Diversity and Richness Estimators (median values).

Microbial diversity and richness indices. Median values of bacterial community richness and diversity calculated for samples groups are displayed. The observed number of OTUs was highest for the rectal samples, compared to appendix. Among the rectal samples, samples from subjects with perforated appendicitis had the highest number of observed OTUs (478 OTUs), compared to non-perforated appendicitis (411 OTUs) and subjects with normal appendix (220 OTUs). Similarly, with respect to the appendix samples, samples from subjects with perforated appendicitis had the highest number of observed OTUS (344 OTUs), compared to non-perforated appendicitis and normal appendix (228 and 237 OTUs, respectively). This suggests that severity in diagnosis of appendicitis seems to be characterized by a higher number of observed OTUs, compared to normal appendices. The rectal samples from patients with appendicitis also had a larger number of OTUs than samples from patients with normal appendices. Rectal samples from patients with perforated appendicitis had a larger number of OTUs than samples from patients with non-perforating appendicitis. The Chao1 and ACE richness estimators also showed that sample richness was higher for rectal samples compared to appendix samples. Chao1 and ACE richness estimators also showed greater richness for rectal samples from patients with appendicitis than samples from patients with normal appendices. The richness estimators for the rectal samples were higher for patients with perforating appendicitis than for patients with non-perforating appendicitis. The Shannon diversity index displayed a similar trend with rectal samples displaying a higher diversity compared to appendix samples, and with diversity was highest for samples from patients with the most severe form of appendicitis, for both rectal and appendix samples.