Lung microbiome in children with hematological malignancies and lower respiratory tract infections

Background: Respiratory infectious complications remain a major cause of
morbidity and mortality in children with hematological malignancies.
Knowledge regarding the lung microbiome in the aforementioned children is
limited. Methods: A prospective cohort was conducted, enrolling 16
children with hematological malignancies complicated
with moderate to severe lower respiratory tract
infections(LRTIs), versus 21 LRTIs children with age, gender,
weight, infection severity matched, with no underlying
malignancies, to evaluate the lung
microbiome from bronchoalveolar lavage fluid samples in different
groups. Results: Lung microbiome from children with hematological
malignancies and LRTIs showed obviously decreased α and β diversity,
increased microbial function in infectious disease:bacteria/parasite, drug
resistance:antimicrobial and human pathogenesis than the control group,
and significantly reduced proportion of Firmicutes, Bacteroidota,
Actinobacteriota , increased Proteobacteria at the phylum level,
distinctly elevated Parabacteroides, Klebsiella, Grimontia,
Escherichia_Shigella, unclassified_Enterobacteriaceae at the genus level
than the control group. Besides, it was revealed that α diversity
(Shannon), β diversity (Bray Curtis dissimilarity), Proteobacteria at the
phylum level, and unclassified_Enterobacteriaceae and Escherichia_Shigella
at the genus level were significantly negatively associated with
hospitalization course, whereas Firmicutes at the phylum level was
established positively correlated with hospitalization course.
Conclusions: Children with hematological malignancies and LRTIs showed
obviously decreased α and β diversity, significantly increased function in
infectious disease pathogenesis, antimicrobial drug resistance, and
unfavorable environment tolerance. Besides, α diversity (Shannon), β
diversity (Bray Curtis dissimilarity), Proteobacteria may be used as
negatively correlated predictors for hospitalization course in these
children whereas Firmicutes is a positively correlated
predictor.