Effects of an Antibiotic Alternative Additive on Growth Performance, Intestinal Histomorphology, Multi-Omics...

The ban on antibiotic growth promoters has created an urgent need for effective alternatives to maintain intestinal health and production performance. This exploratory study evaluated the effects of a novel antibiotic alternative additive at graded inclusion levels (control, 1%, 3%, 5%) on growth performance, intestinal histomorphology, gut microbiome ecology, and host metabolome in Tibetan pigs (n = 40). Forty Tibetan pigs were randomly assigned to four dietary treatment groups for a 21-day feeding trial. Growth performance, intestinal histopathology, metatranscriptomic sequencing (bacteria, viruses, fungi), and untargeted metabolomics were analyzed. Tibetan pigs fed the 3% additive diet exhibited the highest numerical average daily gain (0.197 vs. 0.148 kg/d, +33.1%) and lowest feed conversion ratio (2.61 vs. 3.59, -27.3%), with overall treatment effects reaching statistical significance (ADG: p = 0.027; FCR: p = 0.023). Metatranscriptomic profiling revealed fundamentally distinct microbial communities between the duodenum and colon. Multi-omics integration identified 79 significant microbiome-pathology associations in the duodenum and 38 in the colon, with SCFA-producing bacteria positively correlated with mucosal architectural parameters. The multi-omics network revealed a core-periphery architecture with Eubacterium, Lactobacillus, and Escherichia as keystone hubs. Dietary supplementation at 3% showed the most favorable effects on growth performance and metabolic modulation without compromising intestinal structural integrity, supporting its potential as a viable antibiotic alternative.