## 3 Results and Discussion
### Cell Survival and Attachment of L. rhamns OIXAL-1 Cells through an In Vivo Mouse Model  
Taking into account the results of the in vitro digestion model, the freeze-dried immobilized cell culture exhibiting the highest survival rate was chosen for further assessment within an in vivo BALB/c mouse model. Freeze-dried immobilized _L. rhamns_ OIXAL-1 cells on oat flakes demonstrated a survival rate of 81.22%, trailing slightly behind the wet immobilized _L. rhamns_ OIXAL-1 cells on oat flakes, with a survival rate of 84.76%. The selection of the freeze-dried culture, despite the lower survival rate, was based on industrial and commercial requirements for stability and convenience. For comparison purposes, three control mice groups were also included in the study (CD, OD and FD), in order to assess the effect of oat flakes on lactobacilli counts in feces, intestinal fluid and intestinal tissue. According to the results (Figure 4), lactobacilli levels in mice feces were encountered at levels ranging from 7.00 to 7.12 log CFU/g [46] at baseline level (day 0) in all groups. Following administration of both immobilized and free _L. rhamns_ OIXAL-1 cells (groups ID and FD), a significant (\(p<0.05\)) increase in lactobacilli populations was observed in mice feces after the 10-day period compared to baseline. A significant (\(p<0.05\)) increase in lactobacilli counts was also observed in the feces of the ID group compared to the FD group after the 10-day _L. rhamns_ administration (8.02 log CFU/g and 7.64 log CFU/g, respectively). In contrast, in the control groups CD and OD, which received a control diet and an oat-flakes-supplemented control diet, respectively, stable lactobacilli counts at approximately 7 log CFU/g were determined, indicating that neither the rodent chow nor the oat flakes supplementation affected lactobacilli numbers. A similar pattern was also observed in the intestinal fluids of mice obtained from the ileum, cesium and colon after euthanasia. According to Table 2, lactobacilli counts in the intestinal fluid samples derived from the ileum, cesium and colon were higher (\(p<0.05\)) in groups ID and FD compared to the control groups (CD and OD). Additionally, an increase in lactobacilli counts (\(p<0.05\)) was observed in group ID compared to group FD, aligning with the findings of Figure 4. Higher (\(p<0.05\)) lactobacilli counts were also determined in the tissue samples (ileum, cesium and colon) in groups ID and FD compared to control groups CD and OD. However, it is noteworthy that, although higher lactobacilli counts were observed in both the intestinal fluids and feces of the ID group compared to the FD group, this difference was not observed in the intestinal tissue specimens, where the lactobacilli counts did not differ (\(p>0.05\)) between these two groups. Reviewing the results presented in Figure 4 and Table 2, it can be clearly suggested that the oral administration of \(L\). _rhammosus_ OXLAL-1 cells, either in immobilized or free form, led to a significant rise in lactobacilli counts in the intestinal epithelium, fluids and mice feces. In contrast, the inclusion of oat flakes (with no \(L\). _rhammosus_ OXLAL-1 cells) in the mice's diet did not yield the same outcome. Furthermore, the implementation of cell immobilization seemed to positively influence the survival, but not the attachment,