Livestock farming affects the airway microbiome of COPD patients

Intensive livestock has been associated with health risks. Residential exposure to its emitted endotoxin was linked to increased species richness in COPD.

Streptococcaceae and Veillonellaceae dominated the samples

Living in a livestock-dense area has been associated with adverse health effects. Especially COPD patients may suffer from complications when living close to livestock. Livestock farm emissions involve excretion of gases, like endotoxin, which could be harmful to health. Mr Warner van Kersen (Utrecht University, the Netherlands) investigated whether livestock affects the airway microbiome of COPD patients¹. In his study, the airway microbiome of COPD patients was compared with the microbiome of healthy controls.

Oropharyngeal swabs were taken from participants (n=283) in a livestock-dense area in the Southeast of the Netherlands. Age, smoking, use of lung medication, and antibiotics discriminated cases (n=99) from healthy controls (n=184). Accordingly, samples were analysed using 16s rRNA sequencing and the DADA2 pipeline. Most samples were dominated by Streptococcaceae and Veillonellaceae. No difference in species richness was observed for cases versus controls. However, an increased species richness was seen for atopy, medium versus low education level, and livestock-emitted endotoxin exposure.

Most of the effects were mainly present in the COPD group. No effect was seen of case control status on microbiome composition either, although a small gender effect was seen. To investigate the stability of the oropharyngeal microbiome over time, randomly selected participants (n=20) were sampled over a course of 3 time points. Individual patterns over time could be distinguished, indicating stable differences between individuals. In conclusion, an increase in species richness in COPD patients could be explained by residential exposure to livestock-emitted endotoxin.