Understanding the Lung-Gut Axis by Modeling the Influence of Welding Fume Inhalation Exposure and Lifestyle on the Profile of Gut Microbiome and Systemic Immune Cells

Details

• Personal Author:
  Antonini J ; Boots T ; Boyce G ; Erdely A ; Eye T ; Kashon M ; Kodali V ; Meighan T ; Roach K ; Roberts J ; Shoeb M ; Zeidler-Erdely P
• Description:
  The gut microbiome has a regulatory influence on various systemic organs, and altered microbiome diversity correlates with various diseases and pathological conditions. The goal of the current work was to profile and correlate the influence of occupational pulmonary exposure (welding fume), lifestyle (high fat diet) and age on the gut microbiome and immune cell phenotype populations in blood, lung lymph nodes and spleen. Male Sprague-Dawley rats were maintained on a regular chow (RG) or high fat (HF) diet for 24 wk. At wk 7, groups of rats maintained on each diet were exposed by inhalation to stainless steel welding fume (WF; 20 mg/m3 x 3 hr/d x 4 d/wk x 5 wk) or filtered air until wk 12, at which time some animals from each group were euthanized. A separate set of rats from each group were allowed to recover from WF exposure until wk 24. At these three time points, immune cells from various systemic locations were profiled using flow cytometry. The DNA from the lower gut feces was extracted and sequenced for 16s. The ratio of firmicutes to bacteroidetes consistently decreased in RG-fed rats and increased for HF-fed rats over the 24 wk period. This was further exacerbated in WF-exposed animals. Random forest classifiers were used to distinctly identify specific alterations at genus and species level for the various treatments. There was no change in total leukocyte number but there was a significant increase in neutrophils recovered from the blood of rats fed the HF vs the RG diet. In the lungs, there was no change in the leukocyte profile between rats with various diets after WF exposure; however, following a recovery period, lung neutrophil and lymphocyte numbers, in addition to percent of pulmonary macrophages, remained significantly elevated in rats maintained on the HF diet. In the spleen and lymph nodes, like the lung, WF exposure did not change the response with various diets. However, as the animals aged, the HF diet caused a significantly elevated B:T lymphocyte ratio in both the spleen and mesenteric lymph nodes compared to the RG diet. The percent of CD8+ T-lymphocytes remained elevated in the lymph nodes of the HF but not RG-fed rats. Taken together, the data suggests that diet by itself causes a dysbiosis in the gut microbiome and immune populations. This effect is irrecoverably exacerbated over time when exposed to a secondary pulmonary insult, such as welding fume. [Description provided by NIOSH]
• Subjects:
  Age Factors Air Pollutants, Occupational Behavior Blood Cells, Cultured Diet Environmental Exposure Hazardous Substances Immune System Laboratories Lung Lymphatic System Macrophages Microbiology Occupational Health Respiratory System Safety Toxicology Welding

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• Keywords:
  Age Factors Bacteria Biological Systems Blood Cells Cell Alteration Cell Cultures Cell Culture Techniques Cytometric Analysis Deoxyribonucleic Acids DNA Exposure Assessment Exposure Levels Fats Gastrointestinal System Immune Reaction Inhalation Laboratory Animals Laboratory Testing Leukocytes Lung Cells Lymph Nodes Lymphocytes Microorganisms Neutrophils Pulmonary System Spleen Disorders Stainless Steel Toxic Fumes Welding Fumes

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• ISSN:
  1096-6080
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  Maryland ; OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  240-241
• Volume:
  168
• Issue:
  1
• NIOSHTIC Number:
  nn:20054965
• Citation:
  Toxicologist 2019 Mar; 168(1):240-241
• CAS Registry Number:
  Stainless Steel (CAS RN 12597-68-1)
• Federal Fiscal Year:
  2019
• NORA Priority Area:
  Construction
• Peer Reviewed:
  False
• Source Full Name:
  The Toxicologist. Society of Toxicology 58th Annual Meeting and ToxExpo, March 10-14, 2019, Baltimore, Maryland
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:6f0a51d54737b1200f5294af9a4afdc5ed6516d24c2e176813531d015947a030c0615c6b4aa125fb1f2b528c3a8fbaaf768079ed029ef56ded3a7851b12bad5c
• Download URL:
  https://stacks.cdc.gov/view/cdc/217371/cdc_217371_DS1.pdf
• File Type:
  [PDF - 907.95 KB ]