The Spearmen rank correlation coefficient was calculated to
assess correlation between the agar well diffusion assay and the
broth co-culture for both C. difficile and C. perfringens. The unpaired
T-test was used to compare the pH of inhibitory and non-inhibitory
probiotic supernatants if the means and standard deviations were
not significantly different, and a Gaussian distribution was found
using the Kolgorov and Smirnoff test (supernatant harvested at
12 h, 24 h and 36 h). The ManneWhitney test was used to compare
the pH of inhibitory and non-inhibitory probiotic supernatants of
the remaining time points to account for a non-normal distribution
and significant differences in standard deviation. P < 0.05 was
considered significant in all calculations.