Temporal response patterns of swine gut microbiota to arabinoxylan

Arabinoxylan (AX) is a major dietary fiber that is depolymerized and fermented by gut microbiota to produce short-chain fatty acids (SCFAs), thereby influencing host energy harvest and gut homeostasis. However, it remains unclear how baseline differences in the gut microbiota among individuals shape the temporal dynamics and metabolic outcomes of AX fermentation.

This study aimed to investigate how preexisting variation in swine gut microbial ecosystems affects the utilization of AX.

We employed an in vitro fermentation model inoculated with fecal microbiota from two genetically divergent pig breeds: Jinhua (JH, a native breed) and Duroc × Landrace × Yorkshire (DLY, a commercial crossbred). Microbial succession was characterized by 16S rRNA gene amplicon sequencing coupled with time-series clustering, co-occurrence network reconstruction, and co-abundance response groups (CARGs) analysis. We used PICRUSt2 to predict the functional potential of the microbial communities and assessed fermentation outputs by measuring pH, SCFA concentrations, and key enzyme activities.

JH and DLY maintained distinct baseline community structures and displayed pronounced, stage-dependent succession during AX fermentation, with most structural changes occurring within 24 h. The JH microbiota consistently exhibited higher α-diversity than DLY, driven by enrichment of fiber-degrading bacteria. Functional prediction identified the pentose and glucuronate interconversion pathways as key functional differences between the two microbial ecosystems. CARG analysis revealed a consortium of Limosilactobacillus species (L. mucosae, L. balticus, L. agrestimuris) and Lactobacillus delbrueckii subsp. jakobsenii as keystone taxa positively correlated with acetate production.

Our findings elucidate temporal ecological principles governing AX metabolism by distinct swine gut microbial communities and identify key microbial players, offering a basis for developing microbiome-targeted nutritional strategies.