Trehalose (TRE) was used to improve the gastrointestinal tolerance of Lactobacillus plantarum embedded with whey protein concentrate/pullulan (WPC/PUL) hydrogel and the embedded L. plantarum was applied to juice. The study indicated that 5% TRE significantly increased the viable counts of L. plantarum embedded in WPC/PUL hydrogel from (8.83 ± 0.03) to (9.14 ± 0.04) (lg (CFU/g)) in simulated gastric juice (SGJ) and from (9.13 ± 0.04) to (9.38 ± 0.04) (lg (CFU/g)) in simulated intestinal juice, respectively. The addition of TRE improved the glass transition temperature of WPC/PUL hydrogel and decreased the hardness and its solubility in SGJ, which may be responsible for the improved protection of WPC/PUL hydrogels on L. plantarum. In addition, TRE increased the viable counts of L. plantarum in WPC/PUL probiotic microcapsule juice at low pH and high temperature during storage.

Lactiplantibacillus plantarum 104, which was previously screened in the laboratory, has been confirmed to have the effect of lowering lipids and regulating intestinal microbial homeostasis. However, the mechanism of action of its fermentation supernatant in alleviating metabolic disorders is unclear. L. plantarum 104 cell-free supernatant (LP104s) was fed to high-fat C57BL/6N mice for 8 weeks. The intervention of LP104s increased the concentration of conjugated bile acids in the ileum, especially taur-α/β-muricholic acid sodium salt (T-α-MCA or T-β-MCA), inhibited intestinal farnesoid X receptor (FXR)-related signaling pathways. LP104s reduced cholesterol levels by increasing the synthesis of hepatic cholic acid (CA), chenodeoxycholic acid (CDCA), and the excretion of bile acids in feces. Moreover, western blotting results showed that TLR2/NF-ҡB signaling pathway expression was inhibited. In addition, 16S rDNA sequencing results showed that LP104s regulated the relative abundance of bacteria associated with inflammatory response and obesity (Prevotella, Ruminococcus, and Clostridium). Therefore, this paper further elaborates the role of gut microbiology and bile acids in improving metabolism from the perspective of secondary bile acids and intestinal chronic inflammation and also lays a theoretical foundation for the next step in the development of fermentation products of this strain.

The gut microbiota and it´s metabolism are vital targets of probiotics regulating high fat-diet (HFD) induced hyperlipidemia, which can relieve the pressure caused by the striking growth of sub-health people. Pediococcus pentosaceus PP04 (PP04) could colonize in intestine to regulate gut microbiota and it´s metabolites directly, the rebalanced intestinal flora mediated by PP04 could facilitate the secretion of short chain fatty acids to control body weight gain, PP04 intervention also changed bile acids (BAs) profiles and enhanced the ileal concentrations of antagonists including tauro-α/β-muricholic acid sodium salt and ursodeoxycholic acid to inhibit intestinal farnesoid X receptor/fibroblast growth factor 15 (FXR/FGF15) signaling coupled with the activation of hepatic FXR/small heterodimer partners signaling (SHP), which accelerated the hepatic BAs de novo synthesis and excretion with feces to eliminate HFD caused hyperlipemia effectively. This study provided important evidence regarding PP04 as dietary supplement to relieve hyperlipidemia by influencing BAs enterohepatic circulation.