桑黄多糖对小鼠肠道菌群的影响

The Effect of Sanghuangporus spp. Polysaccharides on the Intestinal Flora of Mice

摘要:

为了研究杨树桑黄多糖（Sanghuangporus vaninii polysaccharides, SVP）和桑树桑黄多糖（Sanghuangporus sanghuang polysaccharides, SSP）对正常生物体（包括人）肠道菌群的调节作用，本文以正常小鼠为试验对象，通过动物喂养试验结合微生物高通量测序，对肠道菌群进行系统分析。将30只小鼠随机分成对照组、SVP组和SSP组，两种试验组内又分为低剂量组和高剂量组（分别灌胃200、400 mg·kg-1·d）。结果表明，SVP和SSP对小鼠生长状态、体质量、胸腺系数无显著影响，但是会显著降低脾脏系数（P<0.05）；对小鼠粪便中微生物进行高通量测序分析发现，SVP和SSP均能显著降低肠道中厚壁菌门与拟杆菌门的比值（与CK14相比均降低55%以上）；SSP能够显著增加Alistipes属的丰度（与CK14相比，SL14、SH14分别增加59.25%和65.62%）；SVP和SSP均能增加疣微菌门和Muribaculum的丰度，暗示两种桑黄多糖均具有潜在的抵抗代谢性疾病的作用；热图结合层级聚类分析表明影响小鼠肠道菌群的主要因素是桑黄多糖剂量而非种类。综上，SVP和SSP均可对肠道菌群产生有益影响，为桑黄在功能食品和保健品的应用提供理论依据。

Abstract:

To investigate the regulatory effects of Sanghuangporus vaninii polysaccharides (SVP) and Sanghuangporus sanghuang polysaccharides (SSP) on the intestinal microbiota in normal organism (including human beings), normal mice were applied as experimental animals in the work to conduct a systematic analysis on the intestinal flora through animal feeding experiments combined with high-throughput sequencing of microorganisms. Thirty mice were randomly divided into control group, SVP group, and SSP group, with the latter two groups being further subdivided into low-dose and high-dose subgroups (administered 200 and 400 mg·kg-1·d via gavage, respectively). It was demonstrated that SVP and SSP had no significant effects on the growth status, body weight and thymus coefficient of mice, but could significantly reduce the spleen coefficient (P<0.05). The results from high-throughput sequencing analysis on microorganisms in mice feces revealed that both SSP and SVP could significantly reduce the ratio of Firmicutes to Bacteroidetes in the intestinal tract (both decreased by more than 55% compared with CK14). The abundance of the Alistipes was significantly increased by SSP (compared with CK14, increased by 59.25% and 65.62% in SL14 and SH14, respectively). The abundance enhancement of Verrucomicrobia and Muribaculum was detected in both SVP and SSP treated groups, suggesting the potential resistance to metabolic diseases mediated by SVP and SSP. Heatmap and hierarchical clustering analysis demonstrated that the primary factor influencing the intestinal microbiota of mice was identified as the dosage rather than the type of Sanghuangporus spp. polysaccharides. It was concluded that both SVP and SSP could have beneficial effects on the intestinal flora, and thereby provide a theoretical foundation for the application of Sanghuangporus spp. in functional foods and health-care products.