Differences in airway microbiome and metabolome of single lung transplant recipients

Abstract

Background: Recent studies suggest that alterations in lung microbiome are associated with occurrence of chronic lung diseases and transplant rejection. To investigate the host-microbiome interactions, we characterized the airway microbiome and metabolome of the allograft (transplanted lung) and native lung of single lung transplant recipients. Methods: BAL was collected from the allograft and native lungs of SLTs and healthy controls. 16S rRNA microbiome analysis was performed on BAL bacterial pellets and supernatant used for metabolome, cytokines and acetylated proline-glycine-proline (Ac-PGP) measurement by liquid chromatography-high-resolution mass spectrometry. Results: In our cohort, the allograft airway microbiome was distinct with a significantly higher bacterial burden and relative abundance of genera Acinetobacter & Pseudomonas. Likewise, the expression of the pro-inflammatory cytokine VEGF and the neutrophil chemoattractant matrikine Ac-PGP in the allograft was significantly higher. Airway metabolome distinguished the native lung from the allografts and an increased concentration of sphingosine-like metabolites that negatively correlated with abundance of bacteria from phyla Proteobacteria. Conclusions: Allograft lungs have a distinct microbiome signature, a higher bacterial biomass and an increased Ac-PGP compared to the native lungs in SLTs compared to the native lungs in SLTs. Airway metabolome distinguishes the allografts from native lungs and is associated with distinct microbial communities, suggesting a functional relationship between the local microbiome and metabolome.

Mild and severe SARS-CoV-2 infection induces respiratory and intestinal microbiome changes in the K18-hACE2 transgenic mouse model

“…A significant difference among the F/B ratio was observed among the control and high dose group suggesting dysbiosis in the lung microbiome post SARS-CoV-2 infection with a high dose. Similar results were observed in patients that underwent lung transplants but to our knowledge, this has not been thoroughly examined in respiratory viral infections (69).…”

Mild and Severe SARS-CoV-2 Infection Induces Respiratory and Intestinal Microbiome Changes in the K18-hACE2 Transgenic Mouse Model

“…A significant difference among the F/B ratios was observed between the control and high-dose groups, suggesting dysbiosis in the lung microbiome post-SARS-CoV-2 infection with a high dose. Similar results were observed in patients that underwent lung transplants, but to our knowledge, this has not been thoroughly examined in respiratory viral infections ( 69 ).…”

Nutritional immunity: the impact of metals on lung immune cells and the airway microbiome during chronic respiratory disease

“…Despite the advances in microbiome research, our knowledge of the airway microbiome is still way behind compared to that of the gut microbiome. And as such, lung microbiota composition, microbiota derived metabolites and how they could contribute to lung inflammation, immunity and disease is only in its infancy [ 239 , 240 ]. Alterations in bacterial burden, gut microbial species and the metabolites they produce are associated with altered inflammation and immunity in the lungs as well as the development of lung diseases.…”