Ferulic acid (FA) and vanillic acid (VA) are considered as major phenolic metabolites of cyanidin 3-glucoside, a polyphenol that widely exists in plants that possess a protective effect against oxidative stress and inflammation in our previous study. This study aimed to investigate the effect of FA and VA on inflammation, gut barrier function, and growth performance in a weaned piglet model challenged with lipopolysaccharide (LPS). Thirty-six piglets (PIC 337 × C48, 28 d of age) were randomly allocated into 3 treatments with 6 replicate pens (2 piglets per pen). They were fed with a basal diet or a diet containing 4,000 mg/kg of FA or VA. Dietary supplementation of VA significantly increased average daily gain (ADG) (P < 0.05). Both FA and VA decreased serum levels of thiobarbituric acid reactive substances (TBARS), interlukin (IL)-1β, IL-2, IL-6, and tumor necrosis factor (TNF)-α ( P < 0.05), and enhanced the expression of tight junction protein oclaudin ( P < 0.05). Analysis of gut microbiota indicated that both FA and VA increased the Firmicutes/Bacteroidetes ratio alongside reducing the relative abundance of the Prevotellaceae family including Prevotella 9 and Prevotella 2 genera, but enriched the Lachoiraceaea family including the Lachnospiraceae FCS020 group ( P < 0.05). Moreover, VA reduced the relative abundance of Prevotella 7 and Prevotella 1 but enriched Lachnospira , Eubacterium eligens group, and Eubacterium xylanophilum group ( P < 0.05), while FA showed a limited effect on these genera. The results demonstrated that both VA and FA could alleviate inflammation and oxidative stress, but only VA has a significant positive effect on the growth performance of LPS-challenged piglets potentially through modulating gut microbiota.

As the precursor of vitamin A, β-carotene has a positive effect on reproductive performance. Our previous study has shown that β-carotene can increase antioxidant enzyme activity potentially through regulating gut microbiota in pregnant sows. This study aimed to clarify the effect of β-carotene on reproductive performance and postpartum uterine recovery from the aspect of inflammation and gut microbiota by using a mouse model. Twenty-seven 6 weeks old female Kunming mice were randomly assigned into 3 groups (n=9), and fed with a diet containing 0, 30 or 90 mg/kg β-carotene, respectively. The results showed that dietary supplementation of β-carotene reduced postpartum uterine hyperemia and uterine mass index (P&lt;0.05), improved intestinal villus height and villus height to crypt depth ratio, decreased serum TNF-α and IL-4 concentration (P&lt;0.05), while no differences were observed in litter size and litter weight among three treatments. Characterization of gut microbiota revealed that β-carotene up-regulated the relative abundance of genera Akkermansia, Candidatus Stoquefichus and Faecalibaculum, but down-regulated the relative abundance of Alloprevotella and Helicobacter. Correlation analysis revealed that Akkermansia was negatively correlated with the IL-4 concentration, while Candidatus Stoquefichus and Faecalibaculum had a negative linear correlation with both TNF-α and IL-4 concentration. On the other hand, Alloprevotella was positively correlated with the TNF-α, and Helicobacter had a positive correlation with both TNF-α and IL-4 concentration. These data demonstrated that dietary supplementation of β-carotene contributes to postpartum uterine recovery by decreasing postpartum uterine hemorrhage and inhibiting the production of inflammatory cytokines potentially through modulating gut microbiota.

Eucommia ulmoides bark has been traditionally used as a Chinese medicine to attenuate stress, but the leaf, which is rich in polyphenols and polysaccharides, has been rarely used. This study aimed to investigate the effect of Eucommia ulmoides leaf extracts (EULEs) on oxidative stress and meat quality of broilers. A total of 252 broilers were randomly divided into 3 treatments and fed with a control basal diet (CON), or a diet containing 250 mg/kg or 1,000 mg/kg of EULE for 51 days. Results showed that dietary supplementation of 250 mg/kg EULE increased significantly the average daily gain of broilers in the early stage (1–21 days), while 250 mg/kg or 1,000 mg/kg of EULE decreased the feed conversion ratio in the whole period (P &lt; 0.05). Supplementation of 250 mg/kg EULE reduced the level of MDA in the liver (P &lt; 0.05), while 1,000 mg/kg EULE decreased the serum level of MDA (P &lt; 0.05), and the HDL level in serum was increased by 250 mg/kg or 1,000 mg/kg EULE (P &lt; 0.05). Additionally, 250 mg/kg EULE decreased abdominal fat ratio and serum triglyceride (TC) level in broilers, while 250 or 1,000 mg/kg of EULE reduced drip loss in breast muscle (P &lt; 0.05), and 1,000 mg/kg EULE reduced the cooking loss in thigh muscle (P &lt; 0.05). In conclusion, dietary supplementation of 250 mg/kg of EULE could attenuate oxidative stress and improve the growth performance and meat quality in broilers.

Objective: To assess the protective effects and mechanisms of cyanidin 3-glucoside (C3G) and its major phenolic metabolites including protocatechuic acid (PCA), phloroglucinaldehyde (PGA), vanillic acid (VA) and ferulic acid (FA) on non-alcoholic fatty liver disease (NAFLD). Design: First, C57BL/6J mice were fed a low-fat diet (LFD), high-fat diet (HFD) only, or HFD containing 0.4% C3G, PCA, PGA, VA or FA for 12 weeks to understand their protective effects against NAFLD. Next, the dose-dependent effect and mechanism of PCA against NAFLD were studied in a mouse model by supplementing 0.025% or 0.1% PCA in HFD. Eventually, the bacteriostatic effect of PCA on Enterococcus faecalis was confirmed in vitro, and the role of Enterococcus faecalis in NAFLD was discovered by fecal microbiota transplantation (FMT) experiment.Results: As the major phenolic metabolite of C3G, PCA dose-dependently reduced intraperitoneal and hepatic fat deposition, with alleviated insulin resistance, hepatic inflammation and lipid peroxidation. Characterization of gut microbiota indicated that PCA decreased the Firmicutes/Bacteroidetes ratio mainly by reducing the relative abundance of Roseburia, Intestinibacter and Enterococcus. Lipidomics and correlation analysis revealed that Enterococcus had a significant correlation with the changed lipid metabolites by PCA. In vitro bacteriostatic experiment showed that PCA has a direct inhibitory effect against Enterococcus faecalis, which has been proved to accelerate NAFLD by fecal microbiota transplantation.Conclusion: This study demonstrated the first time that PCA can protect against NAFLD through inhibiting Enterococcus faecalis.