**6. Risks inherent in the use of probiotics**

The absence of clinical side effects is an important benefit of using probiotics. However, some of the species and/or bacterial strains can present risks, they can be responsible for a series of problems to animal, human health and the environment, causing mild reactions or serious and potentially fatal infections [20]. In addition, no probiotic can be considered 100% safe or at zero risk.

Risk reports on the use of probiotics are scarce. However there is a probable risk of transmission of antibiotic resistance (eg, *Enterococcus* genus) to pathogenic microbiota or enterotoxin production (eg, *Bacillus cereus* strain) [19].

In the USA, probiotics and other microorganisms used as food additives must have the status of Generally Regarded as Safe (GRAS), regulated by the FDA. In Europe, the use of the term Qualified Safety Assumption (QPS) has been regulated by EFSA. Crucial criteria for the selection of probiotic microorganisms in animals were jointly established by (WHO), (FAO) and EFSA, where they stand out: Security, functionality and technological utility [19].

Security - stipulates that the origin of the strain to be used as a probiotic must be from the intestine of this animal species; whose antibiotic resistance profile must be non-existent; in addition to the need for a total absence of association with pathogenic cultures.

Functionality- as an important criterion, functionality is about the viability of the strain within the conditions of the intestine, which must be greater; in addition to the efficiency in adherence to epithelial cells, reduced intestinal permeability of the mucosa and proven immunomodulatory effects.

Technological utility - no influence of probiotic microorganisms on the sensory properties of meat or meat products should be observed. Phage resistance is also an important property in this criterion, as well as the guarantee of viability of the microorganism during processing, and good stability in the product and in the storage time.

Current levels of information about probiotics are not sufficient to declare any group of probiotics completely safe without a case-by-case risk assessment. The results of the studies do not allow establishing the existence of a real risk for probiotics, but they also do not guarantee total safety.
