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The American Journal of Clinical... Nov 2018Studies have identified viscous dietary fiber as potentially attenuating cholesterol, including psyllium, which reduces LDL cholesterol and thus may complement... (Meta-Analysis)
Meta-Analysis
Effect of psyllium (Plantago ovata) fiber on LDL cholesterol and alternative lipid targets, non-HDL cholesterol and apolipoprotein B: a systematic review and meta-analysis of randomized controlled trials.
BACKGROUND
Studies have identified viscous dietary fiber as potentially attenuating cholesterol, including psyllium, which reduces LDL cholesterol and thus may complement cardiovascular disease (CVD) treatment.
OBJECTIVES
The aims of this study were to update evidence on the effect of psyllium on LDL cholesterol and to provide an assessment of its impact on alternate markers: non-HDL cholesterol and apolipoprotein B (apoB).
DESIGN
Medline, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials were searched through 3 October 2017. Independent reviewers extracted relevant data and assessed risk of bias. We included randomized controlled trials with a duration of ≥3 wk that assessed the effect of psyllium on blood lipids in individuals with or without hypercholesterolemia. Data were pooled by using the generic inverse variance method with random-effects models and expressed as mean differences (MDs) with 95% CIs. Heterogeneity was assessed by Cochran's Q statistic and quantified by the I2 statistic. Overall quality of the evidence was assessed by using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach.
RESULTS
We included 28 trials in our analysis (n = 1924). Supplementation of a median dose of ∼10.2 g psyllium significantly reduced LDL cholesterol (MD = -0.33 mmol/L; 95% CI: -0.38, -0.27 mmol/L; P < 0.00001), non-HDL cholesterol (MD = -0.39 mmol/L; 95% CI: -0.50, -0.27 mmol/L; P < 0.00001), and apoB (MD = -0.05 g/L; 95% CI: -0.08, -0.03 g/L; P < 0.0001). Effect estimates for LDL cholesterol and non-HDL cholesterol were graded as moderate quality on the basis of downgrades for inconsistency and graded as high quality for apoB.
CONCLUSION
Psyllium fiber effectively improves conventional and alternative lipids markers, potentially delaying the process of atherosclerosis-associated CVD risk in those with or without hypercholesterolemia. This trial is registered at www.clinicaltrials.gov as NCT03346733.
Topics: Adult; Apolipoproteins B; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Dietary Fiber; Female; Humans; Hypercholesterolemia; Male; Middle Aged; Plantago; Psyllium
PubMed: 30239559
DOI: 10.1093/ajcn/nqy115 -
Nutrients May 2021A disequilibrium of the gut microbial community has been closely associated with systemic inflammation and metabolic syndromes including type 2 diabetes. While low fibre... (Meta-Analysis)
Meta-Analysis
The Effect of Dietary Fibre on Gut Microbiota, Lipid Profile, and Inflammatory Markers in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomised Controlled Trials.
BACKGROUND
A disequilibrium of the gut microbial community has been closely associated with systemic inflammation and metabolic syndromes including type 2 diabetes. While low fibre and high fat diets may lead to dysbiosis of the gut microbiome as a result of the loss of useful microbes, it has been reported that a high fibre diet may prevent the fermentation of protein and may promote eubiosis of gut microbiota.
AIM
This review aims to evaluate the effect of dietary fibre (DF) on gut microbiota, lipid profile, and inflammatory markers in patients with type 2 diabetes.
METHODS
The PRISMA framework was relied on to conduct this systematic review and meta-analysis. Searches were carried out using electronic databases and reference list of articles.
RESULTS
Eleven studies were included in the systematic review, while ten studies were included in the meta-analysis. The findings revealed five distinct areas including the effects of DF on (a) gut microbiota (122 participants); (b) lipopolysaccharides (LPS, 79 participants) and lipopolysaccharides binding protein (LBP, 81 participants); (c) lipid profile; (d) inflammatory markers; and (e) body mass index (BMI, 319 participants). The relative abundance of increased by 0.73 (95% CI: 0.57, 0.89) in the DF group in contrast to the control ( < 0.05). With respect to LPS, the level was lower in the DF group than the control and the difference was significant ( < 0.05). The standardised mean difference for LPS was -0.45 (95% CI: -0.90, -0.01) although the difference between the two groups in relation to LBP was not significant ( = 0.08) and the mean difference was 0.92 (95% CI: -0.12, 1.95). While there was a decrease of -1.05 (95% CI: -2.07, -0.02) with respect to total cholesterol (356 participants) in the DF group as compared with the control ( < 0.05), both groups were not significantly different ( > 0.05) in the other lipid parameters. The difference between the groups was significant ( < 0.05) in relation to C-reactive protein, and the mean difference was 0.43 (95% CI: 0.02, 0.84). This could be due to the short duration of the included studies and differences in participants' diets including the amount of dietary fibre supplements. However, the groups were not significantly different ( > 0.05) with respect to the other inflammatory markers. The meta-analysis of the BMI showed that the DF group decreased by -0.57 (95% CI: -1.02, -0.12) as compared with the control and this was significant ( < 0.01).
CONCLUSION
DF significantly ( < 0.05) increased the relative abundance of and significantly decreased ( < 0.05) LPS, total cholesterol, and BMI as compared with the control. However, DF did not seem to have an effect that was significant on LBP, triglyceride, HDL cholesterol, LDL cholesterol, IL-6, TNF-α, adiponectin, and leptin. These findings have implications for public health in relation to the use of dietary fibre in nutritional interventions and as strategies for managing type 2 diabetes.
Topics: Acute-Phase Proteins; Bifidobacterium; Biomarkers; Body Mass Index; C-Reactive Protein; Carrier Proteins; Databases, Factual; Diabetes Mellitus, Type 2; Dietary Fiber; Dysbiosis; Gastrointestinal Microbiome; Humans; Lipids; Membrane Glycoproteins; Metabolic Syndrome; Randomized Controlled Trials as Topic; Triglycerides
PubMed: 34073366
DOI: 10.3390/nu13061805 -
Advances in Nutrition (Bethesda, Md.) Mar 2022Inulin-type fructans (ITF), including short-chain fructooligosaccharides (scFOS), oligofructose, and inulin, are commonly used fibers that are widely regarded as... (Review)
Review
Inulin-type fructans (ITF), including short-chain fructooligosaccharides (scFOS), oligofructose, and inulin, are commonly used fibers that are widely regarded as prebiotic for their ability to be selectively utilized by the intestinal microbiota to confer a health benefit. However, to our knowledge the literature thus far lacks a thorough discussion of the evidence from human clinical trials for the prebiotic effect of ITF, including beneficial effects on intestinal microbiota composition and intestinal and extraintestinal processes (e.g., glucose homeostasis, lipids, mineral absorption and bone health, appetite and satiety, inflammation and immune function, and body composition). Additionally, there has been a lack of discussion regarding aspects such as the effect of ITF chain length on its intestinal and extraintestinal effects. The overall objective of this systematic review was to summarize the prebiotic potential of ITF based on the results of human clinical trials in healthy adult populations. Evidence from studies included in the current review suggest that ITF have a prebiotic effect on the intestinal microbiota, promoting the abundances of Bifidobacterium, Lactobacillus, and Faecalibacterium prausnitzii. Beneficial health effects reported following ITF intake include improved intestinal barrier function, improved laxation, increased insulin sensitivity, decreased triglycerides and an improved lipid profile, increased absorption of calcium and magnesium, and increased satiety. Although there is some evidence for differing effects of ITF based on chain length, the lack of direct comparisons and detailed descriptions of physicochemical properties limits the ability to draw conclusions from human clinical studies. Future research should focus on elucidating the mechanisms by which the intestinal microbiota mediates or modifies the effects of ITF on human health and the contribution of individual factors such as age and metabolic health to the movement toward personalization of prebiotic applications.
Topics: Adult; Humans; Inulin; Fructans; Prebiotics; Intestines; Calcium, Dietary
PubMed: 34555168
DOI: 10.1093/advances/nmab119 -
Nutrients Oct 2020The prevalence of type 2 diabetes is on the increase worldwide, and it represents about 90% of adults who are diagnosed with diabetes. Overweight and obesity, lifestyle,... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The prevalence of type 2 diabetes is on the increase worldwide, and it represents about 90% of adults who are diagnosed with diabetes. Overweight and obesity, lifestyle, genetic predisposition and gut microbiota dysbiosis have been implicated as possible risk factors in the development of type 2 diabetes. In particular, low intake of dietary fibre and consumption of foods high in fat and sugar, which are common in western lifestyle, have been reported to contribute to the depletion of specific bacterial taxa. Therefore, it is possible that intake of high dietary fibre may alter the environment in the gut and provide the needed substrate for microbial bloom.
AIM
The current review is a systematic review and meta-analysis which evaluated the role of dietary fibre in modulating gut microbiota dysbiosis in patients with type 2 diabetes.
METHODS
This is a systematic review and meta-analysis of randomised controlled trials which relied on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework. Electronic searches were conducted using EBSCOHost with links to Health Sciences Research Databases, EMBASE and Google Scholar. The reference lists of articles were also searched for relevant studies. Searches were conducted from date of commencement of the database to 5 August 2020. The search strategy was based on the Population, Intervention, Comparator, Outcomes, Studies (PICOS) framework and involved the use of synonyms and medical subject headings (MesH). Search terms were combined with Boolean operators (OR/AND).
RESULTS
Nine studies which met the inclusion criteria were selected for the systematic review and meta-analysis, and four distinct areas were identified: the effect of dietary fibre on gut microbiota; the role of dietary fibre on short-chain fatty acids (SCFAs); glycaemic control; and adverse events. There was significant difference ( < 0.01) in the relative abundance of Bifidobacterium with a mean difference of 0.72 (95% CI, 0.56, 0.89) between the dietary fibre group compared with placebo. In relation to the meta-analysis for SCFAs, while there was significant difference ( = 0.02) between the dietary fibre group and placebo with a standardised mean difference of 0.5 (95% CI, 0.08, 0.91) regarding total SCFAs, the differences were not significant ( > 0.05) in relation to acetic acid, propionic acid and butyric acid. There was only significant improvement ( = 0.002) with respect to glycated haemoglobin with a mean difference of -0.18 (95% CI, -0.29, -0.06) between the dietary fibre group and placebo group. Differences between the two groups were not significant ( > 0.05) in relation to fasting blood glucose and homeostatic model assessment of insulin resistance (HOMA-IR). Furthermore, there were no significant differences between the two groups in subjects who reported adverse events. It is possible that the promotion of SCFA producers in greater diversity and abundance by dietary fibre in this review led to improvement in glycated haemoglobin, partly due to increased glucagon-like peptide-1 (GLP-1) production. In addition, Bifidobacterium lactis has been reported to increase glycogen synthesis, decrease expression of hepatic gluconeogenesis genes, improve translocation of glucose transport-4 and promote glucose uptake. It is also possible that the reduction in body weight of participants in the intervention group compared with control may have contributed to the observed improvement in glycated haemoglobin.
CONCLUSION
This systematic review and meta-analysis have demonstrated that dietary fibre can significantly improve ( < 0.05) the relative abundance of Bifidobacterium, total SCFAs and glycated haemoglobin. However, dietary fibre did not appear to have significant effect ( > 0.05) on fasting blood glucose, HOMA-IR, acetic acid, propionic acid, butyric acid and adverse events.
Topics: Adult; Diabetes Mellitus, Type 2; Dietary Fiber; Dysbiosis; Fatty Acids, Volatile; Female; Gastrointestinal Microbiome; Glucagon-Like Peptide 1; Glycated Hemoglobin; Glycemic Control; Humans; Male; Randomized Controlled Trials as Topic
PubMed: 33113929
DOI: 10.3390/nu12113239 -
Nutrients Jul 2018Epidemiological studies are inconclusive regarding the association between dietary fiber intake and endometrial cancer risk. Thus, we aimed to conduct a meta-analysis to... (Meta-Analysis)
Meta-Analysis Review
Epidemiological studies are inconclusive regarding the association between dietary fiber intake and endometrial cancer risk. Thus, we aimed to conduct a meta-analysis to clarify the association between dietary fiber and endometrial cancer risk. We searched the PubMed and ISI Web databases for relevant studies through March 2018. The association between dietary fiber and endometrial cancer risk was evaluated by conducting a meta-analysis including 3 cohort and 12 case⁻control studies. A significant negative association was observed between total dietary fiber intake and endometrial cancer risk in 11 case⁻control studies (odds ratios (OR) 0.76, 95% confidence interval (CI): 0.64⁻0.89, ² = 35.2%, = 0.117), but a marginal positive association was observed in three cohort studies (relative risk (RR) 1.22, 95% CI: 1.00⁻1.49, ² = 0.0%, = 0.995). Particularly, a negative association was observed in North America (OR = 0.70, 95% CI: 0.59⁻0.83, ² = 8.9%, = 0.362). In addition, a positive association was observed in cereal fiber (RR = 1.26, 95% CI: 1.03⁻1.52, ² = 0.0%, = 0.530, 3 cohort studies) and a negative association was observed in vegetable fiber (OR = 0.74, 95% CI: 0.58⁻0.94, ² = 0.0%, = 0.445, 3 case⁻control studies). In conclusion, negative associations with endometrial cancer risk were observed for higher total dietary fiber intake and higher vegetable fiber intake in the case⁻control studies. However, results from the cohort studies suggested positive relationships of higher total fiber intake and higher cereal fiber intake with endometrial cancer risk.
Topics: Dietary Fiber; Endometrial Neoplasms; Female; Humans; Risk Factors
PubMed: 30037138
DOI: 10.3390/nu10070945 -
European Journal of Nutrition Aug 2017While the prevalence of children on vegetarian diets is assumed to be on the rise in industrialized countries, there are hardly any representative data available. In... (Review)
Review
PURPOSE
While the prevalence of children on vegetarian diets is assumed to be on the rise in industrialized countries, there are hardly any representative data available. In general, vegetarian diets are presumed to be healthy; nevertheless, there are concerns as to whether the dietary specifications required during infancy, childhood, and adolescence can be met. Therefore, the objective of this systematic review was to evaluate studies on the dietary intake and the nutritional or health status of vegetarian infants, children, and adolescents.
METHODS
The database MEDLINE was used for literature search. In addition, references of reviews and expert opinions were considered. Inclusion criteria were (1) sufficient dietary information to define vegetarian type diet and (2) characteristics of nutritional or health status. Case reports and studies from non-industrialized countries were excluded.
RESULTS
24 publications from 16 studies published from 1988 to 2013 met our criteria. Study samples covered the age range from 0 to 18 years, and median sample size was 35. Five studies did not include a control group. With regard to biomarkers, anthropometry, and dietary or nutritional intake, the outcomes were diverse. Growth and body weight were generally found within the lower reference range. The intakes of folate, vitamin C, and dietary fiber were relatively high compared to reference values and/or control groups. Low status of vitamin B was reported in one study and low status of vitamin D in two studies.
CONCLUSIONS
Due to the study heterogeneity, the small samples, the bias towards upper social classes, and the scarcity of recent studies, the existing data do not allow us to draw firm conclusions on health benefits or risks of present-day vegetarian type diets on the nutritional or health status of children and adolescents in industrialized countries.
Topics: Adolescent; Adolescent Development; Body Weight; Bone Development; Child; Child Development; Child, Preschool; Diet, Vegan; Diet, Vegetarian; Dietary Fiber; Humans; Infant; Infant, Newborn; Micronutrients; Observational Studies as Topic
PubMed: 28299420
DOI: 10.1007/s00394-017-1416-0 -
Nutritional Neuroscience Feb 2023Findings of previous studies on relationship between dietary fiber intake and depression were inconsistent. We performed a meta-analysis on the association of dietary... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Findings of previous studies on relationship between dietary fiber intake and depression were inconsistent. We performed a meta-analysis on the association of dietary fiber intake with depression and anxiety in epidemiologic studies.
METHODS
We conducted a systematic search of electronic databases, up to May 2021. Data from 18 publications (12 cross-sectional, five cohort and one case-control studies) on dietary fiber consumption in relation to depression or anxiety were included. For depression, fifteen studies were conducted on adults and three others on adolescents. Anxiety was not included in the analysis, due to insufficient eligible studies.
RESULTS
Total dietary fiber intake was associated with a 10% lower odds of depression (OR = 0.90; 95% confidence interval [CI]: 0.86, 0.95) in adults and a 57% lower odds (OR = 0.43, 95% CI: 0.32, 0.59) in adolescents. Dose-response meta-analysis revealed an inverse linear association between total dietary fiber intake and odd of depression in adults; such that each 5-g increase in total dietary fiber intake was associated with a 5% reduction in risk of depression (OR = 0.95; 95% CI: 0.94, 0.97). An inverse significant association was observed between intake of fiber from vegetables (OR = 0.73; 95% CI: 0.66, 0.82) and soluble fiber (OR = 0.80, 95% CI: 0.71, 0.91) and odds of depression. However, cereal fiber, fiber from fruits and insoluble fiber were marginally associated with a reduction in having depression.
CONCLUSIONS
High intake of dietary fiber was protectively associated with depression in adults, in a dose-response fashion.
Topics: Adult; Humans; Adolescent; Risk Factors; Cross-Sectional Studies; Depression; Fruit; Dietary Fiber
PubMed: 36692989
DOI: 10.1080/1028415X.2021.2020403 -
Nutrients May 2020Lactose intolerance (LI) is characterized by the presence of primarily gastrointestinal clinical signs resulting from colonic fermentation of lactose, the absorption of... (Meta-Analysis)
Meta-Analysis
Lactose intolerance (LI) is characterized by the presence of primarily gastrointestinal clinical signs resulting from colonic fermentation of lactose, the absorption of which is impaired due to a deficiency in the lactase enzyme. These clinical signs can be modified by several factors, including lactose dose, residual lactase expression, concurrent ingestion of other dietary components, gut-transit time, and enteric microbiome composition. In many of individuals with lactose malabsorption, clinical signs may be absent after consumption of normal amounts of milk or, in particular, dairy products (yogurt and cheese), which contain lactose partially digested by live bacteria. The intestinal microbiota can be modulated by biotic supplementation, which may alleviate the signs and symptoms of LI. This systematic review summarizes the available evidence on the influence of prebiotics and probiotics on lactase deficiency and LI. The literature search was conducted using the MEDLINE (via PUBMED) and SCOPUS databases following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and included randomized controlled trials. For each study selected, the risk of bias was assessed following the Cochrane Collaboration methodology. Our findings showed varying degrees of efficacy but an overall positive relationship between probiotics and LI in relation to specific strains and concentrations. Limitations regarding the wide heterogeneity between the studies included in this review should be taken into account. Only one study examined the benefits of prebiotic supplementation and LI. So further clinical trials are needed in order to gather more evidence.
Topics: Abdominal Pain; Animals; Databases, Factual; Diarrhea; Diet; Flatulence; Food, Fortified; Gastrointestinal Microbiome; Humans; Lactase; Lactose; Lactose Intolerance; Milk; Prebiotics; Probiotics; Vomiting
PubMed: 32443748
DOI: 10.3390/nu12051487 -
BMJ Clinical Evidence Mar 2015Prevalence of childhood constipation has been estimated at 1% to 30% in the general population worldwide; most children have no obvious aetiological factors. One third... (Review)
Review
INTRODUCTION
Prevalence of childhood constipation has been estimated at 1% to 30% in the general population worldwide; most children have no obvious aetiological factors. One third of children with chronic constipation continue to have problems beyond puberty. Half of the children with chronic faecal impaction and faecal incontinence have experienced an episode of painful defecation, and many children with chronic constipation exhibit withholding behaviour.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of fibre for children with chronic constipation? What are the effects of probiotics for children with chronic constipation? We searched: Medline, Embase, The Cochrane Library, and other important databases up to May 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 12 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: fibre and probiotics.
Topics: Child; Constipation; Dietary Fiber; Humans; Probiotics; Treatment Outcome
PubMed: 25758093
DOI: No ID Found -
International Journal of Environmental... Nov 2021The burden of pancreatic cancer varies greatly across countries, with the number of deaths, incident cases, and disability-adjusted life years more than doubling in... (Meta-Analysis)
Meta-Analysis Review
The burden of pancreatic cancer varies greatly across countries, with the number of deaths, incident cases, and disability-adjusted life years more than doubling in recent years, and with high-income countries having the highest incidence and mortality rates. We conducted this systematic review with meta-analysis with the goal of summarizing the current evidence on dietary fiber intake and its role in reducing the risk of pancreatic cancer, given the importance of identifying risk factors. This systematic review followed the guidelines of the Cochrane Collaboration and the Meta-analysis of Observational Studies in Epidemiology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020. The structured literature search was conducted on PubMed/Medline and Scopus, combining free text words and medical subject headings. Our review contained 18 records at the end of the process. Our results show that dietary fiber intake reduces the risk of pancreatic cancer. When the analysis was differentiated according to the type of fiber considered, sub-grouped by gender (reduction of around 60% among women), and when case-control studies were conducted, the strength of the association increased. Clinicians and policymakers should improve interventions to raise the population's awareness regarding the consumption of high-fiber diets, both in practice and in terms of public health policy.
Topics: Case-Control Studies; Dietary Fiber; Female; Humans; Incidence; Observational Studies as Topic; Pancreatic Neoplasms; Risk Factors
PubMed: 34770068
DOI: 10.3390/ijerph182111556