State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China.
School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
J Agric Food Chem. 2024 Sep 25;72(38):20930-20943. doi: 10.1021/acs.jafc.4c03408. Epub 2024 Sep 15.
The probiotic properties of () and its impact on immune function are well-documented. Lipoteichoic acid (LTA) is a crucial immune molecule in Gram-positive bacteria. Despite extensive research on LTA's structural diversity, the immunomodulatory mechanisms of LTA remain largely unexplored. This study investigates the immunomodulatory effects of L1 LTA at various concentrations on RAW 264.7 cells and mice under normal and inflammatory conditions. We found that LTA does not significantly affect healthy subjects; however, low-concentration LTA can reduce inflammation induced by LPS in cells and mice, enhancing the abundance of dominant intestinal bacteria. In contrast, high-concentration LTA exacerbates intestinal damage and dysbiosis. Creatinine may play a role in this differential response. In summary, while LTA does not alter immune homeostasis in healthy organisms, low-concentration LTA may mitigate damage from immune imbalance, but high-concentration LTA can worsen it. This suggests a quantitative requirement for probiotic intake. Our study provides critical theoretical support for understanding the immunomodulatory effects of probiotics on the host and paves the way for future research into the immune mechanisms of probiotics.
（）的益生菌特性及其对免疫功能的影响已得到充分证实。脂磷壁酸（LTA）是革兰氏阳性菌中一种重要的免疫分子。尽管对 LTA 的结构多样性进行了广泛的研究，但 LTA 的免疫调节机制在很大程度上仍未得到探索。本研究探讨了不同浓度的 L1 LTA 在正常和炎症条件下对 RAW 264.7 细胞和小鼠的免疫调节作用。我们发现 LTA 对健康受试者没有显著影响；然而，低浓度的 LTA 可以减轻 LPS 诱导的细胞和小鼠炎症，增加优势肠道细菌的丰度。相比之下，高浓度的 LTA 会加重肠道损伤和菌群失调。肌酐可能在这种差异反应中发挥作用。总之，虽然 LTA 不会改变健康机体的免疫稳态，但低浓度的 LTA 可能减轻免疫失衡引起的损伤，但高浓度的 LTA 会加重损伤。这表明益生菌的摄入需要定量。本研究为理解益生菌对宿主的免疫调节作用提供了重要的理论支持，并为益生菌免疫机制的未来研究奠定了基础。
