Lactobacillus frumenti mediates energy production via fatty acid β-oxidation in the liver of early-weaned piglets

Abstract Background Early-weaning of piglets is often accompanied by severe disorders, especially diarrhea. The gut microbiota and its metabolites play a critical role in the maintenance of the physiologic and metabolic homeostasis of the host. Our previous studies have demonstrated that oral administration of Lactobacillus frumenti improves epithelial barrier functions and confers diarrhea resistance in early-weaned piglets. However, the metabolic response to L. frumenti administration remains unclear. Then, we conducted simultaneous serum and hepatic metabolomic analyses in early-weaned piglets administered by L. frumenti or phosphate-buffered saline (PBS). Results A total of 100 6-day-old crossbred piglets (Landrace × Yorkshire) were randomly divided into two groups and piglets received PBS (sterile, 2 mL) or L. frumenti (suspension in PBS, 108 CFU/mL, 2 mL) by oral administration once per day from 6 to 20 days of age. Piglets were weaned at 21 days of age. Serum and liver samples for metabolomic analyses were collected at 26 days of age. Principal components analysis (PCA) showed that L. frumenti altered metabolism in serum and liver. Numerous correlations (P