# Maternal supplementation of functional fiber improves reproduction performance by modulating gut microbiota during pregnancy

## TL;DR

Adding functional fiber to pregnant sows' diets improves their reproductive outcomes by changing gut bacteria and increasing healthy piglet births.

## Contribution

This study demonstrates that functional fiber supplementation during pregnancy enhances gut microbiota stability and reproductive performance in sows.

## Key findings

- Functional fiber increased total born, healthy piglets, and litter birth weight while reducing intrauterine growth retardation.
- The DF group showed enhanced gut microbial diversity and network stability compared to the control group.
- The NK4A214_group was positively correlated with healthy piglet numbers and bile acid metabolites like GCDCA.

## Abstract

This study aimed to investigate the impacts of gestation diets supplemented with functional fiber on performance and gut microbiome of sows.

A total of 1,000 healthy sows of comparable body weight (DanBred Landrace × DanBred Yorkshire, parities 1–2) were selected and randomly assigned to two dietary treatment groups after artificial insemination: a control group (CON, composed of beet pulp and barley as fiber sources) and a dietary fiber group [DF, supplemented with 1% functional fiber, consisted of 85.7% resistant starch (Hangzhou, China) and 14.3% guar gum (Yunzhou, China)].

DF treatment increased the numbers of total born, healthy piglets and litter birth weight (p < 0.05), whereas markedly decreased (p < 0.05) the number of intrauterine growth retardation (IUGR) compared with the CON group. Gut microbiota compositions underwent significant changes across gestation stages. Gut microbial diversity in DF group exhibited enhanced stability and resilience. Co-occurrence network analysis further demonstrated that the DF group maintained higher network stability at both G30 d and G109 d, with topological parameters consistently supporting these findings. In addition, Treponema showed a significant increase in the CON group starting from G30 d and persisted into late pregnancy (p < 0.05), whereas NK4A214_group showed a significant increase in the DF group at G30 d, G109 d and L14 d (p < 0.05). The abundance of Treponema was negatively correlated with the numbers of total born (p < 0.01) and healthy piglets (p < 0.05). NK4A214_group showed a positive correlated with the numbers of total born and born alive (p < 0.05), and a highly significant positive correlated with the numbers of healthy piglets (p < 0.01). Fecal non-targeted metabolomics revealed that differential metabolites were significantly enriched in bile secretion and prolactin signaling pathways, with a series of bile acids, including hyodeoxycholic acid (HDCA), chenodeoxycholic acid (CDCA), glycochenodeoxycholic acid (GCDCA), cholic acid (CA), lithocholic acid (LCA), ursodeoxycholic acid (UDCA) and γ-muricholic acid (γ-MCA), were significantly increased in the DF group. And the abundance of NK4A214 was positively correlated with GCDCA (p < 0.05) and progesterone (p < 0.01).

The abundance of Oscillospiraceae, especially NK4A214_group of DF sows during gestation, may improve the numbers of total born and healthy piglets, with GCDCA likely playing a significant role in this process.