AUTHOR=Qi Jiancheng , Cai Dongjie , Cui Yaocheng , Tan Tianyu , Zou Huawei , Guo Wei , Xie Yue , Guo Hongrui , Chen Shi-Yi , Ma Xiaoping , Gou Liping , Cui Hengmin , Geng Yi , Zhang Ming , Ye Gang , Zhong Zhijun , Ren Zhihua , Hu Yanchun , Wang Ya , Deng Junliang , YU Shumin , Cao Suizhong , Wanapat Metha , Fang Jing , Wang Zhisheng , Zuo Zhicai TITLE=Metagenomics Reveals That Intravenous Injection of Beta-Hydroxybutyric Acid (BHBA) Disturbs the Nasopharynx Microflora and Increases the Risk of Respiratory Diseases JOURNAL=Frontiers in Microbiology VOLUME=11 YEAR=2021 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.630280 DOI=10.3389/fmicb.2020.630280 ISSN=1664-302X ABSTRACT=

It is widely accepted that maintenance of microbial diversity is essential for the health of the respiratory tract; however, there are limited reports on the correlation between starvation and respiratory tract microbial diversity. In the present study, saline/β-hydroxybutyric acid (BHBA) intravenous injection after dietary restriction was used to imitate different degrees of starvation. A total of 13 healthy male yaks were imposed to different dietary restrictions and intravenous injections, and their nasopharyngeal microbiota profiles were obtained by metagenomic shotgun sequencing. In healthy yaks, the main dominant phyla were Proteobacteria (33.0%), Firmicutes (22.6%), Bacteroidetes (17.2%), and Actinobacteria (13.2%); the most dominated species was Clostridium botulinum (10.8%). It was found that 9 days of dietary restriction and 2 days of BHBA injection (imitating severe starvation) significantly decreased the microbial diversity and disturbed its structure and functional composition, which increased the risk of respiratory diseases. This study also implied that oral bacteria played an important role in maintaining nasopharynx microbial homeostasis. In this study, the correlation between starvation and nasopharynx microbial diversity and its potential mechanism was investigated for the first time, providing new ideas for the prevention of respiratory diseases.