Alpha Diversity
Alpha diversity, measured by the Observed species, Chao1, Shannon, Simpson, ACE and Pielou index, was described in the methods. The indices of bacterial alpha diversity were listed in Table 3. The Observed species, Chao1 and ACE (which calculate alpha diversity measures of richness) were much higher in the moderate/severe cohort (Figure 1A, Observed species,P =0.044; Figure 1B, Chao1, P = 0.023; Figure 1C, ACE, P = 0.010). The Shannon index (Figure 1D, P = 0.015) and Simpson (Figure 1E, P = 0.024) illustrated the bacterial diversity was markedly lower in the mild symptoms patients. However, the Pielou index (Figure 1F, P = 0.064) indicated that there was no significant difference in bacterial evenness between the two groups.
The Observed species, Chao1, ACE, and Shannon’s Indices were significantly correlated to OABSS of the overall participant population (Figure 2A, B, C, D), and Simpson’s Index (Figure 2E) approached significance for this trend; however, there was no correlation with Pielou’s values (Figure 2F). Therefore, OAB scores correlated with richness, but not evenness.