Fig. 1

Diversity indexes of the bacterial communities of the HF. (a) Alpha-diversity per samples from the lower, middle, and upper HF regions, as depicted by the Shannon’s alpha-diversity. (b) Species richness and (c) Pielou’s eveness index. Mean ± SEM, from 3 independent donors (n = 3 HFs per region), D’Agostino & Pearson omnibus normality test, no Gaussian distribution, Kruskal-Wallis test (p = 0.0982 [Shannon diversity], p < 0.001 [species richness] and p = 0.9492 [Pielou’s evenness]), Tukey’s multiple comparisons test, *p < 0.05, ***p < 0.01, and Mann–Whitney test, ##p < 0.01 and ###p < 0.001