## 3 Results
### In Vivo Effect of FRB Administration on Natural Killer (NK) Cell Activity  
To verify the NK cell activity-promoting effect of FRB, RB, and red ginseng extracts (positive control), which have been reported to have an immune-enhancing effect through NK cell activity [38], were used as positive controls, and the in vivo NK cell activity-promoting effect was measured. Figure 4 shows the results of using the spleen of an animal model (BALB/c mice) following administration of FRB (0.5 g/kg-bw), RB (0.5 g/kg-bw), and a positive control group (Red Ginseng Extract 0.5 g/kg-bw) once a day for 10 days. After combining the RPMI 1640 suspension containing splenocytes and the culture medium of culturing YAC-1 cells, and after culturing for 4 h, lactate dehydrogenase (LDH) released by the destruction of YAC-1 cells by NK cells in the splenocytes was measured. In this experiment, red ginseng was used as a positive control since it is a well-defined immunomoddulator and has secured functional certification (official health claim: helps in enhancing immunity) from the Korea Food and Drug Administration.  
NK cell activities at 1:50 ratio of YAC-1 cells to splenocytes were significantly increased in red ginseng extract 0.5 g/kg (64.93 \(\pm\) 4.72%, _p_! 0.05), compared to that of Normal Control (62.29 \(\pm\) 4.45%, _p_! 0.05) and RB 0.5 g/kg-bw (50.84 \(\pm\) 3.28%).  
NK cell activities at a 1:25 ratio of YAC-1 cells to splenocytes were significantly increased in the positive control: Red Ginseng Extract 0.5 g/kg (38.64 \(\pm\) 2.13%), FRB  
Figure 4: In vivo effect of red ginseng extracts, and FRB (FRB: FRB 0.5 g/kg-b.w., RB: RB 0.5 g/kg-b.w.) on the NK cell activity. After the samples were orally administered for 10 days, spleens were removed from the experimental animals. NK cell activity was investigated at Yac-1 cell and splenocyte ratios of 25:1 and 50:1. In a 96-well culture plate YAC-1 (0.5 \(\times\) 10\({}^{5}\) cell/mL) and splenocyte were cultured at ratios of 50:1 and 25:1 for 4 h (37 \({}^{\circ}\)C, 5% CO\({}_{2}\)). \({}^{\rm a-d}\) Different letters indicate statistically significant differences between groups one-way ANOVA followed by [PERSON]’s test of _p_! 0.05. Significantly different from the CY Control group (\({}^{\bullet}\)_p_! 0.05). (NC: normal control, CY: negative control (CY only), GS: positive control (CY with Ginseng extract 0.5 kg/kg-bw), FRB: CY with FRB 0.5 g/kg-bw, RB: CY with RB 0.5 g/kg-bw).  
(\(34.85\pm 3.45\%\)), and RB (25.00 \(\pm\) 4.18%), compared to that of the negative control CY group (12.67 \(\pm\) 3.23%), (Figure 4). It is important to note that FRB shows activity similar to the NK cell activation-promoting effect seen in red ginseng extract, which is the positive control (Figure 4). Furthermore, in both ratios, FBR showed higher activity than that of RB. These results indicate that the increase in the content and solubility of water-soluble substances through improvement of the fermentation process is an effective process to enhance immune activities.  
Through the confirmation of the expression level of cytokines secreted from these splenocytes, ingestion of FRB promotes the proliferation of B cells, T cells, and NK cells in the splenocytes, and as the B cells increase, the antibody proteins IgM and IgA are activated. It can be seen that promoting the phagocytosis and destruction of infiltrating pathogens promotes antigen neutralization and aggregation reactions, and as NK cell activity (IL-12 and INF-\(\gamma\)) increases, it has a significant effect on the involvement of complement activation. there was. In view of the above results, it is thought that FRB can effectively act on immune activity by directly promoting an immune response or affecting other immune responses related thereto.