scholarly journals Effects of Weight-Loss Interventions on Short-Chain Fatty Acid Concentrations in Blood and Feces of Adults: A Systematic Review

2019 ◽  
Vol 10 (4) ◽  
pp. 673-684 ◽  
Author(s):  
Solomon A Sowah ◽  
Lena Riedl ◽  
Antje Damms-Machado ◽  
Theron S Johnson ◽  
Ruth Schübel ◽  
...  

ABSTRACT Short-chain fatty acids (SCFAs, mainly acetate, propionate, and butyrate), which are primarily derived from the gut microbiome, may exert anti-inflammatory and immunomodulatory effects, and regulate energy homeostasis. It has been suggested that weight loss may affect SCFA metabolism, but a systematic review of intervention studies is lacking. We aimed to systematically assess the effects of dietary, physical activity–based, and surgical weight-loss interventions among overweight [body mass index (BMI) 25–29.9 kg/m2)] or obese (BMI ≥30 kg/m2) adults (≥18 y) on concentrations of acetate, propionate, butyrate, and total SCFAs in blood, urine, or feces. We conducted a systematic literature search in PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) up to April 30, 2018 for randomized and nonrandomized weight-loss trials among overweight or obese adults, in which the concentrations of individual and total SCFAs were assessed. A total of 9 studies consisting of 2 randomized parallel-arm trials, 4 crossover trials, and 3 nonrandomized clinical or surgical trials were included. In the majority of studies, changes in fecal SCFA concentrations were assessed, whereas changes in serum SCFAs were reported from 1 trial. Individual and total SCFA concentrations either remained unchanged or decreased significantly following weight loss. Three of the dietary interventions that resulted in decreased SCFA concentrations were low (≤5% of energy) in total carbohydrates. Most of the studies had a high risk of bias. Decreases in SCFA concentrations may accompany weight loss induced by bariatric surgery or dietary restriction among overweight or obese adults, particularly when carbohydrate intake is reduced. However, findings were inconsistent and based on studies with high to unclear risk of bias, and small sample sizes. Because measurements of fecal SCFAs may not be ideal due to limited sample standardization, well-powered trials with repeated blood measurements of SCFAs are required. This review was registered at PROSPERO as CRD42018088716.

Nutrients ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 452
Author(s):  
Solomon A. Sowah ◽  
Frank Hirche ◽  
Alessio Milanese ◽  
Theron S. Johnson ◽  
Mirja Grafetstätter ◽  
...  

Gut microbial-derived short-chain fatty acids (SCFAs) may regulate energy homeostasis and exert anti-carcinogenic, immunomodulatory and anti-inflammatory effects. Smaller trials indicate that dietary weight loss may lead to decreased SCFA production, but findings have been inconclusive. SCFA concentrations were measured by HPLC-MS/MS in plasma samples of 150 overweight or obese adults in a trial initially designed to evaluate the metabolic effects of intermittent (ICR) versus continuous (CCR) calorie restriction (NCT02449148). For the present post hoc analyses, participants were classified by quartiles of weight loss, irrespective of the dietary intervention. Linear mixed models were used to analyze weight-loss-induced changes in SCFA concentrations after 12, 24 and 50 weeks. There were no differential changes in SCFA levels across the initial study arms (ICR versus CCR versus control) after 12 weeks, but acetate concentrations significantly decreased with overall weight loss (mean log-relative change of −0.7 ± 1.8 in the lowest quartile versus. −7.6 ± 2 in the highest, p = 0.026). Concentrations of propionate, butyrate and other SCFAs did not change throughout the study. Our results show that weight-loss, achieved through calorie restriction, may lead to smaller initial decreases in plasma acetate, while plasma SCFAs generally remain remarkably stable over time.


Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 802 ◽  
Author(s):  
Per G Farup ◽  
Jørgen Valeur

The gut microbiota and their metabolites, e.g., short-chain fatty acids (SCFA), are associated with obesity. The primary aims were to study faecal SCFA levels and the changes in SCFA levels after weight-loss interventions in subjects with obesity, and secondarily, to study factors associated with the faecal SCFA levels. In total, 90 subjects (men / women: 15/75) with a mean age of 44.4 (SD 8.4) years, BMI 41.7 (SD 3.7) kg/m2 and morbid obesity (BMI > 40 or > 35 kg/m2 with obesity-related complications) were included. Faecal SCFA and other variables were measured at inclusion and after a six-month conservative weight-loss intervention followed by bariatric surgery (Roux-en-Y gastric bypass or gastric sleeve). Six months after surgery, the total amount of SCFA was reduced, the total and relative amounts of the main straight SCFA (acetic-, propionic-, and butyric- acids) were reduced, and the total and relative amounts of branched SCFA (isobutyric-, isovaleric-, and isocaproic- acids) were increased. The changes indicate a shift toward a proteolytic fermentation pattern with unfavorable health effects. The amount of SCFA was associated with the diet but not with metabolic markers or makers of the faecal microbiota composition. Dietary interventions could counteract the unfavorable effects.


2020 ◽  
Vol 29 (2) ◽  
pp. 79-91 ◽  
Author(s):  
Emer Shanley ◽  
Zena Moore ◽  
Declan Patton ◽  
Tom O’Connor ◽  
Linda Nugent ◽  
...  

Objective: To investigate the impact of patient education interventions on preventing the recurrence of venous leg ulcers (VLU). Method: A systematic review was undertaken using the following databases: Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library); Ovid; Ovid (In-process and Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL. Trial registries and reference lists of relevant publications for published and ongoing trials were also searched. There were no language or publication date restrictions. Randomised controlled trials (RCTs) and cluster RCTs of patient educational interventions for preventing VLU recurrence were included. Review authors working independently assessed trials for their appropriateness for inclusion and for their risk of bias, using pre-determined inclusion and quality criteria. Results: A total of four studies met the inclusion criteria (274 participants). Each trial explored different interventions as follows: the Lively legs programme; education delivered via a video compared with education delivered via a pamphlet; the Leg Ulcer Prevention Programme and the Lindsay Leg Club. Only one study reported the primary outcome of incidence of VLU recurrence. All studies reported at least one of the secondary outcomes: patient behaviours, patient knowledge and patient quality of life (QoL). It is uncertain whether patient education programmes make any difference to VLU recurrence at 18 months (risk ratio [RR]: 0.82; 95% confidence interval: [CI] 0.59 to 1.14) or to patient behaviours (walked at least 10 minutes/five days a week RR: 1.48; 95%CI: 0.99 to 2.21; walked at least 30 minutes/five days a week: RR 1.14; 95%CI: 0.66 to 1.98; performed leg exercises: RR: 1.47; 95%CI: 1.04 to 2.09); to knowledge scores (MD (mean difference) 5.12, 95% CI –1.54 to 11.78); or to QoL (MD: 0.85, 95% CI –0.13 to 1.83), as the certainty of evidence has been assessed as very low. It is also uncertain whether different types of education delivery make any difference to knowledge scores (MD: 12.40; 95%CI: –5.68 to 30.48). Overall, GRADE assessments of the evidence resulted predominantly in judgments of very low certainty. The studies were at high risk of bias and outcome measures were imprecise due to wide CIs and small sample sizes. Conclusion: It is uncertain whether education makes any difference to the prevention of VLU recurrence. Therefore, further well-designed trials, addressing important clinical, QoL and economic outcomes are justified, based on the incidence of the problem and the high costs associated with VLU management.


2021 ◽  
pp. 105566562110593
Author(s):  
Woranuch Chetpakdeechit ◽  
Poonsak Pisek ◽  
Waranuch Pitiphat ◽  
Siwanon Rattanakanokchai

Objective This study aimed to review all research evidence of presurgical cleft size and related factors to success of secondary alveolar bone grafting (SABG). Design and Setting The systematic review searched the OVID-Medline®, PubMed®, Embase®, and Cochrane Central Register of Controlled Trials (CENTRAL) up to August 2020. Two reviewers independently selected potential abstracts for full review. Disagreeements were resolved by consensus. The first author extracted data and assessed the risk of bias using Risk of Bias in Non-randomized studies—of Interventions tool. Patients and Interventions Patients with non-syndromic clefts who received SABG were selected. Presurgical cleft size/volume and treatment results must be available. Main Outcome Measures Level of the grafted bone, achievement of orthodontic tooth movement into the grafted area, need for re-operation. Results From 962 abstracts, 23 publications were included. Mean cleft width was 6.80 ± 1.98 mm, cleft area 20–240 mm2, and mean volume 0.89 ± 0.33 cm3. No definite conclusion was achieved on whether a narrow or wide cleft showed better treatment outcomes, but other potentially related factors were good oral hygiene and eruptive force of the maxillary canines. Lack of a standard definition of cleft size, a small sample size, varying outcome parameters, and moderate-to-high risk of bias contributed to the summary. A meta-analysis could not be performed because of the heterogeneity. Conclusion Due to insufficient evidence, cleft width/volume could not be specified leading to more successful SABG. Care of patients could be improved in both research by following rigorous methodology, and practice by clear communication.


2022 ◽  
pp. BJGP.2021.0537
Author(s):  
Loes de Kleijn ◽  
Julie Pedersen ◽  
Hanneke Rijkels-Otters ◽  
Alessandro Chiarotto ◽  
Bart Koes

Background: Long-term opioid treatment in patients with chronic pain is often ineffective and possibly harmful. These patients are often managed by general practitioners, who are calling for a clear overview of effective opioid reduction strategies for primary care. Aim: Evaluate effectiveness of opioid reduction strategies applicable in primary care for patients with chronic pain on long-term opioid treatment. Design: Systematic review of controlled trials and cohort studies. Method Literature search conducted in Embase, Medline, Web of Science, Cochrane CENTRAL register of trials, CINAHL, Google Scholar and PsychInfo. Studies evaluating opioid reduction interventions applicable in primary care among adults with long-term opioid treatment for chronic non-cancer pain were included. Risk of bias was assessed using Cochrane risk of bias (RoB) 2.0 tool or Risk-of-Bias in Non-randomized studies of Interventions (ROBINS-I) tool. Narrative synthesis was performed due to clinical heterogeneity in study designs and types of interventions. Results: Five RCTs and five cohort studies were included (total n= 1717, range 35-985) exploring various opioid reduction strategies. Six studies had high RoB, three moderate RoB, and one low RoB. Three cohort studies investigating a GP supervised opioid taper (critical ROBINS-I), an integrative pain treatment (moderate ROBINS-I) and group medical visits (critical ROBINS-I) demonstrated significant between-group opioid reduction. Conclusion: Results carefully point in the direction of a GP supervised tapering and multidisciplinary group therapeutic sessions to reduce long term opioid treatment. However, due to high risk of bias and small sample sizes, no firm conclusions can be made demonstrating need for more high-quality research.


BMJ ◽  
2021 ◽  
pp. m4743
Author(s):  
Joshua Z Goldenberg ◽  
Andrew Day ◽  
Grant D Brinkworth ◽  
Junko Sato ◽  
Satoru Yamada ◽  
...  

Abstract Objective To determine the efficacy and safety of low carbohydrate diets (LCDs) and very low carbohydrate diets (VLCDs) for people with type 2 diabetes. Design Systematic review and meta-analysis. Data sources Searches of CENTRAL, Medline, Embase, CINAHL, CAB, and grey literature sources from inception to 25 August 2020. Study selection Randomized clinical trials evaluating LCDs (<130 g/day or <26% of a 2000 kcal/day diet) and VLCDs (<10% calories from carbohydrates) for at least 12 weeks in adults with type 2 diabetes were eligible. Data extraction Primary outcomes were remission of diabetes (HbA 1c <6.5% or fasting glucose <7.0 mmol/L, with or without the use of diabetes medication), weight loss, HbA 1c , fasting glucose, and adverse events. Secondary outcomes included health related quality of life and biochemical laboratory data. All articles and outcomes were independently screened, extracted, and assessed for risk of bias and GRADE certainty of evidence at six and 12 month follow-up. Risk estimates and 95% confidence intervals were calculated using random effects meta-analysis. Outcomes were assessed according to a priori determined minimal important differences to determine clinical importance, and heterogeneity was investigated on the basis of risk of bias and seven a priori subgroups. Any subgroup effects with a statistically significant test of interaction were subjected to a five point credibility checklist. Results Searches identified 14 759 citations yielding 23 trials (1357 participants), and 40.6% of outcomes were judged to be at low risk of bias. At six months, compared with control diets, LCDs achieved higher rates of diabetes remission (defined as HbA 1c <6.5%) (76/133 (57%) v 41/131 (31%); risk difference 0.32, 95% confidence interval 0.17 to 0.47; 8 studies, n=264, I 2 =58%). Conversely, smaller, non-significant effect sizes occurred when a remission definition of HbA 1c <6.5% without medication was used. Subgroup assessments determined as meeting credibility criteria indicated that remission with LCDs markedly decreased in studies that included patients using insulin. At 12 months, data on remission were sparse, ranging from a small effect to a trivial increased risk of diabetes. Large clinically important improvements were seen in weight loss, triglycerides, and insulin sensitivity at six months, which diminished at 12 months. On the basis of subgroup assessments deemed credible, VLCDs were less effective than less restrictive LCDs for weight loss at six months. However, this effect was explained by diet adherence. That is, among highly adherent patients on VLCDs, a clinically important reduction in weight was seen compared with studies with less adherent patients on VLCDs. Participants experienced no significant difference in quality of life at six months but did experience clinically important, but not statistically significant, worsening of quality of life and low density lipoprotein cholesterol at 12 months. Otherwise, no significant or clinically important between group differences were found in terms of adverse events or blood lipids at six and 12 months. Conclusions On the basis of moderate to low certainty evidence, patients adhering to an LCD for six months may experience remission of diabetes without adverse consequences. Limitations include continued debate around what constitutes remission of diabetes, as well as the efficacy, safety, and dietary satisfaction of longer term LCDs. Systematic review registration PROSPERO CRD42020161795.


BMJ Open ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. e042350
Author(s):  
Maximilian Sohn ◽  
Ayman Agha ◽  
Igors Iesalnieks ◽  
Anna Tiefes ◽  
Alfred Hochrein ◽  
...  

IntroductionAcute diverticulitis of the sigmoid colon is increasingly treated by a non-operative approach. The need for colectomy after recovery from a flare of acute diverticulitis of the left colon, complicated diverticular abscess is still controversial. The primary aim of this study is to assess the risk of interval emergency surgery by systematic review and meta-analysis.Methods and analysisThe systematic review and meta-analysis will be conducted in accordance to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols statement. PubMed/MEDLINE, Cochrane Central Register of Controlled Trials and EMBASE will be screened for the predefined searching term: (Diverticulitis OR Diverticulum) AND (Abscess OR pelvic abscess OR pericolic abscess OR intraabdominal abscess) AND (surgery OR operation OR sigmoidectomy OR drainage OR percutaneous drainage OR conservative therapy OR watchful waiting). All studies published in an English or German-speaking peer-reviewed journal will be suitable for this analysis. Case reports, case series of less than five patients, studies without follow-up information, systematic and non-systematic reviews and meta-analyses will be excluded. Primary endpoint is the rate of interval emergency surgery. Using the Review Manager Software (Review Manager/RevMan, V.5.3, Copenhagen, The Nordic Cochrane Centre, The Cochrane Collaboration, 2012) meta-analysis will be pooled using the Mantel-Haenszel method for random effects. The Risk of Bias in Non-randomized Studies of Interventions tool will be used to assess methodological quality of non-randomised studies. Risk of bias in randomised studies will be assessed using the Cochrane developed RoB 2-tool.Ethics and disseminationAs no new data are being collected, ethical approval is exempt for this study. This systematic review is to provide a new insight on the need for surgical treatment after a first attack of acute diverticulitis, complicated by intra-abdominal or pelvic abscesses. The results of this study will be presented at national and international meetings and published in a peer-reviewed journal.PROSPERO registration numberCRD42020164813.


Sign in / Sign up

Export Citation Format

Share Document