不同摄入量小米对小鼠肠道菌群和短链脂肪酸的影响

摄入一定量杂粮可降低一些慢性代谢疾病的发病率,但目前杂粮摄入量没有统一的标准,尚不清楚杂粮摄入过多是否会对健康产生不良影响。以小米添加量为20%、40%、60%、80%的饲料喂养3周龄C57BL/6J小鼠,持续12周,采用自动血生化分析仪、16S rRNA高通量基因测序、气相色谱-质谱联用仪分析了不同摄入量小米对小鼠血脂水平、肠道菌群和粪便短链脂肪酸的影响。结果发现,80%摄入量的小米显著增加了小鼠血清的总胆固醇、高密度脂蛋白胆固醇和低密度脂蛋白胆固醇的水平,同时增加了肠道丙酸、丁酸、异丁酸和戊酸的含量。肠道菌群分析结果表明,所有小米干预组的拟杆菌门(Bacteroidota)、Muribaculaceae的丰度上升,厚壁菌门(Firmicutes)、放线菌门(Actinobacteriota)、乳杆菌科(Lactobacillaceae)、双歧杆菌属 (Bifidobacterium)的丰度下降。摄入不同添加量小米的小鼠肠道菌群组成具有较大差异,其中20%小米摄入量组的小鼠菌群中显著富集了另枝菌属(Alistipes)、副拟杆菌属(Parabacteroides)、肠杆菌属(Enterorhabdus),而80%摄入量小米显著降低了小鼠菌群中的粪杆菌属(Faecalibaculum)、布劳特氏菌属(Blautia)和罗氏菌属(Roseburia)的丰度。研究结果表明,20%摄入量的小米就能有效调节小鼠肠道菌群,而过高摄入量(80%)的小米使小鼠血脂水平升高,降低了肠道菌群的多样性和均匀度以及有益菌的丰度,所以要理性看待杂粮的营养价值,避免过量摄入。

Effects of Different Foxtail Millet Intake on Gut Microbiota and Short Chain Fatty Acids in Mice

Coarse cereals intake can reduce the incidence of some chronic metabolic diseases. However, there is no uniform standard for coarse cereals intake, and unknown whether high coarse cereals intakes have adverse effect on health remains. In this study, 3-week-old C57BL/6J mice were intervened by adding different ratios of foxtail millet in feed, including 20%, 40%, 60%, and 80% additions for 12 weeks. Using the automatic biochemical analyzer, high-throughput sequencing of 16S rRNA gene, gas chromatography mass spectrometry, the effects of different ratios of foxtail millet on lipid blood levels, gut microbiota and short-chain fatty acids in mice were analyzed. The results showed that the feed with 80% supplementation foxtail millet significantly increased the total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, propionic acid, butyric acid, isobutyric acid and valeric acid. In addition, foxtail millet intake increased the abundance of Bacteroidota and Muribaculaceae, decreased the abundance of Firmicutes, Actinobacteriota, Lactobacillaceae and Bifidobacterium. The gut microbiota composition in mice varied with different levels of foxtail millet. The microbiota of mice fed with the supplementation of 20% were enriched in Alistipes, Parabacteroides, Enterorhabdus. However, the abundances of Faecalibaculum, Blautia and Roseburia were reduced for the mice fed with the supplementation of 80%. The results showed that, 20% intake of foxtail millet was sufficient to regulate gut microbiota, while 80% intake led to abnormally elevated lipid levels in blood, reduced the diversity and evenness of gut microbiota, and decreased the abundance of probiotics. Therefore, coarse cereals'' nutritional value should be rational considered and excessive intake patterns for coarse cereals should be avoided.