Department of Gastroenterology, First Affiliated Hospital, China Medical University, Shenyang, 110001 Liaoning Province, China.
Department of Geriatrics, First Affiliated Hospital, China Medical University, Shenyang, 110001 Liaoning Province, China.
J Immunol Res. 2021 Mar 6;2021:5084713. doi: 10.1155/2021/5084713. eCollection 2021.
Vitamin B (nicotinamide (NAM)), one of the most important nutritional components for humans, exerts anti-inflammatory activity. This study was aimed at investigating the effect of NAM on the gut microbiota and short-chain fatty acids (SCFAs) in mice with chronic colitis. Colitis was induced in C57BL/6 male mice by administration of 1.5% dextran sulfate sodium (DSS), and the mice were intraperitoneally injected with normal saline (NS) or NAM. NAM treatment ameliorated weight loss and changes in colon length, disease activity index (DAI) score, and histologic scores. Moreover, enzyme-linked immunosorbent assay (ELISA) analysis of LPL cells revealed that the level of interleukin- (IL-) 6, IL-12p70, IL-1, tumor necrosis factor- (TNF-) , interferon- (IFN-) , IL-21, and IL-17A was increased, while IL-10 was reduced, in the chronic colitis group compared to the control group, but the levels of all these factors were restored after NAM treatment. Then, 16S rRNA sequencing of the large intestinal content was performed, and analysis of alpha diversity and beta diversity showed that the richness of the gut microbiota was decreased in the DSS group compared to the control group and restored after NAM treatment. In addition, NAM modulated specific bacteria, including Odoribacter, Flexispira, and Bifidobacterium, in the NAM+chronic colitis group. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis indicated that NAM treatment restored disruptions in the functions of the gut microbiota (replication and repair, cell motility) in mice with DSS-induced colitis. Furthermore, NAM also restored the reduction in valeric acid in mice with DSS-induced chronic colitis. Our results suggest that NAM treatment could alleviate DSS-induced chronic colitis in mice by inhibiting inflammation and regulating the composition and function of gut microbiota.
维生素 B（烟酰胺（NAM））是人类最重要的营养成分之一，具有抗炎活性。本研究旨在探讨 NAM 对慢性结肠炎小鼠肠道微生物群和短链脂肪酸（SCFAs）的影响。通过给予 1.5%葡聚糖硫酸钠（DSS）诱导 C57BL/6 雄性小鼠结肠炎，并用生理盐水（NS）或 NAM 对其进行腹腔注射。NAM 治疗改善了体重减轻和结肠长度变化、疾病活动指数（DAI）评分和组织学评分。此外，通过酶联免疫吸附试验（ELISA）分析 LPL 细胞，发现与对照组相比，慢性结肠炎组白细胞介素-（IL-）6、IL-12p70、IL-1、肿瘤坏死因子-（TNF-）、干扰素-（IFN-）、IL-21 和 IL-17A 的水平升高，而 IL-10 的水平降低，但 NAM 治疗后所有这些因素的水平均恢复正常。然后，对大肠内容物进行 16S rRNA 测序，α多样性和β多样性分析表明，与对照组相比，DSS 组肠道微生物群的丰富度降低，而 NAM 治疗后恢复正常。此外，NAM 调节了特定的细菌，包括 Odoribacter、Flexispira 和 Bifidobacterium，在 NAM+慢性结肠炎组中。群落重建的未观察状态的系统发育分析（PICRUSt）表明，NAM 治疗恢复了 DSS 诱导的结肠炎小鼠肠道微生物群功能（复制和修复、细胞运动）的紊乱。此外，NAM 还恢复了 DSS 诱导的慢性结肠炎小鼠中戊酸的减少。我们的研究结果表明，NAM 治疗可以通过抑制炎症和调节肠道微生物群的组成和功能来缓解 DSS 诱导的慢性结肠炎。
