A bile salt hydrolase gene of Lactobacillus plantarum BBE7 with high cholesterol-removing activity

Sixteen Lactobacillus strains were screened using a plate agar containing glycodeoxycholic acid or taurodeoxycholic acid and quantitative BSH assay method, along with cholesterol-removing properties in vitro. Most BSH-positive strains tested were more efficient in hydrolyzing glycoconjugated bile salts than tauroconjugated bile salts. Among these strains, Lactobacillus plantarum isolate BBE7 had a relatively high BSH activity toward both bile salts and a higher cholesterol-removing activity (about 72.8?%) from cholesterol (100???g/mL)-containing MRS culture, as compared with other tested strains. The bsh gene of this strain composed of about 43?kDa protein was cloned, sequenced, and overexpressed in Escherichia coli BL21 (DE3). The bsh gene contained a single ORF of 975 nucleotides flanked by a methionine start codon and translational termination codon and encoded a 324-amino-acid protein.     

Microbial characterization of Iranian traditional Lighvan cheese over manufacturing and ripening via culturing and PCR-DGGE analysis: identification and typing of dominant lactobacilli

This paper reports on the diversity and dynamics of the dominant microbial populations during manufacturing and ripening of Lighvan, a traditional, starter-free Iranian cheese made from raw ewe and goat’s milk as determined by culturing and PCR-DGGE. Similar dominant populations, composed of Lactococcus lactis and Lactobacillus spp. strains, were found by both techniques. However, discrepancies regarding the identity of the Lactobacillus species were encountered. Lactobacillus curvatus and Lactobacillus sakei proved to be dominant by PCR-DGGE; in contrast, Lactobacillus paraplantarum, Lactobacillus paracasei, Lactobacillus brevis and Lactobacillus plantarum were the majority cultivable organisms. RAPD typing of lactobacilli isolates showed wide genetic diversity among the species. Moreover, strain compositions change over time; L. brevis and L. paraplantarum were dominant in milk and were replaced by L. plantarum and L. paracasei strains as ripening progressed.     

Phylogenetic study of Lactobacillus acidophilus group, L. casei group and L. plantarum group based on partial hsp60, pheS and tuf gene sequences

The partial nucleotide sequences encoding elongation factor Tu (tuf gene), 60-kDa heat shock protein (hsp60 gene) and phenylalanyl-tRNA synthase (pheS gene) were determined to assess the suitability as phylogenetic markers for discriminating the closely related species in Lactobacillus acidophilus group, L. casei group and L. plantarum group. A total of 234 lactobacilli were chosen from traditional fermented dairy products that were not exactly assigned to species based on biochemical tests and 16S rRNA gene sequences. The sequencing of partial tuf, hsp60 and pheS gene of all strains was performed, and then, the phylogenetic trees were constructed by neighbor-joining method. Phylogenetic tree revealed three genes provided better resolution of each Lactobacillus species than 16S rDNA, and all of strains were clearly identified as L. casei (63 strains), L. plantarum (58 strains) and L. helveticus (113 strains) by comparison of sequences with the type strains. From our results, the partial sequences of three genes had a higher discriminatory power than 16S rRNA gene sequences and were an alternative molecular tool for the taxonomical analysis of L. casei group, L. plantarum group and L. acidophilus group.     

Nucleotide Sequence Identities of horA Homologues and Adjacent DNA Regions Identified in Three Species of Beer‐Spoilage Lactic Acid Bacteria

The horA homologues and adjacent DNA regions identified in beer‐spoilage Lactobacillus lindneri DSM 20690^Tand L. paracollinoides DSM15502^Twere examined and compared with the corresponding DNA region of beer‐spoilage L. brevis ABBC45, a strain in which the hop‐resistance gene horA was originally identified. The PCR analysis suggests ORFB1‐B5 regions surrounding horA are conserved in all of the strains. The nucleotide sequence comparison of the conserved DNA regions revealed extremely high levels of identities among the three beer‐spoilage strains that are not typical for distinct species. The PCR methods using primers specific to the adjacent ORFs were found to be able to differentiate beer‐spoilage Lactobacillus strains from non‐spoilers, indicating these ORFs are also useful genetic markers for determining the beer‐spoilage ability of lactobacilli. The presence or absence of the adjacent ORFs in 92 bacterial strains was completely identical with that of horA homologues, indicating the ORFB1‐B5 regions are generally conserved in beer‐spoilage Lactobacillus strains. Taken together, these results suggest the ORFB1‐B5 regions have been acquired by beer‐spoilage lactobacilli through horizontal gene transfer and provide a theoretical basis for applying a trans‐species genetic marker such as horA to deal with unencountered species of beer‐spoilage lactobacilli.     

Technological and probiotic role of adjunct cultures of non-starter lactobacilli in soft cheeses

The influence of two cheese-isolated Lactobacillus strains on cheese composition, acceptability and probiotic capacity was assessed. Soft cheeses with and without the addition of Lactobacillus plantarum I91 or Lactobacillus paracasei I90 were prepared. Gross composition was assessed and secondary proteolysis was described by soluble fractions and free amino acids profiles. Acceptability was determined by a panel of 98 non-trained consumers. Cheeses harboring added Lactobacillus strains were also studied in vivo to evaluate their probiotic capacity. Gross composition of the cheeses was similar for control and treated (Lactobacillus-added) cheeses. Peptidolysis increased in cheeses with added lactobacilli, which was evidenced by a higher free amino acid content. Overall, the acceptability of the cheeses was good: 65%–80% of the consumers said that they “liked very much” or “liked” the cheeses. Cheeses with L. plantarum I91 showed the highest changes in composition and proteolysis and were the most accepted ones. On the contrary, composition of cheeses with L. paracasei I90 was similar to that of the controls, but these samples were less accepted than cheeses without lactobacilli. The oral administration of cheese containing L. plantarum I91 or L. paracasei I90 proved to be safe and able to enhance the number of IgA + cells in the small intestine lamina propria of mice. The use of selected strains of NSLAB exerted a technological and probiotic role: it contributed to the standardization of cheese quality and induced benefic health effects at the gut mucosa in vivo.     

Size-Exclusion HPLC Separation of Bitter and Astringent Fractions from Cheddar Cheese Made with Added Lactobacillus Strains to Accelerate Ripening

Lactobacillus strains were added as an adjunct to the regular lactic starter in Cheddar cheese manufacture in order to accelerate ripening. Microbial cheese proteolysis resulted in the release of free amino acids which were extracted with the astringent and bitter fractions and separated by size-exclusion and reversed-phase HPLC chromatography. Lactobacillus strains generally increased the degree of proteolysis. L. plantarum and L. brevis produced off-flavors possibly due to an accumulation of medium-size peptides. The control cheese (without lactobacilli) had the most peptides with a mean molecular- weight of < 1000 daltons and had a flavor described as slightly bitter. Addition of L. casei-casei L2A accelerated ripening and yielded a well-aged Cheddar cheese without any bitterness even after 7 months at 6°C.     

Anti‐adhesive effects of sialic acid and Lactobacillus plantarum on Staphylococcus aureus in vitro

Staphylococcus aureus (S. aureus) is a common food‐borne pathogen that causes severe diseases after adhesion to epithelial cells. Lactobacillus inhibits pathogenic bacterial adhesion and infection. In addition, sialic acid (SA) is widely known for its beneficial biological functions. A new way of reducing the occurrence of diseases and curbing the overuse of antibiotics is ingesting prebiotics and probiotics that regulate the intestinal flora. In this study, we first evaluated the anti‐adhesive effects of several strains of Lactobacillus on S. aureus. The study revealed that the S. aureus adhesion was inhibited by all the strains of Lactobacillus. Besides, the rate of inhibition by L. plantarum Z‐4 was significantly higher than other Lactobacillus species. We then investigated the effects of different SA concentrations (40, 100, 150, 200, and 260 μg/ml) on the growth and adhesion characteristics of L. plantarum and S. aureus. The results showed that SA influences bacterial adhesion by regulating the bacteria's growth characteristics. Finally, the effects of SA combined with Lactobacillus on the adhesion of S. aureus were assessed by competition, exclusion and displacement methods. SA with a concentration of 260 μg/mL combined with L. plantarum had the highest inhibition effect on the competition assays. In addition, the expression of S. aureus adhesion‐related genes was reduced. This provides a new perspective on the application of SA and/or L. plantarum and its potential to resist adhesion of S. aureus.     

Diversity of stress tolerance in Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus paraplantarum: A multivariate screening study

Sixty-three strains of the taxonomically related species Lactobacillus plantarum subsp. plantarum, L. plantarum subsp. argentoratensis, L. paraplantarum and L. pentosus isolated from sourdoughs and other food and non-food sources and 14 strains of other members of the genus Lactobacillus were screened for their tolerance of acid, alkaline, heat, oxidative, osmotic, detergent and starvation stresses in order to evaluate the diversity of stress response. Most strains of the L. plantarum group were highly tolerant of acid, alkaline and osmotic stress and highly sensitive to detergent stress, while a larger diversity was found for other stress. Multivariate analysis allowed grouping the strains in clusters with similar response patterns. Stress response patterns in the L. plantarum group were similar to those of species of the L. casei/L. paracasei group but clearly different from those of other mesophilic Lactobacillus. No relationship was found between grouping obtained on the basis of stress response patterns and by genotypic fingerprinting (rep-PCR), nor with the taxonomic position or isolation source of the strains. Further experiments with selected strains showed that exponential phase cells were generally but not always more sensitive than stationary phase cells. The ability to grow under stressful conditions showed a slightly better correlation with the ecological conditions prevailing in the isolation niches of the strains.This study will be the basis for further investigations to identify and exploit the basis of diversity in the stress response of lactic acid bacteria.     

Biocontrol of Gray Mold Disease on Strawberry Fruit by Integration of Lactobacillus plantarum A7 with Ajwain and Cinnamon Essential Oils

This study was conducted to evaluate the efficacy of the Lactobacillus plantarum A7 (L. Plantarum), ajwain and cinnamon essential oils (AO and CO, respectively) in suppressing gray mold rot in strawberry fruit. AO and CO showed over 90% inhibition of radial mycelia growth with lower concentration of the oils per plate for all tested pathogens. Combined application of L. plantarum with AO and CO was tested to assess the possible synergistic effects of these 3 elements on the control of tested plant pathogens. In this case both combinations of L. plantarum + AO and L. plantarum + CO inhibited the mycelia growth of the pathogens completely. Results showed that the combined treatment of strawberry fruits with L. plantarum + AO (50 μL) and L. plantarum + CO (100 μL) resulted in remarkably improved control of Botrytis infections, in comparison with application of L. plantarum or essential oils alone. Quality attributes (that is pH, acidity, vitamin C, and total soluble solid) of the strawberry fruits did not change significantly (P < 0.01) when combination of Lactobacillus and essential oils was used. To the best of our knowledge, this is the first report on the effects of combination of a Lactobacillus as an antagonist bacterium with essential oils to increase the shelf life of strawberry.     

Lactobacillus spp. from Washington State Wines: Isolation and Characterization

Species of Lactobacillus were isolated and identified from commercial Washington state grapes and wines including L. brevis (4 strains), L. hilgardii (4), L. plantarum (3), and L. fructivorans (1). Unlike other strains, L. brevis and L. pluntarum grew in media at relatively low pH (pH 3.16 and 3.34). Sulfur dioxide inhibited all strains as growth was delayed in 33 mg/L total SO2 (pH 3.5). None of the strains grew in 12% or 14% ethanol. Alcoholic fermentations of two grape musts were not slowed in the presence of strains of L. brevis, L. hilgardii, or L. plantarum.     

DNA Arrays and Membrane Hybridization Methods for Screening of Six Lactobacillus Species Common in Food Products

Dot blot and deoxyribonucleic acid (DNA) array hybridization assays for the traceability of Lactobacillus species in food have been developed to monitor and validate typical food products. A primer set was designed to amplify the 540-bp region located at +157 of the tuf (Elongation factor Tu) gene of the Lactobacillus genus. An oligonucleotide array, containing 73 Lactobacillus species-specific tuf sequences representing 21 species, was developed and tested for identifying L. paracasei, L. rhamnosus, L. plantarum, and L. buchneri. We also tested a rapid screening method for monitoring the species present in airy samples. Dot blot hybridization identified polymerase chain reaction amplicons immobilized on nylon membranes, using six tuf-based cyanine-3-labeled 18-mer oligonucleotides, specific for L. paracasei, L. zeae, L. fermentum, L. plantarum, L. rhamnosus, and L. buchneri. This method discriminates between multiple species of Lactobacilli isolated directly from cheese samples, simultaneously. The tuf gene sequences, verified here with the DNA array method and used in dot blot hybridization, were shown to be a reliable tool for the simultaneous detection and differentiation of four Lactobacillus species. The hybridization techniques developed in this study may be useful in food processing and the analysis of food origin traceability.     

Probiotic potential of Lactobacillus strains with anti-allergic effects from kimchi for yogurt starters

Lactobacillus strains were isolated from kimchi and investigated for their potential use for probiotic yogurt starters. Two of the isolated strains have over 90% survival rate to artificial gastric acid (pH 2.5, 1% pepsin) and artificial bile acid (0.3% oxgall). These strains were identified as Lactobacillus plantarum by 16S rRNA sequencing, and named as L. plantarum SY11 and L. plantarum SY12. The known carcinogenic enzyme, β-glucuronidase was not produced by L. plantarum SY11 and L. plantarum SY12. These 2 strains were found to be resistant to several antibiotics and strongly adhered to intestinal cells. Antiallergic effect of L. plantarum SY11 and L. plantarum SY12 was demonstrated using nitric oxide (NO) and cytokine production. L. plantarum SY11 and L. plantarum SY12 were capable of significantly decreasing NO production, and reduced T helper 2-associated cytokines, cyclooxygenase-2, tumor necrosis factor-α, and inducible nitric oxide synthase compared to control. Yogurt samples produced using L. plantarum SY11 and L. plantarum SY12 did not show significant differences in microbiological, physicochemical, and sensory properties compared with yogurt sample produced using commercial strain. Therefore, these two strains could be used as probiotic yogurt starters with antiallergic effects.     

Effect of 3 lactobacilli on immunoregulation and intestinal microbiota in a β-lactoglobulin–induced allergic mouse model

Milk is one of the earliest and most common allergen sources in the world, with β-lactoglobulin representing a major allergen protein. Numerous studies have reported that probiotics exert antiallergic and anti-inflammatory effects. Here, we examined the effects of 3 strains of Lactobacillus on immunomodulatory functions, intestinal barrier functions, and intestinal microbiota through a β-lactoglobulin–induced allergic mouse model. We found that the oral administration of Lactobacillus plantarum ZDY2013 and Lactobacillus rhamnosus GG suppressed allergic response, attenuating serum IgE and relieving anaphylaxis symptoms. The 3 strains of Lactobacillus could induce T helper (Th) 1 or T regulatory cells to differentiate to inhibit the Th2-biased response for regulating Th1/Th2 immune balance. Furthermore, L. plantarum ZDY2013 and L. rhamnosus GG enhanced intestinal barrier function through the regulation of tight junction. We also found that L. plantarum ZDY2013 and L. plantarum WLPL04 could regulate alterations in intestinal microbiota caused by allergies. In particular, Rikenella, Ruminiclostridium, and Lachnospiraceae UCG-006 were considerably reduced after treatment with L. plantarum ZDY2013 and L. plantarum WLPL04. These results suggested that 3 Lactobacillus strains may serve as an effective tool for the treatment of food allergies by regulating immune and gut microbiota.     

Molecular Characterization of Lactobacilli Isolated from Piper betle L. var. Pachaikodi and Comparative Analysis of the Antimicrobial Effects of Isolate Lactobacillus plantarum KJB23 and Betel Leaves Extract

Traditionally Piper betle L. leaves have been used in India for fermenting certain foods. In our previous study, while fermenting Uttapam batter along with Piper betle L. var. Pachaikodi leaves led to suppression of gas formation and altered Lactic acid bacteria profile, especially in bacilli isolates compared to those observed in plain Uttapam batter fermentation. Hence, the aim of the present study was to understand the rationale behind these changes through characterization of Lactobacillus isolates from Piper betle L. var. Pachaikodi and also the leaves extracts for antimicrobial activity. Out of 72 isolates obtained from the betel leaves, only 10 isolates were bacilli which were chosen for their molecular characterization and to elucidate their inhibitory effects against major food borne pathogens and gas-forming bacteria and to compare with the effect of betel leaves extract. Random amplified polymorphic DNA (RAPD)-PCR and phenotype analysis was used to differentiate the isolates at strain level, 16S rRNA gene sequence for phylogenetic analysis and species-specific multiplex PCR analysis for sub-species identification. All isolates were identified as Lactobacillus plantarum subsp. plantarum. All Lactobacillus isolates were indigenous to leaf as they were resistant to betel leaves extract and showed maximum activity against some LAB and non-LAB indicator strains except Lactobacillus plantarum MTCC 6160 which was resistant. Among them, KJB23, 36 and 47 were the most effective. Particularly, the isolate KJB23 and ethanolic betal leaf extract showed rivaling inhibitory activity against major food borne pathogens, while dissimilar activity against gas forming bacteria. This study revealed that either Piper betle L. leaf or Lactobacillus strains from the leaves can be valuable for food applications when added to fermented products.     

Comparison and evaluation of molecular methods used for identification and discrimination of lactic acid bacteria

BACKGROUND: Lactobacillus and Bifidobacterium strains are present in a great variety of habitats, including fermented products, probiotic concoctions and the human colon. Some species are so closely related that it is difficult to distinguish them by microbiological techniques. Nevertheless, discrimination of isolates is an important issue in respect of application, and molecular methods such as restriction fragment length polymorphism (RFLP), random amplification of polymorphic DNA (RAPD) or species‐specific polymerase chain reaction (PCR) might help in resolving this problem. In this study, PCR, RFLP and sequencing were applied to identify lactobacilli and bifidobacteria originating from various sources and the DSMZ strain collection. RESULTS: The microbiological composition of foods was analysed by molecular methods. Using species‐specific PCR primers, three restriction enzymes (AluI, HhaI and RsaI) and sequencing, three Bifidobacterium and six Lactobacillus reference strains could be distinguished and four additional lactobacilli of food origin were identified. CONCLUSION: A combination of three molecular methods resulted in successful discrimination of nine reference strains and four isolates of food origin. Since these methods are not always accurate owing to their high genetic homogeneity, it is advisable to use more than one method for the identification of L. casei and closely related species. Copyright © 2012 Society of Chemical Industry     

Short communication: Improving the activity of bile salt hydrolases in Lactobacillus casei based on in silico molecular docking and heterologous expression

Bile salt hydrolase (BSH) plays an essential role in the cholesterol-removing effect of lactic acid bacteria, which hydrolyze conjugated bile salts to amino acid and deconjugated bile salts. However, Lactobacillus casei lacks the bsh gene, which may make it highly sensitive to bile salt stress. We wanted to improve the BSH activity of L. casei for various food-industry applications (e.g., milk fermentation). Plate assay testing indicated that Lactobacillus plantarum AR113 has the highest BSH activity. We cloned and sequenced 4 bsh genes from the genome of L. plantarum AR113. Structure modeling and molecular docking of BSH indicated that BSH1 and BSH3 could react efficiently with bile salts, so we selected BSH1 and BSH3 for heterologous expression in L. casei. Compared with single expression of BSH1 or BSH3, co-expression of both protein sequences showed the highest hydrolysis activity by HPLC analysis. Our results suggested that heterologous expression of BSH in L. casei can significantly improve host activity against bile salts, and in silico molecular docking could be an efficient method of rapid screening for BSH with high activity.     

Comparison of rpoA and pheS Gene Sequencing to 16S rRNA Gene Sequencing in Identification and Phylogenetic Analysis of LAB from Probiotic Food Products and Supplements

An investigation of the relevance of sequenced protein-coding genes in comparison with 16S rRNA gene sequences to correctly delineate and discriminate between closely related Lactobacillus isolates is presented. These reportedly probiotic Lactobacillus strains were obtained from probiotic supplements and food products. Probiotic Lactobacillus species have been found to have several potential health benefits and technological properties which may be strain-dependent. It was deemed necessary to investigate molecular techniques for the identification and discrimination between closely related isolates. The 16S rRNA, pheS, and rpoA genes were amplified in a polymerase chain reaction using the oligonucleotide pairs 27F/1492R, pheS-21-F/pheS-23-R, and rpoA-21-F/rpoA-23-R. The PCR amplicons were separated using gel agarose electrophoresis and observed by the Bio-Rad Gel Doc^TM XR+ Imaging system transilluminator. Sequencing of the PCR amplicons was done in an ABI PRISM^TM 3100 genetic analyzer. MEGA 5.05 software was employed in doing the phylogenetic analysis. Identification by 16S rRNA gene sequencing was confirmed by pheS and rpoA gene sequencing. Subsequent phylogenetic analysis and concatenation showed that interspecies and intraspecies degrees of diversity and similarity were better enabled by pheS and rpoA primers. Overall, findings revealed cases of inaccurate identification of Lactobacillus strains in probiotic supplements on the market, highlighting the relevance of the multigenic approach in more accurately identifying Lactobacillus strains. Supplemental materials are available for this article; see the publisher's online edition of Food Biotechnology to view the supplemental file.     

Characterisation and partial purification of an antimutagenic peptide produced by Lactobacillus plantarum JNU 2116

The antimutagenic activities of sixteen strains of Lactobacillus were evaluated using three mutagens (4‐nitroquinoline‐N'‐oxide, 4‐NQO; N‐methyl‐N'nitro‐N‐nitrosoguanidine, MNNG; and 2‐amino‐3‐methylimidazole quinoline, IQ). Among the tested Lactobacillus strains, Lactobacillus plantarum strain JNU 2116 had the highest antimutagenic activity in the presence of 4‐NQO, MNNG and IQ (21.5, 25.8 and 34.54% inhibition, respectively). The molecular weight of the antimutagenic peptide was estimated at approximately 762 Da, and the N‐terminal amino acid residue sequence of the purified peptide was identified as NH₂‐ XLEXKKAEXITTXX. This peptide may be able to counteract the activity of carcinogens and other toxins if it is added to functional dairy products.     

Discrimination of the Lactobacillus acidophilus group using sequencing, species-specific PCR and SNaPshot mini-sequencing technology based on the recA gene

BACKGROUND: To clearly identify specific species and subspecies of the Lactobacillus acidophilus group using phenotypic and genotypic (16S rDNA sequence analysis) techniques alone is difficult. The aim of this study was to use the recA gene for species discrimination in the L. acidophilus group, as well as to develop a species‐specific primer and single nucleotide polymorphism primer based on the recA gene sequence for species and subspecies identification. RESULTS: The average sequence similarity for the recA gene among type strains was 80.0%, and most members of the L. acidophilus group could be clearly distinguished. The species‐specific primer was designed according to the recA gene sequencing, which was employed for polymerase chain reaction with the template DNA of Lactobacillus strains. A single 231‐bp species‐specific band was found only in L. delbrueckii. A SNaPshot mini‐sequencing assay using recA as a target gene was also developed. The specificity of the mini‐sequencing assay was evaluated using 31 strains of L. delbrueckii species and was able to unambiguously discriminate strains belonging to the subspecies L. delbrueckii subsp. bulgaricus. CONCLUSION: The phylogenetic relationships of most strains in the L. acidophilus group can be resolved using recA gene sequencing, and a novel method to identify the species and subspecies of the L. delbrueckii and L. delbrueckii subsp. bulgaricus was developed by species‐specific polymerase chain reaction combined with SNaPshot mini‐sequencing. Copyright © 2012 Society of Chemical Industry     

Short communication: Complete genome sequence of Lactobacillus plantarum J26, a probiotic strain with immunomodulatory activity

Lactobacillus plantarum J26, a significant probiotic isolated from Chinese traditional fermented dairy products, exerts a positive immunomodulatory effect by regulating the expression of immune-related genes. We investigated expression of the cytokines IL-1α, IL-1β, IL-6, and tumor necrosis factor-α in the intestinal tract of mice stimulated by L. plantarum J26. In vivo, these cytokines were upregulated, peaked on d 5, and then decreased to the control level, indicating that L. plantarum J26 could induce expression of the genes encoding these proinflammatory cytokines. Teichoic acids produced by L. plantarum are recognized as key immunomodulatory molecules involved in the regulation of the host immune response. To better understand the genetic basis of this immunomodulatory mechanism, we sequenced and analyzed the whole genome of L. plantarum J26. The genome of L. plantarum J26 contains a circular chromosome and 4 circular plasmids. Lactobacillus plantarum J26 was predicted to synthesize ribitol-type backbones of wall teichoic acid. Furthermore, orthologous average nucleotide identity (OrthoANI) values showed that the genome was highly similar (>98.00%) to other L. plantarum strains, especially to L. plantarum ST-III and JDM1. The genomic data of L. plantarum J26 provide a genetic basis to further elucidate its mechanism of immunoregulation and will facilitate its application in the functional dairy food industry.