The objective of this study and analysis were Swiss-type cheeses manufactured using a probiotic culture of Lactobacillus paracasei LPC-37. Owing to the similar chemical composition of the cheeses studied, the diversification of their water activity was slight. It was reported that after 4 and 6 weeks of ripening, the cheeses showed a higher decrease in water activity than after 2 weeks of ripening. When comparing the count of lactobacilli in the cheeses of a varying degree of ripeness, it is found that the most intensive growth of micro-organisms occurred during the first two weeks of ripening. A statistically significant dependence (r=0.86) between the number of Lactobacillus and water activity was found only in cheeses that have been stored for one month.