Characterization of feline-originated probiotics Lactobacillus rhamnosus CACC612 and Bifidobacterium animalis subsp. lactis CACC789 and and evaluation of their host response

Abstract

Background: Probiotics are beneficial for animal health and new potential probiotics need to be characterized for their prospective use in improving animal health. In this study, 32 bacterial strains were isolated from a Norwegian forest cat (castrated, 12 years old) and a Persian cat (castrated, 10 years old), which were privately owned and had indoor access.

Results: Lactobacillus rhamnosus CACC612 (CACC612) and Bifidobacterium animalis subsp. lactis CACC789 (CACC789) were selected as potential probiotics; characterization of the two strains showed equivalent acid tolerance, similar cell adhesion rates on the HT-29 monolayer cell line, and superior bile tolerance compared to Lactobacillus rhamnosus GG (LGG). Subsequently, they exhibited inhibitory effects against a broad spectrum of pathogenic bacteria, including E. coli (KCTC 2617), Salmonella Derby (NCCP 12,238), Salmonella Enteritidis (NCCP 14,546), Salmonella Typhimurium (NCCP 10,328), Clostridium difficile JCM 1296T. From evaluating host effects, the viability of the feline macrophage cell line (Fcwf-4) increased with the treatment of CACC612 or CACC789 (P < 0.05). The induced expression of immune-related genes such as IFN-γ, IL1β, IL2, IL4, and TNF-α by immune stimulation was significantly attenuated by the treatment of CACC612 or CACC789 (P < 0.05). When 52 clinical factors of sera from 21 healthy cats were analyzed using partial least squares discriminant analysis (PLS-DA), the animals were obviously clustered before and after feeding with CACC612 or CACC789. In addition, hemoglobin and mean corpuscular hemoglobin concentration (MCHC) significantly increased after CACC612 feeding (P < 0.05).

Conclusions: In this study, feline-originated probiotics were newly characterized and their potentially probiotic effects were evaluated. These results contribute to our understanding of the functional effects of feline-derived probiotics and support their industrial applications.

Keywords: Animal health; Feline; Immune; Probiotic characterization.

Fig. 1

Cell viability was determined by WST-1 assay. Probiotics treatment in Fcwf-4 cells (a) and probiotics treatment in immune-stimulated Fcwf-4 cells (b). LGG (Reference strain), Lactobacillus rhamnosus GG (ATCC53103); NC, only bacterial broth media; p, 100 ng/ml poly(I:C) treatment

Fig. 2

Relative expression of immune-related genes. Only Pfoldchange (FC) = Log2 (p/NT) and the other FCs = Log2 (each treatment/p). LGG (Reference strain), Lactobacillus rhamnosus GG (ATCC53103); NC, only bacterial broth media; p, 100 ng/ml poly(I:C) treatment; *, P < 0.05; **, P < 0.01; ***, P < 0.001

Fig. 3

Partial Least-Squares Discriminant Analysis (PLS-DA) based on 52 parameters from analysis of whole blood and electrolyte tests before and after application of CACC612, CACC789, and the commercial product. all individuals were distributed before and after the application (left panel) and distributed before and after the application according to the application group (right panel)