Excessive body fat and the related dysmetabolic diseases affect both developed and developing countries. The aim of this study was to investigate the beneficial role of a bacterial culture supernatant (hereafter: BS) of Lactobacillus and Bifidobacterium and their potential mechanisms of action on white-fat browning and lipolysis. For selection of four candidates among 55 Lactic acid producing bacteria (LAB) from human infant faeces, we evaluated by Oil Red O staining and Ucp1 mRNA quantitation in 3T3-L1 preadipocytes. The expression of browning and lipolysis markers was examined along with in vitro assays. The possible mechanism was revealed by molecular and biological experiments including inhibitor and small interfering RNA (siRNA) assays. In a mouse model, physiological, histological, and biochemical parameters and expression of some thermogenesis-related genes were compared among six experimental groups fed a high-fat diet and one normal-diet control group. The results allow us to speculate that BS treatment promotes browning and lipolysis both in vitro and in vivo. Moreover, the BS may activate thermogenic programs via a mechanism involving PKA-CREB signaling in 3T3-L1 cells. According to our data, we can propose that two LAB strains, Bifidobacterium longum DS0956 and Lactobacillus rhamnosus DS0508, may be good candidates for a dietary supplement against obesity and metabolic diseases; however, further research is required for the development as dietary supplements or drugs.

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A facultatively anaerobic, Gram-stain-positive, catalase-negative, rod-shaped lactic acid bacterium, designated SG816, was isolated from small intestine of a swine. Optimal growth occurred at 37 °C and pH 7.0. Furthermore, growth occurred in NaCl up to 0.5 % (w/v) but not at levels of salinity higher than 1 %. Comparative 16S rRNA gene sequencing and the matrix-associated laser desorption/ionization-time-of-flight mass spectometry profiling showed that strain SG816 was closely related to Lactobacillus delbrueckiisubsp. bulgaricus KCTC 3635 (95.9 %) and Lactobacillus delbrueckiisubsp. indicus JCM 15610 (95.9 %), followed by other Lactobacillus delbrueckii subspecies (95.9-95.7 %) and Lactobacillus equicursoris DSM 19284 (95.6 %). A comparison of two housekeeping genes, RNA polymerase alpha subunit (rpoA) and phenylalanyl-tRNA synthase alpha subunit (pheS), revealed that strain SG816 formed a separate branch within the clade of the genus Lactobacillus. The DNA G+C content level of the strain SG816 was 51.5 mol%. The strain was homofermentative and produced d-lactic acid from glucose fermentation. The major cellular fatty acids (>10 %) of the isolate were C18 : 1ω9c and C16 : 0. The peptidoglycan type was A4α l-Lys-d-Asp. On the basis of distinct phenotypic and phylogenetic properties, strain SG816 represents a novel species of the genus Lactobacillus, for which the name Lactobacillus porci sp. nov. is proposed. The type strain is SG816 (=KCTC 21090=NBRC 112917).