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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 -
Nutrients May 2023Ultra-processed foods (UPF) are energy-dense, nutritionally unbalanced products, low in fiber but high in saturated fat, salt, and sugar. Recently, UPF consumption has... (Review)
Review
Ultra-processed foods (UPF) are energy-dense, nutritionally unbalanced products, low in fiber but high in saturated fat, salt, and sugar. Recently, UPF consumption has increased likewise the incidence of obesity and cardiometabolic diseases. To highlight a possible relationship, we conducted a systematic review of prospective studies from PubMed and Web of Science investigating the association between UPF consumption and the incidence of obesity and cardiometabolic risk factors. Seventeen studies were selected. Eight evaluated the incidence of general and abdominal obesity, one the incidence of impaired fasting blood glucose, four the incidence of diabetes, two the incidence of dyslipidemia, and only one the incidence of metabolic syndrome. Studies' quality was assessed according to the Critical Appraisal Checklist for cohort studies proposed by the Joanna Briggs Institute. Substantial agreement emerged among the studies in defining UPF consumption as being associated with the incident risk of general and abdominal obesity. More limited was the evidence on cardiometabolic risk. Nevertheless, most studies reported that UPF consumption as being associated with an increased risk of hypertension, diabetes, and dyslipidemia. In conclusion, evidence supports the existence of a relationship between UPF consumption and the incidence of obesity and cardiometabolic risk. However, further longitudinal studies considering diet quality and changes over time are needed.
Topics: Adult; Humans; Prospective Studies; Food, Processed; Obesity, Abdominal; Cardiometabolic Risk Factors; Incidence; Food Handling; Fast Foods; Obesity; Diet; Hypertension
PubMed: 37299546
DOI: 10.3390/nu15112583 -
Psychiatrike = Psychiatriki Sep 2022Autism is a complex spectrum of disorders with genetic, epigenetic, autoimmune, oxidative stress, and environmental etiologies. Treatment of ASD using dietary approach...
Autism is a complex spectrum of disorders with genetic, epigenetic, autoimmune, oxidative stress, and environmental etiologies. Treatment of ASD using dietary approach is a promising strategy, especially owing to its safety and availability. Our study critically analysed the roles and efficacy of antioxidants, probiotics, prebiotics, camel milk and vitamin D. This systematic review provides an updated synopsis of human studies that investigated therapeutic benefits of these dietary interventions in autism. A total of 943 papers were identified out of which 21 articles were included in the systematic review. The selected studies investigated the impact of 5 different dietary supplementations in ASD symptom and behaviours. These agents include; antioxidants/polyphenolic compounds, probiotics, prebiotics, camel milk and vitamin D. From the results of the present review, antioxidants/polyphenolic compounds decreased the levels of inflammatory cytokines and improved behavioural symptoms. Probiotics improved behavioural and GI symptoms as well as restored gut microbiota equilibrium. Prebiotics decreased levels of inflammatory cytokines, improved behavioural and GI symptoms and improved gut microbiota. Vitamin D improved behavioural symptoms and offered protective effects against neurotoxicity. Camel milk reduced inflammatory responses and oxidative stress. Given the chronic nature as well as early onset of ASD, dietary supplements become useful to complement nutritional deficiencies in children with ASD. Key benefits of these agents stem from their ability to target multiple physiological areas via the gut brain-axis and are devoid of potential harmful or aggravating effects on ASD patients. The evidence collated in this review propose that dietary intervention may provide a new platform for the management of autism.
Topics: Animals; Antioxidants; Autism Spectrum Disorder; Camelus; Child; Cytokines; Humans; Prebiotics; Vitamin D
PubMed: 35477082
DOI: 10.22365/jpsych.2022.073 -
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 -
The American Journal of Gastroenterology Jun 2018
Topics: Anti-Bacterial Agents; Antidepressive Agents; Behavior Therapy; Constipation; Diarrhea; Diet; Dietary Fiber; Dietary Supplements; Exercise; Humans; Irritable Bowel Syndrome; Mentha piperita; Parasympatholytics; Plant Oils; Prebiotics; Probiotics; Randomized Controlled Trials as Topic; Synbiotics
PubMed: 29950604
DOI: 10.1038/s41395-018-0084-x -
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 -
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 -
The Cochrane Database of Systematic... Mar 2019Infantile colic is typically defined as full-force crying for at least three hours per day, on at least three days per week, for at least three weeks. Infantile colic... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Infantile colic is typically defined as full-force crying for at least three hours per day, on at least three days per week, for at least three weeks. Infantile colic affects a large number of infants and their families worldwide. Its symptoms are broad and general, and while not indicative of disease, may represent a serious underlying condition in a small percentage of infants who may need a medical assessment. Probiotics are live microorganisms that alter the microflora of the host and provide beneficial health effects. The most common probiotics used are of Lactobacillus, Bifidobacterium and Streptococcus. There is growing evidence to suggest that intestinal flora in colicky infants differ from those in healthy infants, and it is suggested that probiotics can redress this balance and provide a healthier intestinal microbiota landscape. The low cost and easy availability of probiotics makes them a potential prophylactic solution to reduce the incidence and prevalence of infantile colic.
OBJECTIVES
To evaluate the efficacy and safety of prophylactic probiotics in preventing or reducing severity of infantile colic.
SEARCH METHODS
In January 2018 we searched CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, 10 other databases and two trials registers. In addition, we handsearched the abstracts of relevant meetings, searched reference lists, ran citation searches of included studies, and contacted authors and experts in the field, including the manufacturers of probiotics, to identify unpublished trials.
SELECTION CRITERIA
Randomised control trials (RCTs) of newborn infants less than one month of age without the diagnosis of infantile colic at recruitment. We included any probiotic, alone or in combination with a prebiotic (also known as synbiotics), versus no intervention, another intervention(s) or placebo, where the focus of the study was the effect of the intervention on infantile colic.
DATA COLLECTION AND ANALYSIS
We used standard methodological procedures of Cochrane.
MAIN RESULTS
Our search yielded 3284 records, and of these, we selected 21 reports for full-text review. Six studies with 1886 participants met our inclusion criteria, comparing probiotics with placebo. Two studies examined Lactobacillus reuteri DSM, two examined multi-strain probiotics, one examined Lactobacillus rhamnosus, and one examined Lactobacillus paracasei and Bifidobacterium animalis. Two studies began probiotics during pregnancy and continued administering them to the baby after birth.We considered the risk of bias for randomisation as low for all six trials; for allocation concealment as low in two studies and unclear in four others. All studies were blinded, and at low risk of attrition and reporting bias.A random-effects meta-analysis of three studies (1148 participants) found no difference between the groups in relation to occurrence of new cases of colic: risk ratio (RR) 0.46, 95% confidence interval (CI) 0.18 to 1.19; low-certainty evidence; I = 72%.A random-effects meta-analysis of all six studies (1851 participants) found no difference between the groups in relation to serious adverse effects (RR 1.02, 95% CI 0.14 to 7.21; low-certainty evidence; I not calculable (only four serious events for one comparison, two in each group: meconium plug obstruction, patent ductus arteriosus and neonatal hepatitis).A random-effects meta-analysis of three studies (707 participants) found a mean difference (MD) of -32.57 minutes per day (95% CI -55.60 to -9.54; low-certainty evidence; I = 93%) in crying time at study end in favour of probiotics.A subgroup analysis of the most studied agent, Lactobacillus reuteri, showed a reduction of 44.26 minutes in daily crying with a random-effects model (95% CI -66.6 to -21.9; I = 92%), in favour of probiotics.
AUTHORS' CONCLUSIONS
There is no clear evidence that probiotics are more effective than placebo at preventing infantile colic; however, daily crying time appeared to reduce with probiotic use compared to placebo. There were no clear differences in adverse effects.We are limited in our ability to draw conclusions by the certainty of the evidence, which we assessed as being low across all three outcomes, meaning that we are not confident that these results would not change with the addition of further research.
Topics: Bifidobacterium; Breast Feeding; Colic; Crying; Female; Gastrointestinal Microbiome; Humans; Infant; Infant, Newborn; Limosilactobacillus reuteri; Prebiotics; Pregnancy; Probiotics; Randomized Controlled Trials as Topic; Time Factors
PubMed: 30865287
DOI: 10.1002/14651858.CD012473.pub2 -
International Journal of Environmental... Apr 2020Creatine monohydrate is a nutritional supplement often consumed by athletes in anaerobic sports. Creatine is naturally found in most meat products; therefore,...
BACKGROUND
Creatine monohydrate is a nutritional supplement often consumed by athletes in anaerobic sports. Creatine is naturally found in most meat products; therefore, vegetarians have reduced creatine stores and may benefit from supplementation.
OBJECTIVE
to determine the effects of creatine supplementation on vegetarians.
DATA SOURCES
PubMed and SPORTDiscus. Eligibility criteria: Randomized controlled trials (parallel group, cross-over studies) or prospective studies.
PARTICIPANTS
Vegetarians.
INTERVENTION
Creatine supplementation. Study appraisal and synthesis: A total of 64 records were identified, and eleven full-text articles (covering nine studies) were included in this systematic review.
RESULTS
Creatine supplementation in vegetarians increased total creatine, creatine, and phosphocreatine concentrations in vastus lateralis and gastrocnemius muscle, plasma, and red blood cells, often to levels greater than omnivores. Creatine supplementation had no effect on brain levels of phosphocreatine. Creatine supplementation increased lean tissue mass, type II fiber area, insulin-like growth factor-1, muscular strength, muscular endurance, Wingate mean power output, and brain function (memory and intelligence) in vegetarian participants. Studies were mixed on whether creatine supplementation improved exercise performance in vegetarians to a greater extent compared to omnivores.
LIMITATIONS
Studies that were reviewed had moderate-high risk of bias.
CONCLUSIONS
Overall, it appears vegetarian athletes are likely to benefit from creatine supplementation.
Topics: Athletes; Cognition; Creatine; Diet, Vegetarian; Dietary Supplements; Humans; Memory; Physical Fitness; Prospective Studies; Vegetarians
PubMed: 32349356
DOI: 10.3390/ijerph17093041 -
Nutrients Dec 2020PubMed, Web of Science, and the Cochrane Database of Systematic Reviews were searched for meta-analyses that provided risk estimates (±95% confidence intervals) for...
PubMed, Web of Science, and the Cochrane Database of Systematic Reviews were searched for meta-analyses that provided risk estimates (±95% confidence intervals) for associations between intakes of whole and refined grains and risk of total and site-specific cancer. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed. Only meta-analyses that included whole grains and refined grains as separate food groups, and not as part of dietary patterns, were included. A total of 17 publications were identified that met inclusion criteria. Within these, results from a total of 54 distinct meta-analyses were reported for whole grains and 5 meta-analyses for refined grains. For total cancer mortality, 7 meta-analyses of cohort studies indicated that whole grain intake was associated with 6% to 12% lower risk in comparison of highest vs. lowest intake groups, and 3% to 20% lower risk for doses ranging from 15 to 90 g/day. For site-specific cancers, meta-analyses indicated that whole grain intake was consistently associated with lower risks of colorectal, colon, gastric, pancreatic, and esophageal cancers. Limited data were available for refined grains, with only 4 publications providing risk estimates, and only 1 of the meta-analyses included more than 3 studies. High intake of refined grains was associated with increased risk of colon and gastric cancer. By contrast, in the only dose-response meta-analysis, each 90 g/day consumption of refined grains was associated with a 6% lower risk of total cancer. In addition to the limited number of published meta-analyses on refined grains, results were also weakened due to the fact that refined grains were frequently defined to include both staple grain foods and indulgent grain foods, and the majority of studies included in the meta-analyses provided no specific definition of refined grains. Overall, meta-analyses of cohort and case-control studies consistently demonstrate that whole grain intake is associated with lower risk of total and site-specific cancer, and support current dietary recommendations to increase whole grain consumption. By contrast, the relationship between refined grain intake and cancer risk is inconclusive.
Topics: Adult; Aged; Case-Control Studies; Cohort Studies; Diet; Diet, Healthy; Edible Grain; Female; Humans; Male; Meta-Analysis as Topic; Middle Aged; Neoplasms; Observational Studies as Topic; Risk Factors; Whole Grains
PubMed: 33297391
DOI: 10.3390/nu12123756