BACKGROUND Higher protein intakes may help reduce sarcopenia and facilitate recovery from illness and injury in older adults. However, high-protein diets (HPDs) including animal-sourced foods may negatively perturb the microbiota, and provision of probiotics and prebiotics may mitigate these effects. OBJECTIVE The aim of this study was to examine the effects of HPD, with and without a probiotic and/or prebiotic, on gut microbiota and wellness in older women. DESIGN We conducted an 18-week, double-blind, placebo-controlled, crossover study. PARTICIPANTS/SETTING Participants were healthy, older women (mean age±standard deviation=73.7±5.6 years; n=26) recruited from Florida. INTERVENTION Participants received a weight-maintenance HPD for 2-week periods and the following, in random order: HPD alone (1.5 to 2.2 g/kg/day protein); HPD plus multistrain probiotic formulation (1.54×109Bifidobacterium bifidum HA-132, 4.62×109Bifidobacterium breve HA-129, 4.62×109Bifidobacterium longum HA-135, 4.62×109Lactobacillus acidophilus HA-122, and 4.62×109Lactobacillus plantarum HA-119), HPD plus prebiotic (5.6 g inulin), and HPD plus synbiotic (probiotic plus inulin), separated by 2-week washouts. Stools were collected per period for quantitative polymerase chain reaction (strain recovery) and 16S ribosomal RNA gene amplicon sequencing analyses (microbiota profile). Measures of gastrointestinal and general wellness were assessed. MAIN OUTCOME MEASURES Microbiota composition and probiotic strain recovery were measured. STATISTICAL ANALYSES Microbiota composition was analyzed by Wilcoxon signed-rank test and t test. Secondary outcomes were analyzing using generalized linear mixed models. RESULTS The microbiota profile demonstrated relative stability with the HPD; representation of Lactobacillus, Lactococcus, and Streptococcus were enhanced, whereas butyrate producers, Roseburia and Anaerostipes, were suppressed. Lactococcus was suppressed with synbiotic vs other HPD periods. Recovery was confirmed for all probiotic strains. Indicators of wellness were unchanged, with the exception of a minimal increase in gastrointestinal distress with inulin. Fat-free mass increased from baseline to study end. CONCLUSIONS An HPD adhering to the recommended acceptable macronutrient distribution ranges maintains wellness in healthy older women and exerts minor perturbations to the microbiome profile, a group that may benefit from a higher protein intake. ClinicalTrials.gov ID: NCT #02445560.

中文翻译：

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对含或不含益生元、益生菌和合生元的高蛋白饮食的微生物群稳定性和胃肠道耐受性：一项针对老年女性的随机、双盲、安慰剂对照试验

背景较高的蛋白质摄入量可能有助于减少肌肉减少症并促进老年人从疾病和损伤中恢复。然而，包括动物源性食品在内的高蛋白饮食 (HPD) 可能会对微生物群产生负面影响，而益生菌和益生元的提供可能会减轻这些影响。目的 本研究的目的是检查 HPD（含或不含益生菌和/或益生元）对老年女性肠道微生物群和健康的影响。设计 我们进行了一项为期 18 周的双盲、安慰剂对照、交叉研究。参与者/环境参与者是从佛罗里达招募的健康老年女性（平均年龄±标准差=73.7±5.6 岁；n=26）。干预 参与者接受为期 2 周的体重维持 HPD，并以随机顺序进行： 单独的 HPD（1.5 至 2.2 g/kg/天蛋白质）；HPD 加多菌株益生菌制剂（1.54×109 双歧杆菌 HA-132、4.62×109 短双歧杆菌 HA-129、4.62×109 长双歧杆菌 HA-135、4.62×109 乳酸杆菌 1226 和 19×19 乳酸杆菌-嗜酸乳杆菌、19×19 乳酸杆菌-嗜酸乳杆菌 HA益生元（5.6 克菊粉）和 HPD 加合生元（益生菌加菊粉），间隔 2 周。每个时期收集粪便用于定量聚合酶链反应（菌株恢复）和 16S 核糖体 RNA 基因扩增子测序分析（微生物群谱）。评估胃肠道和一般健康的措施。主要观察指标测量微生物群组成和益生菌菌株回收率。统计分析 微生物群组成通过 Wilcoxon 符号秩检验和 t 检验进行分析。次要结果是使用广义线性混合模型进行分析。结果 微生物群谱证明了 HPD 的相对稳定性；乳酸杆菌、乳球菌和链球菌的代表性得到增强，而丁酸盐生产者 Roseburia 和 Anerostipes 受到抑制。与其他 HPD 时期相比，合生元抑制了乳球菌。确认所有益生菌菌株的回收率。健康指标没有变化，除了菊粉对胃肠道不适的轻微增加。从基线到研究结束，无脂肪质量增加。结论 坚持推荐的可接受的宏量营养素分布范围的 HPD 可维持健康老年女性的健康，并对微生物组谱产生轻微扰动，微生物组谱可能会受益于较高的蛋白质摄入量。ClinicalTrials.gov ID：NCT #02445560。