Fig. 3

The alpha and beta diversity between the NSIL, CIN1, CIN2 and CIN3 groups. A Shannon index among four groups. B Simpson index among the four groups. C Total species among the four groups. D Principal-coordinate analysis among the four groups. A letter annotation system is employed to depict statistical relationships between data groups, utilizing letters "A," "B," "AB," "AC," and "C". Unique letters indicate statistically significant differences (P < 0.05), while letter combinations show no significant difference. Specifically, "B" different from "C" and "AC", but not from "AB". "AB" and "AC" are statistically similar, as are "AC" and "C", but "AB" different from "C"