Metabolic and Lipidomic Profiling of Vegetable Juices Fermented with Various Probiotics.

Fermented vegetable juices have gained attention due to their various beneficial effects on human health. In this study, we employed gas chromatography-mass spectrometry, direct infusion-mass spectrometry, and liquid chromatography-mass spectrometry to identify useful metabolites, lipids, and carotenoids in vegetable juice (VJ) fermented with Lactobacillus plantarum HY7712, Lactobacillus plantarum HY7715, Lactobacillus helveticus HY7801, and Bifidobacterium animalis ssp. lactis HY8002. A total of 41 metabolites, 24 lipids, and 4 carotenoids were detected in the fermented and non-fermented VJ (control). The lycopene, α-carotene, and ß-carotene levels were higher in VJ fermented with L. plantarum strains (HY7712 and HY7715) than in the control. Proline content was also elevated in VJ fermented with HY7715. Uracil, succinic acid, and α-carotene concentration was increased in VJ fermented with HY7801, while glycine and lycopene levels were raised in VJ fermented with HY8002. This study confirmed that each probiotic strain has distinctive characteristics and produces unique changes to metabolic profiles of VJ during fermentation. Our results suggest that probiotic-fermented VJ is a promising functional beverage that contains more beneficial metabolites and carotenoids than commercial non-fermented VJ.

Screening and selection of Bifidobacterium strains isolated from human feces capable of utilizing resistant starch.

BACKGROUND: Resistant starch (RS) has been studied for its ability to serve as a substrate for the microbiota present in the human large intestine and for its beneficial physiological effects. The aim of this study was to screen and select novel strains of lactic acid bacteria (LAB) in the genus Bifidobacterium isolated from human fecal samples for further application as probiotics relying on their utilization of RS3, a prebiotic. RESULTS: LAB were isolated from human fecal samples, based on their ability to utilize RS3 as a carbon source. Consequently, two LAB were identified as Bifidobacterium adolescentis based on morphological, physiological and biochemical properties, and molecular biological analysis. The RS3-utilizing ability of these isolates was shown by the rapid decrease in pH of RS3-MRS media and by the pinhole traces on the surface of RS3 particles. Isolated B. adolescentis JSC2 was shown to be negative for ß-glucuronidase, suggesting that it would be safe for human use, and was found to be tolerant towards the acidic, bile-salt environment. CONCLUSION: This synbiotics approach of B. adolescentis JCS2, an RS-utilizing probiotics, coupled with RS utilization, is expected to enhance RS utilization in the food industry and be beneficial for the promotion of human health. © 2018 Society of Chemical Industry.