Genome Analysis of a Newly Sequenced B. subtilis SRCM117797 and Multiple Public B. subtilis Genomes Unveils Insights into Strain Diversification and Biased Core Gene Distribution.

The bacterium Bacillus subtilis is a widely used study model and industrial workhorse organism that belongs to the group of gram-positive bacteria. In this study, we report the analysis of a newly sequenced complete genome of B. subtilis strain SRCM117797 along with a comparative genomics of a large collection of B. subtilis strain genomes. B. subtilis strain SRCM117797 has 4,255,638 bp long chromosome with 43.4% GC content and high coding sequence association with macromolecules, metabolism, and phage genes. Genomic diversity analysis of 232 B. subtilis strains resulted in the identification of eight clusters and three singletons. Of 147 B. subtilis strains included, 89.12% had strain-specific genes, of which 6.75% encoded strain-specific insertion sequence family transposases. Our analysis showed a potential role of strain-specific insertion sequence family transposases in intra-cellular accumulation of strain-specific genes. Furthermore, the chromosomal layout of the core genes was biased: overrepresented on the upper half (closer to the origin of replication) of the chromosome, which may explain the fast-growing characteristics of B. subtilis. Overall, the study provides a complete genome sequence of B. subtilis strain SRCM117797, show an extensive genomic diversity of B. subtilis strains and insights into strain diversification mechanism and non-random chromosomal layout of core genes.

Biosorption of arsenite (As[III]) using Saccharomyces cerevisiae SRCM 501804 isolated from Korean turbid rice wine.

The potentiality of Saccharomyces cerevisiae SRCM 501804 to remove arsenite (As[III]) in an aqueous solution was investigated in this study. The S. cerevisiae SRCM 501804 was isolated from Korean turbid rice wine (Makgeolli). The S. cerevisiae SRCM 501804 was characterized by phylogenetic analysis, Fourier transform infrared (FT-IR) spectroscopy, visual minerals technologies (MINTEQ) model, and point of zero charge (pHpzc). The relationship between the factors (pH, biosorbent dosage, contact time, and concentration) and biosorption capacity was investigated. The S. cerevisiae SRCM 501804 was removed 31.1-90.1% of the As(III) depending on the initial biomass dosage within 1 h. Co-existing anions in aqueous solution showed a negative influence on the biosorption performance of As(III) in the order Cl- > NO3- > SO42- > CO32-. The results of isotherms and kinetics suggested the Langmuir (R2 > 0.95) and Pseudo-second order (R2 > 0.99) models fit well with the equilibrium experimental data. The maximum biosorption capacity (qm) of S. cerevisiae SRCM 501804 biomass for As(III) was found to be 113.9 mg/g from Langmuir isotherm. Based on the results, it can be concluded that the biomass of S. cerevisiae SRCM 501804 could be used as an effective bio-sorbent for As(III) biosorption in an aqueous solution.

Significance of LED lights in enhancing the production of vinegar using Acetobacter pasteurianus AP01.

Vinegar is a common food additive produced by acetic acid bacteria (AAB) during fermentation process. Low yield and long incubation time in conventional vinegar fermentation processes has inspired research in developing efficient fermentation techniques by the activation of AAB for acetic acid production. The present study intends to enhance vinegar production using acetic acid bacteria and light emitting diode (LED). A total of eight acetic acid bacteria were isolated from Korean traditional vinegar and assessed for vinegar production. Isolate AP01 exhibited maximum vinegar production and was identified as Acetobacter pasteurianus based on the 16S rRNA sequences. The optimum fermentation conditions for the isolate AP01 was incubation under static condition at 30 °C for 10 days with 6% initial ethanol concentration. Fermentation under red LED light exhibited maximum vinegar production (3.6%) compared to green (3.5%), blue (3.2%), white (2.2%), and non-LED lights (3.0%). Vinegar produced using red LED showed less toxicity to mouse macrophage cell line (RAW 264.7) and high inhibitory effects on nitric oxide and IL-6 production. The results confirmed that red LED light could be used to increase the yield and decrease incubation time in vinegar fermentation process.

Effects of indigenous yeasts on physicochemical and microbial properties of Korean soy sauce prepared by low-salt fermentation.

This study deals with understanding the effects of salt reduction on both the physicochemical and microbiological properties of soy sauce fermentation and also the application of indigenous yeast starters to compensate for undesirable changes occurring in salt-reduced processes. Fermentation was tested in situ at a Korean commercial soy sauce processing unit. Salt reduction resulted in higher acidity as well as lower pH and contents of residual sugar and ethanol. Moreover, undesired flavor characteristics, due to a lack of distinctive compounds, was observed. In addition, putrefactive Staphylococcus and Enterococcus spp. were present only during salt-reduced fermentation. To control these adverse effects, a single or mixed culture of two indigenous yeasts, Torulaspora delbrueckii and Pichia guilliermondii, producing high ethanol and 3-methyl-1-butanol, respectively, were tested. Overall, all types of yeast applications inhibited undesirable bacterial growth despite salt reduction. Of the starter cultures tested, the mixed culture resulted in a balance of more complex and richer flavors with an identical flavor profile pattern to that obtained from high salt soy sauce. Hence, this strategy using functional yeast cultures offers a technological option to manufacture salt-reduced soy sauce while preserving its typical sensory characteristics without affecting safety.

Evaluation of Menopausal Syndrome Relief and Anti-Obesity Efficacy of the Korean Fermented Food Doenjang: A Randomized, Double-Blind Clinical Trial.

Foods that help improve menopausal syndrome are being studied worldwide. Doenjang is a traditional Korean fermented soybean food with potential health benefits for menopausal women. In this clinical trial using Doenjang, we aimed to compare the effectiveness of traditional Doenjang and commercial Doenjang in menopausal women. Furthermore, we compared whether Doenjang has a better effect if the number of beneficial microbes is higher. The analyses included the following groups: traditional Doenjang containing either a high dose (HDC; n = 18) or low dose (LDC; n = 18) of beneficial microbes and commercial Doenjang (CD; n = 20). The Kupperman index and hematological changes were examined before and after the use of Doenjang pills. The effects of Doenjang on obesity and body composition were studied before and after ingestion. Lastly, the microorganisms and short-chain fatty acid changes in the stool were compared. The Kupperman index decreased after Doenjang consumption in all three groups, with the greatest decrease in the LDC group. Only the groups that took traditional Doenjang pills exhibited reduced LDL cholesterol. No changes in obesity and inflammation-related indicators were observed. The number of Firmicutes, associated with obesity, decreased in the CD group but the numbers of Bacteroidetes increased in the HDC and CD groups. Thus, traditional Doenjang is more effective in alleviating menopausal syndrome than commercial Doenjang. Further research on the anti-obesity effect or changes in microbiomes and short-chain fatty acids in feces is needed.

Doenjang Ameliorates Diet-Induced Hyperlipidemia and Hepatic Oxidative Damage by Improving Lipid Metabolism, Oxidative Stress, and Inflammation in ICR Mice.

Hyperlipidemia, characterized by elevated cholesterol, lipids, and triglycerides in the bloodstream, is linked to hepatic oxidative damage. Doenjang, a traditional Korean condiment made from fermented soybeans, is known for its health benefits, yet its anti-hyperlipidemic effects remain understudied. Our study aimed to assess the hypolipidemic and hepatic protective effects of Doenjang on male ICR mice fed a high-fat cholesterol diet for 8 weeks. Mice were divided into three groups: the normal diet (ND), the high-fat cholesterol diet (HD), and the Doenjang-supplemented HD diet (DS) group. Doenjang supplementation significantly regulated total cholesterol, triglycerides, LDL cholesterol, and HDL cholesterol levels compared to the HD group. It also downregulated lipogenic genes, including PPARγ, FAS, and ACC, and positively influenced the cholesterol metabolism-related genes HMGCR and LXR. Moreover, Doenjang intake increased serum glutathione levels, activated oxidative stress defense genes (NRF2, SOD, GPx1, and CAT), positively modulated inflammation genes (NF-kB and IL6) in hepatic tissue, and reduced malondialdehyde levels. Our findings highlight the effectiveness of traditional Doenjang in preventing diet-induced hyperlipidemia and protecting against hepatic oxidative damage.

Anti-Inflammatory Effect of Korean Soybean Sauce (Ganjang) on Mice with Induced Colitis.

Inflammatory bowel disease (IBD), characterized by chronic inflammation of the gut, is caused by several factors. Among these factors, microbial factors are correlated with the gut microbiota, which produces short-chain fatty acids (SCFAs) via anaerobic fermentation. Fermented foods are known to regulate the gut microbiota composition. Ganjang (GJ), a traditional fermented Korean soy sauce consumed worldwide, has been shown to exhibit antioxidant, anticancer, anti-colitis, and antihypertensive activities. However, its effects on the gut microbiota remain unknown. In the present study, we aimed to compare the anti-inflammatory effects of GJ manufactured using different methods and investigate its effect on SCFA production in the gut. To evaluate the anti-inflammatory effects of GJ in the gut, we performed animal experiments using a mouse model of dextran sulfate sodium (DSS)-induced colitis. All GJ samples attenuated DSS-induced colitis symptoms, including reduced colonic length, by suppressing the expression of inflammatory cytokines. In addition, GJ administration modulated SCFA production in the DSS-induced colitis model. Overall, GJ exerted anti-inflammatory effects by reducing DSS-induced symptoms via regulation of inflammation and modulation of SCFA levels in a DSS-induced colitis model. Thus, GJ is a promising fermented food with the potential to prevent IBD.

Lactic acid bacteria-malted vinegar: fermentation characteristics and anti-hyperlipidemic effect.

In this study, the fermentation characteristics and functional properties of lactic acid bacteria-malted vinegar (LAB-MV) were investigated during the fermentation period. Changes in the components (organic acids, free sugars, free amino acids, ß-glucan, and gamma-aminobutyric acid (GABA)) of MV (BWAF0d, BWAF10d, BWAF20d) and LAB-MV (LBWAF0d, LBWAF10d, LBWAF20d) were analyzed according to the fermentation time. The amounts of ß-glucan and GABA in LBWAF20d were greater than those in BWAF20d (122.00 µg/mL, 83.06 µg/mL and 531.00 µg/mL, 181.31 µg/mL, respectively). The ACE1 and HMG-CoA reductase inhibitory activities of LBWAF20d were 98.16% (1/20 dilution factor, DF) and 91.01% (1/25 DF), respectively. The lipid accumulation ratio and total cholesterol levels in HepG2 cells treated with LBWAF20d (1/200 DF) were reduced by 45.85% and 54.48%, respectively, compared to those in the untreated group. These results suggest that LAB-MV, which comprises barley wine manufactured from LAB and yeast, may improve hepatic lipid metabolism.

Gochujang, a traditional Korean fermented food, protects through suppressed inflammatory pathways and histological structure disruption in dextran sodium sulfate (DSS)-induced colitis mice.

The mechanisms underlying chronic inflammatory diseases remain unclear. Therefore, researchers have explored the mechanisms underlying colitis using diverse materials. Recently, there has been an increasing interest in fermented products and bioconversion materials, their potential efficacy is being actively studied. Gochujang, a traditional Korean fermented product, is crafted by blending fermented Meju powder, gochu (Korean chili) powder, glutinous rice, and salt. In our study, we explored the effectiveness of Gochujang (500 mg/kg; Cheongju and Hongcheon, Korea) in dextran sulfate sodium (DSS)-induced colitis mice model. Gochujang was orally administered for 2 weeks, followed by the induction of colitis using 3% DSS in the previous week. During our investigation, Gochujang variants (TCG22-25, Cheongju and TCG22-48, Hongcheon) did not exhibit significant inhibition of weight reduction (p = 0.061) but notably (p = 0.001) suppressed the reduction in large intestine length in DSS-induced colitis mice. In the serum from colitis mice, TCG22-48 demonstrated reduced levels of the inflammatory cytokines interleukin (IL)-6 (p = 0.001) and tumor necrosis factor (TNF)-α (p = 0.001). Additionally, it inhibited the phosphorylation of Erk (p = 0.028), p38, and NF-κB (p = 0.001) the inflammatory mechanism. In our study, TCG22-25 demonstrated a reduction in the IL-6 level (p = 0.001) in serum and inhibited the phosphorylation of p38 and NF-κB (p = 0.001). Histological analysis revealed a significant (p = 0.001) reduction in the pathological score of the large intestine from TCG22-25 and TCG22-48. In conclusion, the intake of Gochujang demonstrates potent anti-inflammatory effects, mitigating colitis by preventing the large intestine length reduction of animals with colitis, lowering serum levels of TNF-α and IL-6 cytokines, and inhibiting histological disruption and inflammatory mechanism phosphorylation.

The influence of the Korean traditional Chungkookjang on variables of metabolic syndrome in overweight/obese subjects: study protocol.

BACKGROUND: Metabolic syndrome is a set of disorders that increases the risk of developing cardiovascular disease. The primary target of treatment of patients with metabolic syndrome is therapeutic lifestyle change. Numerous preclinical study have reported positive effects of chungkookjang in in vivo models of diabetes and obesity, but there is a paucity of controlled clinical trials on variables of metabolic syndrome in obese subjects. Thus, the objective of this trial is to examine the effect of chungkookjang compared to placebo on variables of metabolic syndrome in overweight/obese subjects. METHODS: This double-blind randomized controlled crossover trial will be conducted on 120 overweight/obese subjects; aged 19-29 years. Subjects will be recruited from the Chonbuk National University, Jeonju, South Korea. Enrolled subjects will be randomly assigned to two groups of equal number; one group received 35 g of chungkookjang (n = 60) and the other group received placebo (n = 60) on a regular daily basis for 12 weeks. After a 12-week washout period, the groups will be crossed over. In addition to anthropometric measures and blood pressure, glucose parameter, lipid profile, adipocytokine, and carnitine assay will be determined at baseline and 12 week. Also, safety will be assessing by measuring total bilirubin, alkaline phosphatase, alanine transaminase, aspartate aminotransferase, total protein, albumin, blood urea nitrogen, creatinine, and creatine kinase at baseline and 12 weeks. 24-hour dietary recalls were collected at the baseline and at the end of the trial. DISCUSSION: This trial will evaluate the effects of chungkookjang on variables of metabolic syndrome in overweight/obese subjects. The results of this study may contribute to the reduction of risk factor for metabolic syndrome caused by obesity. TRIAL REGISTRATION: Clinical trials NCT01811511.

Standardized chungkookjang, short-term fermented soybeans with Bacillus lichemiformis, improves glucose homeostasis as much as traditionally made chungkookjang in diabetic rats.

As the traditional homemade chungkookjang is replaced by standardized chungkookjang fermented by inoculating Bacillus spp., it is desirable to maintain the anti-diabetic efficacy of the most potent traditional varieties. Preliminary in vitro research suggested that anti-diabetic efficacy can be achieved by using B. lichemiformis as a starter and fermenting for 48 h. Experimental type 2 diabetic male rats induced by partial pancreatectomy and high fat diets were administered either control diet, 10% cooked soybeans, 10% traditional chungkookjang with potent anti-diabetic efficacy, or standardized chungkookjang fermented with B. lichemiformis for 48 h. Rats were fed their respective diets for 8 weeks after surgery. Cooked soybeans as well as both chungkookjangs partially restored fasting serum glucose concentrations, but only the chungkoojangs increased fasting insulin levels. That trend was also seen in the glucose-stimulated insulin secretion during hyperglycemic clamp and was explained by the greater ß-cell mass and BrdU incorporation indicating increased proliferation of ß-cells. The euglycemic hyperinsulinemic clamp indicated that all soy products improved insulin sensitivity. Phosphorylation of Akt and AMPK in the liver increased in an ascending order of the control, cooked soybeans, traditional chungkookjang and standardized chungkookjang while PEPCK expression was lowered in a descending order of the control, cooked soybeans, traditional chungkookjang and standardized chungkookjang. These results indicate that standardized chungkookjang is most effective for improving hepatic insulin signaling. In conclusion, chungkookjang fermented with B. lichemiformis retains the anti-diabetic properties of the most efficacious traditional chungkookjang and it may be even more effective for improving insulin function than traditionally prepared chungkookjang.

Evaluation of Body Changes and the Anti-Obesity Effect after Consumption of Korean Fermented Food, Cheonggukjang: Randomized, Double-Blind Clinical Trial.

Cheonggukjang is a traditional Korean fermented soybean food with potential health benefits. For this reason, Cheonggukjang is consumed in the form of pills in addition to being used as a food ingredient. There are few clinical studies that have evaluated changes in various health indicators through blood and stool tests before and after consumption of Cheonggukjang. In this study, symptoms and hematological changes were analyzed before and after the intake of traditional Cheonggukjang pills containing high-dose (n = 19) or low-dose (n = 20) beneficial bacteria and commercial Cheonggukjang pills (n = 20). Anti-obesity effects and body composition changes were determined before and after Cheonggukjang consumption. Lastly, the changes in microorganisms and short-chain fatty acids in the stool were compared. No changes in obesity and inflammation-related indicators were observed before and after Cheonggukjang consumption. The Firmicutes/Bacteroidetes ratio, associated with obesity, decreased in all three groups after Cheonggukjang consumption, but no statistical significance was indicated. Cheonggukjang contained various BAs, but they did not adversely affect symptoms and hematological changes in the participants. BAs generated during the manufacturing process of Cheonggukjang did not have any adverse effects in this randomized, double-blind clinical trial. Further research is needed in future concerning the anti-obesity effect or regarding changes in the microbiome and short-chain fatty acids in feces.

Improvement of Estrogen Deficiency Symptoms by the Intake of Long-Term Fermented Soybeans (Doenjang) Rich in Bacillus Species through Modulating Gut Microbiota in Estrogen-Deficient Rats.

Traditionally made doenjang (TMD) produced by the long-term fermentation of soybeans with salt may improve symptoms of estrogen deficiency. We aimed to evaluate the effects of four TMD types, containing low and high amounts of Bacillus species and biogenic amines (HBHA, HBLA, LBHA, and LBLA), on energy, glucose, and lipid metabolism, by altering the gut microbiota in estrogen-deficient ovariectomized (OVX) rats. Their mechanisms were also examined. The OVX rats were divided into the control, cooked soybean (CSB), HBHA, LBHA, HBLA, and LBLA groups. Sham-operated rats were the normal control group. Serum 17ß-estradiol concentrations were similar among all OVX groups. Tail skin temperatures, which are indicative of hot flashes, were higher in the control than the HBHA and HBLA groups and were similar to the normal control group. Weight gain and visceral fat mass were lower in the TMD and CSB intake groups but not as low as in the normal control group. Lean body mass showed a trend opposite to that of visceral fat in the respective groups. The hepatic triglyceride content decreased with the TMD intake compared to the control and CSB groups. mRNA expressions of the peroxisome proliferator-activated receptor-γ (PPAR-γ) and carnitine palmitoyltransferase-1 in the TMD and CSB groups were as high as in the normal control group, and the PPAR-γ mRNA expression was more elevated in the HBLA group than in the normal control group. The morphology of the intestines improved in the TMD groups compared to the control, and the HBHA and HBLA groups showed an enhanced improvement compared to the CSB group. The HBHA, HBLA, and LBHA groups increased the α-diversity of the cecal microbiota compared to the control. Akkermenia and Lactobacillus were higher in the HBLA and LBLA groups compared to the control. The expression of the estrogen, forkhead box proteins of the class-O subgroup, and insulin-signaling pathways were lower in the control group, and HBHA and HBLA prevented their decrement. In conclusion, long-term treatment with TMD containing high amounts of Bacillus potentially improves estrogen deficiency symptoms more than unfermented soybeans.

Effects of Cheonggukjang (Fermented Soybean) on the Development of Colitis-Associated Colorectal Cancer in Mice.

Colorectal cancer (CRC) is the third most common type of cancer and is caused by multiple factors. Chronic inflammation, known to cause inflammatory bowel disease (IBD), is closely associated with CRC. Cheonggukjang (CJ), a traditional Korean fermented soybean, is a functional food with anti-inflammatory effects in the intestines, but its anti-cancer effects have not yet been explored. In this study, we investigated the cancer-protective effects of cheonggukjang in an azoxymethane/DSS (AOM/DSS)-induced colitis-associated colorectal cancer (CAC) mouse model. The CJ alleviated AOM/DSS-induced pathological symptoms such as colonic shortening, increased spleen weight, tumor formation, and histological changes. It also modulated pro-inflammatory and anti-inflammatory cytokine levels via the suppression of NF-κB and inflammatory mediator signaling pathways. Furthermore, the CJ improved intestinal integrity by regulating mucin-associated and tight junction proteins. In addition, it suppressed tumor growth by regulating apoptosis and proliferation. These results highlight the anti-tumor effects of CJ in an AOM/DSS-induced CAC mouse model.

Optimal production of L-threo-2,3-dihydroxyphenylserine (L-threo-DOPS) on a large scale by diastereoselectivity-enhanced variant of L-threonine aldolase expressed in Escherichia coli.

This study examined the efficient production and optimal separation procedures for pure L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) from a mixture of diastereomers synthesized by whole-cell aldol condensation reaction, harboring diastereoselectivity-enhanced L-threonine aldolase in Escherichia coli JM109. The addition of the reducing agent sodium sulfite was found to stimulate the production of L-threo-DOPS without affecting the diastereoselectivity ratio, especially at the 50 mM concentration. The optimal pH for diastereoselective synthesis was 6.5. The addition of Triton X-100 also strongly affected the synthesis yield, showing the highest conversion yield at a 0.75% concentration; however, the diastereoselectivity of the L-threonine aldolase was not affected. Lowering the temperature to 10°C did not significantly affect the diastereoselectiviy without affecting the synthesis rate. At the optimized conditions, a mixture of L-threo-DOPS and L-erythro-DOPS was synthesized by diastereoselectivity-enhanced L-threonine aldolase from E. coli in a continuous process for 100 hr, yielding an average of 4.0 mg/mL of L-threo-DOPS and 60% diastereoselectivity (de), and was subjected to two steps of ion exchange chromatography. The optimum separation conditions for the resin and solvent were evaluated in which it was found that a two-step process with the ion-exchange resin Dowex 50 W × 8 and activated carbon by washing with 0.5 N acetic acid was sufficient to separate the L-threo-DOPS. By using two-step ion-exchange chromatography, synthesized high-purity L-threo-DOPS of up to 100% was purified with a yield of 71%. The remaining substrates, glycine and 3,4-dihydroxybenzaldehyde, were recovered successfully with a yield of 71.2%. Our results indicate this potential procedure as an economical purification process for the synthesis and purification of important L-threo-DOPS at the pharmaceutical level.

Anti-Obesity Effects of Traditional and Commercial Kochujang in Overweight and Obese Adults: A Randomized Controlled Trial.

Kochujang shows anti-obesity effects in cell and animal models. Kochujang is traditionally prepared via slow fermentation or commercially using Aspergillus oryzae. We analyze the anti-obesity effects of two types of Kochujang in overweight and obese adults. The analyses included the following groups: traditional Kochujang containing either a high-dose (HTK; n = 19), or a low-dose of beneficial microbes (LTK; n = 18), and commercial Kochujang (CK; n = 17). Waist circumference decreased significantly in the HTK and CK groups. Total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels decreased in the HTK and LTK groups. Visceral fat is significantly reduced in the HTK group. The population of beneficial microorganisms in stool samples increased in all groups. Consumption of Kochujang reduces visceral fat content and improves the lipid profile, which can be enhanced by enrichment with beneficial microbes. These results suggest that Kochujang has the potential for application in obesity prevention.

Protective effect of traditional Korean fermented soybean foods (doenjang) on a dextran sulfate sodium-induced colitis mouse model.

Objective: The cause of ulcerative colitis (UC) is unknown, and the use of anti-inflammatory and immunosuppressive drugs with certain side effects is currently replacing treatment. Therefore, it is important to find new healthy foods or ingredients that exhibit potential protective and anti-inflammatory effects on UC. This study investigated the potential protective effect of doenjang on dextran sulfate sodium (DSS)-induced colitis in a mouse model. Materials and methods: Four doenjang samples (TCD21-51-1, TCD21-55-1, TMD21-16-1, and TFD21-1-1) were used. To examine the effects of the four doenjang samples on UC caused by DSS in a mouse model, the clinical symptoms of UC, such as body weight, disease activity index (DAI), and colon macroscopic damage index (CMDI) were analyzed. Moreover, immune-related blood cell counts, serum levels and protein expression of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6), and nitric oxide (NO) production were measured in DSS-induced UC in mice for analysis. Results: The four doenjang samples increased the colon length shortened by DSS, reduced DAI (diarrhea and hemoccult), CMDI (ulceration, inflammation, and hemorrhage) and the content of immune-related cells in the blood. Moreover, the levels of TNF-α, IL-6, and NO increased by DSS were decreased by doenjang, and tissue damage was significantly reduced. Conclusions: These findings confirmed that doenjang exerts protective effects against UC, suggesting its possible use in developing therapeutic strategies or functional products.

Comparison of laxative effects of fermented soybeans (Cheonggukjang) containing toxins and biogenic amines against loperamide-induced constipation mouse model.

BACKGROUND/OBJECTIVES: Cheonggukjang is a traditional fermented soybean paste with significant health-promoting effects. On the other hand, there have been insufficient studies on the safety and efficacy of Cheonggukjang, which is produced using traditional methods containing toxins and biogenic amines (BAs). This study compared the laxative effect of Cheonggukjang, containing high or low levels of toxins and BAs (HTBC or LTBC) in a loperamide (Lop)-induced constipation mouse model. MATERIALS/METHODS: To induce constipation, Lop (5 mg/kg) was administered orally to ICR mice twice a day for 4 days, and the dose was increased to 8 mg/kg after a 3-day rest period. Cheonggukjang (500 mg/kg, HTBC, or LTBC respectively) was administered for four weeks before the Lop treatment. RESULTS: The number of stools, fecal weight, water contents, gastrointestinal transit, and histological alterations were recovered significantly in the HTBC or LTBC groups. HTBC and LTBC administration did not induce significant changes in body weight, dietary intake, and behavior. The opioid-receptor downstream signaling pathway in colon tissues was also evaluated. The c-Kit, stem cell kinase, and mitogen-activated protein kinases subfamilies, including extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinases, and p38, were all downregulated in the HTBC or LTBC-administered mice colon compared to the Lop group. CONCLUSION: These results show that Cheonggukjang, containing high levels of toxins and BAs, have a similar laxative effect in a mouse model of Lop-induced constipation.

Protective Effects of Fermented Soybeans (Cheonggukjang) on Dextran Sodium Sulfate (DSS)-Induced Colitis in a Mouse Model.

Inflammatory bowel disease (IBD) is a chronic inflammatory disease, and the incidence of IBD is increasing every year owing to changes in dietary structure. Although the exact pathogenesis of IBD is still unclear, recent evidence suggests that gut dysbiosis is closely associated with IBD pathogenesis. Cheonggukjang is a traditional Korean fermented soybean paste produced using traditional and industrial methods, and contains probiotics, which affect the gut microbiota composition. However, the protective effect of Cheonggukjang against IBD is unknown. In this study, we investigated the bacterial community structure of traditional and commercial Cheonggukjang samples, as well as the protective effect of Cheonggukjang on a dextran sulfate sodium (DSS)-induced colitis mouse model. Traditional and commercial Cheonggukjang were found to contain various type of useful probiotics in their bacterial community structure. Cheonggukjang reduced the progression of DSS-induced symptoms, such as body weight loss, colonic shortening, disease activity index, and histological changes. Further, Cheonggukjang improved the intestinal epithelial barrier integrity on DSS-induced colitis mice. In addition, Cheonggukjang suppressed the expression of proinflammatory cytokines and inflammatory mediators through the inactivation of NF-κB and MAPK signaling pathways. These results indicate that Cheonggukjang exerts protective effects against DSS-induced colitis, suggesting its possible application as a functional food for improving inflammatory diseases.

γ-PGA-Rich Chungkookjang, Short-Term Fermented Soybeans: Prevents Memory Impairment by Modulating Brain Insulin Sensitivity, Neuro-Inflammation, and the Gut-Microbiome-Brain Axis.

Fermented soybean paste is an indigenous food for use in cooking in East and Southeast Asia. Korea developed and used its traditional fermented foods two thousand years ago. Chungkookjang has unique characteristics such as short-term fermentation (24-72 h) without salt, and fermentation mostly with Bacilli. Traditionally fermented chungkookjang (TFC) is whole cooked soybeans that are fermented predominantly by Bacillus species. However, Bacillus species are different in the environment according to the regions and seasons due to the specific bacteria. Bacillus species differently contribute to the bioactive components of chungkookjang, resulting in different functionalities. In this review, we evaluated the production process of poly-γ-glutamic acid (γ-PGA)-rich chungkookjang fermented with specific Bacillus species and their effects on memory function through the modulation of brain insulin resistance, neuroinflammation, and the gut-microbiome-brain axis. Bacillus species were isolated from the TFC made in Sunchang, Korea, and they included Bacillus (B.) subtilis, B. licheniformis, and B. amyloliquefaciens. Chungkookjang contains isoflavone aglycans, peptides, dietary fiber, γ-PGA, and Bacillus species. Chungkookjangs made with B. licheniformis and B. amyloliquefaciens have higher contents of γ-PGA, and they are more effective for improving glucose metabolism and memory function. Chungkookjang has better efficacy for reducing inflammation and oxidative stress than other fermented soy foods. Insulin sensitivity is improved, not only in systemic organs such as the liver and adipose tissues, but also in the brain. Chungkookjang intake prevents and alleviates memory impairment induced by Alzheimer's disease and cerebral ischemia. This review suggests that the intake of chungkookjang (20-30 g/day) rich in γ-PGA acts as a synbiotic in humans and promotes memory function by suppressing brain insulin resistance and neuroinflammation and by modulating the gut-microbiome-brain axis.