Fig. 5

Disruptor species are dominant in SIBO samples and correlate with GI symptoms and the inflammatory cytokine IL8. A Principal component analysis (PCA) of absolute microbial abundances at the genus level. Colors indicate non-SIBO (grey) or SIBO (orange) participants as determined by culture. “X” markers indicate samples from non-SIBO participants that contained Lactobacillus. The PC1 axis correlates with total load and the PC2 axis correlates with the abundance of disruptor taxa. B Histogram with overlaid kernel-density estimate of the total microbial loads in samples from SIBO and non-SIBO participants. C Volcano plot indicating the taxa that differed between SIBO and non-SIBO samples. The red dashed line indicates the significance threshold at q = 0.01. D Correlation between PC2 (disruptor axis) and patient-reported symptom scores (on a 0–100 scale). The red dashed line represents significance threshold at q = 0.05. E Correlation between PC2 and patient serum cytokine levels. The red dashed lines represent the significance thresholds at q = 0.05. F Boxplot indicating increasing average total microbial load with increasing number of disruptor taxa with loads greater than 10⁴ rRNA gene copies/mL (not including Lactobacillus). A significant difference between total load in samples with zero disruptor taxa and total load in samples with at least 1 disruptor taxa was observed (P < 0.001). G Percentage of samples from patients with either 0 symptoms or 5–6 symptoms (out of 6 categories) for individuals with varying loads of disruptor taxa (not including Lactobacillus)