# Temporal Dynamics of Fecal Microbiome and Short-Chain Fatty Acids in Sows from Early Pregnancy to Weaning

## TL;DR

This study tracks gut microbes and fatty acids in sows from pregnancy to weaning, showing how diet and microbes influence weight and health.

## Contribution

The study reveals dynamic shifts in gut microbiota and SCFAs across gestation and lactation in sows, linking them to maternal weight changes.

## Key findings

- High-fiber diets during gestation influence gut microbiota composition in sows.
- Prevotella species dominate during pregnancy, while Eubacterium and Lachnospiraceae groups dominate during lactation.
- Fecal propionate levels negatively correlate with body weight change, while acetate positively correlates.

## Abstract

The gut microbiota and its metabolites, particularly short-chain fatty acids (SCFAs), play crucial roles in maternal metabolism and health during pregnancy. However, the dynamic changes in fecal microbiota and SCFAs across the entire reproductive cycle—from pregnancy to weaning—in sows remain poorly understood. In this study, we systematically characterized the gut microbial composition and SCFA profiles of 25 sows at four key time points: early pregnancy (T1), late pregnancy (T2), early lactation (T3), and weaning (T4). We found that high-fiber diets during gestation may influence the composition of the gut microbiota. During pregnancy, Prevotella species are the predominant microbes in the sow gut, while Eubacterium_coprostanoligenes_group and Lachnospiraceae_NK4A136_group became dominant in the microbiota during lactation. Notably, fecal propionate levels were negatively correlated with body weight change, while acetate showed a positive correlation. Additionally, certain Prevotella species were linked to arachidonic acid metabolism and SCFA production. These findings highlight the importance of the gut microbiota and SCFAs during the gestation-to-weaning period in sows, and provide a scientific basis for future microbiome-targeted interventions aimed at improving maternal health.

Although age-related changes in the gut microbiome of pigs have been extensively studied, the dynamic patterns of fecal microbiota and SCFAs during the gestation-to-weaning period in sows remain poorly characterized. We aim to characterize the changes in fecal microbiota and SCFAs from pregnancy to weaning, and to investigate their associations with maternal weight gain during gestation. We systematically collected 100 fecal samples at four time points (day 30 of pregnancy (T1), 1–2 days before delivery (T2), day 10 after delivery (T3), and day 21 of weaning stage (T3)), and measured the body weight of sows at T1 (132 kg ± 10.8) and T2 (205 kg ± 12.1). The primary nutrient components of the diets during the gestation and lactation periods are summarized. All fecal samples were subjected to 16S rRNA gene sequencing. We found that a high proportion of crude fiber (bran) is a key feature of the gestation diet, which may affect enterotype shifts and gut microbial composition. Sows fed a high-fiber diet showed significant enrichment of gut microbiota, including genera such as Prevotellaceae_UCG-003, Prevotellaceae_NK3B31_group, and Prevotella_9 during the gestational period (LDA score > 2). Moreover, Eubacterium_coprostanoligenes_group (average relative abundance: 5.5%) and Lachnospiraceae_NK4A136_group (average relative abundance: 2.5%) were the dominant bacteria during the lactation stage. Fecal propionate and butyrate levels were lowest in late gestation, and propionate negatively and acetate positively correlated with body weight change (p < 0.05). Additionally, certain Prevotella taxa were associated with arachidonic acid metabolism and acetate production (p < 0.05). Our study identified key microbial communities across four stages from gestation to weaning and revealed that dietary patterns can shape the sow gut microbiota. Furthermore, we observed significant correlations between SCFAs and body weight change during pregnancy. These findings provide a scientific basis and theoretical support for future strategies aimed at modulating gut microbiota and targeting SCFAs to improve maternal health and productivity throughout the gestation-to-weaning period.