Since doenjang quality depends on the bacterial composition, which ambient bacteria in the environment and production conditions influence, a complete understanding of the bacteria community in traditionally madetraditionally made doenjang (TMD) from different regions is needed. We aimed to investigate the bacteria composition and quality of TMD in the following areas: Chonbuk (CB), Chonnam (CN), Kyungsang (KS), Kangwon (KW), Chungchung (CC) provinces, and Jeju island (JJ) of Korea. Twenty-nine TMD samples from different regions were used to assess biogenic amine contents, bacteria composition using next-generation methods, and metabolic functions of the bacteria using Picrust2. Bacillus spp. were isolated, and their antioxidant and fibrinolytic activities were determined. Most TMD contained high amounts of beneficial bacteria (Bacillus, Lactobacillus, Pediococcus and Weissella). However, some KS samples contained harmful bacteria (Cronobacter, Proteus and Acinetobacter) and less beneficial B. velezensis bacteria. There was no similarity among the regional groups, and each TMD showed a different bacteria composition. Shannon index, α-diversity index, was lower in TMD from JJ and CB than the other areas, but there was no β-diversity among TMD from the six area groups. Picrust2 analysis revealed that the functional potential for arachidonic acid metabolism was lowest in JJ and CN, that for supporting insulin action was highest in KS and JJ, and that for carbohydrate digestion and absorption was lowest in CB and JJ among all groups (p < 0.05) according to the Kyoto Encyclopedia of Genes and Genomes Orthology. Histamine contents were lower in CN and CC, and tyramine contents did not differ significantly. B. velezensis, B. subtilis, B. licheniformis, B. siamensis, and B. amyloliquefaciens were isolated from TMD. None of the isolated Bacillus spp. contained the B. cereus gene. B. subtilis from CN had the highest fibrinolytic activity, and B. velezensis from CB had the highest antioxidant activity. In conclusion, TMD mainly contained various Bacillus spp., and the predominant one was B. velezensis, which had antioxidant and fibrinolytic activity regardless of the regional origin.

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.

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Traditionally made Kochujang (TMK) is a long-term fermented soybean and rice mixture with red pepper and salts. The ambient bacteria in rice straw and nutrient components of Kochujang influence the bacteria community. We aimed to investigate the bacterial composition and quality of TMK from different provinces of Korea: Chungcheung (CC), Jeolla (JL), Kyungsang (KS), and GeongGee plus Kangwon (GK) provinces, and Jeju island (JJ). Furthermore, Bacillus spp. isolated from TMK were studied to have anti-cerebrovascular disease activity and probiotic properties. Seventy-three TMK samples from different regions were collected to assess the biogenic amine contents, bacteria composition using next-generation methods, and bacterial functions using Picrust2. Bacillus spp. was isolated from the collected TMK, and their antioxidant, fibrinolytic, and angiotensin I conversion enzyme (ACE) inhibitory activities and probiotic properties were examined. KS TMK had lower sodium contents than the other TMK. There were no significant differences in histamine and tyramine contents among the TMK samples in different provinces. The predominant bacteria in TMK was Bacillus spp., but KS included much less Bacillus spp. and higher Enterococcus and Staphylococcus than the other TMK. Gene expression related to lipopolysaccharide biosynthesis was higher in KS TMK than the other TMK in Picrust2. The predominant Bacillus spp. isolated from TMK was B. subtilis and B. velezensis. B. subtilis SRCM117233, SRCM117245, and SRCM117253 had antioxidant activity, whereas B. subtilis had higher fibrinolytic activity than other Bacillus spp. Only B. velezensis SRCM117254, SRCM117311, SRCM117314, and SRCM117318 had over 10% ACE inhibitory activity. In conclusion, KS had less Bacillus related to lower sodium contents than the other TMK. The specific strains of B. subtilis and B. velezensis had antioxidant, fibrinolytic, and ACE inhibitory activity, and they can be used as a starter culture to produce better quality controlled Kochujang with anti-cerebrovascular disease activities.

A high salt intake may exacerbate menopausal symptoms and substituting for different types of traditionally made kanjang (TMK; soy sauce) may prevent it. This study examined whether substituting salt with lyophilized TMK containing low and high Bacillus and biogenic amines in a high-fat diet might modulate the menopausal symptoms and the energy, glucose, and lipid metabolism in ovariectomized (OVX) rats. They were categorized into salt (Control), TMK with high Bacillus and low biogenic amines (HBLB), TMK with high Bacillus and high biogenic amines (HBHB), TMK with low Bacillus and low biogenic amines (LBLB), and TMK with low Bacillus and high biogenic amines (LBHB). Sham-operated rats consumed the same diet as the Control. HBLB, HBHB, and LBHB prevented increased tail skin temperature compared to the Control. HBHB and HBLB partially inhibited the increased weight gain and abdominal fat mass by reducing the food efficiency without changing the serum 17β-estradiol concentrations. Serum glucose and insulin concentrations and the insulin resistance index by the homeostatic model assessment for insulin resistance showed a positive association for weight gain. HBLB and HBHB decreased the serum malondialdehyde and tumor-necrosis factor-α levels. Hepatic triglyceride storage was lower in all TMK groups than in the Control, while hepatic glycogen accumulation was higher in the HBLB, HBHB, and LBHB groups than in the Control and LBLB groups. Accordingly, the mRNA expression of peroxisome proliferator-activated receptors-γ(PPAR-γ) was higher in the HBLB and HBHB groups compared to the Control, and that of fatty acid synthase was opposite to PPAR-γ expression. However, HBLB and HBHB improved dyslipidemia and insulin resistance compared to the Control, but their improvement did not reach that of the Normal-control. The acetic acid concentrations in the portal vein were lower in the LBLB than in the Control, while the butyric acid contents were higher in the LBHB and HBLB groups than in the Control. HBHB, HBLB, and LBHB elevated Akkermansia and Lactobacillus, and HBLB and LBLB increased Bacteroides and Ruminococcus compared to the Control. Polycyclic aromatic hydrocarbon degradation, bile acid synthesis, and unsaturated fatty acid biosynthesis were significantly higher in the HBLB group than in the Control group. In conclusion, substituting salts to TMK with a high Bacillus content regardless of the bioamine contents partially improved the menopausal symptoms and metabolic disturbance in estrogen-deficient animals.

Fermentation characteristics of mulberry (Cudrania tricuspidata) fruit vinegar produced by acetic acid bacteria isolated from traditional fermented foods

Two bacterial strains, named as LE17 and LE22, were isolated from traditionally fermented soybean products in order to select lactic acid bacteria for the reduction of biogenic amines and harmful bacteria. Both strains were identified as Pediococcus pentosaceus by 16S rRNA sequence analysis and additional biochemical tests. The strain LE17 reduced the amines by 13.7% for histamine and by 25.9% for tyramine, when it grew in minimal synthetic media containing 0.1% (w/v) histamine and 0.1% tyramine at 30℃ for 48 h, while the strain LE22 reduced the amines by 23.7% for histamine and by 15.7% for tyramine. Both strains also had broad inhibition spectra against pathogens. Considering their properties, they could be used as starters for industrial soybean fermentation. Keywords

Short-term fermented soybeans (chungkookjang) with specific Bacillus (B.) spp. have anti-obesity, antidiabetic, and anti-stroke functions. We examined the hypothesis that the long-term consumption of B. amyloliquefaciens SCGB 1 fermented (CKJ1) and B. subtilis SCDB 291 (CKJ291) chungkookjang can alleviate clinical symptoms and hyperglycemia after ischemic stroke by promoting the gut microbiota–brain axis. We examined this hypothesis in Mongolian male gerbils with stroke symptoms induced by carotid artery occlusion. The artery-occluded gerbils were divided into five groups: no supplementation (Control, Normal-control), 4% cooked soybeans (CSB), CKJ1, or CKJ291 in a high-fat diet for 3 weeks. The carotid arteries of gerbils in the Control, CSB, CKJ1, and CKJ291 groups were occluded for 8 min and they then continued on their assigned diets for an additional 3 weeks. Normal-control gerbils had no artery occlusion. The diets in all groups contained an identical macronutrient composition using starch, casein, soybean oil, and dietary fiber. The CSB, CKJ1, and CKJ291 groups exhibited less neuronal cell death than the Control group, while the CKJ1 group produced the most significant reduction among all groups, as much as 85% of the Normal-control group. CKJ1 and CKJ291 increased the blood flow and removal of blood clots, as determined by Doppler, more than the Control. They also showed more improvement in neurological disorders from ischemic stroke. Their improvement showed a similar tendency as neuronal cell death. CKJ1 treatment improved memory impairment, measured with Y maze and passive avoidance tests, similar to the Normal-control. The gerbils in the Control group had post-stroke hyperglycemia due to decreased insulin sensitivity and β-cell function and mass; the CKJ291, CSB, and CKJ1 treatments protected against glucose disturbance after artery occlusion and were similar to the Normal-control. CKJ1 and CKJ291 also reduced serum tumor necrosis factor-α concentrations and hippocampal interleukin-1β expression levels, compared to the Control. CKJ1 and CKJ291 increased the contents of Lactobacillus, Bacillus, and Akkermansia in the cecum feces, similar to the Normal-control. Picrust2 analysis showed that CKJ1 and CKJ291 increased the propionate and butyrate metabolism and the starch and glucose metabolism but reduced the lipopolysaccharide biosynthesis and fatty acid metabolism compared to the Control. In conclusion, daily CKJ1 and CKJ291 intake prevented neuronal cell death and memory dysfunction from the artery occlusion by increasing blood flow and β-cell survival and reducing post-stroke-hyperglycemia through modulating the gut microbiome composition and metabolites to influence the host metabolism, especially inflammation and insulin resistance, protecting against neuronal cell death and brain dysfunction. CKJ1 had better effects than CKJ291.