The Role of the Respiratory Microbiome in the Pathogenesis of Aspiration Pneumonia: Implications for Diagnosis and Potential Therapeutic Choices

Abstract

Although the lungs were considered to be sterile until recently, the advent of molecular biology techniques, such as polymerase chain reaction, 16 S rRNA sequencing and metagenomics has led to our expanding knowledge of the lung microbiome. These methods may be particularly useful for the identification of the causative agent(s) in cases of aspiration pneumonia, in which there is usually prior administration of antibiotics. The most common empirical treatment of aspiration pneumonia is the administration of broad-spectrum antibiotics; however, this may result in negative cultures from specimens taken from the respiratory tract. Therefore, in such cases, polymerase chain reaction or metagenomic next-generation sequencing may be life-saving. Moreover, these modern molecular methods may assist with antimicrobial stewardship. Based upon factors such as age, altered mental consciousness and recent hospitalization, there is a shift towards the predominance of aerobes, especially Gram-negative bacteria, over anaerobes in aspiration pneumonia. Thus, the therapeutic choices should be expanded to cover multi-drug resistant Gram-negative bacteria in selected cases of aspiration pneumonia.

Molecular Accounting and Profiling of Human Respiratory Microbial Communities: Toward Precision Medicine by Targeting the Respiratory Microbiome for Disease Diagnosis and Treatment

“…Probiotics (external microbes administered for health), prebiotics (nonabsorbed molecules that promote specific bacterial growth), antibiotics, and quorum-sensing molecule inhibitors are all examples of ways in which the microbiome of the lungs could be manipulated to correct dysbiosis and restore “healthy” microbial communities. It is considered that variations in the composition of the microbiota contribute to the vast spectrum of illness incidence and manifestation, which may provide an opportunity for therapeutic manipulation and precision medicine [ 23 , 24 ].…”

The impact of concurrent bacterial lung infection on immunotherapy in patients with non-small cell lung cancer: a retrospective cohort study

“…NSCLC is diagnosed in 85 percent of lung cancer cases ( Nyein et al., 2022 ; Xi et al., 2022 ). Bacterial lung infection (BLI) refers to a disease caused by microbial infection in the lungs, which induces inflammation and alters the lung microbiome environment ( Oliva and Terrier, 2021 ; Vallianou et al., 2023 ). In particular, BLI, as referred in this study, involves a variety of bacterial pathogens such as Streptococcus pneumoniae, Haemophilus influenzae, and Pseudomonas aeruginosa, all known for their capacity to colonize the respiratory tract and trigger infection.The World Health Organization’s 2021 Global Cancer Report indicated that 60% to 80% of NSCLC patients have concurrent BLI ( He et al., 2021 ).…”

Characteristics of the pulmonary microbiota in patients with mild and severe pulmonary infection

“…mNGS maps the acquired sequence information to the microbial resource database, overcoming the limitations of targeted detection methods, and characterizes all microorganisms in the human system through a single detection. The rapid development of mNGS has increased our understanding of the diversity, composition, and function of the lung microbiome (Miao et al, 2022;Xiao et al, 2022;Vallianou et al, 2023).…”