Blood Loss Leads to Increase in Relative Abundance of Opportunistic Pathogens in the Gut Microbiome of Rabbits.

Massive blood loss, a common pathological complication in the clinic, is often accompanied by altered gut integrity and intestinal wall damage. Little is known to what extent the gut microbiome could be correlated with this process. The gut microbiome plays a crucial role in human health, especially in immune and inflammatory responses. This study aims to determine whether acute blood loss affects the gut microbiome and the dynamic variation of the gut microbiome following the loss of blood. We used New Zealand rabbits to mimic the blood loss complication and designed a five-time-point fecal sampling strategy including 24-h pre-blood loss procedure, 24 h, 36 h, 48 h, and 1-week post-blood loss procedure. Gut microbiome composition and diversity were analyzed using 16S rRNA gene sequencing and downstream α-diversity, ß-diversity, and taxonomy analysis. The gut microbiome changed dramatically after blood loss procedure. There was a significant increase in diversity and richness of the gut microbiome at 24-h post-procedure (P = 0.038). Based on an analysis of similarities, the composition of gut microbiome in the samples collected at 24-h post-procedure was significantly different from that of pre-procedure samples (r = 0.79, P = 0.004 weighted unifrac distance; r = 0.99, P = 0.002, unweighted unifrac distance). The relative abundance of Lactobacillus was significantly decreased in the post-procedure samples (P = 0.0006), while the relative abundance of Clostridiales (P = 0.018) and Bacteroidales (P = 0.015) was significantly increased after procedure. We also found the relative abundance of Bacilli, Lactobacillus, Myroides, and Prevotella decreased gradually at different time points after blood loss. The relative abundance of the Clostridia, Alphaproteobacteria, and Sporosarcina increased at 24-h post-procedure and decreased thereafter. This preliminary study discovered potential connections between blood loss and dysbiosis of gut microbiome. The diversity and abundance of the gut microbiome was affected to various extents after acute blood loss and unable to be restored to the original microbiome profile even after one week. The increase in relative abundance of opportunistic pathogens after blood loss could be an important indication to reconsider immune and inflammatory responses after acute blood loss from the perspective of gut microbiome.

Dysbiosis of the Salivary Microbiome Is Associated With Non-smoking Female Lung Cancer and Correlated With Immunocytochemistry Markers.

Background: Association between oral bacteria and increased risk of lung cancer have been reported in several previous studies, however, the potential association between salivary microbiome and lung cancer in non-smoking women have not been evaluated. There is also no report on the relationship between immunocytochemistry markers and salivary microbiota. Method: In this study, we assessed the salivary microbiome of 75 non-smoking female lung cancer patients and 172 matched healthy individuals using 16S rRNA gene amplicon sequencing. We also calculated the Spearman's rank correlation coefficient between salivary microbiota and three immunohistochemical markers (TTF-1, Napsin A and CK7). Result: We analyzed the salivary microbiota of 247 subjects and found that non-smoking female lung cancer patients exhibited oral microbial dysbiosis. There was significantly lower microbial diversity and richness in lung cancer patients when compared to the control group (Shannon index, P < 0.01; Ace index, P < 0.0001). Based on the analysis of similarities, the composition of the microbiota in lung cancer patients also differed from that of the control group (r = 0.454, P < 0.001, unweighted UniFrac; r = 0.113, P < 0.01, weighted UniFrac). The bacterial genera Sphingomonas (P < 0.05) and Blastomonas (P < 0.0001) were relatively higher in non-smoking female lung cancer patients, whereas Acinetobacter (P < 0.001) and Streptococcus (P < 0.01) were higher in controls. Based on Spearman's correlation analysis, a significantly positive correlation can be observed between CK7 and Enterobacteriaceae (r = 0.223, P < 0.05). At the same time, Napsin A was positively associated with genera Blastomonas (r = 0.251, P < 0.05). TTF-1 exhibited a significantly positive correlation with Enterobacteriaceae (r = 0.262, P < 0.05). Functional analysis from inferred metagenomes indicated that oral microbiome in non-smoking female lung cancer patients were related to cancer pathways, p53 signaling pathway, apoptosis and tuberculosis. Conclusions: The study identified distinct salivary microbiome profiles in non-smoking female lung cancer patients, revealed potential correlations between salivary microbiome and immunocytochemistry markers used in clinical diagnostics, and provided proof that salivary microbiota can be an informative source for discovering non-invasive lung cancer biomarkers.