BACKGROUND Inulin-type fructo-oligosaccharides (FOSs) purified from Morinda officinalis How., an effective oral antidepressant for mild to moderate depression, have a largely unknown efficacy and poor bioavailability. PURPOSE Therefore, the microbiota-gut-brain axis was used to investigate the antidepressive properties of FOSs at the interface of the gut microbiota (GM). STUDY DESIGN AND METHODS FOSs was introduced via intragastric gavage to rats exposed to chronic unpredictable mild stress (CUMS), and the antidepressive effects were investigated through behavioral tests, intestinal morphology and corticosterone levels. Bacterial genomic DNA was extracted from feces, and the GM was profiled for using enterobacterial repetitive intergenic consensus (ERIC)-PCR analysis, partial least squares-discriminant analysis (PLS-DA) and 16S rRNA gene pyrosequencing. RESULTS It was observed that FOSs alleviated depression-like behaviors and repaired intestinal epithelia damages. FOSs treatment lowered corticosterone levels in the plasma and urine of the model rats. Moreover, the GM compositions of normal and model rats were distantly clustered and were mainly related to the disappearance of beneficial bacteria (e.g., Acinetobacter, Barnesiella, Coprococcus, Dialister, Lactobacillus, and Paenibacillus) and appearance of depression-associated bacteria (e.g., Anaerostipes, Oscillibacter, Proteobacteria, and Streptococcus) in depressive rats. Interestingly, the dysbiosis in depressive rats' gut was reinstated with FOSs treatments. Notably, FOSs promoted the abundance of the bacterial phylum Cyanobacteria, a group of bacteria known for the secretion of pharmacologically important metabolites, such as H2S, that exhibit antidepressant-like properties. Apparently, FOSs-induced modulation of GM was more antidepressive compared to a component of FOSs, degrees of polymerization (DP) 5, and fluoxetine, the standard antidepressant drug. CONCLUSION In conclusion, this study implied that antidepressant efficacy of FOSs was inseparable from and strongly associated with the modulation of the host' s GM.

中文翻译：

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巴戟天的低聚果糖重塑了肠道菌群，减轻了应激大鼠模型的抑郁特征。

背景技术从巴戟天（Morinda officinalis How。）纯化的菊粉型低聚果糖（FOS）是用于轻度至中度抑郁症的有效口服抗抑郁药，其功效很大程度上未知，并且生物利用度较差。目的因此，微生物群-肠脑轴用于研究肠道微生物群（GM）界面上的FOS的抗抑郁特性。研究设计和方法通过胃内灌胃法将FOS引入暴露于慢性不可预测轻度应激（CUMS）的大鼠中，并通过行为测试，肠道形态和皮质酮水平研究其抗抑郁作用。从粪便中提取细菌基因组DNA，并使用肠细菌重复基因间共有序列（ERIC）-PCR分析对GM进行分析，偏最小二乘判别分析（PLS-DA）和16S rRNA基因焦磷酸测序。结果观察到FOS减轻了抑郁症样行为并修复了肠上皮损伤。FOSs处理降低了模型大鼠血浆和尿液中的皮质酮水平。此外，正常和模型大鼠的GM成分远距聚集，并且主要与有益细菌（例如，不动杆菌，Barnesiella，Coprococcus，Dialister，乳杆菌和Paenibacillus）的消失以及与抑郁相关的细菌（例如厌氧菌）的出现有关。 ，Oscillibacter，Proteobacteria和Streptococcus）。有趣的是，用FOSs治疗可恢复抑郁大鼠肠道的营养不良。值得注意的是，FOS促进了细菌门蓝细菌的丰富，一组因分泌具有药理学意义的重要代谢产物（例如H2S）而闻名的细菌，这些代谢产物具有抗抑郁样的特性。显然，与FOS的成分，聚合度（DP）5和标准抗抑郁药氟西汀相比，FOS诱导的GM调节具有更高的抗抑郁作用。结论总之，这项研究暗示FOS的抗抑郁功效与宿主GM的调制是分不开的，并与之密切相关。