A lagging recovery: the delayed restoration of gut microbial diversity in Rhinolophus sinicus post-hibernation

Hibernation enables animals to survive extreme environments, yet gut microbiome dynamics across the full hibernation cycle remain poorly understood, particularly in chiropterans with unique physiological traits. This study aimed to precisely characterize seasonal microbial succession in wild Rhinolophus sinicus using 16S rRNA gene sequencing across 6 physiological stages, with a focus on taxonomic and functional shifts linked to hibernation-associated fasting and post-hibernation activity. Alpha diversity followed a pronounced V-shaped trajectory, declining during hibernation and recovering only gradually—remaining suppressed in the early active stage and rebounding markedly by mid–late active stages. Beta diversity revealed a clear separation between hibernation and active phases, with physiological stage explaining 34.9% of community variation. At the phylum level, Pseudomonadota was the dominant taxon during hibernation, while Bacillota became the most abundant phylum in the active period. At the genus level, Yokenella was the core genus in the hibernation stage, and Lactococcus was the dominant genus in the active period. Functional predictions showed enrichment of lipid and amino acid metabolism during hibernation, supporting energy maintenance under fasting, while active-phase microbiota were oriented toward carbohydrate metabolism, matching increased energy demands. Our findings demonstrate that hibernation drives directional restructuring of the gut microbiota in R. sinicus, offering new insights into microecological strategies underlying bat survival under extreme conditions.