# Multi-Omics Insights into the Impact of Fermented Wheat Bran-Soybean Meal-Broussonetia papyrifera Mixture Substance on the Gut Microbiota of Late Gestation Sows In Vitro

## TL;DR

This study shows that fermenting a mix of wheat bran, soybean meal, and Broussonetia papyrifera improves gut microbiota and short-chain fatty acid production in late-gestation sows.

## Contribution

The novel contribution is demonstrating how fermentation of a specific plant-based feed mixture modulates gut microbiota and enhances bioactive metabolite production in late-gestation sows.

## Key findings

- Fermentation reduced dietary fiber and increased crude protein and amino acids.
- FMS enriched organic acids, amino acids, and short peptides, enhancing gut microbiota.
- Fermentation increased Limosilactobacillus and Lactobacillus abundance and short-chain fatty acid production.

## Abstract

Strategic nutritional interventions during the late gestational period constitute a critical determinant for optimizing maternal-fetal health outcomes. Fermented diets are increasingly recognized as a promising dietary strategy for gestating sows. This in vitro fermentation study demonstrates that bacterial-enzymatic co-fermentation of a wheat bran–soybean meal–Broussonetia papyrifera mixed substrate enhances microbial substrate utilization and increases short-chain fatty acid production through the following mechanisms: (1) reduction in dietary fiber content and (2) enrichment of flavor compounds and bioactive metabolites. These findings provide a foundation for developing dietary strategies to improve maternal health during late gestation.

Comprehensive maternal nutritional interventions, particularly during late gestation, enhance perinatal outcomes and support long-term maternal-offspring health by modulating the microbiota. Fermented diets are recommended for inclusion in dietary guidelines during gestation, yet the specific metabolites after fermentation and their specific regulatory effects on gut microbiota during late gestation remain unclear. This study investigates the functional benefits of a fermented wheat bran–soybean meal–Broussonetia papyrifera mixed substrate (FMS) on the late-gestation gut microbiota using an in vitro fermentation model. The FMS was first fermented for 72 h with bacterial and enzymatic agents (2% v/v), then anaerobically incubated with fecal inocula from Jinhua pigs. Fermentation significantly enhanced nutritional profiles, increasing crude protein and amino acids while reducing fiber components (neutral detergent fiber, acid detergent fiber, and non-starch polysaccharide, p < 0.05). Metabolome analysis revealed a significant increase in the abundance of organic acids, amino acids, and short peptides in FMS, along with the enrichment of D-amino acid and sphingolipid pathways (p < 0.05). In addition, FMS significantly increased the abundance of Limosilactobacillus and Lactobacillus, as well as short-chain fatty acids production, compared to the unfermented group (p < 0.05). These findings demonstrate that fermentation pretreatment reduces fiber components, enhances flavor compounds and bioactive metabolites, thereby optimizing microbial utilization and increasing short-chain fatty acids production.