Effects of mixed extract from two tropical plants on gut microbiome and metabolome in piglets.

In this study, we performed a quantitative analysis of 12 compounds derived from Piper sarmentosum extract (PSE) and guava leaf extract (GE). In addition, we investigated the effects of mixed extract (ME) of PSE and GE (1:1) on piglets' gut microbiome and metabolome. A total of 200 piglets (Duroc × Landrace × Large Yorkshire, 21-day-old) were randomly assigned into two groups with five replicates of 20 piglets/pen having the same initial body weight. Piglets were fed a basal diet supplemented with ME at 0 (T0) or 200 mg/kg (T1) for 3 weeks. The quantitation results by ultraperformance liquid chromatography linked to triple-quadrupole tandem mass spectrometry showed that vitexin 2-O-rhamnoside and pellitorine were the greatest abundant among six compounds detected in the PSE. In addition, quercetin, isoquercitrin and avicularin were found to be the richest of all detected compounds in the GE. Findings on experimental animals indicated that three differential metabolites, comprising L-alanine, sarcosine and dihydrofolic acid, in T1 compared with T0 groups, have exactly opposite levels trends in serum and faeces. Moreover, two metabolic pathways (i.e., urea cycle and glutamate metabolism) differed significantly in the serum and faeces of piglets between T0 and T1 (p < 0.05). At the same time, T1 had significantly higher relative abundances of Agathobacter and Alloprevotella than T0 at genus level (p < 0.05). Correlation analysis revealed that the genus Agathobacter correlated positively with carbamoyl phosphate (p < 0.01) and oxoglutaric acid (p < 0.05), and negatively with succinic acid (p < 0.01) and ornithine (p < 0.05). These four differential metabolites were also involved in the urea cycle and/or glutamate metabolism pathways. The results here indicated that the tested plant extract mixture represents a worthy feed additive with obvious antioxidative properties.

Impact of dietary protein and energy levels on fatty acid profile, gut microbiome and cecal metabolome in native growing chickens.

The present study investigated the optimal concentration of dietary ME and CP for the fatty acid profile of meat, gut microbiome, and cecal metabolome in Danzhou chickens from 120 to 150 d of age. A total of seven hundred and twenty 120-d-old Danzhou female chickens, with a similar BW, were randomly allocated into 6 treatments with 6 replicates and each of 20 birds. The chickens were fed 2 levels of dietary ME (11.70 MJ/kg, 12.50 MJ/kg), and 3 levels of dietary CP (13%, 14%, and 15%). The results showed that dietary ME and CP levels didn't affect final BW, ADG, ADFI, and feed gain ratio (g: g) (P > 0.05). The serum concentrations of triglyceride, insulin, and glucose in the 12.50 MJ/kg group were the highest (P < 0.05). Dietary ME, CP levels, and their interactions affected (P < 0.05) the fatty acid content in the breast muscle, thigh muscle, and liver. The levels of C18:0, C20:0, C22:0, C22:1, C18:2, C18:3, C22:6, and SFA of the liver in the high ME group were higher than those in the low ME group (P < 0.05). The levels of C16:0, C14:1, C18:1, C22:5, SFA, MUFA and USFA in the low CP group were higher than the corresponding values in the other groups (P < 0.05). Dietary ME and CP levels altered the composition and relative abundance of microbiota in the cecum of chickens at various taxonomic levels to different extents. Significant effects of interactions were found between dietary ME and CP on the relative abundance of 10 species (P < 0.05), and among these species, 6 species belonged to the genus Bacteroides. Notably, the relative abundance of 2 probiotic species including Lactobacillus crispatus and Lactobacillus salivarius was significantly increased (P < 0.05) with increasing dietary ME level. There were 6 differential metabolites in the cecum, comprising thromboxane A2, 5,6-DHET, prostaglandin D2, 20-hydroxyeicosatetraenoic acid, 12(S)-HPETE and prostaglandin I2 significantly reduced (P < 0.05) with increasing the dietary ME level; all of them are involved in arachidonic acid metabolism. In conclusion, the present study suggested that the dietary levels of 12.50 MJ/kg ME and 14% CP enhanced meat quality in terms of fatty acid composition, and showed benefits for maintaining intestinal health via positive regulation of cecal microbiota in native growing Danzhou chickens.