将中文句子翻译为英文段落使逻辑清晰更加学术化：首先收集小鼠粪便提取肠道细菌的总基因组DNA进行16sRNA的基因测序。考虑到短链脂肪酸是肠道微生物的产物不同组间微生物的差异也会影响短链脂肪酸的水平从而进一步影响机体免疫功能。因此采用全自动气相色谱仪检测小鼠盲肠粪便中的短链脂肪酸。结果表明：DEX作用小鼠后能增加肠道有害的丰度而经LNT作用后能显著增加有益菌的丰度p005。LNT能够改善DEX引起的

To begin with, mouse feces were collected and the total genomic DNA of intestinal bacteria was extracted for 16sRNA gene sequencing. Considering that short-chain fatty acids (SCFAs) are products of gut microbiota, differences in microbiota among groups can also affect the level of SCFAs, which in turn affects the immune function of the host. Therefore, an automated gas chromatography was used to detect SCFAs in mouse cecum feces. The results showed that DEX treatment increased the abundance of harmful bacteria in the gut, while LNT treatment significantly increased the abundance of beneficial bacteria (p<0.05). LNT could improve the suppressed metabolic pathways caused by DEX (p<0.05) and increase the levels of acetate and butyrate in feces (p<0.05).