The aim of this work is to evaluate the impact on the rat microbiota of long-term feeding with phenolic compounds (PC) rich grape pomace extracts. Thirty, 2-mo-old rats, were divided into 5 groups. Four groups were treated with different concentrations of PC (2.5, 5, 10, and 20 mg/kg/d diluted in 0.1% DMSO), and 1 group received 0.1% Dimethyl Sulfoxide (DMSO) alone (control group). The daily treatment lasted 14 mo. Major phenolic compounds constituents were characterized by the high-performance liquid chromatography and free radical scavenging capacity was measured by means of the DPPH assay. Fecal samples from young rats (2-mo old), and rats daily fed with PC or DMSO were collected at 6 and 14 mo posttreatment. The gut microbiota composition was analyzed by quantitative polymerase chain reaction. Bifidobacterium was significantly higher in the groups PC 2.5 and PC 5 than in control and young rats. Lactobacillus decreased with time in all treated and untreated groups. Bacteroides, Clostridium leptum subgroup (Clostridium cluster IV), and Enterococcus were not significantly changed by PC at any concentration when compared to control; nevertheless, after 14 mo of treatment all concentrations of PC abolished the increase of Clostridium sensu stricto (cluster I) (Clostridium Cluster I) observed in the control group when compared to young rats. PC do modulate selectively rat gut microbiome to a healthier phenotype in long-term feeding rats, and could counteract the adverse outcomes of aging on gut bacterial population. PRACTICAL APPLICATION This research shows that phenolic-rich grape pomace extracts exhibiting a high antioxidant activity, selectively modulate rat gut microbiota to a healthier phenotype within age in a long-term feeding rats.

中文翻译：

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长期摄入富含酚类化合物的葡萄渣对大鼠肠道微生物群的影响

这项工作的目的是评估长期饲喂富含酚类化合物 (PC) 的葡萄渣提取物对大鼠微生物群的影响。30 只 2 个月大的大鼠被分成 5 组。四组用不同浓度的 PC（2.5、5、10 和 20 mg/kg/d 稀释于 0.1% DMSO）治疗，1 组单独接受 0.1% 二甲基亚砜（DMSO）（对照组）。每日治疗持续14个月。通过高效液相色谱法表征主要酚类化合物成分，并通过DPPH测定法测量自由基清除能力。在治疗后 6 个月和 14 个月收集年轻大鼠（2 个月大）和每天喂食 PC 或 DMSO 的大鼠的粪便样本。通过定量聚合酶链反应分析肠道微生物群组成。PC 2.5 和PC 5 组的双歧杆菌显着高于对照组和年轻大鼠。在所有治疗组和未治疗组中，乳酸菌随时间减少。与对照相比，任何浓度的 PC 均未显着改变拟杆菌属、梭状梭菌亚组（Clostridium cluster IV）和肠球菌；然而，与年轻大鼠相比，在 14 个月的治疗后，所有浓度的 PC 都消除了在对照组中观察到的狭义梭菌（簇 I）（Clostridium Cluster I）的增加。PC 确实可以选择性地将大鼠肠道微生物群调节为长期喂养大鼠的更健康表型，并且可以抵消衰老对肠道细菌群的不利影响。实际应用 这项研究表明，富含酚类的葡萄渣提取物具有很高的抗氧化活性，