Changes In Intestinal Microflora In Rats With Acute Respiratory Distress Syndrome

[Objective] To implement high-throughput 16S rDNA sequencing to study microbial diversity in the fecal matter of rats with acute lung injury/acute respiratory distress syndrome (ALI/ARDS).[Metheds] Intratracheal instillation of lipopolysaccharide was used to induce ALI, and the pathological changes in the lungs and intestines were observed. D-lactate levels and diamine oxidase (DAO) activities were determined by ELLISA. The fragments encompassing V4 16S rDNA hypervariable regions were PCR amplified from fecal samples, and the PCR products of V4 were sequenced by Illumina MiSeq. Informatics analysis on microbiota was conducted with Illumina MiSeq based on information of OTU peak degree.[Results] Increased D-lactate levels and DAO activities were observed in the model group (P<0.01). Intestinal mucosa was damaged in ARDS group by light and electron microscopy. Sequencing results revealed the presence of 3780 and 4142 OTUs in the control and model groups, respectively. The percentage of shared OTUs was 18.8419%. Compared with the control group, the model group had higher diversity indexes and increased unevenness estimations and a lower number of species of Fusobacteria (at the phylum level), Helicobacter and Roseburia (at the genus level) (P <0.01).[Conclusions] Intratracheal instillation of lipopolysaccharide could induce ALI/ARDS successfully. Intestinal mucosal barrier was damaged when suffering from ARDS. Differences in species diversity, structure, distribution and composition were found between the control group and early ARDS group. The model group had higher levels of biodiversity and unevenness estimations than the normal group.