Influences of dietary Eucommia ulmoides leaf extract on the hepatic lipid metabolism, inflammation response, intestinal antioxidant capacity, intestinal microbiota, and disease resistance of the channel catfish (Ictalurus punctatus).

The purpose of the study was to investigate the effects of Eucommia ulmoides leaf extract (ELE) on the common occurrence of liver steatosis, chronic inflammation, oxidative stress, disturbance of gut microbiota, and disease susceptibility in high-fat diet-fed channel catfish. Channel catfish fed three diets, including a high-fat diet (11% crude fat) and ELE-supplemented diets containing 1‰ or 2‰ ELE for 4 weeks. The results showed the contents of liver triacylglycerol of 1‰ and 2‰ ELE groups were reduced, and ELE treatments decreased the expression of lipogenesis related genes (srebp-1c, pparγ, and acc-1), and increased the expression of lipolysis related genes (pparα). In addition, the supplementation of ELE improved the inflammatory response of the liver and intestine. ELE could improve the destruction of intestinal morphology structure and increase the expression level of hif-1a and tight junction proteins (Occludin, Claudin2, Claudin15). 2‰ ELE significantly enhanced the antioxidant capacity of intestine by increasing the activity of SOD enzyme. Moreover, the supplement of ELE significantly increased the abundance of Cetobacterium and Romboutsia (p < 0.05). Compared with the control group, the expression of immune factor nf-κb had a significant decrease, and il-1ß showed a tendency to decrease in the ELE supplement groups after pathogenic bacteria challenge. In conclusion, the ELE alleviated fatty liver disease and inflammation response, improved the oxidative capacity and physiological structure of intestine, and improved the structure of intestinal microbiota and disease resistance in HFD-fed channel catfish.

Supplemental Plant Extracts From Flos lonicerae in Combination With Baikal skullcap Attenuate Intestinal Disruption and Modulate Gut Microbiota in Laying Hens Challenged by Salmonella pullorum.

Dietary inclusions of baicalin and chlorogenic acid were beneficial for intestinal health in pigs. Nevertheless, it is unknown whether these plant-derived products had protection for intestine against bacterial challenge in chickens. This study was aimed at evaluating the potential mitigating effects of plant extracts (PE) from Flos lonicerae combined with Baikal skullcap (the active components are chlorogenic acid and baicalin) on intestinal disruption and dysbacteriosis induced by Salmonella pullorum in laying hens. A total of 216 41-week-old layers were randomly divided into 3 groups (6 replicates per group): negative control (NC), S. pullorum-infected positive control (PC), and the S. pullorum-infected group with supplementation of PE at 1000 mg/kg. All birds except those in NC were challenged with S. pullorum at the end of 4 weeks of the experiment. S. pullorum challenge impaired (P < 0.05) the production performance (egg production, feed intake, and feed efficiency) of laying hens, increased (P < 0.05) serum endotoxin content and frequency of Salmonella-positive organs, as well as up-regulated (P < 0.05) ileal expression of pro-inflammatory cytokines including IFNG, TNFA, IL8, and IL1B, whereas PE addition reversed (P < 0.05) these changes and increased (P < 0.05) ileal IL10 expression. Supplemental PE moderated ileal microbiota dysbiosis in challenged birds, characterized by a reduced abundance of Firmicutes along with increased abundances of Bacteroidetes (Bacteroides), Deferribacteres and several butyrate-producers such as Prevotellaceae, Faecalibacterium, Blautia, Butyricicoccus, Lachnoclostridium, and Olsenella, which may assist with energy harvesting and boost anti-inflammatory capacity of host. The decreased abundance of Firmicutes with the increased abundance of Bacteroidetes caused by PE addition had positive correlations with the decreased expression of ileal pro-inflammatory cytokines. The increased abundances of Bacteroidetes (Bacteroides) and Prevotellaceae following PE addition were also positively correlated with the improvement of performance (egg production and feed intake) of laying hens. Collectively, supplemental PE from Flos lonicerae in combination with Baikal skullcap alleviated S. pullorum-induced intestinal disruption and performance impairment in laying hens, which could be at least partially responsible by the modulation of gut microbial composition.