## 3 Results and Discussion
### Improving Growth of Probiotics
Similarly, as for _Bifidobacterium adolescents_, the \(N_{max}\) and \(\mu_{\rm max}\) were changed from 1.537 \(\pm\) 0.036 (OD\({}_{600}\)) to 1.710 \(\pm\) 0.017 (OD\({}_{600}\)), and 0.183 \(\pm\) 0.006 h\({}^{-1}\) to 0.283 \(\pm\) 0.013 h\({}^{-1}\), respectively. As the concentration further increased, the \(N_{max}\) and \(\mu_{\rm max}\) decreased a little. Therefore, GE was able to improve the growth of the two probiotics. [PERSON] indicated that the addition of different \(\beta\)-glucans--from barley, seaweed, mushroom, etc.--could increase observably the  
Figure 2: Effect of the addition of GE on the growth of _Lactobacillus bulgaricus_ (**A**) and _Bifidobacterium adolescents_ (**B**). populations of _Bifidobacterium adolescents_ during 24 h of in vitro fermentation [21]. It was reported that \(\beta\)-glucan from oat bran also made a positive contribution to the growth of _Bifidobacterium adolescents_ and _Lactobacillus bulgaricus_ under different fermentation conditions, respectively [22; 23]. Fructooligosaccharide is commonly regarded as an excellent prebiotic factor, so it was chosen in our study to compare with GE on the ability of improving the growth of _Lactobacillus bulgaricus_ and _Bifidobacterium adolescents_[24], and the results were shown in Figure 3A,C. Figure 3: Evolution profiles of strains biomass (**A**,**C**) and specific growth rate (**B**,**D**) of _Lactobacillus bulgaricus_ and _Bifidobacterium adolescents_ involving in the addition of GE (20 mg/mL) and fructooligosaccharide (20 mg/mL) with culture time. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{\(\beta\)-Glucan (mg/mL)} & \multicolumn{4}{c}{_Lactobacillus bulgaricus_} \\ \cline{2-5}  & \(N_{0}\) (OD\({}_{600}\)) & \(N_{\text{max}}\) (OD\({}_{600}\)) & \(t_{\text{max}}\) (h) & \(\mu_{\text{max}}\) (h\({}^{-1}\)) \\ \hline
0 & 0.264 \(\pm\) 0.011 & 1.196 \(\pm\) 0.059 & 14.98 \(\pm\) 0.247 & 0.098 \(\pm\) 0.005 \\
0.4 & 0.260 \(\pm\) 0.014 & 1.235 \(\pm\) 0.024 & 13.58 \(\pm\) 0.356 & 0.111 \(\pm\) 0.006 \\
0.8 & 0.263 \(\pm\) 0.013 & 1.295 \(\pm\) 0.013 & 13.58 \(\pm\) 0.236 & 0.111 \(\pm\) 0.008 \\
1.2 & 0.259 \(\pm\) 0.008 & 1.310 \(\pm\) 0.018 & 12.73 \(\pm\) 0.121 & 0.112 \(\pm\) 0.009 \\
1.6 & 0.261 \(\pm\) 0.006 & 1.391 \(\pm\) 0.029 & 12.16 \(\pm\) 0.147 & 0.118 \(\pm\) 0.007 \\
2.0 & 0.261 \(\pm\) 0.015 & 1.340 \(\pm\) 0.023 & 12.16 \(\pm\) 0.054 & 0.112 \(\pm\) 0.005 \\ \hline \hline \multicolumn{5}{c}{_Bifidobacterium adolescents_} \\ \cline{2-5}  & \(N_{0}\) (OD\({}_{600}\)) & \(N_{\text{max}}\) (OD\({}_{600}\)) & \(t_{\text{max}}\) (h) & \(\mu_{\text{max}}\) (h\({}^{-1}\)) \\ \hline
0 & 0.240 \(\pm\) 0.008 & 1.537 \(\pm\) 0.036 & 15.83 \(\pm\) 0.214 & 0.183 \(\pm\) 0.006 \\
0.4 & 0.242 \(\pm\) 0.006 & 1.566 \(\pm\) 0.047 & 15.83 \(\pm\) 0.175 & 0.195 \(\pm\) 0.012 \\
0.8 & 0.245 \(\pm\) 0.011 & 1.594 \(\pm\) 0.032 & 15.55 \(\pm\) 0.236 & 0.206 \(\pm\) 0.014 \\
1.2 & 0.251 \(\pm\) 0.010 & 1.666 \(\pm\) 0.025 & 15.55 \(\pm\) 0.147 & 0.234 \(\pm\) 0.008 \\
1.6 & 0.259 \(\pm\) 0.008 & 1.710 \(\pm\) 0.017 & 14.70 \(\pm\) 0.089 & 0.283 \(\pm\) 0.013 \\
2.0 & 0.253 \(\pm\) 0.014 & 1.640 \(\pm\) 0.028 & 14.98 \(\pm\) 0.072 & 0.263 \(\pm\) 0.007 \\ \hline \hline \end{tabular} \(N_{0}\), initial strain biomass. \(N_{\text{max}}\), maximum strain biomass. \(t_{\text{max}}\), arrival time. \(\mu_{\text{max}}\), maximum specific growth rate.  
\end{table} 
Table 3: Growth dynamic parameters of Lactobacillus bulgaricus and Bifidobacterium adolescents. The strains biomass of the two probiotics increased with culture time. When the time reached 22 h, the biomass peaked. Noteworthily, the addition of fructoligosaccharide could promote the growth of _Lactobacillus bulgarcius_ more than GE, while GE could improve the growth of _Bifidobacterium adolescents_ more than fructoligosaccharide (\(p<0.05\)).