青春双歧杆菌对溃疡性结肠炎小鼠的缓解作用

Bifidobacterium adolescentis alleviates ulcerative colitis in mice

摘要:

【目的】 探究具有较强抗氧化能力的青春双歧杆菌对溃疡性结肠炎小鼠的作用效果。【方法】 以2,2-联苯基-1-苦基肼基自由基清除率、还原能力和过氧化氢耐受能力作为抗氧化指标，筛选具有较强抗氧化能力的青春双歧杆菌进行后续动物实验。通过构建葡聚糖硫酸钠诱导的结肠炎小鼠模型，探究抗氧化能力较强的青春双歧杆菌对溃疡性结肠炎的缓解效果。【结果】 在26株青春双歧杆菌中，青春双歧杆菌TH02767、TH03658和TH03664表现出较强的抗氧化能力。在葡聚糖硫酸钠诱导的结肠炎小鼠模型中，仅有TH02767在疾病活动指数和脾脏指数方面表现出对结肠炎具有显著缓解效果(P<0.05)。此外，TH02767的干预显著降低了结肠中肿瘤坏死因子-α、白细胞介素-6、白细胞介素-1β和髓过氧化物酶的含量(P<0.05)，并显著增加了白细胞介素-10的含量(P<0.05)。TH02767降低了结肠炎小鼠肠道菌群中脱铁杆菌门的丰度，增加了拟杆菌门丰度，并在属水平上显著增加了鼠杆状菌属(Muribaculum)和鼠杆状菌科(Muribaculaceae)的丰度(P<0.05)。【结论】 本研究筛选得到的具有较强抗氧化能力的青春双歧杆菌TH02767，不仅能够改善葡聚糖硫酸钠诱导的结肠炎小鼠的相关临床症状，还能显著降低促炎细胞因子含量，并有效调节肠道菌群。

Abstract:

[Objective] To study the therapeutic effect of Bifidobacterium adolescentis strains with strong antioxidant capacity on a mouse model of ulcerative colitis (UC). [Methods] The B. adolescentis strains with strong antioxidant capacity were screened based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging rate, reducing capacity, and hydrogen peroxide tolerance. Subsequently, we established a mouse model of dextran sulfate sodium (DSS)-induced colitis to investigate the alleviating effects of the B. adolescentis strains with strong antioxidant capacity on UC. [Results] Among the 26 strains of B. adolescentis, TH02767, TH03658, and TH03664 demonstrated strong antioxidant capacity. Only TH02767 showed an alleviating effect on UC in terms of disease activity index and spleen index in the mouse model (P<0.05). Moreover, the intervention with TH02767 lowered the levels of tumor necrosis factor-α, interleukin-6, interleukin-1β, and myeloperoxidase (P<0.05), while enhancing the production of interleukin-10 (P<0.05) in the colon. In addition, TH02767 modulated gut microbiota in the mice by reducing the relative abundance of Deferribacterota and increasing the relative abundance of Bacteroidetes. At the genus level, it increased the relative abundance of Muribaculum and Muribaculaceae (P<0.05). [Conclusion] B. adolescentis TH02767 screened out in this study for its robust antioxidant capacity not only ameliorates the clinical symptoms associated with DSS-induced colitis in mice but also significantly reduces the levels of pro-inflammatory cytokines and modulates the gut microbiota.