Bailey J R, Vince V, Williams N A, Cogan T A
1 Mucosal Microbiology, School of Veterinary Sciences, University of Bristol, BS40 5DU, United Kingdom.
2 KWS BioTest Ltd., Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, United Kingdom.
Benef Microbes. 2017 Aug 24;8(4):605-614. doi: 10.3920/BM2016.0110. Epub 2017 Jun 16.
Treatment of inflammatory bowel disease (IBD) is mainly based on suppression of symptoms, often with numerous side effects. Trials of probiotics in IBD have frequently produced disappointing results. The majority of probiotics are unusual, since they do not require iron for growth, unlike many bacteria resident in the intestine. The IBD intestine is iron-rich due to bleeding and use of oral iron supplements; conventional probiotics would be rapidly outcompeted. We have evaluated an iron-responsive Streptococcus thermophilus strain for its potential to reduce signs of colitis. Efficacy of S. thermophilus was evaluated in the dextran sodium sulphate mouse model of colitis. Treated animals were given 1×10 cfu S. thermophilus per day and clinical observations were taken daily. At termination, gross and histopathological signs of disease, cellular infiltration, location of bacteria, and cytokine expression in the intestine were determined. S. thermophilus delayed onset of colitis and reduced clinical signs of disease, including bodyweight loss and gastrointestinal bleeding. It reduced bacterial translocation into the colonic tissue. Increased numbers of CD8 intraepithelial lymphocytes were seen in control animals treated with S. thermophilus. S. thermophilus had no effect on gross pathology, histopathology or cytokine production in either colitic or control animals. We propose that S. thermophilus promotes maintenance of mucosal barrier function which reduces bacterial translocation, thereby reducing immune stimulation and associated inflammation. This allows mucosal healing, reducing gastrointestinal bleeding and weight loss. This could be studied as a locally-acting adjunct or alternative to current IBD treatments.
炎症性肠病（IBD）的治疗主要基于症状抑制，且往往伴有诸多副作用。IBD的益生菌试验常常产生令人失望的结果。大多数益生菌与众不同，因为它们生长不需要铁，这与许多肠道常驻细菌不同。由于出血和口服铁补充剂的使用，IBD患者的肠道富含铁；传统益生菌会很快被淘汰。我们评估了一种铁反应性嗜热链球菌菌株减轻结肠炎症状的潜力。在葡聚糖硫酸钠诱导的小鼠结肠炎模型中评估了嗜热链球菌的疗效。给治疗组动物每天服用1×10 cfu嗜热链球菌，并每天进行临床观察。实验结束时，测定疾病的大体和组织病理学征象、细胞浸润、细菌定位以及肠道中的细胞因子表达。嗜热链球菌延迟了结肠炎的发作并减轻了疾病的临床症状，包括体重减轻和胃肠道出血。它减少了细菌向结肠组织的移位。在用嗜热链球菌治疗的对照动物中，上皮内CD8淋巴细胞数量增加。嗜热链球菌对结肠炎动物或对照动物的大体病理学、组织病理学或细胞因子产生均无影响。我们认为，嗜热链球菌促进黏膜屏障功能的维持，从而减少细菌移位，进而减少免疫刺激和相关炎症。这使得黏膜愈合，减少胃肠道出血和体重减轻。这可以作为当前IBD治疗的局部作用辅助手段或替代方法进行研究。
