Characterization of fungal communities transmitted from sow to piglet.

Understanding the composition of the healthy gut microbiota in neonatal piglets is critical during the early stages of life, particularly in the context of environmental change and immune development. The gut microbiota of newborn piglets is closely related to that of their sows. However, research on the characteristics of gut microbiota transmitted from mother to offspring has primarily focused on gut bacteria, with comparatively less attention given to gut fungi. In this study, vaginal and fecal samples were collected from 12 sows, along with fecal samples from 12 newborn piglets. The internal transcribed spacer 1 (ITS1) rRNA gene was sequenced to characterize the gut fungal communities. The results indicated that sow feces exhibited the greatest diversity of fungal communities, followed by piglet feces, while the least diverse fungal communities were found in sow vaginas. Significant differences in beta diversity of fungal communities were observed among the three groups, with clear segregation of the fungal communities. The composition of gut fungal communities in sow vaginas and feces, as well as in piglet feces, was dominated by Ascomycota and Basidiomycota. Fast expectation-maximization microbial source tracking (FEAST) analysis showed that 47.1 and 4.2% of the fungal communities in piglet feces originated from sow feces and sow vagina, respectively, while the remaining 48.7% were from unknown sources. At both the genus and species levels, six fungal genera or species were identified among the top fungal taxa across the three groups, suggesting that they may represent core dominant fungi transmitted from sows to piglets. Functional predictions for all three groups of fungal communities were associated with animal pathogens. These findings contribute to our understanding of the microbiological composition of the gut during early life and highlight the importance of fungal communities. IMPORTANCE: Our results highlight the association between sow fecal and piglet fecal fungal communities. The findings indicate significant differences among the fungal communities in maternal feces, maternal vagina, and piglet feces. However, the fungal communities in maternal feces and piglet feces were more similar to each other than to those found in the maternal vagina, suggesting potential vertical transmission to newborn piglets. This study describes the structure and composition of fungal communities in maternal feces, maternal vagina, and piglet feces, providing insights into the gut microbial composition during early life.