Partial least squares discriminant analysis (PLS-DA) loading plot based on the relative abundance of bacterial taxa determined by 454 sequence analysis of the microbiota of sputum from patients reporting current stability (green circle) and sputum from patients reporting a current exacerbation (blue circle). PLS1 (R
X = 0.169, R
Y = 0.232, Q
2 = 0.0287) and PLS 2 (R
X = 0.107, R
Y = 0.124, Q
2 = 0.0601) are given. The solid ellipse indicates Hotellings T
2 range, at 95% confidence. Patient samples derived from current exacerbators contained within the dashed ellipse, and including BX6 are deemed to be the major outliers, having a microbial community composition which is dissimilar to the stable and a small proportion of exacerbating patients. Some sample labels have been removed for ease of interpretation.