• Journal of Microbiology and Biotechnology
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• v.34 no.4
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• pp.871-879
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• 2024

Our group had isolated Bifidobacterium breve strain BS2-PB3 from human breast milk. In this study, we sequenced the whole genome of B. breve BS2-PB3, and with a focus on its safety profile, various probiotic characteristics (presence of antibiotic resistance genes, virulence factors, and mobile elements) were then determined through bioinformatic analyses. The antibiotic resistance profile of B. breve BS2-PB3 was also evaluated. The whole genome of B. breve BS2-PB3 consisted of 2,268,931 base pairs with a G-C content of 58.89% and 2,108 coding regions. The average nucleotide identity and whole-genome phylogenetic analyses supported the classification of B. breve BS2-PB3. According to our in silico assessment, B. breve BS2-PB3 possesses antioxidant and immunomodulation properties in addition to various genes related to the probiotic properties of heat, cold, and acid stress, bile tolerance, and adhesion. Antibiotic susceptibility was evaluated using the Kirby-Bauer disk-diffusion test, in which the minimum inhibitory concentrations for selected antibiotics were subsequently tested using the Epsilometer test. B. breve BS2-PB3 only exhibited selected resistance phenotypes, i.e., to mupirocin (minimum inhibitory concentration/MIC >1,024 ㎍/ml), sulfamethoxazole (MIC>1,024 ㎍/ml), and oxacillin (MIC >3 ㎍/ml). The resistance genes against those antibiotics, i.e., ileS, mupB, sul4, mecC and ramA, were detected within its genome as well. While no virulence factor was detected, four insertion sequences were identified within the genome but were located away from the identified antibiotic resistance genes. In conclusion, B. breve BS2-PB3 demonstrated a sufficient safety profile, making it a promising candidate for further development as a potential functional food.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.20 no.3
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• pp.139-146
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• 2017

The number of papers discussing probiotics increases tremendously that limits the possibility for primary care physicians and clinicians to stay updated. Therefore, the aim of this paper will be to summarize available evidence of probiotic use in well-defined clinical indications of importance for pediatricians. Based on currently available evidence certain probiotic strains (Lactobacillus rhamnosus GG [LGG] and Saccharomyces boulardii) have proven effect in the treatment of acute gastroenteritis and prevention of antibiotic associated diarrhea. Furthermore, LGG was proven to be effective in prevention of nosocomial diarrhea and respiratory tract infection in day care centers. In conclusion, not all probiotic strains have same efficacy for all clinical indications, therefore, only strains with proven efficacy and safety should be recommended.

• Food Science of Animal Resources
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• v.43 no.4
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• pp.685-702
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• 2023

Lactic acid bacteria (LAB) are commonly used as probiotics; however, not all LAB strains have the same beneficial effects. To successfully use LAB as probiotics in canines, LAB species should originate from the canine intestinal tract as they display host specificity. The objective of this study was to investigate the phenotypic and genomic traits of potential probiotic LAB isolated from canine fecal samples. Twenty LAB samples were evaluated for their potential probiotic characteristics including resistance to low pH, bile salts, hydrophobicity, auto-aggregation, co-aggregation, adhesion to epithelia or mucosa, and production of inhibitory compounds. Additionally, we evaluated their safety and other beneficial effects on canine health, such as DPPH free radical scavenging, and β-galactosidase. Four strains demonstrated potential probiotic characteristics and were selected: Enterococcus hirae Pom4, Limosilactobacillus fermentum Pom5, Pediococcus pentosaceus Chi8, and Ligilactobacillus animalis FB2. Safety evaluations showed that all strains lacked hemolytic activity, could not produce biogenic amines, and did not carry any pathogenic genes. In addition, L. fermentum Pom5 and P. pentosaceus Chi8 displayed susceptibility to all antibiotics and concordant with the absence of antibiotic resistance genes. Based on their phenotypic and genomic characteristics, L. fermentum Pom5 and P. pentosaceus Chi8 were identified as potential probiotic candidates for canines.

• Journal of Microbiology and Biotechnology
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• v.33 no.4
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• pp.519-526
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• 2023

Panax ginseng is one of the most important herbal medicinal plants consumed as health functional food and can be fermented to achieve better efficacy. Lacticaseibacillus, one of the representative genera among lactic acid bacteria (LAB), has also been used as a probiotic material for health functional foods due to its beneficial effects on the human body. To achieve a synergistic effect by using these excellent dietary supplement ingredients together, a novel LAB strain was isolated from the root of 6-year-old ginseng. Through similarity analysis of 16S rRNAs and whole-genome sequences, the strain was confirmed as belonging to the genus Lacticaseibacillus and was named L. casei KGC1201. KGC1201 not only met all safety standards as food, but also showed excellent probiotic properties such as acid resistance, bile salt resistance, and intestinal adhesion. In particular, KGC1201 exhibited superior acid resistance through morphological observation identifying that the cell surface damage of KGC1201 was less than that of the L. casei type strain KCTC3109. Gene expression studies were conducted to elucidate the molecular mechanisms of KGC1201's acid resistance, and the expression of the glycosyltransferase gene was found to be significantly elevated under acidic conditions. Exopolysaccharides (EPSs) biosynthesized by glycosyltransferase were also increased in KGC1201 compared to KCTC3109, which may contribute to better protection of KGC1201 cells from strong acidity. Therefore, KGC1201, with its increased acid resistance through molecular mechanisms and excellent probiotic properties, can be used in health functional foods to provide greater benefit to overall human health and well-being.

• Genomics & Informatics
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• v.17 no.4
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• pp.43.1-43.5
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• 2019

Lactobacillus acidophilus UBLA-34, L. paracasei UBLPC-35, L. plantarum UBLP-40, and L. reuteri UBLRU-87 were isolated from different varieties of fermented foods. To determine the probiotic safety at the strain level, the whole genome of the respective strains was sequenced, assembled, and characterized. Both the core-genome and pan-genome phylogeny showed that L. reuteri was closest to L. plantarum than to L. acidophilus, which was closest to L. paracasei. The genomic analysis of all the strains confirmed the absence of genes encoding putative virulence factors, antibiotic resistance, and the plasmids.

• The Korean Journal of Food And Nutrition
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• v.33 no.3
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• pp.223-236
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• 2020

In this study, a safety evaluation was conducted to confirm if the Enterococcus faecium CKDB003 strain obtained by selection from a mixed fermentation of fruit and milk is suitable for use as a probiotic. The MIC value for the 10 antibiotics specified in the EFSA guidance was below the acceptable cut-off value. The antibiotic resistance genes aac(6')-li, eatAv, and msr(C) exist by whole genome sequencing, but are in the chromosome and not in the plasmid, thus confirming that there is no possibility of transmission to other microorganisms. It was confirmed that cytolysin (cylA, cylB, cylI, cylL-l, cylL-s, cylM, cylR1, cylR2), aggregation substance (asa1, asp1), collagen adhesion (ace), enterococcal surface protein (esp), endocarditis antigen (efaA), hyaluronidase (hyl) and gelatinase (gelE) were not present in the genome by examining the genes of factors related to virulence. Also, the biochemical analysis showed no toxic enzyme activities, and no virulence genes were detected by the PCR method. Thus, the E. faecium CKDB003 strain can be safely used as a health functional food probiotic, based on the results of the safety assessment.

• Journal of Microbiology and Biotechnology
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• v.33 no.12
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• pp.1625-1634
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• 2023

Leuconostoc lactis strain DMLL10 was isolated from kimchi, a fermented vegetable, as a starter candidate through safety and technological assessments. Strain DMLL10 was susceptible to ampicillin, chloramphenicol, clindamycin, erythromycin, gentamicin, kanamycin, streptomycin, and tetracycline. It did not show any hemolytic activity. Regarding its phenotypic results related to its safety properties, genomic analysis revealed that strain DMLL10 did not encode for any toxin genes such as hemolysin found in the same genus. It did not acquire antibiotic resistance genes either. Strain DMLL10 showed protease activity on agar containing NaCl up to 3%. The genome of DMLL10 encoded for protease genes and possessed genes associated with hetero- and homo-lactic fermentative pathways for lactate production. Finally, strain DMLL10 showed antibacterial activity against seven common foodborne pathogens, although bacteriocin genes were not identified from its genome. These results indicates that strain DMLL10 is a novel starter candidate with safety, enzyme activity, and bacteriocin activity. The complete genomic sequence of DMLL10 will contribute to our understanding of the genetic basis of probiotic properties and allow for assessment of the effectiveness of this strain as a starter or probiotic for use in the food industry.

• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.644-655
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• 2023

Safety assessment and functional analysis of probiotic candidates are important for their industrial applications. Lactiplantibacillus plantarum is one of the most widely recognized probiotic strains. In this study we aimed to determine the functional genes of L. plantarum LRCC5310, isolated from kimchi, using next-generation, whole-genome sequencing analysis. Genes were annotated using the Rapid Annotations using Subsystems Technology (RAST) server and the National Center for Biotechnology Information (NCBI) pipelines to establish the strain's probiotic potential. Phylogenetic analysis of L. plantarum LRCC5310 and related strains showed that LRCC5310 belonged to L. plantarum. However, comparative analysis revealed genetic differences between L. plantarum strains. Carbon metabolic pathway analysis based on the Kyoto Encyclopedia of Genes and Genomes database showed that L. plantarum LRCC5310 is a homofermentative bacterium. Furthermore, gene annotation results indicated that the L. plantarum LRCC5310 genome encodes an almost complete vitamin B₆ biosynthetic pathway. Among five L. plantarum strains, including L. plantarum ATCC 14917^T , L. plantarum LRCC5310 detected the highest concentration of pyridoxal 5'-phosphate with 88.08 ± 0.67 nM in MRS broth. These results indicated that L. plantarum LRCC5310 could be used as a functional probiotic for vitamin B₆ supplementation.

• Journal of Life Science
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• v.31 no.6
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• pp.595-602
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• 2021

Human intestinal microbiota play an important role in the regulation of the host's metabolism. There is a close pathological and physiological interaction between dysbiosis of the intestinal microflora and obesity and metabolic syndrome. Akkermansia muciniphila, which was recently isolated from human feces, accounts for about 1-4% of the intestinal microbiota population. The use of A. muciniphila- derived external membrane protein Amuc_1100 and extracellular vesicles (EVs) could be a new strategy for the treatment of obesity. A. muciniphila is considered a next-generation probiotic (NGP) for the treatment of metabolic disorders, such as obesity. Faecalibacterium prausnitzii accounts for about 5% of the intestinal microbiota population in healthy adults and is an indicator of gut health. F. prausnitzii is a butyrate-producing bacterium, with anti-inflammatory effects, and is considered an NGP for the treatment of immune diseases and diabetes. Postbiotics are complex mixtures of metabolites contained in the cell supernatant secreted by probiotics. Parabiotics are microbial cells in which probiotics are inactivated. Paraprobiotics and postbiotics have many advantages over probiotics, such as clear chemical structures, safe dose parameters, and a long shelf life. Thus, they have the potential to replace probiotics. The most natural strategy to restore the imbalance of the intestinal ecosystem normally is to use NGPs among commensal bacteria in the gut. Therefore, it is necessary to develop new foods or drugs such as parabiotics and postbiotics using NGPs.

• Journal of Food Hygiene and Safety
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• v.33 no.6
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• pp.474-482
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• 2018

The aim of this study was to determine and analyze probiotic contents, pH, and acidity of 120 samples of health functional and processed foods containing lactic acid bacteria distributed in 2017. The changes due to the preservation methods were also determined and analyzed in five probiotic products. Two samples of the 85 health functional food products had lactic acid bacteria at lower levels than the marked amount required to meet Korean food standards, whereas the 35 processed products were all suitable for distribution. The averages for probiotic contents, pH, and acidity were $1.2{\times}10^{10}CFU/g$, 5.35, and 1.29%, respectively. The average count of lactic acid bacteria in the 17 samples with marked amount among the 35 processed foods was $5.8{\times}10^8CFU/g$. The effects of preservation temperature ($-20^{\circ}C$, $4^{\circ}C$, $20^{\circ}C$, and $40^{\circ}C$) and storage period (1, 3, and 6 months) on probiotic content, pH, and acidity were determined for 5 probiotic products. After 1 to 6 months, the average reduction in probiotic content was by 59%; the lowest reduction occurred at $4^{\circ}C$ and the highest reduction occurred at $40^{\circ}C$. In addition, 3 of the 5 products showed a rapid decrease in probiotic content by more than 70% at $40^{\circ}C$ after a storage period of 1 to 3 months. Therefore, from this study results, it is recommended that products containing lactic acid bacteria should be refrigerated and consumed shortly after purchase.