Functional fiber supplementation improves reproductive performance in sows by reshaping gut microbial functions...

Dietary fiber has been reported to regulate reproductive performance, yet its role in microbial functions during late gestation remains unclear. This study aimed to explore the effect of functional fiber supplementation on the gut microbiome and reproductive performance of sows in late gestation, as well as the potential underlying mechanisms.

A subset of sows from a large-scale feeding trial was selected and assigned to either a control diet (CON, n = 501) or a functional fiber-supplemented diet (DF, n = 409). Relevant indicators including reproductive performance, plasma physiological parameters, and gut microbiome were detected and analyzed.

Compared with the CON group, DF treatment significantly increased the numbers of total born, born alive and healthy piglets (P < 0.05). Sows in the DF group exhibited higher plasma IL-10 levels, lower plasma reactive oxygen species, reduced insulin resistance and improved insulin sensitivity (higher HOMA-IS) (P < 0.05). Microbiome analyses revealed enrichment of NK4A214_group associated taxa and suppression of Treponema-dominated communities. Further functional profiling showed increased antigen processing and presentation, estrogen signaling pathway, IL-17 signaling pathway, progesterone-mediated oocyte maturation and Th17 cell differentiation pathways, alongside decreased biofilm formation - Pseudomonas aeruginosa pathways. These microbial changes were associated with improved reproductive performance.

Taken together, these results indicate that functional fiber improves reproductive outcomes by functionally remodeling the gut microbiome toward enhanced immune regulation and metabolic homeostasis during late gestation, providing a theoretical basis for the application of functional fiber in late gestation sow feeding.