Quinolone prophylaxis is recommended for patients with advanced cirrhosis at high risk of spontaneous bacterial peritonitis (SBP) or with prior SBP. Yet, the impact of long-term antibiotic prophylaxis on the microbiome of these patients is poorly characterized. Patients with liver cirrhosis receiving long-term quinolone prophylaxis to prevent SBP were prospectively included and sputum and stool samples were obtained at baseline, 1, 4 and 12 weeks thereafter. Both bacterial DNA and RNA were assessed with 16S rRNA sequencing. Relative abundance, alpha and beta diversity were calculated and correlated with clinical outcome. Overall, 35 stool and 19 sputum samples were obtained from 11 patients. Two patients died (day 9 and 12) all others were followed for 180 days. Reduction of Shannon diversity and bacterial richness was insignificant after initiation of quinolone prophylaxis (p > 0.05). Gut microbiota were significantly different between patients (p < 0.001) but non-significantly altered between the different time points before and after initiation of antibiotic prophylaxis (p > 0.05). A high relative abundance of Enterobacteriaceae > 20% during quinolone prophylaxis was found in three patients. Specific clinical scenarios (development of secondary infections during antibiotic prophylaxis or the detection of multidrug-resistant Enterobacteriaceae) characterized these patients. Sputum microbiota were not significantly altered in individuals during prophylaxis. The present exploratory study with small sample size showed that inter-individual differences in diversity of gut microbiota were high at baseline, yet quinolone prophylaxis had only a moderate impact. High relative abundances of Enterobacteriaceae during follow-up might indicate failure of or non-adherence to quinolone prophylaxis. However, our results may not be clinically significant given the limitations of the study and therefore future studies are needed to further investigate this phenomenon.

中文翻译：

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喹诺酮类药物预防自发性细菌性腹膜炎期间的粪便和痰微生物组：一项探索性研究

对于自发性细菌性腹膜炎 (SBP) 高风险或既往 SBP 的晚期肝硬化患者，建议使用喹诺酮类药物进行预防。然而，长期抗生素预防对这些患者微生物组的影响尚不清楚。前瞻性纳入接受长期喹诺酮类药物预防以预防 SBP 的肝硬化患者，并在基线、此后 1、4 和 12 周获得痰和粪便样本。细菌 DNA 和 RNA 均通过 16S rRNA 测序进行评估。计算了相对丰度、α和β多样性，并与临床结果相关联。总体而言，从 11 名患者中获得了 35 份粪便样本和 19 份痰样本。两名患者死亡（第 9 天和第 12 天），所有其他患者均被随访 180 天。开始喹诺酮类药物预防后，香农多样性和细菌丰富度的降低并不显着（p > 0.05）。患者之间的肠道微生物群存在显着差异（p < 0.001），但在开始抗生素预防之前和之后的不同时间点之间没有显着变化（p > 0.05）。在 3 名患者中发现在喹诺酮类药物预防期间肠杆菌科的相对丰度 > 20%。特定的临床情况（抗生素预防期间继发感染的发展或检测到多重耐药肠杆菌科细菌）以这些患者为特征。在预防期间，个体的痰微生物群没有显着改变。目前的小样本探索性研究表明，肠道微生物群多样性的个体间差异在基线时很高，但喹诺酮类药物的预防作用只有中等程度的影响。随访期间肠杆菌科的相对丰度较高可能表明喹诺酮类药物预防失败或不依从。然而，鉴于研究的局限性，我们的结果可能没有临床意义，因此需要未来的研究来进一步研究这一现象。