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Updated: Jun 26, 2025
Bronchoalveolar Lavage Exosomes in Lipopolysaccharide-induced Septic Lung Injury
Published on: May 21, 2018
Throat microbiota drives alterations in pulmonary alveolar microbiota in patients with septic ARDS
Na-Na Li1, Kai Kang1, Yang Zhou1
1Departments of Critical Care Medicine, the First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Harbin, Heilongjiang, China.
Objectives:
The translocation of intestinal flora has been linked to the colonization of diverse and heavy lower respiratory flora in patients with septic ARDS, and is considered a critical prognostic factor for patients.
Methods:
On the first and third days of ICU admission, BALF, throat swab, and anal swab were collected, resulting in a total of 288 samples. These samples were analyzed using 16S rRNA analysis and the traceability analysis of new generation technology.
Results:
On the first day, among the top five microbiota species in abundance, four species were found to be identical in BALF and throat samples. Similarly, on the third day, three microbiota species were found to be identical in abundance in both BALF and throat samples. On the first day, 85.16% of microorganisms originated from the throat, 5.79% from the intestines, and 9.05% were unknown. On the third day, 83.52% of microorganisms came from the throat, 4.67% from the intestines, and 11.81% were unknown. Additionally, when regrouping the 46 patients, the results revealed a significant predominance of throat microorganisms in BALF on both the first and third day. Furthermore, as the disease progressed, the proportion of intestinal flora in BALF increased in patients with enterogenic ARDS.
Conclusions:
In patients with septic ARDS, the main source of lung microbiota is primarily from the throat. Furthermore, the dynamic trend of the microbiota on the first and third day is essentially consistent.It is important to note that the origin of the intestinal flora does not exclude the possibility of its origin from the throat.
Insights
In patients with septic acute respiratory distress syndrome (ARDS), lung microbiota primarily originates from the throat, not the intestines. Intestinal flora
Area of Science:
- Microbiology
- Pulmonology
- Critical Care Medicine
Background:
- Translocation of intestinal flora is linked to lower respiratory tract colonization in septic ARDS.
- This translocation is a critical prognostic factor for patients with ARDS.
Purpose of the Study:
- To investigate the origin and dynamics of lung microbiota in patients with septic ARDS.
- To determine the contribution of throat and intestinal flora to lung microbiota composition.
Main Methods:
- Collected bronchoalveolar lavage fluid (BALF), throat, and anal swabs from ICU patients on days 1 and 3.
- Utilized 16S rRNA sequencing and next-generation technology for microbial analysis.
Main Results:
- On day 1, 85.16% of lung microorganisms originated from the throat, with only 5.79% from the intestines.
- Throat microbiota predominated in BALF on both sampling days, with a slight increase in intestinal flora proportion as ARDS progressed.
- Microbiota composition showed consistency between BALF and throat samples.
Conclusions:
- The primary source of lung microbiota in septic ARDS is the throat.
- While intestinal flora translocation is possible, throat origin is more significant.
- Microbiota dynamics in the lungs are consistent between early and later stages of ARDS.
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