: 0.48, 0.66) and CD (RR: 0.52; 95% CI: 0.46, 0.59). In conclusion, dietary intake of fruit and vegetables was inversely associated with risk of IBD and its subtypes. Dietary fiber intake was also inversely associated with incidence of IBD and CD, but not with UC. Further studies are warranted to examine the association of other fiber-rich foods with IBD.
Topics: Dietary Fiber; Fruit; Humans; Inflammatory Bowel Diseases; Prospective Studies; Risk Factors; Vegetables
PubMed: 33186988
DOI: 10.1093/advances/nmaa145 -
JPEN. Journal of Parenteral and Enteral... Jul 2021Enteral nutrition (EN) is the preferred route of nutrition support for patients with critical illness undergoing intensive care. Experts in the field caution against... (Meta-Analysis)
Meta-Analysis Review
Enteral nutrition (EN) is the preferred route of nutrition support for patients with critical illness undergoing intensive care. Experts in the field caution against using fiber during EN because of perceived adverse patient outcomes; however, a comprehensive assessment of this topic is not evident to date. In this systematic review and meta-analysis, we searched four databases from inception to April 20, 2020, for studies on adverse events or health outcomes associated with using EN formulations containing fiber in hospitalized adults with critical illness. Nineteen articles were included. Random-effects meta-analysis models showed significantly lower diarrhea scores for fiber groups compared with nonfiber groups (pooled mean difference: -2.78; 95% CI, -4.10 to -1.47) but mixed results for risk of diarrhea between groups, depending on measures used for diarrhea (Hart and Dobb scale, pooled risk ratio [RR]: 0.68; 95% CI, 0.45-1.02; other diarrhea scales, pooled RR: 0.42; 95% CI, 0.20-0.89). Models showed 39% lower risk of gastrointestinal (GI) complications overall for fiber compared with nonfiber groups (pooled RR: 0.61; 95% CI, 0.47-0.79) but no group differences for individual GI complications, mortality, and intensive care unit or hospital length of stay. Analyses stratified by soluble- or mixed-fiber interventions reduced heterogeneity in models but showed identical conclusions. EN formulas with fiber may help reduce incidence and severity of diarrhea and GI complications overall in critically ill patients, without increased risk of other adverse events. Bias among specific GI measures indicates more high-quality studies are needed to verify these conclusions.
Topics: Adult; Critical Care; Critical Illness; Dietary Fiber; Enteral Nutrition; Humans; Intensive Care Units
PubMed: 34165812
DOI: 10.1002/jpen.2210 -
European Journal of Nutrition Jun 2021It is unclear how dietary intake influences the ovarian cancer. The present paper sets out to systematically review and meta-analyze research on dietary intake to... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
It is unclear how dietary intake influences the ovarian cancer. The present paper sets out to systematically review and meta-analyze research on dietary intake to identify cases having high- or low-risk ovarian cancer.
METHODS
Scopus, PubMed, and Wiley Online Libraries were searched up to the date November 24, 2019. Two reviewers were requested to independently extract study characteristics and to assess the bias and applicability risks with reference to the study inclusion criteria. Meta-analyses were performed to specify the relationship between dietary intake and the risk of ovarian cancer identifying 97 cohort studies.
RESULTS
No significant association was found between dietary intake and risk of ovarian cancer. The results of subgroup analyses indicated that green leafy vegetables (RR = 0.91, 95%, 0.85-0.98), allium vegetables (RR = 0.79, 95% CI 0.64-0.96), fiber (RR = 0.89, 95% CI 0.81-0.98), flavonoids (RR = 0.83, 95% CI 0.78-0.89) and green tea (RR = 0.61, 95% CI 0.49-0.76) intake could significantly reduce ovarian cancer risk. Total fat (RR = 1.10, 95% CI 1.02-1.18), saturated fat (RR = 1.11, 95% CI 1.01-1.22), saturated fatty acid (RR = 1.19, 95% CI 1.04-1.36), cholesterol (RR = 1.13, 95% CI 1.04-1.22) and retinol (RR = 1.14, 95% CI 1.00-1.30) intake could significantly increase ovarian cancer risk. In addition, acrylamide, nitrate, water disinfectants and polychlorinated biphenyls were significantly associated with an increased risk of ovarian cancer.
CONCLUSION
These results could support recommendations to green leafy vegetables, allium vegetables, fiber, flavonoids and green tea intake for ovarian cancer prevention.
Topics: Dietary Fiber; Eating; Female; Humans; Ovarian Neoplasms; Risk; Risk Factors; Vegetables
PubMed: 32661683
DOI: 10.1007/s00394-020-02332-y -
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 -
International Journal of Environmental... Apr 2021PubMed/Medline, Excerpta Medica dataBASE (EMBASE) and Scopus were searched in January 2021 in order to retrieve evidence assessing the association between dietary fibre... (Meta-Analysis)
Meta-Analysis Review
PubMed/Medline, Excerpta Medica dataBASE (EMBASE) and Scopus were searched in January 2021 in order to retrieve evidence assessing the association between dietary fibre intake and the risk of colorectal adenoma in adults. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used for the reporting of results. Only primary observational studies were included. Publication bias was estimated through the Egger's test and the visual inspection of the funnel plot. Heterogeneity between studies was calculated with I statistics. The search strategy identified 683 papers, 21 of which were included in our meta-analysis. Having evaluated a total of 157,725 subjects, the results suggest a protective effect of dietary fibre intake against colorectal adenoma. Effect Size (ES) was [0.71 (95% CI = 0.68-0.75), = 0.000)]. Moderate statistical heterogeneity (Chi = 61.68, df = 23, I = 62.71%, = 0.000) was found. Findings show a statistically significant ( = 0.000) and robust association between a higher intake of dietary fibre and a lower risk of colorectal adenoma, considering both the prevalent and incident risk. Moreover, the meta-regression analysis showed a borderline significant negative linear correlation between the amount of dietary fibre intake and colorectal adenoma. Lastly, we performed a subgroup analysis by sex, showing a higher protective effect for men.
Topics: Adenoma; Adult; Colorectal Neoplasms; Dietary Fiber; Humans; Male; Physical Examination
PubMed: 33920845
DOI: 10.3390/ijerph18084168 -
JPEN. Journal of Parenteral and Enteral... Jul 2022Although some studies have explored the relationships between dietary fiber (DF) supplement and gut barrier function, changes of gut microbiota, and clinical outcomes in... (Meta-Analysis)
Meta-Analysis
Effect of dietary fiber on gut barrier function, gut microbiota, short-chain fatty acids, inflammation, and clinical outcomes in critically ill patients: A systematic review and meta-analysis.
BACKGROUND
Although some studies have explored the relationships between dietary fiber (DF) supplement and gut barrier function, changes of gut microbiota, and clinical outcomes in critically ill patients, the results were not consistent.
OBJECTIVE
The purpose was to explore the effect of DF on gut barrier function, gut microbiota, short-chain fatty acids (SCFAs), inflammation, and clinical outcomes in critically ill patients.
METHODS
A search was performed through five databases from inception to July 12, 2021. Data were expressed as mean difference (MD) or odds ratio (OR) with CI.
RESULTS
Twenty-one studies involving 2084 critically ill patients were included. There was a significant reduction in intestinal permeability, demonstrated by lactulose/rhamnose ratio (MD, -0.04; 95% CI, -0.08 to -0.00; P = 0.03) on day 8, C-reactive protein on day 14 (MD, -36.66; 95% CI, -44.40 to -28.93; P < 0.001) and duration of hospital stay (MD, -3.16; 95% CI, -5.82 to -0.49; P < 0.05) after DF supplement. There were no significant differences in SCFA levels, duration of mechanical ventilation, and mortality between two groups. However, subgroup analysis results indicated significant decreases in duration of hospital stay and risk of mortality were seen in the subgroups with a supplementary fiber dose ≥20 g/day (MD, -5.62 [95% CI, -8.04 to -3.21; P < 0.0001]; OR, 0.18 [95% CI, 0.06-0.57; P = 0.004]), as well as in the medical intensive care unit (MD, -4.77 [95% CI, -7.48 to -2.07; P < 0.01]; OR, 0.13 [95% CI, 0.03-0.65; P < 0.05]).
CONCLUSIONS
DF may improve gut barrier function, modulate intestinal microbiota, decrease systemic inflammatory response, and advance clinical outcomes in critically ill patients.
Topics: Critical Illness; Dietary Fiber; Fatty Acids, Volatile; Gastrointestinal Microbiome; Humans; Inflammation
PubMed: 34951702
DOI: 10.1002/jpen.2319 -
Toxins Mar 2021The aim of this systematic review is to investigate the effects of the use of a medium cut-off membrane (MCO) and dietary fiber on the concentration of protein-bound...
The aim of this systematic review is to investigate the effects of the use of a medium cut-off membrane (MCO) and dietary fiber on the concentration of protein-bound uremic toxins (PBUTs) and inflammatory markers in hemodialysis (HD) patients. Of 11,397 papers originally found, eight met the criteria of randomized controlled trial design. No study examined the effects of MCO membranes on PBUTs. Three studies examined the reduction in inflammatory markers with MCO membranes compared to high-flux HD membranes and showed no significant differences. Five studies of dietary fiber supplementation showed an inconclusive positive effect on PBUT levels and a significant positive effect on the reduction in inflammatory markers (interleukin-6 reduction: standardized difference in means -1.18; 95% confidence interval -1.45 to -0.9 for dietary fiber supplementation vs. control; < 0.001). To date, no study has combined the use of an MCO membrane and fiber supplementation to reduce PBUT levels and inflammation with online hemodiafiltration as a comparator. A rationale and protocol for an interventional trial using a combination of MCO membrane dialysis and fiber supplementation to lower inflammatory markers and PBUT concentrations are presented.
Topics: Animals; Combined Modality Therapy; Dietary Fiber; Filtration; Humans; Inflammation Mediators; Membranes, Artificial; Protein Binding; Randomized Controlled Trials as Topic; Renal Dialysis; Renal Insufficiency, Chronic; Toxins, Biological; Treatment Outcome; Uremia
PubMed: 33805509
DOI: 10.3390/toxins13040244 -
European Journal of Nutrition Aug 2021Probiotics have been reported to be beneficial for inflammatory bowel disease (IBD), but the types, number of strains, dosage, and intervention time of probiotics used... (Meta-Analysis)
Meta-Analysis
PURPOSE
Probiotics have been reported to be beneficial for inflammatory bowel disease (IBD), but the types, number of strains, dosage, and intervention time of probiotics used remain controversial. Furthermore, the changes of gut microbiota in IBD's patients are also intriguing. Thus, this meta-analysis was to explore the clinical effects and gut microbiota changes of using probiotics, prebiotics and synbiotics in IBD.
METHODS
The search was performed in PubMed, Web of Science and the Cochrane library from inception to April 2020. Qualified randomized controlled trials were included. IBD's remission rate, disease activity index and recurrence rate were extracted and analyzed. Changes in the gut microbiota of patients with IBD are comprehensively described.
RESULTS
Thirty-eight articles were included. Probiotics, prebiotics and synbiotics can induce/maintain IBD's remission and reduce ulcerative colitis (UC) disease activity index (RR = 1.13, 95% CI 1.02, 1.26, P < 0.05; SMD = 1.00, 95% CI 0.27, 1.73, P < 0.05). In subgroup analyses of IBD remission rate and UC disease activity index, we obtained some statistically significant results in some subgroup (P < 0.05). To some extent, probiotic supplements can increase the number of beneficial bacteria (especially Bifidobacteria) in the intestinal tract of patients with IBD.
CONCLUSIONS
Our results support the treatment of IBD (especially UC) with pro/pre/synbiotics, and synbiotics are more effective. Probiotic supplements that are based on Lactobacillus and Bifidobacterium or more than one strain are more likely to be beneficial for IBD remission. The dose of 10-10 CFU/day may be a reference range for using probiotics to relieve IBD.
Topics: Gastrointestinal Microbiome; Humans; Inflammatory Bowel Diseases; Prebiotics; Probiotics; Synbiotics
PubMed: 33555375
DOI: 10.1007/s00394-021-02503-5