Screening of probiotic Lactobacillus to reduce peanut allergy and with potential anti-allergic activity.

BACKGROUND: Peanut is a significant source of nutrition and a valuable oilseed crop. It is also a serious allergy source, which poses a threat to 1.1% of the population. This study aimed to screen lactic acid bacteria (LAB) with the capacity to alleviate peanut allergenicity and exhibit anti-allergic properties. RESULT: The results show that LAB can make use of substances in peanuts to reduce the pH of peanut milk from 6.603 to 3.593-4.500 by acid production and that it can utilize the protein in peanuts to reduce the allergenic content (especially Ara h 1) and improve biological activity in peanut pulp. The content of Ara h 1 peanut-sensitizing protein was reduced by 74.65% after fermentation. The protein extracted from fermented peanut pulp is more readily digestible by gastrointestinal juices. The inhibitory activity assay of hyaluronidase (an enzyme with strong correlation to allergy) increased from 46.65% to a maximum of 90.57% to reveal that LAB fermentation of peanut pulp exhibited a robust anti-allergic response. CONCLUSION: The strains identified in this study exhibited the ability to mitigate peanut allergenicity partially and to possess potential anti-allergic properties. Lactobacillus plantarum P1 and Lactobacillus salivarius C24 were identified as the most promising strains and were selected for further research. © 2023 Society of Chemical Industry.

Limosilactobacillus fermentum NCU003089 and Lactiplantibacillus plantarum NCU001261, two probiotics with inhibition of Escherichia coli and Cronobacter sakazakii translocation in vitro.

The subject of this study was to screen lactic acid bacteria (LAB) with pathogen translocation inhibition and investigate the potential inhibition mechanism of it. Pathogens colonized in the intestine could cross the intestinal barrier to access blood circulation, causing severe complications. This study aimed to screen LAB with favorable inhibitory effects on the translocation of enterinvasive Escherichia coli CMCC44305 (E. coli) and Cronobacter sakazakii CMCC45401 (C. sakazakii), which were two common intestinal opportunistic pathogens. After an elaborate screening procedure including adhesion, antibacterial, and translocation assay, Limosilactobacillus fermentum NCU003089 (L. fermentum NCU3089) and Lactiplantibacillus plantarum NCU0011261 (L. plantarum NCU1261) were found to inhibit 58.38% and 66.85% of pathogen translocation, respectively. Subsequently, LAB pre-treatment suppressed the decline in TEER of Caco-2 monolayers caused by pathogens. Meanwhile, L. fermentum NCU3089 significantly inhibited claudin-1, ZO-1, and JAM-1 degradation caused by E. coli, and L. plantarum NCU1261 markedly reduced claudin-1 degradation caused by C. sakazakii. Also, the two LAB strains significantly decreased TNF-α level. In addition, L. fermentum NCU3089 but not L. plantarum NCU1261 tolerated well in the gastrointestinal fluids, and they were both sensitive or intermediate to nine common clinical antibiotics without hemolytic activity. In short, the two LAB strains could inhibit pathogen translocation by competing for adhesion sites, secreting antibacterial substances, reducing inflammatory cytokines levels, and maintaining intestinal barrier integrity. This study provided a feasible solution to prevent pathogen infection and translocation, and the two LAB strains were safe and had potential in food and pharmaceutical applications.

Metatranscriptomics reveals the gene functions and metabolic properties of the major microbial community during Chinese Sichuan Paocai fermentation.

Chinese Sichuan Paocai (CSP) is one of the world's best-known fermented vegetables with a large presence in the Chinese market. The dynamic microbial community is the main contributor to Paocai fermentation. However, little is known about the ecological distribution and functional importance of these community members. In this study, metatranscriptomics was used to comprehensively explore the active microbial community members and key transcripts with significant functions in the Paocai fermentation process. Enterobacter, Leuconostoc, and Lactobacillus dominated the three-fermentation stages (Pre-, Mid- and Lat-), respectively. Carbon metabolism was the most abundant pathway. GH (glycoside hydrolase) and GT (lycosyl transferase) were the two most highly expressed carbohydrate-active enzymes. The most highly differentially expressed genes were grouped in the biosynthesis of amino acids, followed by glycolysis. Meta-pathways in the Sichuan Paocai fermentation ecosystem were reconstructed, Lactobacillaceae and Enterobacteriaceae were the two most important metabolic contributors. In addition, the nrfA and nirB were two genes referred to distinct nitrite reductase enzymes and 9 specialized genes, such as eclo, ron and ent were expressed to produce autoinducer 2 (AI-2) kinase in response to population density. The present study revealed functional enzymes and meta-pathways of the active microbial communities, which provide a deeper understanding of their contribution to CSP products.

Probiotic-fermented tomato with hepatic lipid metabolism modulation effects: analysis of physicochemical properties, bioactivities, and potential bioactive compounds.

Lactiplantibacillus plantarum NCUH001046 (LP)-fermented tomatoes exhibited the potential to alleviate obesity in our previous study. This subsequent study further delves deeper into the effects of LP fermentation on the physicochemical properties, bioactivities, and hepatic lipid metabolism modulation of tomatoes, as well as the analysis of potential bioactive compounds exerting obesity-alleviating effects. Results showed that after LP fermentation, viable bacterial counts peaked at 9.11 log CFU mL-1 and sugar decreased, while organic acids, umami amino acids, total phenols, and total flavonoids increased. LP fermentation also improved the inhibition capacities of three digestive enzyme activities and Enterobacter cloacae growth, as well as antioxidant activities. Western blot results indicated that fermented tomatoes, especially live probiotic-fermented tomatoes (LFT), showed improved effects compared to unfermented tomatoes in reducing hepatic lipid accumulation by activating the AMPK signal pathway. UHPLC-Q-TOF/MS-based untargeted metabolomics analysis showed that chlorogenic acid, capsiate, tiliroside, irisflorentin, and homoeriodictyol levels increased after fermentation. Subsequent cell culture assays demonstrated that irisflorentin and homoeriodictyol reduced lipid accumulation via enhancing AMPK expression in oleic acid-induced hyperlipidemic HepG2 cells. Furthermore, Spearman's correlation analysis indicated that the five phenols were positively associated with hepatic AMPK pathway activation. Consequently, it could be inferred that the five phenols may be potential bioactive compounds in LFT to alleviate obesity and lipid metabolism disorders. In summary, these findings underscored the transformative potential of LP fermentation in enhancing the bioactive profile of tomatoes and augmenting its capacity to alleviate obesity and lipid metabolism disorders. This study furnished theoretical underpinnings for the functional investigation of probiotic-fermented plant-based foods.

Effects of fermentation with Lactiplantibacillus plantarum NCU116 on the antihypertensive activity and protein structure of black sesame seed.

Effects of fermentation by Lactobacillus Plantarum NCU116 on the antihypertensive potential of black sesame seed (BSS) and structure characteristics of fermented black sesame seed protein (FBSSP) were investigated. Angiotensin-I-converting enzyme (ACE) inhibition and zinc chelating ability of fermented black sesame seed hydrolysate (FBSSH) reached the highest of 60.78 ± 3.67 % and 2.93 ± 0.04 mg/mL at 48 h and 60 h of fermentation, respectively. Additionally, the antioxidant activities of FBSSH and surface hydrophobicity of FBSSP were increased noticeably by fermentation. The α-helix and ß-rotation of FBSSP tended to decrease and increase, respectively, during fermentation. Correlation analysis indicated strong positive relationships between ß-turn and ACE inhibition activity as well as zinc chelating ability with correlation coefficients r of 0.8976 and 0.8932. Importantly, novel ACE inhibitory peptides LLLPYY (IC50 = 12.20 µM) and ALIPSF (IC50 = 558.99 µM) were screened from FBSSH at 48 h using in silico method. Both peptides showed high antioxidant activities in vitro. Molecular docking analysis demonstrated that the hydrogen bond connected with zinc ions of ACE mainly attributed to the potent ACE inhibitory activity of LLLPYY. The findings indicated that fermentation by Lactobacillus Plantarum NCU116 is an effective method to enhance the antihypertensive potential of BSS.

Modulation of the Microbiome-Fat-Liver Axis by Lactic Acid Bacteria: A Potential Alleviated Role in High-Fat-Diet-Induced Obese Mice.

The major characteristics of obesity are abnormal lipid metabolism, chronic inflammation, and imbalanced gut microbiota. It has been reported that lactic acid bacteria (LAB) possess potential for alleviating obesity, considering which the strain-specific functions and diverse mechanisms and the roles and mechanisms of various LAB are worthy of investigation. This study aimed to validate and investigate the alleviating effects and underlying mechanisms of three LAB strains, Lactiplantibacillus plantarum NCUH001046 (LP), Limosilactobacillus reuteri NCUH064003, and Limosilactobacillus fermentum NCUH003068 (LF), in high-fat-diet-induced obese mice. The findings demonstrated that the three strains, particularly LP, suppressed body weight gain and fat deposition; ameliorated lipid disorders, liver and adipocyte morphology, and chronic low-grade inflammation; and reduced lipid synthesis via activating the adenosine 5'-monophosphate-activated protein kinase (AMPK) signaling pathway. In addition, LP and LF decreased the enrichment of bacteria positively correlated with obesity, like Mucispirillum, Olsenella, and Streptococcus, but facilitated the growth of beneficial bacteria negatively correlated with obesity, like Roseburia, Coprococcus, and Bacteroides, along with increasing the short-chain fatty acid levels. It is deduced that the underlying alleviating mechanism of LP was to modulate the hepatic AMPK signaling pathway and gut microbiota by the microbiome-fat-liver axis to alleviate obesity development. In conclusion, as a diet supplement, LP has promising potential in obesity prevention and treatment.

Effects of enzyme treatment on the antihypertensive activity and protein structure of black sesame seed (Sesamum indicum L.) after fermentation pretreatment.

Effects of enzyme treatment on the hypertensive potential and protein structure of black sesame seed (BSS) were investigated. Compared with BSS, Angiotensin-converting enzyme (ACE) inhibition of fermented black sesame seed (FBSS) has significantly improved after acid protease processing and reached 75.39% at 2 U/g in 3 h. Meanwhile, the zinc chelating ability and antioxidant activity of FBSS hydrolysate as well as surface hydrophobicity, free sulfhydryl content, and peptide content of FBSS protein, were significantly increased. The results illustrated that this strategy promoted the protein unfolding and exposure of hydrophobic residues, thus contributing toward enzymatic hydrolysis. Secondary structure results indicated that the α-helix of FBSS protein and ß-sheet of BSS protein decreased after hydrolyzing. The differences in ACE inhibition may also result from the difference in peptide sequence except for peptide content. In conclusion, the combination of fermentation pretreatment and enzyme treatment is an effective method to enhance the antihypertensive potential of BSS.

Isolation and characterization of potential Lactobacillus acidophilus strains isolated from pig feces.

The aim of this study was to isolate and characterize Lactic Acid Bacteria (LAB) from 16 feces samples of pig farm, and to evaluate the probiotic potential of these isolates as potential oral probiotic candidates. The selection process was based on the isolation, identification, and a series of experiments for the selection of appropriate candidates with beneficial properties. The results demonstrated that most of LAB showed relatively strong resistance to pH 2.5 and high bile salts (1%), and had good survival in simulated gastric and intestinal juice. 9 isolates displayed antimicrobial activities against Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa and Enterobacter sakazakii. Almost all isolates were sensitive to ampicillin, chloramphenicol, vancomycin and amoxicillin, and most of isolates exhibited resistance against tetracycline and vancomycin. The adhesion rates of LAB varied greatly. The results of the study suggested that the Lactobacillus acidophilus NCUA065001 have the important functional property of probiotic candidates to enhance gut integrity and could considered to be the potential antibiotic alternatives in the pig feed industry.

Correlation between microbiota and flavours in fermentation of Chinese Sichuan Paocai.

Sichuan Paocai (SCP), a traditional fermentationed food, possesses unique flavours driven by various microbiota in fermentation ecosystems. However, the association between these microbiota and flavours is poorly understood. Here, we measured the structural dynamics of the microbial diversity and flavour compounds during SCP fermentation (0-7 days) using high-throughput sequencing and flavour analyses. Firstly, a total of 90 bacteria and 135 fungi were identified. The results showed that fermentation process was initiated by environmental microorganisms, such as Micrococcaceae, followed by a heterolactic fermentation phase dominated by Leuconostocaceae, and finally succeeded by homolactic fermentation led by Lactobacillaceae. Secondly, 6 organic acids, 12 amino acids and 86 volatile flavours were detected. The fermentation process was divided into 4 stages based on flavours: Day 0; Days 1-3; Days 4-6; and Day 7. Analysis of the correlation between microbiota and flavours indicated that bacteria contributed more to flavours formation than did fungi, and Lactobacillus, Leuconostoc, Achromobacter and Pediococcus were closely correlated with flavours. This study provides a systematic method for understanding the characteristics of fermented foods and useful guidelines for screening of strains that produce desirable flavours and functional substances.