German Cancer Research Center (DKFZ), Division of Cancer Epidemiology, Im Neuenheimer Feld 581, Heidelberg, Germany.
Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany.
Adv Nutr. 2019 Jul 1;10(4):673-684. doi: 10.1093/advances/nmy125.
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.
短链脂肪酸（SCFAs，主要包括乙酸盐、丙酸盐和丁酸盐）主要来源于肠道微生物群，可能具有抗炎和免疫调节作用，并调节能量稳态。有人提出，体重减轻可能会影响 SCFA 代谢，但缺乏针对干预研究的系统评价。我们旨在系统评估超重（体重指数 [BMI] 25-29.9 kg/m2）或肥胖（BMI ≥30 kg/m2）成年人中，饮食、基于体力活动和手术减肥干预对血液、尿液或粪便中乙酸盐、丙酸盐、丁酸盐和总 SCFA 浓度的影响。我们在 PubMed、Web of Science 和 Cochrane 中央对照试验注册库（CENTRAL）中进行了系统文献检索，检索截止日期为 2018 年 4 月 30 日，以获取超重或肥胖成年人的随机和非随机减肥试验，其中评估了个体和总 SCFA 的浓度。共纳入 9 项研究，包括 2 项随机平行臂试验、4 项交叉试验和 3 项非随机临床或手术试验。在大多数研究中，评估了粪便 SCFA 浓度的变化，而只有 1 项试验报告了血清 SCFA 的变化。体重减轻后，个体和总 SCFA 浓度要么保持不变，要么显著下降。导致 SCFA 浓度降低的 3 种饮食干预措施中，总碳水化合物含量均较低（≤能量的 5%）。大多数研究的偏倚风险较高。超重或肥胖成年人中，减肥手术或饮食限制可能会伴随 SCFA 浓度降低，尤其是当减少碳水化合物摄入时。然而，这些发现并不一致，并且基于高到不确定偏倚风险的研究，以及小样本量的研究。由于粪便 SCFA 的测量可能并不理想，因为样本标准化有限，因此需要进行具有重复 SCFA 血液测量的、有充分效能的试验。本综述在 PROSPERO 注册为 CRD42018088716。
