The species
Lacticaseibacillus paracasei is bacterium that operates by commensalism. It is the most frequently isolated species from dairy environment among the other lacticaseibacilli [
15]. Some of these species strains could be labeled as beneficial because of their probiotic properties among which also a bacteriocin-production can be involved [
16]. Tolinacki et al. [
9] reported bacteriocin -producing substance from the
L. paracasei BGUB 9 strain isolated from homemade hard cheese. Its bacteriocin substance UB9 retained the antimicrobial activity within the pH range 1-10 and after treatment at 100 ˚C for 30 min. Similarly, bacteriocin substance produced by
L. paracasei LPa 12/1 strain retained activity at 60 ˚C and -20 ˚C and up to now it showed narrow antimicrobial spectrum as was also noted in UB9 substance. The production of bacteriocins by beneficial/probiotic strains can provide additional benefits concerning their application potential in food industry [
9]. Colonization of products by beneficial strains can be influenced by their adhesive ability. E.g. Lauková et al. [
17] described different adhesive ability in lactobacilli under in vitro condition in relation with autochthonous character of its source. Very important is also application form of the beneficial strain. As formerly mentioned, the most simple way/form of encapsulation is dry freezing [
18]. Encapsulated LPa 12/1 strain reached sufficient colonization in both types of yoghurts, although its higher counts were determined in ewe-goat milk yoghurt in comparison with cow milk yoghurts. Probably because of autochthonous strain. On the other hand, cow milk yoghurts retained better consistency during 14 days in comparison with ewe-goat milk yoghurts. When ewe-goat milk yoghurt was supplemented with the strain
Lactiplantibacillus plantarum LP17/1 (10
9 cfu/ml) and maintained at 4 ˚C it colonized sufficiently yoghurt with stability during 10 days without changes of the product quality [
18]. Speranza et al. [
19] reported functional cream cheese with
L. reuteri DSM 20016 strain (and
Bifidobacterium animalis subsp.
lactis DSM 10140). The cheese resulted in favorable viability of both strains during 28 days of storage at 4 ˚C with good sensory characteristics. Also Patrovský et al. [
20] reported that bacteriocins introduced into foodstuffs via protective cultures in situ offer new perspectives on enhancing food quality and safety. They used freeze-dried preparations of bacterial strains producing particular bacteriocins. Plantaricin was found to exhibit the highest anti-listerial effect. Besides lactobacilli, in yoghurt also antimicrobial effect of bacteriocin (enterocin, Ent 4231) produced by
Enterococcus faecium CCM 4231 was reported [
21]. There yoghurt was experimentally contaminated with
Listeria monocytogenes Oxford 209P strain. A retardation in the Oxford 209P count was detected in yoghurt after 1 day storage in comparison with the control (10
3 vs. 10
0 cfu/ml/g), a decrease of 3 orders of magnitude. Taking into account present and previous results obtained and/or reported, LAB in general or their individual representatives seem to be the most suitable as beneficial strains because of their ability to modify the microenvironment, in which they have been delivered, via producing various metabolites such as e.g. inhibitory substances-bacteriocins and/or competitive exclusion [2022]. Together with animal products consumption, health safety has been associated. As formerly mentioned the beneficial strain safety has to be assessed/confirmed. In this study, experimental model using BALB/c mice was used. No mortality of mice was assessed and coliforms were significantly reduced in feces, jejunum and mathematically also in liver after LPa 12/1 strain application. The highest count of LPa 12/1 strain was in feces, then in jejunum and almost the same also in liver. Moreover, increase in PA was mentioned. It means that safety aspect of LPa 12/1 strain was fulfilled. Moreover, some representatives of lactobacilli can be successfully used as additives to biotherapy in case of trichinelosis [
11]. E.g. when mice BALB/c were infected with
Trichinella spiralis (400 larvae) on day 7 of treatment with beneficial strain
L. plantarum LP17L/1, the strain restored the CD4+ T cell numbers in the epithelium and lamina propria at the control level from 11 dpi.
T. spiralis infection significantly inhibited lymphocytes subpopulations from 5 to 25 day post-infection (dpi). The strain LP17L/1 stimulated the CD8+ T cells numbers in infected mice, which were restored in lamina propria on 11 dpi and in the epithelium on day 32. The immunomodulatory effect of LP17L/1 strain was confirmed. It is supposed also in case of LPa 12/1 strain. Studies are in processing. Th safe, beneficial strain LPa 12/1 has shown promising application potential in yoghurts. Based on already published immunomodulatory effect of the other strain of dairy origin (LP17L/1), understanding immunological mechanism allows risk reduction of parasitic infection or allows to enrich anti-parasitic therapy and/or to reduce anti-helmintics dosage. The promosing way is indicate via dairy products.