Lactobacilli in Probiotic Consortia: Profile and Prospects

Probiotics are live microorganisms that confer documented health benefits upon the host. Among these, Lactobacilli remain the most popular probiotic cultures, largely due to their efficacy in preventing metabolic disorders. This article evaluates the probiotic potential of several Lactobacillus strains as key functional ingredients in metabolic dietary supplements and functional foods. The research featured Lactobacillus plantarum (B-5772, B-11264, B-3242), Lactobacillus fermentum (B-7574, B-7573), Lactobacillus acidophilus (B-194, B-2585, B-2900), and Lactobacillus casei (B-7951). The disc diffusion method revealed the degree of antibiotic resistance while the agar diffusion method made it possible to assess their antagonistic activity. The nutrient media were tested for carbohydrate sources to maximize the biomass accumulation in optical density units. The chromatographic analysis demonstrated the qualitative and quantitative composition of metabolites, i.e., B vitamins, organic acids, and amino acids. The biocompatibility of the strains was determined by co-cultivation. B-194 and B-7951 were resistant to streptomycin. B-7951 exhibited intermediate resistance to azithromycin while B-7573 and B-7951 were resistant to gentamicin, and B-3242 and B-7573 demonstrated a lack of susceptibility to streptomycin. B-11264 and B-7573 showed high antagonistic activity (≥23 mm) against Pseudomonas aeruginosa; B-7573 was effective against Bacillus cereus; B-11264, B-3242, and B-7951 resisted Enterococcus faecalis; B-11264, B-3242 and B-7573 showed good resistance to Klebsiella pneumoniae. The strains accumulated biomass better in the presence of lactulose. The chromatographic analysis showed that B-3242 produced vitamin B1 (25.98 ± 0.33 mg/g); B-7573 generated vitamin B3 (5.60 ± 0.03 mg/g); B-7573 yielded citric acid (52.6 ± 0.7 mg/L); B-2585 produced citric (58.0 ± 0.8 mg/L) and succinic (326.5 ± 3.2 mg/L) acids; B-7951 generated oxalic (17.1 ± 0.2 mg/L) and tartaric (17.1 ± 0.2 mg/L) acids. B-11264 produced tryptophan (16.2 ± 0.2 mg/g), glutamic acid (15.1 ± 0.2 mg/g), glycine (19.1 ± 0.2 mg/g), and proline (21.8 ± 0.3 mg/g). The strains demonstrated biocompatibility in co-cultivation. The strains involved in this research represent promising candidates for integration into probiotic nutraceuticals and functional food formulations.