色氨酸吲哚衍生物吲哚-3-甲醛(indole-3-carboxaldehyde, IAld)是微生物的特有代谢产物,已被证明在体外具有一定的抗炎、抗肿瘤活性,然而肠道微生物是否在体内通过产生IAld发挥相关作用仍不清楚。为此,该研究以1株高产IAld的益生菌——动物双歧杆菌SHXXA4M1为研究对象,通过构建结肠炎相关结直肠肿瘤小鼠模型,以评估其对结直肠肿瘤进程中肠道炎症的保护作用。结果显示,SHXXA4M1干预组小鼠相较于模型组小鼠,体重、存活率、结肠长度以及脾脏指数等各项表观指标得到改善;小鼠粪便中双歧杆菌相对丰度显著升高(P<0.05),结肠内IAld含量也显著升高(P<0.05),IL-1β、IL-17A、IFN-γ等促炎因子水平下降,而抗炎因子IL-10水平上升;肠道屏障功能相关基因的mRNA相对表达量也明显上升。以上研究结果说明,补充高产IAld的动物双歧杆菌能够通过调节免疫和增强肠道屏障功能缓解结肠炎相关结直肠肿瘤小鼠的炎症。
Indole-3-carbaldehyde (IAld), a derivative of tryptophan, is a unique metabolic product of microorganisms that has been proven in in vitro studies to have certain anti-inflammatory and anti-tumor activities.However, it is still unclear whether gut microbiota exerts related effects in vivo through the production of IAld.This study is centered on investigating the potential protective effects of a probiotic strain of Bifidobacterium animalis SHXXA4M1, which produces a high level of IAld, in a colitis-associated colorectal mouse model.The findings indicated that compared with the model group, mice in the SHXXA4M1 intervention group exhibited enhancements in several markers, including body weight, survival rate, colon length, and spleen index.Following the probiotic intervention, the relative abundance of Bifidobacterium significantly increased (P<0.05), IAld content in the colon also significantly increased (P<0.05), along with decreased levels of pro-inflammatory factors IL-1β, IL-17A, and IFN-γ, and increased levels of the anti-inflammatory factor IL-10.Additionally, there was a notable increase in the relative expression level of mRNA associated with intestinal barrier function, as well as observed apoptosis of tumor cells in the colon.The aforementioned findings suggest that supplementation of high-yield IAld Bifidobacterium animalis may mitigate inflammation in colitis-associated colorectal tumor mice through modulation of immune response and enhancement of intestinal barrier function.
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