Heat stress (HS) disrupts intestinal microbiota, glycolipid metabolism, and hepatic mitochondrial function in late gestational mice. Baicalin (BAI), a Chinese herbal medicine known for its heat-clearing and anti-inflammatory properties, has shown promise in modulating intestinal microecology and mitigating inflammation in various organs. This study investigates whether baicalin attenuates HS-induced intestinal microbial dysbiosis and liver damage in pregnant mice during late gestation. Twenty-four pregnant mice were randomly assigned to four groups, including thermoneutral (TN) (24 ± 1 ℃), HS (35 ± 1 ℃), HS+BAI200 (oral gavaged with 200 mg/kg BW of BAI), and HS+BAI400 (oral gavaged with 400 mg/kg BW of BAI). 400 mg/kg BAI treatment markedly decreased the rectal temperature and increased fetal weight in HS pregnant mice. Furthermore, 400 mg/kg BAI administration effectively ameliorated HS-induced hepatic damage and lipid disorders, reducing HSP70, AST, and ALT levels while increasing TG concentration. Notably, it activated a network of genes involved in lipid synthesis, including fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), and oxidation, such as peroxisome proliferator-activated receptor alpha (PPARα), carnitine palmityl transferase 1 beta (CPT1β). Moreover, BAI intervention restored the intestinal morphology and barrier function, evidenced by increased intestinal villus height, the ratio of villus height to crypt depth, and colonic goblet cells numbers. 400 mg/kg of BAI treatment up-regulated the expression of tight junction proteins, such as claudin-1 and Zonula Occludens-1 (ZO-1), in the jejunum and ileum, counteracting HS-induced downregulation. High-throughput sequencing showed that BAI treatment altered cecal microbial composition, increasing the relative abundance of beneficial Bacteroidota and decreasing Deferribacterota, Turicibacter, and Akkermansia. Spearman's correlation analysis highlighted significant correlations between differential cecal microbiota and physiological indexes. In conclusion, BAI administration alleviated adverse impacts in heat-exposed mice during late gestation, improving maternal physiological parameters, and ameliorating hepatic damage with altered cecal microbial composition. The findings suggest that BAI may regulate the gut-liver axis by modulating intestinal morphology, microecology, and hepatic function.

In this paper, we investigated the effects of a diet with a moderate reduction of dietary crude protein (CP) level, supplemented with five crystalline amino acids (Lys, Met, Thr, Try, and Val), on the growth, metabolism, and fecal microbiota of Sushan nursery pigs. Seventy Sushan nursery pigs with an average body weight of 19.56 ± 0.24 kg were randomly allocated to two experimental dietary treatments: 18% CP (high protein; group HP), and 15% CP (low protein; group LP). We found that the differences in the two diets had no significant effect on the growth performance of Sushan nursery pigs. Nursery pigs on the 15% CP diet showed significantly improved protein, amino acid, and energy utilization. Furthermore, the LP diet cloud optimized the gut microflora composition to some extent. The functional structure of bacterial communities implied improved metabolic capabilities in group LP. Additionally, correlation analysis between fecal microbiota and metabolic profiles confirmed that the increase of beneficial bacterial in the feces was beneficial to the health and metabolism of the nursery pigs. In conclusion, a moderate reduction in the dietary protein level can improve growth and metabolism due to the improvement of intestinal microbiota in Sushan nursery pigs. This finding could provide useful reference data for the application of a different nutrition strategy in indigenous pig production.