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

Abstract

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.