2.4. Survival of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 under Simulated GI Conditions

To assess the survival of probiotics under simulated GI conditions, samples were collected from R1 and R2 during the treatment period. For lactobacilli, the microdilution technique was used [50], followed by plating on MRS agar (Merck^®). For bifidobacteria, one mL of the serial dilution was plated in MRS agar supplemented with lithium chloride (2 g/L (Merck^®, Darmstadt, Germany)) and sodium propionate (3 g/L (Merck^®, Germany)). Both samples were diluted in sterile peptone water. After, plates were incubated in anaerobic conditions for 72 h at 37 °C [51].