INTRODUCTION Changes in the composition of the gut microbiota have been associated with the development of irritable bowel syndrome (IBS). However, to what extent specific bacterial species relate to clinical symptoms remains poorly characterized. We investigated the clinical relevance of bacterial species linked with increased proteolytic activity, histamine production, and superantigen (SAg) production in patients with IBS. METHODS Fecal (n = 309) and nasal (n = 214) samples were collected from patients with IBS and healthy volunteers (HV). Clinical symptoms and gut transit time were evaluated. Bacterial abundance in feces and nasal swabs as well as fecal trypsin-like activity were assessed. RESULTS The percentage of fecal samples containing Staphylococcus aureus was significantly higher in IBS compared with HV. Forty-nine percent of S. aureus -positive fecal samples from patients with IBS were also positive for SAgs, compared with 12% of HV. Patients with IBS and positive fecal SAg-producing S. aureus reported higher pain scores than those without S. aureus . Moreover, increased fecal proteolytic activity was associated with abdominal pain. Fecal abundance of Paraprevotella clara and Alistipes putredinis was significantly decreased in IBS, particularly in samples with higher proteolytic activity. Patients with lower Alistipes putredinis or Faecalibacterium prausnitzii abundance reported more severe abdominal pain. DISCUSSION In keeping with our preclinical findings, we show that increased presence of SAg-producing S. aureus in fecal samples of patients with IBS is associated with increased levels of abdominal pain. We also show that increased fecal proteolytic activity is associated with increased abdominal pain in patients with IBS.

中文翻译：

---

粪便蛋白水解细菌和葡萄球菌超抗原与肠易激综合征的腹痛严重程度相关。


简介 肠道微生物群组成的变化与肠易激综合征 (IBS) 的发生有关。然而，具体细菌种类与临床症状的相关程度仍不清楚。我们研究了与 IBS 患者蛋白水解活性增加、组胺产生和超抗原 (SAg) 产生相关的细菌种类的临床相关性。方法 从 IBS 患者和健康志愿者 (HV) 采集粪便 (n = 309) 和鼻腔 (n = 214) 样本。评估临床症状和肠道通过时间。评估了粪便和鼻拭子中的细菌丰度以及粪便胰蛋白酶样活性。结果 IBS 患者的粪便样本中含有金黄色葡萄球菌的百分比明显高于 HV 患者。 IBS 患者的金黄色葡萄球菌阳性粪便样本中，49% 的 SAgs 也呈阳性，而 HV 的比例为 12%。患有IBS且粪便中产生SAg的金黄色葡萄球菌呈阳性的患者报告的疼痛评分比没有金黄色葡萄球菌的患者更高。此外，粪便蛋白水解活性的增加与腹痛有关。 IBS 患者粪便中 Paraprevotella clara 和 Alistipes putredinis 的丰度显着降低，尤其是在蛋白水解活性较高的样本中。腐臭臭苋或普拉梭杆菌丰度较低的患者报告腹痛更严重。讨论 根据我们的临床前研究结果，我们发现 IBS 患者粪便样本中产生 SAg 的金黄色葡萄球菌含量增加与腹痛程度增加相关。我们还发现，粪便蛋白水解活性的增加与 IBS 患者腹痛的增加有关。