Abstract

The gut microbiota plays an important role in multifaceted physiological functions in the host. Previous studies have assessed the probiotic effects of Lactobacillus salivarius LI01. In this study, we aimed to investigate the potential effects and putative mechanism of L. salivarius LI01 in immune modulation and metabolic regulation through the monocolonization of germ-free (GF) Sprague-Dawley (SD) rats with L. salivarius LI01. The GF rats were separated into two groups and administered a gavage of L. salivarius LI01 or an equal amount of phosphate-buffered saline. The levels of serum biomarkers, such as interleukin (IL)-1α, IL-5, and IL-10, were restored by L. salivarius LI01, which indicated the activation of Th0 cell differentiation toward immune homeostasis. L. salivarius LI01 also stimulated the immune response and metabolic process by altering transcriptional expression in the ileum and liver. A Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed significant enrichment of the 5′-adenosine monophosphate-activated protein kinase (AMPK) signaling pathway, which indicated that L. salivarius LI01 exerts an effect on energy accumulation. The LI01 group showed alterations in fecal carbohydrates accompanied by an increased body weight gain. In addition, L. salivarius LI01 produced indole-3-lactic acid (ILA) and enhanced arginine metabolism by rebalancing the interconversion between arginine and proline. These findings provide evidence showing that L. salivarius LI01 can directly impact the host by modulating immunity and metabolism.

Key points

• Lactobacillus salivarius LI01 conventionalizes the cytokine profile and activates the immune response.

• LI01 modulates carbohydrate metabolism and arginine transaction.

• LI01 generates tryptophan-derived indole-3-lactic acid.

• The cytochrome P450 family contributes to the response to altered metabolites.

中文翻译：

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益生菌唾液乳杆菌LI01定植的无菌大鼠免疫应答和代谢的调节

摘要

肠道菌群在宿主的多种生理功能中起重要作用。先前的研究已经评估了唾液乳杆菌LI01的益生菌作用。在这项研究中，我们旨在研究唾液乳杆菌LI01通过无菌（GF）Sprague-Dawley（SD）大鼠与唾液乳杆菌LI01的单菌落化来研究唾液乳杆菌LI01在免疫调节和代谢调节中的潜在作用和推测的机制。将GF大鼠分成两组，并管饲唾液乳杆菌LI01或等量的磷酸盐缓冲盐水。唾液乳杆菌恢复了血清生物标志物的水平，例如白介素（IL）-1α，IL-5和IL-10LI01，表明Th0细胞分化朝着免疫稳态的活化。唾液乳杆菌LI01还通过改变回肠和肝脏中的转录表达来刺激免疫反应和代谢过程。京都基因与基因组百科全书（KEGG）途径分析显示5'-腺苷单磷酸激活的蛋白激酶（AMPK）信号传导途径显着富集，这表明唾液乳杆菌LI01对能量积累产生影响。LI01组显示粪便碳水化合物发生变化，并伴有体重增加。此外，唾液乳杆菌LI01通过重新平衡精氨酸和脯氨酸之间的相互转化，产生了吲哚-3-乳酸（ILA）并增强了精氨酸的代谢。这些发现提供了证据，表明唾液乳杆菌LI01可通过调节免疫力和代谢直接影响宿主。

关键点

•唾液乳杆菌LI01常规化细胞因子谱并激活免疫反应。

• LI01调节碳水化合物的代谢和精氨酸的交易。

• LI01产生色氨酸衍生的吲哚-3-乳酸。

•细胞色素P450家族有助于改变代谢产物。