Key Points L. paracasei inhibits NLRP3 inflammasome activation in vitro. The inhibitory effect of L. paracasei on the inflammasome is dependent on IL-10. Oral administration of L. paracasei prevents inflammation-related disorders. Some strains of lactic acid bacteria (LAB) have anti-inflammatory effects, but the mechanism underlying the alleviation of inflammation by LAB is not fully understood. In this study, we examined the inhibitory effect of a certain strain of LAB, Lactobacillus paracasei, on inflammasome activation, which is associated with various inflammatory disorders. Using bone marrow–derived macrophages from BALB/c mice, we found that L. paracasei, but not L. rhamnosus, suppressed NLRP3 inflammasome activation and inhibited subsequent caspase-1 activation and IL-1β secretion. L. paracasei also had inhibitory effects on AIM2 and NLRC4 inflammasome activation as well as the NLRP3 inflammasome. These inhibitory effects of L. paracasei on inflammasome activation were dependent on autocrine IL-10 induced by L. paracasei–stimulated macrophages. Furthermore, IL-10 production by L. paracasei–stimulated macrophages was involved with phagocytosis and the NOD2 signaling pathway in macrophages. In addition to in vitro studies, oral administration of L. paracasei in C57BL/6 mice reduced monosodium urate crystal–induced peritoneal inflammation in vivo. Moreover, continuous intake of L. paracasei in C57BL/6 mice alleviated high fat diet–induced insulin resistance and aging-induced expression of biomarkers for T cell senescence. Taken together, we demonstrated that L. paracasei inhibits inflammasome activation in vitro and exhibits an anti-inflammatory function in vivo. These results indicate that LAB that have inhibitory effects on inflammasome activation might contribute to the alleviation of inflammation-related disorders.

中文翻译：

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乳酸菌的一种特殊菌株，副干酪乳杆菌，在体外抑制炎症小体激活并预防炎症相关疾病

关键点 L. paracasei 在体外抑制 NLRP3 炎性体激活。L. paracasei 对炎性体的抑制作用取决于 IL-10。口服副干酪乳杆菌可预防炎症相关疾病。一些乳酸菌 (LAB) 菌株具有抗炎作用，但 LAB 缓解炎症的机制尚不完全清楚。在这项研究中，我们检查了某种 LAB 菌株副干酪乳杆菌对炎症小体激活的抑制作用，炎症小体激活与各种炎症性疾病有关。使用来自 BALB/c 小鼠的骨髓来源的巨噬细胞，我们发现副干酪乳杆菌（而不是鼠李糖乳杆菌）抑制了 NLRP3 炎性体激活并抑制了随后的 caspase-1 激活和 IL-1β 分泌。L。副干酪还对 AIM2 和 NLRC4 炎症小体的激活以及 NLRP3 炎症小体具有抑制作用。L. paracasei 对炎症小体激活的这些抑制作用取决于 L. paracasei 刺激的巨噬细胞诱导的自分泌 IL-10。此外，副干酪乳杆菌刺激的巨噬细胞产生的 IL-10 与巨噬细胞中的吞噬作用和 NOD2 信号通路有关。除了体外研究外，在 C57BL/6 小鼠中口服副干酪乳杆菌可减少体内尿酸单钠晶体诱导的腹膜炎症。此外，在 C57BL/6 小鼠中持续摄入副干酪乳杆菌可减轻高脂肪饮食诱导的胰岛素抵抗和衰老诱导的 T 细胞衰老生物标志物的表达。综上所述，我们证明了 L. paracasei 在体外抑制炎症小体激活，并在体内表现出抗炎功能。这些结果表明，对炎症小体激活具有抑制作用的 LAB 可能有助于缓解炎症相关疾病。