Table 2

Three gut bacterial community clusters in the asthmatic group differ in several clinical and inflammatory features (median values unless otherwise noted)

FeatureCluster 1 (n=8)Cluster 2 (n=3)Cluster 3 (n=13)P values
FEV1 (L)2.823.92.60.03
FEV1 (%predicted)99.586%79%
FVC (L)3.45.354.220.04
PC20 (mg/mL)0.760.370.38
PD20 (µg)209.59798
Bronchodilator reversibility (L)
Bronchodilator reversibility (%)6711.5
BMI (kg/m2)35.226.625
Obese (BMI≥30) (%)6333150.08
Adult-onset asthma305
Inhaled steroid use4 (50%)1 (33%)9 (69%)
Total caloric intake (daily)187615791878
Total carbohydrate (g)(daily)261160213
Total protein (g) (daily)655576
Total fat (g) (daily)656178
Fruit total (daily equivalent or eq.)2.1 cup eq0.9 cup eq1.4 cup eq0.03
Shannon index3.212.863.710.001
Blood sRAGE (pg/mL)84.9125.994.70.09
Sputum eosinophils (%)01.20.4
Sputum IL-8 (pg/mL)661.2259613780.09
Sputum IL1-β (pg/mL)11.0 (0.6–314.6)99.3 (82–138)31.3 (0–2252)0.10
Sputum TNF-α (pg/mL)3.1 (0–45)32.8 (10–35)129.6 (0–426)
Top taxa Blautia (OTU0026) 8.8% Prevotella (OTU0017) 36.9% Roseburia (OTU0024) 6.0%
Mean relative abundance (%) Bacteroides (OTU0015) 8.6%Prevotellaceae (unclassified) (OTU0088) 7.3% Bacteroides (OTU0015) 5.56%
Bifidobacterium (OTU0028) 6.3% Roseburia (OTU0024) 3.3% Faecalibacterium (OTU0022) 5.5%
Prevotella (OTU0017) 5.6% Faecalibacterium (OTU0022) 3.2% Ruminococcus (OTU0034) 4.3%
Megasphaera (OTU0048) 3.8% Prevotella (OTU0162) 2.7% Blautia (OTU0026) 3.6%
Anae rostipes (OTU0037) 3.0% Bifidobacterium (OTU0028) 2.1% Anaerostipes (OTU0037) 3.6%
  • Only p values ≤0.10 shown, otherwise not significant between clusters.

  • ACQ-7, Asthma Control Questionnaire-7; ACT, Asthma Control Test;BMI, body mass index; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; IL, interleukin; OTU, operational taxonomic unit; PC20 or PD20, provocative concentration or dose resulting in 20% decline in FEV1; TNF, tumour necrosis factor; sRAGE, soluble receptor for advanced glycation end-products.