Anti-aging effects and mechanisms of kimchi during fermentation under stress-induced premature senescence cellular system

Catechin with Lactic Acid Bacteria Starters Enhances the Antiobesity Effect of Kimchi

The antiobesity effects of kimchi with catechin and lactic acid bacteria as starters were studied in C57BL/6 mice with high-fat diet (HFD)-induced obesity. We prepared four types of kimchi: commercial kimchi, standard kimchi, green tea functional kimchi, and catechin functional kimchi (CFK). Body weight and weight of adipose tissue were significantly lower in the kimchi-treated groups than in the HFD and Salt (HFD +1.5% NaCl) groups. In addition, in the CFK group, the serum levels of triglycerides, total cholesterol, and low-density lipoprotein cholesterol were significantly lower and those of high-density lipoprotein cholesterol were markedly higher than the corresponding levels in the HFD and Salt groups. Moreover, CFK reduced fat cells and crown-like structures in the liver and epididymal fat tissues. The protein expression of adipo/lipogenesis-related genes in the liver and epididymal fat tissues was significantly lower (1.90-7.48-fold) in the CFK group than in the HFD and Salt groups, concurrent with upregulation of lipolysis-related genes (1.71-3.38-fold) and downregulation of inflammation-related genes (3.17-5.06-fold) in epididymal fat tissues. In addition, CFK modulated the gut microbiomes of obese mice by increasing the abundance of Bacteroidetes (7.61%), while in contrast, Firmicutes (82.21%) decreased. In addition, the presence of the Erysipelotrichaceae (8.37%) family in the CFK group decreased, while the number of beneficial bacteria of the families, Akkermansiaceae (6.74%), Lachnospiraceae (14.95%), and Lactobacillaceae (38.41%), increased. Thus, CFK exhibited an antiobesity effect through its modulation of lipid metabolism and the microbiome.

Reduction in Biogenic Amine Content in Baechu (Napa Cabbage) Kimchi by Biogenic Amine-Degrading Lactic Acid Bacteria

This study was performed to mine biogenic amine (BA)-degrading lactic acid bacteria (LAB) from kimchi and to investigate the effects of the LAB strains on BA reduction in Baechu kimchi fermentation. Among 1448 LAB strains isolated from various kimchi varieties, five strains capable of considerably degrading histamine and/or tyramine were selected through in vitro tests and identified as Levilactobacillus brevis PK08, Lactiplantibacillus pentosus PK05, Leuconostoc mesenteroides YM20, L. plantarum KD15, and Latilactobacillus sakei YM21. The selected strains were used to ferment five groups of Baechu kimchi, respectively. The LB group inoculated with L. brevis PK08 showed the highest reduction in tyramine content, 66.65% and 81.89%, compared to the control group and the positive control group, respectively. Other BA content was also considerably reduced, by 3.76–89.26% (five BAs) and 7.87–23.27% (four BAs), compared to the two control groups, respectively. The other inoculated groups showed similar or less BA reduction than the LB group. Meanwhile, a multicopper oxidase gene was detected in L. brevis PK08 when pursuing the BA degradation mechanism. Consequently, L. brevis PK08 could be applied to kimchi fermentation as a starter or protective culture to improve the BA-related safety of kimchi where prolific tyramine-producing LAB strains are present.

Classification of geographical origin of kimchi by volatile compounds analysis using an electronic nose

Food authenticity is one of the largest concerns in recent days. As kimchi has been a global food, its production origin has been important issue, particularly due to the large import from China. Among the potential methods, electronic nose which can measure volatile compounds in foods is considered to be a powerful device for identifying country of production. This study is to classify 69 kinds of kimchi produced in South Korea (39) and China (30) by analyzing volatile compounds in kimchi using electronic nose-mass spectrometry. Two widely used multivariate analyses, discriminant function analysis and principal component analysis, were used. Results showed that both multivariate analyses can completely separate Korean and Chinese kimchi using 10 kinds of molecular weights among 10-160 amu. The results indicate that the volatile compounds in kimchi are a suitable target to determine the geographical origin of kimchi.

Analysis of Cultivable Microbial Community during Kimchi Fermentation Using MALDI-TOF MS

Kimchi, a traditional Korean fermented vegetable, has received considerable attention for its health-promoting effects. This study analyzes the cultivable microbial community in kimchi fermented at different temperatures using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to comprehensively understand the factors affecting the quality of kimchi. Of the 5204 strains isolated from kimchi, aligned with the in-house database, 4467 (85.8%) were correctly identified at the species level. The fermentation temperature affected the microbial community by varying the pH and acidity, which was mainly caused by temperature-dependent competition between the different lactic acid bacteria (LAB) species in kimchi. LAB, such as Levilactobacillus (Lb.) brevis and Lactiplantibacillus (Lpb.) plantarum associated with rancidity and tissue softening, proliferated faster at higher temperatures than at low temperature. In addition, LAB, such as Latilactobacillus (Lat.) sakei and Leuconostoc (Leu.) mesenteroides, which produce beneficial substances and flavor, were mainly distributed in kimchi fermented at 4 °C. This study shows as a novelty that MALDI-TOF MS is a robust and economically affordable method for investigating viable microbial communities in kimchi.

Kimchi markedly induces apoptosis in HT-29 human colon carcinoma cells

This study investigated kimchi-induced apoptosis in HT-29 human colon carcinoma cells. Three types of kimchi samples were prepared: standardized kimchi brined with general commercial Baechu cabbage by a standardized recipe (SK), Amtak Baechu kimchi brined with Amtak Baechu cabbage by a standardized recipe (AmK), and anticancer kimchi brined with organically cultivated Baechu cabbage by a functional recipe (AK). MTT assay, qRT-PCR, and Western blotting analysis were performed. The results indicate that AmK and AK, especially AK significantly upregulated mRNA expression of apoptosis-related genes Bim, Bax, Bak, caspase-8, -9, -3, and p53 but suppressed Bcl-xL and Bcl-2 expression. In addition, AK treatment significantly upregulated protein expression levels of caspase-3 but strikingly reduced the protein expression level of Bcl-2 (p < .05), followed by AmK treatment. Our data suggest that AK and AmK can markedly suppress the proliferation of HT-29 cells via activation of apoptosis. PRACTICAL APPLICATIONS: Colon cancer is the fourth cancer with the highest incidence in the world. Cell apoptosis is a type of programmed cell death and plays an important role in the cancer cells study. Kimchi is a traditional fermented food in Korea, with a relatively high daily consumption. Our present study used three kinds of kimchi which prepared with different main ingredients and recipes. The results suggest that organically cultivated Baechu cabbage and functional recipe in kimchi preparation play an important role in the anticancer efficacy of kimchi, which has been shown to promote induction of apoptosis in HT-29 cells.

Traditional fermented foods with anti-aging effect: A concentric review

Fermentation has been applied since antiquity as a way to preserve foodstuff or as a necessary step in the production of a variety of products. The research was initially focused on accurate description of production procedure and identification of parameters that may affect the composition and dynamics of the developing micro-communities, since the major aim was standardization and commercial exploitation of the products. Soon it was realized that consumption of these products was associated with an array of health benefits, such as anti-hypertensive, anti-inflammatory, anti-diabetic, anti-carcinogenic and anti-allergenic activities. These were credited to the microorganisms present in the fermented products as well as their metabolic activities and the bio-transformations that took place during the fermentation process. Aging has been defined as a gradual decline in the physiological function and concomitantly homeostasis, which is experienced by all living beings over time, leading inevitably to age-associated injuries, diseases, and finally death. Research has focused on effective strategies to delay this process and thus increase both lifespan and well-being. Fermented food products seem to be a promising alternative due to the immunomodulatory effect of microorganisms and elevated amounts of bioactive compounds. Indeed, a series of anti-aging related benefits have been reported, some of which have been attributed to specific compounds such as genistein and daidzein in soybeans, while others are yet to be discovered. The present article aims to collect and critically discuss all available literature regarding the anti-aging properties of fermented food products.

Lower Mg and S contents in solar salt used in kimchi enhances the taste and anticancer effects on HT-29 colon carcinoma cells

The anticancer effects of kimchi prepared with different kinds of solar salts were evaluated in an in vitro cellular system using HT-29 human colon carcinoma cells. Four kinds of kimchi samples were prepared, using different solar salts: conventionally manufactured solar salt (CS), filtered sea water solar salt (FS), dehydrated solar salt by centrifuging (DS), and washed-dehydrated solar salt (WDS). Prepared kimchi samples were presented as CSK, FSK, DSK, and WDSK, respectively. The pH values, acidity, and sensory evaluation were determined after 3 week fermentation at 5 °C (pH 4.3), and WDSK exhibited the best fermented characteristics and taste among the 4 samples examined. In the HT-29 cell growth inhibitory activity assay, all 4 kimchi samples exert dose-dependent cell growth inhibition, with WDSK showing significant growth inhibition of HT-29 cells. mRNA and protein expression levels of apoptosis and cell cycle arrest related factors reveals that WDSK significantly increases the mRNA expression levels of Bax, Bim, caspases-3, caspases-9, and p21 as compared to other kimchi samples, at a concentration of 4.0 mg mL⁻¹. In addition, WDSK treatment strongly decreases the Bcl-2 protein expression (on western blot) in HT-29 cells, as compared to the control group (no kimchi treatment) and significantly increases the protein expression levels of Bax, caspases-3, caspases-9, and p53. Inductively coupled plasma atomic emission spectrometry (ICP-OES) reveals that WDS possesses a different mineral composition when compared to the other three solar salts; notably, the lower Mg (9.3 g kg⁻¹) and S (4.7 g kg⁻¹) content of WDS may cause better taste, fermented characteristcs, and functionality of WDSK. These results indicate WDS to be the ideal solar salt for kimchi preparation, which enhances the taste due to its lower Mg and S contents, and increases the anticancer effects by exerting better pro-apoptosis and cell cycle arrest abilities in HT-29 cells.

The anticancer effects of kimchi prepared with different kinds of solar salts were evaluated in an in vitro cellular system using HT-29 human colon carcinoma cells.

Probiotic characterization of Bacillus subtilis P223 isolated from kimchi

Probiotic characteristics of Bacillus subtilis P223 isolated from kimchi were investigated in this study. Spore cells of B. subtilis P223 showed high tolerance to artificial gastric juice (pH 2.5, 0.3% pepsin, 3 h) and bile salts (0.3% oxgall, 24 h). Spore cells of B. subtilis P223 showed more adherence to intestinal cells (HT-29 cells) than vegetative cells. In addition, B. subtilis P223 showed high autoaggregation ability, similar to a commercial strain (Bacillus clausii ATCC 700160). Moreover, its coaggregation abilities with pathogens were strong. The adherence of three pathogens (Salmonella enteritidis ATCC 13076, Listeria monocytogenes ATCC 15313, and Escherichia coli ATCC 25922) to HT-29 cells was inhibited by B. subtilis P223. It was found that B. subtilis P223 could not produce β-glucuronidase, a carcinogenic enzyme. However, it had amylase and protease activities. Antibiotic susceptibility was measured using disk diffusion assay. It was revealed that B. subtilis P223 was only resistant to streptomycin among eight kinds of antibiotics. In addition, B. subtilis P223 showed no hemolysis activity. It did not have enterotoxin genes. Results of this study suggest that B. subtilis P223 isolated from kimchi has potential as a probiotic strain.

Relationship Between Plant Food (Fruits, Vegetables, and Kimchi) Consumption and the Prevalence of Rhinitis Among Korean Adults: Based on the 2011 and 2012 Korea National Health and Nutrition Examination Survey Data

The aim of the current study was to analyze the relationship between plant food (fruits, vegetables, and kimchi) and the prevalence of rhinitis among Korean adults using data from the 2011 and 2012 Korea National Health and Nutrition Examination Survey. A total of 7494 subjects aged from 19 to 64 years participated in a rhinitis morbidity survey, health behavior interview, and 24-h dietary recall test. Individuals with energy intakes less than 500 kcal or more than 5000 kcal were excluded. The results showed that kimchi intake was inversely associated with the prevalence of rhinitis. The prevalence of rhinitis decreased with increasing kimchi consumption. The quintile 4 (range of kimchi intake: 108.0-180.0 g) groups, compared with the reference of quintile 1 (0-23.7 g), showed a decrease of 18.9% (odds ratio [OR] = 0.811, 95% confidence interval [CI] = 0.672-0.979) in Model 4. In conclusion, consumption of kimchi lowers the risk of rhinitis, suggesting that its use should be encouraged among the Korean population.

Kimchi and Other Widely Consumed Traditional Fermented Foods of Korea: A Review

Different types of fermented foods such as chongkukjang, doenjang, ganjang, gochujang, and kimchi are plentifully available and widely consumed in north eastern Asian countries including Korea. Among them, kimchi is one of the most popular Korean traditional food. It is prepared by fermenting the baechu cabbage together with other vegetables and lactic acid bacteria (LAB) with functional potential. Many types of ingredients are added to kimchi to enhance its taste, flavor, nutritional value, texture etc. A number of bacteria are involved in the fermentation of kimchi, but LAB are the dominant species in the fermentation process. The addition of other sub ingredients and formation of different by-products during fermentation eventually leads to eradication of putrefactive and pathogenic bacteria, and also increase the functionalities, nutritional and nutraceutical potential of kimchi. Kimchi possesses anti-inflammatory, antibacterial, antioxidant, anticancer, antiobesity, probiotic properties, cholesterol reduction, and antiaging properties. In the present review an attempt has been made to review the different types of fermented foods found in the Korean peninsula with detailed scientific research regarding preparation, processing, structure of the microecosystem, and health benefits of kimchi.

Heterofermentative lactic acid bacteria dominate in Korean commercial kimchi

Lactic acid bacterial communities in kimchi prepared by representative Korean kimchi companies were investigated using a pyrosequencing method. The pH values of 9 kimchi varieties (K1-K9) ranged from 4.3 to 4.7, and total lactic acid bacterial (LAB) counts ranged from 1.3x10⁷ to 1.6x10⁹ CFU/g. Weissella, Lactobacillus, and Leuconostoc were the dominant genera accounting for 52, 28, and 20%, respectively, of identified genera. At the species level, Weissella koreensis (35%) dominated, followed by Lactobacillus graminis (13%), and Weissella cibaria (11%). Dominant LAB were all heterofermentative LAB. K1 had the most diverse operational taxonomic units (OTUs), and clustering analysis showed that distributions of microorganisms in K2, K6, K5, and K4 were similar each other. LAB communities in kimchi are diverse and heterofermentative LAB dominate in Korean commercial kimchi.

Health benefits of kimchi (Korean fermented vegetables) as a probiotic food

Kimchi is a traditional Korean food manufactured by fermenting vegetables with probiotic lactic acid bacteria (LAB). Many bacteria are involved in the fermentation of kimchi, but LAB become dominant while the putrefactive bacteria are suppressed during salting of baechu cabbage and the fermentation. The addition of other subingredients and formation of fermentation byproducts of LAB promote the fermentation process of LAB to eventually lead to eradication of putrefactive- and pathogenic bacteria, and also increase the functionalities of kimchi. Accordingly, kimchi can be considered a vegetable probiotic food that contributes health benefits in a similar manner as yogurt as a dairy probiotic food. Further, the major ingredients of kimchi are cruciferous vegetables; and other healthy functional foods such as garlic, ginger, red pepper powder, and so on are added to kimchi as subingredients. As all of these ingredients undergo fermentation by LAB, kimchi is regarded as a source of LAB; and the fermentative byproducts from the functional ingredients significantly boost its functionality. Because kimchi is both tasty and highly functional, it is typically served with steamed rice at every Korean meal. Health functionality of kimchi, based upon our research and that of other, includes anticancer, antiobesity, anticonstipation, colorectal health promotion, probiotic properties, cholesterol reduction, fibrolytic effect, antioxidative and antiaging properties, brain health promotion, immune promotion, and skin health promotion. In this review we describe the method of kimchi manufacture, fermentation, health functionalities of kimchi and the probiotic properties of its LAB.

Kimchi protects against azoxymethane/dextran sulfate sodium-induced colorectal carcinogenesis in mice

The chemopreventive effects of different types and quantities of kimchi prepared with different subingredients, including commercial kimchi (CK), standardized kimchi (SK), cancer-preventive kimchi (CPK), and anticancer kimchi (ACK), on colorectal carcinogenesis in mice were evaluated. The development of colon cancer was induced in male BALB/c mice with a single intraperitoneal injection of azoxymethane (AOM, 10 mg/kg body weight) and subsequent treatment with 2% dextran sulfate sodium (DSS) in drinking water for 7 days for two cycles. After exposure to AOM and DSS, treatment with the methanolic extracts from different kimchis, particularly 1.89 g/kg of ACK, significantly increased colon length, decreased the ratio of colon weight/length, and resulted in the lowest number of tumors compared with the other kimchi-treated groups. Histological observation revealed that ACK was able to suppress AOM- and DSS-induced colonic mucosal damage and neoplasia. ACK also significantly decreased the mRNA levels of proinflammatory cytokines (TNF-α, IL-6, and IFN-γ) as well as the mRNA and protein expression of inducible nitric oxide synthase and cyclooxygenase-2 (COX-2). In addition, the mRNA and protein expression of p53 and p21 was elevated in colon tissues from the ACK-treated mice compared with the other kimchi-treated groups. Our results suggest that kimchi exerted a suppressive effect on AOM- and DSS-induced colorectal carcinogenesis in the BALB/c mice. The anticancer effects of ACK were particularly potent. Thus, it is possible that the health-promoting subingredients added to ACK might be used to prevent colon carcinogenesis in humans.