Inactivated Probiotics

There is evidence that preparations containing dead cells and their metabolites can also produce relevant biological responses that restore normal intestinal homeostasis, in many cases similar to but possibly different from, the situation in living cells. Inactivation of probiotics can be achieved by different methods including heating, chemicals such as formalin, gamma or ultraviolet light, and ultrasound, and different inactivation methods may have different effects on the structural components of the cells and affect their biological activity. In most cases, heat treatment is the method of choice for inactivation of probiotic strains.

The favorable properties of heat-killed bacteria have been observed in vitro, in animal models, and in clinical trials, which demonstrate their benefit in different indications, such as neonates, without the risks associated with living organisms, and with pharmaceutical advantages in transportation and storage. Following bacterial inactivation, dead cells can release bacterial components with key immunomodulatory effects and antagonistic pathogen properties. Different bacterial components, such as lipoteichoic acid, peptidoglycan, or exopolysaccharides (EPS), have been proposed to primarily involve these properties in preparations containing heat-inactivated bacteria.