Abstract
The ruminant gastrointestinal tract hosts a complex microbial ecosystem vital for nutrient absorption, with each segment displaying distinct morphological and microbial compositional features compared to monogastric animals. While most studies rely on fecal samples, these fail to capture region-specific variations, limiting insight into microbe-physiology adaptations. In this study, we investigated Elaphodus cephalophus by measuring circular, longitudinal, and mucosal layer thickness across intestinal segments and by profiling bacterial and fungal communities via 16S and its rRNA sequencing. The results found that the stomach had the thickest circular (484.2 μm) and longitudinal (385.2 μm) muscle layers among all gastrointestinal segments. The thickness of the circular and longitudinal muscle layers in the stomach and duodenum showed a highly consistent variation trend (r > 0.74). Bacterial diversity was highest in the stomach and lowest in the ileum; cecal and rectal communities were similar but distinct from those in the duodenum, ileum, and stomach. Firmicutes and Bacteroidota dominated the bacterial phyla. Fungal abundance and diversity peaked in the cecum and were lowest in the stomach; Ascomycota was overall dominant, whereas Basidiomycota was most abundant in the duodenum. This study provides baseline descriptive data on the gastrointestinal muscle layer morphology and gut microbiota of Elaphodus cephalophus, establishing a basis for further study.