Resumen
Probiotic bacteria confer health benefits to their host, support the intestinal microbiome and fight antibiotic resistance. Probiotic products are used in the food and pharmaceutical industries and, in recent years, have become increasingly popular in the cosmetic industry. However, in the case of cosmetics, it is difficult to meet microbiological requirements while maintaining viable cells. The aim of this research study was to develop an effective way of introducing live bacteria (a strain of L. casei) into cosmetic formulations. A method of encapsulation of the bacteria was used to increase their viability. As part of the results, the effective carriers for the strain of L. casei are reported. Alginate microspheres were prepared for the systems to protect the microorganisms against external factors, such as temperature, UV light and preservatives. The obtained probiotic-loaded alginate microspheres were then used as the active ingredient of cosmetic formulations. Additionally, a preservative system was carefully selected to ensure the microorganisms? viability and the microbiological stability of the products. The obtained results showed a significant improvement in the survival of the microencapsulated probiotic strain in the cosmetic formulations containing antimicrobial agents (6.13 log CFU/g after 120 days of storage) compared with the formulation containing the non-immobilised probiotic strain, where complete elimination of bacterial cells was observed.