Gut microbiota composition and diversity in active and hibernating Nyctalus noctula from the bat rehabilitation center

Bats play an important role in One Health, being the hosts to various microbes. Their ability to fly, relatively long lifespan, and synanthropic behavior contribute to spreading microorganisms to people and domestic animals over long distances and over long time periods. Despite all the above, the gut microbiota of synanthropic bats is still underinvestigated, especially its shifts associated with different physiological states of bats, such as hibernation. In this study, we compared gut microbiota composition and diversity of active and hibernating Nyctalus noctula from the bat rehabilitation center using high-throughput 16S rRNA sequencing data (only reverse reads, as the forward reads did not pass quality check). According to the differential abundance analysis, there were two taxa significantly more abundant (P<0.0001) in hibernating bats (unclassified Peptostreptococcaceae and Romboutsia) and four significantly dominant (P<0.0001) taxa in active bats (unclassified Enterococcaceae, Enterococcus, unclassified Bacilli, and Lactococcus). Also, there were significantly higher values of Shannon (P=0.0016) and Simpson (P=0.0066) alpha diversity in active bats, although there were no differences (P=0.2146) in evenness according to the comparison of the Pielou index. These results are supported by the gut bacterial beta diversity analysis, where there were also significant differences (P<0.0001) between active and hibernating bats. These results correspond to previous studies, where gut bacterial diversity was altered in hibernating animals. Also, this study provides insights into the compositional shifts of the gut microbiota of bats that, in combination with future studies of physiological alterations in bats organisms, such as immune responses and gut-brain axis, could provide valuable insights into host-microbiome interactions.