氣喘是個長期慢性的肺部疾病。當氣喘發作時，會造成不斷間歇的喘息和氣道發炎的一種綜合徵狀。目前此疾病已經影響超過全球3億的人口，所有年齡層的人們皆飽受氣喘疾病之苦，而在兒童時期的氣喘發作為最常見。造成氣喘的原因有很多種，過去許多研究指出早期生活環境與氣喘疾病有強烈相關的現象。本研究透過宏觀基因體學的方法，探討兒童氣喘與環境微生物群落的相關性。我們與成功大學醫學院小兒科醫療團隊王志堯醫師合作，採集了氣喘兒童不同部位的樣本。在鼻腔和喉嚨樣本中，分別採集氣喘發作當下(Attack)的樣本、氣喘回復後(Recovery)的樣本以及沒有氣喘疾病(Control)家人的樣本，對象為5~11歲的兒童。透過引子(primer)放大細菌16S rDNA的片段，再利用Illumina定序平台進行定序，將序列資料比對細菌16S資料庫來鑑定物種。另外為了探討是否環境因素會影響氣喘，我們比較同家族或氣喘個體樣本的相似性或差異性，利用各樣本的序列資料來進行樣本微生物群落的相似度分析。結果顯示氣喘發作與環境皆不是影響菌相的主要因素，所以必須比較同一人氣喘發作前後的菌相才可能找到與氣喘有相關性的微生物。在比較氣喘發作當下(Attack)與回復後(Recovery)的樣本後，我們發現鼻腔Attack樣本的細菌Moraxella catarrhalis比例相對較多，喉嚨Recovery樣本的細菌Leptotrichia spp.比例相對較多。我們推測在兒童身上，這兩種細菌物種可能與氣喘發作或發展相關。在未來研究發展上，探討氣喘微生物可以針對這兩個細菌作分析，作為預防及治療氣喘的可能方案。

Asthma is a chronic (long-term) lung disease involving the airways. It is a heterogeneous syndrome of intermittent wheeze and airway inflammation that affect people of all ages, but it mostly begins during childhood. Asthma is caused by many factors. Many studies have revealed a correlation between asthma and microbes, however, the specific microbes involved are not clear. In this project, we intend to identify specific microbes related to asthma using a metagenomics approach on the microbial communities in different body parts. We collaborated with Dr. Jiu-Yao Wang’s team, who collected asthma attack and asthma recovery samples from nasal cavity and throat of children between five and eleven years old. We amplified bacterial 16S rRNA sequences for Illumina sequencing. For species identification, we aligned the sequence data to the bacterial 16S database. In addition, we performed principle component analysis to compare microbial communities. We found that Moraxella catarrhalis was more abundant in nasal cavity of some attack samples compared to the recovery samples. In contrast, Leptotrichia spp. was more abundant in throat of recovery samples. The two microbes can be targets for further studies of asthma development.

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