Impact of gender and reproductive states on diets and intestinal microbiota in Pratt's leaf-nosed bats (Hipposideros pratti).

Lactation represents a critical evolutionary adaptation in mammals, imposing heightened nutritional demands that drive shifts in foraging behavior and intestinal microbiota to optimize nutrient acquisition. In the sexually dimorphic Pratt's leaf-nosed bat (Hipposideros pratti), males exhibit enlarged transverse lobes posterior to the nasal leaf, a morphological trait may influence echolocation dynamics and dietary niche partitioning. This provides an opportunity to examine dietary and microbiota differences between genders and across various reproductive states. Using high-throughput sequencing of fecal samples from male (HPM), non-lactating female (HPF), and lactating female (HPFL) H. pratti collected in late June, we identified gender- and physiology-linked ecological strategies. While dietary diversity indices showed no significant intergroup differences, compositional analysis revealed distinct prey preferences: both HPM and HPFL predominantly consumed Coleoptera, whereas HPF favored Diptera. Coleoptera's larger size and nutrient profile-rich in leucine, isoleucine, and chitin-likely optimize energy efficiency for HPFL, reducing foraging effort while supplying amino acids critical for mammary gland function and immunity. Gender-based differences were observed in intestinal microbiota diversity, with females demonstrating higher diversity indices compared to males. Males showed a notable abundance of Clostridium sensu stricto 1, a proteolytic genus associated with Coleoptera digestion but linked to inflammatory risks via pathogenic strains. The HPFL group exhibited microbiota enriched in Lactococcus (chitinolytic taxa) and lactation-adapted symbionts: Lachnoclostridium may suppress pro-inflammatory responses via acetate production, while Pseudonocardia may enhance calcium homeostasis and antimicrobial defense. This study advances understanding of host-microbe coadaptation in mitigating life-history trade-offs and highlights ecological drivers of microbiota plasticity in insectivorous bats.