The gut microbiota plays a critical role in the growth, development, nutritional digestion, and overall health of chickens. Furthermore, certain probiotics isolated from poultry intestines have demonstrated the potential to enhance immune function and production performance in chickens. To investigate the differences in gut microbiota among chickens from various geographical environments and different breeds of broiler and laying hens, we conducted 16S rRNA sequencing on the fecal microbiota of 140 Chinese native chickens and ten Roman layers. In addition, we isolated and screened the potential probiotics to examine their biological characteristics, genome profiles, and functionality in animals. Our findings revealed the significant variations in gut microbiota composition and structure between Tibetan chickens (ZJ), which reside in high-altitude regions, and Meihua chickens (MH) and Xuhai chickens (XH), which inhabit low-altitude regions. Specifically, Cupriavidus and Candidatus_Bacilloplasma were identified as unique microbial communities in high and low altitudes, respectively. Notably, among regions with similar altitudes, Luning chickens (LN) exhibited the lowest α diversity, accompanied by a remarkably high relative abundance of Firmicutes and Lactobacillus. Conversely, Wugu chickens (WGs) and Yaoshan chickens (YSs) displayed similar gut microbiota profiles. Furthermore, distinctive gut microbiota patterns were observed between the different breeds of broilers and laying hens. Commercial Roman layers (LMs) exhibited significantly lower alpha diversity compared to native chickens, and broilers and laying hens predominantly harbored Firmicutes, Bacteroidota, and Proteobacteria. Of particular interest, the probiotics Lactobacillus agilis MH1 and Lactobacillus salivarius ZJ1, derived from chicken feces, exhibited favorable genomic profiles, and demonstrated anti-colitis effects and immunomodulatory functions. These findings provide a crucial theoretical foundation for native chicken research and offer insights for the future development and formulation of chicken-derived probiotics.

The harsh conditions of the Qinghai–Tibet Plateau pose significant physiological challenges to local fauna, often resulting in gastrointestinal disorders. However, Tibetan pigs have exhibited remarkable adaptability to the high-altitude stress of the Tibetan Plateau, a phenomenon that remains not fully understood in terms of their gastrointestinal microbiota. This study collected 57 gastrointestinal tract samples from Tibetan pigs (n = 6) and plain black pigs (n = 6) with comparable genetic backgrounds. Samples from the stomach, jejunum, cecum, colon, and rectum, underwent comprehensive metagenomic analysis to elucidate the gut microbiota-related adaptive mechanisms in Tibetan pigs to the extreme high-altitude environment. A predominance of Pseudomonadota was observed within gut microbiome of Tibetan pigs. Significant differences in the microbial composition were also identified across the tested gastrointestinal segments, with 18 genera and 141 species exhibiting differential abundance. Genera such as Bifidobacterium, Megasphaera, Fusobacterium, and Mitsuokella were significantly more abundant in Tibetan pigs than in their lowland counterparts, suggesting specialized adaptations. Network analysis found greater complexity and modularity in the microbiota of Tibetan pigs compared to black pigs, indicating enhanced ecological stability and adaptability. Functional analysis revealed that the Tibetan pig microbiota was particularly enriched with bacterial species involved in metabolic pathways for propionate and butyrate, key short-chain fatty acids that support energy provision under low-oxygen conditions. The enzymatic profiles of Tibetan pigs, characterized by elevated levels of 4-hydroxybutyrate dehydrogenase and glutaconyl-CoA decarboxylase, highlighted a robust fatty acid metabolism and enhanced tricarboxylic acid cycle activity. In contrast, the gut microbiome of plain black pigs showed a reliance on the succinate pathway, with a reduced butyrate metabolism and lower metabolic flexibility. Taken together, these results demonstrate the crucial role of the gastrointestinal microbiota in the adaptation of Tibetan pigs to high-altitude environments by optimizing carbohydrate metabolism and short-chain fatty acid production for efficient energy utilization. This study not only highlights the metabolic benefits conferred by the gut microbiota of Tibetan pigs in extreme environments, but also advances our understanding of the adaptive gastrointestinal mechanisms in plateau-dwelling animals. These insights lay the foundation for exploring metabolic interventions to support health and performance in high-altitude conditions.

Meat quality is influenced by genetic, nutritional, and microbial factors, with increasing attention on the role of gut-derived metabolites. In this study, we conducted untargeted metabolomics of 10 gut tract sites and RNA sequencing (RNA-seq) of longissimus dorsi muscles in Meigu goats and Liangshan black sheep raised under standardized conditions. Results showed that goat muscle contained significantly higher levels of essential amino acids (e.g., methionine) and specific fatty acids (e.g., C18:3_N6, C20:4_N6), suggesting improved nutritional quality. Transcriptomic analysis identified 3133 differentially expressed genes (DEGs), among which ADCY1 and SLC38A4 were upregulated in goats and strongly associated with meat traits. Using integrative correlation analysis, we uncovered 17 genes and 19 gut metabolites that were significantly correlated with more than eight meat quality parameters across multiple gut sites. Notably, these metabolites included bioactive compounds such as L-tyrosine ethyl ester and pelargonidin 3-O-glucoside, while genes were enriched in pathways related to amino acid transport, cAMP signaling, and muscle development. Together, these findings highlight a potential gut–muscle axis involving metabolite-mediated modulation of muscle gene expression, contributing to breed-specific differences in meat composition and quality. This study provides a valuable framework for improving ruminant meat quality through integrative multi-omics analysis.

Musk, a dried secretion from the sac gland near the urethral foramen of adult male forest musk deer (Moschus berezovskii), has significant economic value and is extensively utilized as a valuable component in traditional Chinese medicine. In the practice of forest musk deer breeding, musk with different colors and varying moisture contents is observed during the season when the musk reaches maturity. For many years, researchers have focused mainly on musk composition and symbiotic bacteria. However, the influence of fecal fungi on the production and quality of musk is unknown. In this study, internal transcribed spacer (ITS) analysis was employed to explore the relationships between the fungal composition of musk deer fecal and the quality and production of musk produced by each individual. The results indicate that fungal genera known to cause diseases, such as Colletotrichum and Apiotrichum, are prevalent in the feces of musk deer that produce abnormal musk. Furthermore, the fecal microbiota health index (GMHI) is lower and the intestinal microbiota dysbiosis index (MDI) is greater in musk deer producing white musk than in normal individuals. Additionally, by correlating musk production with fecal fungi, we also found that Dolichousnea and Scolecoleotia were significantly positively correlated with musk production. Moreover, Metschnikowia, Ganodermataceae_gen_Incertae_sedis, Hypoxylon, Neovaginatispora, Didymella, Dothidea, and Trichoderma were negatively correlated with musk production. This study is the first to investigate gut fungi in relation to musk production/quality, establish gut health and fungal dysbiosis links, and identify candidate fungi tightly associated with musk traits. This exploratory approach is critical for exploring uncharted territories like gut fungi in musk deer and musk traits.