Caparros-Martin Jose A, Saladié Montserrat, Agudelo-Romero S Patricia, Nichol Kristy S, Reen F Jerry, Moodley Yuben P, Mulrennan Siobhain, Stick Stephen, Wark Peter A B, O'Gara Fergal
Wal-yan Respiratory Research Centre, The Kids Research Institute Australia, Nedlands, Western Australia, Australia.
Curtin Health Innovation Research Institute (CHIRI), Curtin University, Bentley, Western Australia, Australia.
BMJ Open Respir Res. 2024 Dec 18;11(1):e002552. doi: 10.1136/bmjresp-2024-002552.
Chronic obstructive pulmonary disease (COPD) is a complex disorder with a high degree of interindividual variability. Gastrointestinal dysfunction is common in patients with COPD and has been proposed to influence the clinical progression of the disease. Using the presence of bile acid(s) (BA) in bronchoalveolar lavage (BAL) fluid as a marker of gastric aspiration, we evaluated the relationships between BAs, clinical outcomes and bacterial lung colonisation.
We used BAL specimens from a cohort of patients with COPD and healthy controls. BAs were profiled and quantified in BAL supernatants using mass spectrometry. Microbial DNA was extracted from BAL pellets and quantified using quantitative PCR. We profiled the BAL microbiota using an amplicon sequencing approach targeting the V3-V4 region of the 16S rRNA gene.
Detection of BAs in BAL was more likely at the earliest clinical stages of COPD and was independent of the degree of airway obstruction. BAL specimens with BAs demonstrated higher bacterial biomass and lower diversity. Likewise, the odds of recovering bacterial cultures from BAL were higher if BAs were also detected. Detection of BAs in BAL was not associated with either inflammatory markers or clinical outcomes. We also observed different bacterial community types in BAL, which were associated with different clinical groups, levels of inflammatory markers and the degree of airway obstruction.
Detection of BAs in BAL was associated with alterations in the airway bacterial communities. Further studies are needed to evaluate whether BAs in BAL can be used to stratify patients and predict disease progression trajectories.
慢性阻塞性肺疾病（COPD）是一种具有高度个体间变异性的复杂疾病。胃肠功能障碍在COPD患者中很常见，并且有人提出它会影响该疾病的临床进展。我们以支气管肺泡灌洗（BAL）液中胆汁酸（BA）的存在作为胃内容物误吸的标志物，评估了BA、临床结局与肺部细菌定植之间的关系。
我们使用了一组COPD患者和健康对照者的BAL标本。使用质谱法对BAL上清液中的BA进行分析和定量。从BAL沉淀中提取微生物DNA，并使用定量PCR进行定量。我们使用靶向16S rRNA基因V3 - V4区域的扩增子测序方法对BAL微生物群进行分析。
在COPD的最早临床阶段，BAL中检测到BA的可能性更大，且与气道阻塞程度无关。含有BA的BAL标本显示出更高的细菌生物量和更低的多样性。同样，如果也检测到BA，从BAL中培养出细菌的几率更高。BAL中检测到BA与炎症标志物或临床结局均无关。我们还在BAL中观察到不同的细菌群落类型，它们与不同的临床分组、炎症标志物水平和气道阻塞程度相关。
BAL中检测到BA与气道细菌群落的改变有关。需要进一步研究来评估BAL中的BA是否可用于对患者进行分层并预测疾病进展轨迹。
