The species
Lacticaseibacillus paracasei is a species that operates via commensalism [
15]. Commensal lactobacilli are good candidates for development as probiotics [
15]. Some species show beneficial/probiotic properties, among which bacteriocin production can be involved [
14]. The species
Lacticaseibacillus paracasei is the most frequently isolated species from the dairy environment among the other lacticaseibacilli [
16]. Tolinacki et al. [
9] reported a bacteriocin-producing substance from the
L. paracasei BGUB 9 strain isolated from homemade hard cheese. Its bacteriocin substance UB9 retained an antimicrobial activity within the pH range of 1–10 and after treatment at 100 °C for 30 min. Similarly, a bacteriocin-like inhibitory substance produced by the
L. paracasei LPa 12/1 strain retained activity at 60 °C and −20 °C, and it showed a narrow antimicrobial spectrum up to now. A narrow antimicrobial spectrum was noted in the formerly mentioned bacteriocin substance UB9. The production of bacteriocins and/or bacteriocin-like substances via beneficial/probiotic strains can provide additional benefits for their application potential in the food industry [
9], e.g., antimicrobial, antibiofilm, and cytotoxic effects of bacteriocin lactococcin produced by the dairy origin strain
Lactococcus lactis CH3 reported by Krishnamoorthi et al. [
17]. Biadala et al. [
18] outlined the antibacterial activity of selected LAB for the bioconversion of milk and whey from goat milk. Enriching products using beneficial strains can be influenced by their adhesive ability, e.g., Lauková et al. [
19] described different adhesive abilities in lactobacilli under in vitro conditions in relation to the autochthonous character of its source. The application form of beneficial strains is also very important. As previously mentioned, the simplest form of encapsulation is freeze drying [
20]. The LPa 12/1 strain in encapsulated form sufficiently survived in both types of yoghurts, although its higher count was determined in ewe–goat milk yoghurts compared with cow milk yoghurts, likely from its autochthonous strain. On the other hand, cow milk yoghurts retained better consistency over 14 days than ewe–goat milk yoghurts. When ewe–goat milk yoghurt was supplemented with the strain
Lactiplantibacillus plantarum LP17L/1 (10
9 cfu/mL) and maintained at 4 °C, it sufficiently survived in yoghurts with stability for 10 days without changes in the product quality [
20]. Speranza et al. [
21] reported functional cream cheese with the
L. reuteri DSM 20016 strain (and
Bifidobacterium animalis subsp.
lactis DSM 10140). The cheese resulted in favourable viability in both strains during 28 days of storage at 4 °C with good sensory characteristics. Patrovský et al. [
22] 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 antilisterial effect. Besides lactobacilli, the antimicrobial effect of bacteriocin (enterocin, Ent 4231) produced by
Enterococcus faecium CCM 4231 was reported in yoghurt [
23]. The yoghurt was experimentally contaminated with the
Listeria monocytogenes Oxford 209P strain. A retardation in the Oxford 209P count was detected in yoghurt after one-day storage compared with the control (10
3 vs. 10
0 cfu/mL/g); a decrease of three orders of magnitude was noted. Some bacteria can influence the proteolysis of casein differently and thus influence the processing of product/yoghurt [
24]. In the case of the LPa 12/1 strain, its optimal technological properties, e.g., sufficient clotting capacity in milk were previously described [
25]. Taking into account the 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, e.g., inhibitory substances-bacteriocins and/or competitive exclusion [
26,
27]. Together with animal products consumption, health safety has been associated. As previously mentioned, the beneficial strain safety must be assessed/confirmed. In this study, an experimental model using Balb/c mice was used. No mortality of mice was assessed, and coliforms were significantly reduced in the faeces and jejunum of mice and mathematically decreased in the liver after LPa 12/1 strain application. The highest count of the LPa 12/1 strain was detected in the faeces of mice and then in the jejunum; almost the same count was present in the liver. Finding LPa 12/1 and/or microbiota in the liver can be explained: the gut microbiota and liver have a bidirectional relationship. As a result, bacterial products and metabolites from microbiota can pass through the intestinal barrier and reach the liver via the portal circulatory system. In the case of beneficial bacteria, they can provide a beneficial influence on the liver [
28]. In our case, the safety of LPa 12/1 strain was fulfilled. Moreover, some lactobacilli representatives can be successfully used as additives to biotherapy in the case of trichinelosis [
11], e.g., when Balb/c mice were infected with
Trichinella spiralis (400 larvae) on day 7 of treatment with the 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 lymphocyte subpopulations from 5 to 25 days postinfection (dpi). The strain LP17L/1 stimulated the CD8+ T cell numbers in infected mice, which were restored in
lamina propria on 11 dpi and in the epithelium on day 32. The immune-modulatory effect of the LP17L/1 strain was confirmed. This is also assumed for LPa 12/1 strains. Related studies are in progress. The safe beneficial strain LPa 12/1 has shown promising application potential in yoghurts. Based on the already published immune-modulatory effect of the other strain of dairy origin (LP17L/1), understanding the immunological mechanism allows risk reductions in parasitic infection or allows for the enrichment of antiparasitic therapy and/or reducing antihelmintic dosage. A promising way to obtain this information is indicated via the dairy products.