Research Appraisals
Evidence-based critical appraisals of the latest medical research, systematically evaluated using Oxford CEBM methodology.
Showing 4 appraisals
Food & function
Efficacy of different dietary fibers for chronic idiopathic constipation: a systematic review and network meta-analysis
This study aims to compare the efficacy and safety of different dietary fiber subtypes in treating patients with chronic idiopathic constipation (CIC) through network meta-analysis (NMA). PubMed, Embase, Cochrane Library, and Web of Science were searched from inception to October 23, 2025. The risk of bias was evaluated using the Cochrane RoB 2.0 tool, and treatment rankings were calculated using the surface under the cumulative ranking curve (SUCRA). 17 randomized controlled trials (RCTs) involving 1423 adults with CIC were included. NMA suggested that viscous soluble fibers were associated with greater efficacy compared with placebo in relieving defecation difficulty (high certainty, class 1), and were also associated with improvements in stool consistency and stool frequency relative to placebo (moderate certainty, class 1). According to SUCRA rankings, viscous soluble fibers tended to have a higher probability of favorable performance compared with other dietary fiber subtypes in improving straining during defecation (moderate certainty), stool frequency (low certainty), and stool consistency (low certainty), and was associated with a relatively favorable tolerability profile (moderate certainty). Insoluble dietary fibers showed the highest ranking probability for improvement in overall constipation symptom scores; however, this finding was supported by very low certainty evidence. Overall, the findings suggest that viscous soluble fibers have a higher probability of improving stool consistency, stool frequency, and straining during defecation. In contrast, insoluble fibers showed a relatively higher ranking for improvement in overall constipation symptom scores. These results support a symptom-oriented and individualized approach to dietary fiber selection in the management of CIC.
21 July 2026
Read appraisal →European journal of nutrition
The effect of system-level intervention in early childhood education and care on children's dietary intake and environmental impact of the diet
PURPOSE: Food systems have a large impact on human health and environmental sustainability. Early childhood education and care is an ideal setting for systemic change. We performed a cluster-randomised trial aiming at climate-friendly and healthy sustainable diet at 23 daycare centres in four Finnish municipalities in 2022 and evaluated system-level intervention effects on food consumption and nutrient intake, and climate and biodiversity impacts of the diet. METHODS: The intervention was initially designed by the research group and refined through co-creation workshops with food service and daycare professionals, and municipal decision makers. The 10-month intervention comprised a modified menu towards more plant-based food supply, and food education. Children's (n = 111) diet was assessed at baseline, mid-term, and/or at the end of the intervention by food frequency questionnaires. The climate and biodiversity impacts per megajoule were assessed using previously specified coefficients for the foods. Multilevel linear mixed models were used in the analysis. RESULTS: During the intervention, children's consumption of legumes and legume products and fish from nearby areas increased, while that of red meat, sausages, and other meat products decreased (Bonferroni-corrected p < 0.001). The changes in food consumption were substantial, with effect sizes ranging from 0.9 to 2.69. Nutrient intake was not affected by the intervention. Intervention decreased climate and biodiversity impacts of food provided at daycare (Bonferroni-corrected p < 0.001, p = 0.003, respectively). CONCLUSION: This study demonstrated that well-planned systemic change in meal provision and food education at daycare resulted in healthier and more climate-friendly diets among children.
20 July 2026
Read appraisal →European journal of nutrition
Nutrition interventions in women with polycystic ovary syndrome: a systematic review.
PURPOSE: This systematic review aimed to synthesize current evidence on the effects of various dietary interventions on anthropometric, metabolic, hormonal, inflammatory, and oxidative stress parameters in women with polycystic ovary syndrome (PCOS). METHODS: The review followed the PRISMA guidelines and was prospectively registered in PROSPERO (CRD42025641781). Searches were conducted in PubMed, Cochrane Library, EBSCO, Science Direct, Web of Science, National Thesis Center, Google Scholar, and DergiPark Academic for studies published between February 2015 and February 2025. Experimental and observational studies were included if they evaluated the independent effect of dietary interventions in adult women with PCOS. Methodological quality was assessed using the Joanna Briggs Institute (JBI) critical appraisal tools. RESULTS: A total of 38 studies were included, covering interventions such as calorie-restricted diets, low-glycemic index/load diets, ketogenic diets, intermittent fasting, dietary approaches to stop hypertension, Mediterranean-style, and other diets. Most dietary interventions demonstrated beneficial effects on body weight, body mass index, and waist circumference, as well as improvements in insulin sensitivity, reproductive hormone regulation, and menstrual regularity. However, findings related to lipid metabolism, inflammatory markers, and oxidative stress outcomes were inconsistent. CONCLUSION: Current evidence indicates that dietary interventions are crucial in improving the management of metabolic, anthropometric, hormonal, and clinical outcomes in women with PCOS. Nevertheless, the heterogeneity of dietary approaches, study designs, and outcome measures highlights the need for long-term randomized controlled trials to establish more conclusive recommendations.
30 June 2026
Read appraisal →European journal of nutrition
The effectiveness of a plant-based milk with fermented brown rice on constipation symptoms via gut microbiota modulation: a double-blind randomized controlled trial
PURPOSE: To evaluate the effects of a plant-based milk with fermented brown rice on constipation symptoms in patients with functional constipation and to identify post-intervention gut microbial alterations that may underlie potential mechanisms. METHODS: This is a randomized controlled trial among 100 participants with functional constipation. Participants were randomly assigned to the intervention group (plant-based milk with fermented brown rice, 2 bottles/day, 500 ml in total), or the control group (an isocaloric plant protein milk, equivalent dose) for 3 weeks. The primary outcome is complete spontaneous bowel movement (CSBM) rate, while secondary outcomes include score of individual symptoms assessment of constipation, bowel movement frequency (BMF), and gut microbial changes (metagenomics). RESULTS: A total of 99 participants completed the intervention. CSBM and BMF increased, and GSRS scores decreased over time in both groups, with no significant between-group differences. The plant-based milk with fermented brown rice relieved constipation symptoms more than the control group did, with significant between-group differences in straining, bloating and abdominal pain (all P < 0.05). The intervention group showed increases in 8 species, including three beneficial species in the genus Blautia, associated with relief of abdominal pain after the intervention. Meanwhile, machine learning models identified gut microbiota features predicting intervention responders. CONCLUSION: Our study did not find between-group difference in CSBM, while the plant-based milk with fermented brown rice showed greater effectiveness in relieving constipation symptoms and optimizing gut microbiota. Functional species benefiting intestinal health in response to the intervention were also identified. CLINICAL TRIAL REGISTRY: This study has been registered in the Chinese Clinical Trial Registry (https://www.chictr.org.cn/, ChiCTR2400088688).
30 June 2026
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