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 betweenT0 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.