插管對人體口咽部與氣管內微生物菌相之影響探討

呼吸道重症患者因為無法自主呼吸可能需要進行插管與安裝呼吸器，研究顯示甫插管2週的患者是感染呼吸器相關肺炎(ventilator associated pneumonia, VAP)的高風險群，甚至可能因此死亡，儘管已經知道造成VAP的原因是微生物菌相(microbiota)，但是微生物群包含了病毒、細菌與真菌，而且有些微生物無法以樣本培養的方式分離出，以至於無法得知主要是那些微生物造成VAP感染。本研究分析從研究人員蒐集而來的5位插管病患資料，資料以基因定序(sequenceing)的方式調查出樣本的16S rDNA基因序列是來自哪種細菌，並嘗試以資料視覺化與負二項分布的廣義線性模型來觀察這些病患體內之細菌是如何隨插管改變的，從中推測造成感染的細菌為那些。在長條圖中看出插管後Proteobacteria與Tenericutes的細菌於部分樣本中有增加的情況，而Firmicutes則在大多樣本中發現減少，在模型分析中也發現Firmicutes的細菌只有負的插管效應顯著，表示插管後數量顯著地減少。這些細菌數量的增減可能反映了造成感染疾病的細菌是那些，然而研究中因為樣本數的不足而未能將所有差異因素考慮於分析中，所以無法更全面地解釋細菌數量改變的原因。

關鍵字

負二項迴歸；插管；人體微生物菌相

並列摘要

Patients with respiratory disease are usually provided with endotracheal tube due to respiratory obstacle. Many studies show that they are risky to be infected by ventilator associated pneumonia (VAP). VAP may cause death results from the invasion of the lower respiratory tract and lung parenchyma by microorganisms (virus, bacteria, or fungi). It is difficult for researchers to find out what microorganisms lead to VAP because some of the microorganisms are culture independent. This study analyzed 5 patients who were intubated in ICU. The data are genetic sequence counts from 16S rDNA which can be matched with bacteria species information. This study provides data vidualizrions and adopts the negative binomial regression model to understand the variation of bacteria counts during intubation and inferred the pathogenic bacteria at VAP.According to the bar plots, Proteobacteria and Tenericutes increased after intubation at several parts of the samples. Firmicutes all decreased after intubation and their effects were all significantly negative as well.