Fecal microbiota transplantation is widely used. Large intestinal microbiota (LIM) is more similar to fecal microbiota than small intestinal microbiota (SIM). The SIM communities are very different from those of LIM. Therefore, SIM transplantation (SIMT) and LIM transplantation (LIMT) might exert different influences. Here, healthy adult male C57Bl/6 mice received intragastric SIMT, LIMT, or sterile PBS administration. Microbiota graft samples were collected from small/large intestine of healthy mice of the same age, sex, and strain background. Compared with PBS treatment, SIMT increased pellet number, stool wet weight, and stool water percentage; induced a fecal microbiota profile shift toward the microbial composition of the SIM graft; induced a systemic anti-inflammatory cytokines profile; and ameliorated depressive-like behaviors in recipients. LIMT, however, induced merely a slight alteration in fecal microbial composition and no significant influence on the other aspects. In sum, SIMT, rather than LIMT, affected defecation features, fecal microbial composition, cytokines profile, and depressive-like behaviors in healthy mice. This study reveals the different effects of SIMT and LIMT, providing an interesting clue for further researches involving gut microbial composition change.

中文翻译：

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小肠菌群移植可改变健康小鼠的粪便菌群、粪便、细胞因子和情绪状态。

粪便微生物群移植被广泛使用。大肠微生物群 (LIM) 与粪便微生物群比小肠微生物群 (SIM) 更相似。SIM 社区与 LIM 的社区非常不同。因此，SIM 移植 (SIMT) 和 LIM 移植 (LIMT) 可能会产生不同的影响。在这里，健康的成年雄性 C57Bl/6 小鼠接受了胃内 SIMT、LIMT 或无菌 PBS 给药。从相同年龄、性别和品系背景的健康小鼠的小/大肠中收集微生物群移植物样本。与 PBS 处理相比，SIMT 增加了颗粒数、粪便湿重和粪便水分百分比；诱导粪便微生物群分布向 SIM 移植物的微生物组成转变；诱导全身抗炎细胞因子谱；并改善接受者的抑郁样行为。然而，LIMT 仅引起粪便微生物组成的轻微变化，而对其他方面没有显着影响。总之，SIMT 而非 LIMT 影响了健康小鼠的排便特征、粪便微生物组成、细胞因子谱和抑郁样行为。本研究揭示了 SIMT 和 LIMT 的不同作用，为进一步研究肠道微生物组成变化提供了有趣的线索。