Microbial foods for improving human and planetary health.

The current food production system is negatively impacting planetary and human health. A transition to a sustainable and fair food system is urgently needed. Microorganisms are likely enablers of this process, as they can produce delicious and healthy microbial foods with low environmental footprints. We review traditional and current approaches to microbial foods, such as fermented foods, microbial biomass, and food ingredients derived from microbial fermentations. We discuss how future advances in science-driven fermentation, synthetic biology, and sustainable feedstocks enable a new generation of microbial foods, potentially impacting the sustainability, resilience, and health effects of our food system.

Gut-microbiota-targeted diets modulate human immune status.

Diet modulates the gut microbiome, which in turn can impact the immune system. Here, we determined how two microbiota-targeted dietary interventions, plant-based fiber and fermented foods, influence the human microbiome and immune system in healthy adults. Using a 17-week randomized, prospective study (n = 18/arm) combined with -omics measurements of microbiome and host, including extensive immune profiling, we found diet-specific effects. The high-fiber diet increased microbiome-encoded glycan-degrading carbohydrate active enzymes (CAZymes) despite stable microbial community diversity. Although cytokine response score (primary outcome) was unchanged, three distinct immunological trajectories in high-fiber consumers corresponded to baseline microbiota diversity. Alternatively, the high-fermented-food diet steadily increased microbiota diversity and decreased inflammatory markers. The data highlight how coupling dietary interventions to deep and longitudinal immune and microbiome profiling can provide individualized and population-wide insight. Fermented foods may be valuable in countering the decreased microbiome diversity and increased inflammation pervasive in industrialized society.

Microbiome Assembly in Fermented Foods.

For thousands of years, humans have enjoyed the novel flavors, increased shelf-life, and nutritional benefits that microbes provide in fermented foods and beverages. Recent sequencing surveys of ferments have mapped patterns of microbial diversity across space, time, and production practices. But a mechanistic understanding of how fermented food microbiomes assemble has only recently begun to emerge. Using three foods as case studies (surface-ripened cheese, sourdough starters, and fermented vegetables), we use an ecological and evolutionary framework to identify how microbial communities assemble in ferments. By combining in situ sequencing surveys with in vitro models, we are beginning to understand how dispersal, selection, diversification, and drift generate the diversity of fermented food communities. Most food producers are unaware of the ecological processes occurring in their production environments, but the theory and models of ecology and evolution can provide new approaches for managing fermented food microbiomes, from farm to ferment.

New insight into protective effect against oxidative stress and biosynthesis of exopolysaccharides produced by Lacticaseibacillus paracasei NC4 from fermented eggplant.

Fermented eggplant is a traditional fermented food, however lactic acid bacteria capable of producing exopolysaccharide (EPS) have not yet been exploited. The present study focused on the production and protective effects against oxidative stress of an EPS produced by Lacticaseibacillus paracasei NC4 (NC4-EPS), in addition to deciphering its genomic features and EPS biosynthesis pathway. Among 54 isolates tested, strain NC4 showed the highest EPS yield and antioxidant activity. The maximum EPS production (2.04 ± 0.11 g/L) was achieved by culturing in MRS medium containing 60 g/L sucrose at 37 °C for 48 h. Under 2 mM H2O2 stress, the survival of a yeast model Saccharomyces cerevisiae treated with 0.4 mg/mL NC4-EPS was 2.4-fold better than non-treated cells, which was in agreement with the catalase and superoxide dismutase activities measured from cell lysates. The complete genome of NC4 composed of a circular chromosome of 2,888,896 bp and 3 circular plasmids. The NC4 genome comprises more genes with annotated function in nitrogen metabolism, phosphorus metabolism, cell division and cell cycle, and iron acquisition and metabolism as compared to other reported L. paracasei. Of note, the eps gene cluster is not conserved across L. paracasei. Pathways of sugar metabolism for EPS biosynthesis were proposed for the first time, in which gdp pathway only present in few plant-derived bacteria was identified. These findings shed new light on the cell-protective activity and biosynthesis of EPS produced by L. paracasei, paving the way for future efforts to enhance yield and tailor-made EPS production for food and pharmaceutical industries.

A review on the application of bioinformatics tools in food microbiome studies.

There is currently a transformed interest toward understanding the impact of fermentation on functional food development due to growing consumer interest on modified health benefits of sustainable foods. In this review, we attempt to summarize recent findings regarding the impact of Next-generation sequencing and other bioinformatics methods in the food microbiome and use prediction software to understand the critical role of microbes in producing fermented foods. Traditionally, fermentation methods and starter culture development were considered conventional methods needing optimization to eliminate errors in technique and were influenced by technical knowledge of fermentation. Recent advances in high-output omics innovations permit the implementation of additional logical tactics for developing fermentation methods. Further, the review describes the multiple functions of the predictions based on docking studies and the correlation of genomic and metabolomic analysis to develop trends to understand the potential food microbiome interactions and associated products to become a part of a healthy diet.

The predominant lactic acid bacteria and yeasts involved in the spontaneous fermentation of millet during the production of the traditional porridge Hausa koko in Ghana.

Spontaneous fermentation of cereals like millet involves a diverse population of microbes from various sources, including raw materials, processing equipment, fermenting receptacles, and the environment. Here, we present data on the predominant microbial species and their succession at each stage of the Hausa koko production process from five regions of Ghana. The isolates were enumerated using selective media, purified, and phenotypically characterised. The LAB isolates were further characterised by 16S rRNA Sanger sequencing, typed using (GTG)5 repetitive-PCR, and whole genome sequencing, while 28S rRNA Sanger sequencing was performed for yeast identification. The pH of the millet grains ranged from mean values of 6.02-6.53 to 3.51-3.99 in the final product, depending on the processors. The mean LAB and yeast counts increased during fermentation then fell to final counts of log 2.77-3.95 CFU/g for LAB and log 2.10-2.98 CFU/g for yeast in Hausa koko samples. At the various processing stages, the counts of LAB and yeast revealed significant variations (p < 0.0001). The species of LAB identified in this study were Limosilactobacillus pontis, Pediococcus acidilactici, Limosilactobacillus fermentum, Limosilactobacillus reuteri, Pediococcus pentosaceus, Lacticaseibacillus paracasei, Lactiplantibacillus plantarum, Schleiferilactobacillus harbinensis, and Weissella confusa. The yeasts were Saccharomyces cf. cerevisiae/paradoxus, Saccharomyces cerevisiae, Pichia kudriavzevii, Clavispora lusitaniae and Candida tropicalis. The identification and sequencing of these novel isolates and how they change during the fermentation process will pave the way for future controlled fermentation, safer starter cultures, and identifying optimal stages for starter culture addition or nutritional interventions. These LAB and yeast species are linked to many indigenous African fermented foods, potentially acting as probiotics in some cases. This result serves as the basis for further studies into the technological and probiotic potential of these Hausa koko microorganisms.

Characterization of the broad-spectrum antibacterial activity of bacteriocin-like inhibitory substance-producing probiotics isolated from fermented foods.

Antimicrobial peptides, such as bacteriocin, produced by probiotics have become a promising novel class of therapeutic agents for treating infectious diseases. Selected lactic acid bacteria (LAB) isolated from fermented foods with probiotic potential were evaluated for various tests, including exopolysaccharide production, antibiotic susceptibility, acid and bile tolerance, antibacterial activity, and cell adhesion and cytotoxicity to gastric cell lines. Six selected LAB strains maintained their high viability under gastrointestinal conditions, produced high exopolysaccharides, showed no or less cytotoxicity, and adhered successfully to gastric cells. Furthermore, three strains, Weissella confusa CYLB30, Lactiplantibacillus plantarum CYLB47, and Limosilactobacillus fermentum CYLB55, demonstrated a strong antibacterial effect against drug-resistant Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica serovar Choleraesuis, Enterococcus faecium, and Staphylococcus aureus. Whole genome sequencing was performed on these three strains using the Nanopore platform; then, the results showed that all three strains did not harbor genes related to toxins, superantigens, and acquired antimicrobial resistance, in their genome. The bacteriocin gene cluster was found in CYLB47 genome, but not in CYLB30 and CYLB55 genomes. In SDS-PAGE, the extract of CYLB30 and CYLB47 bacteriocin-like inhibitory substance (BLIS) yielded a single band with a size of less than 10 kDa. These BLIS inhibited the growth and biofilm formation of drug-resistant P. aeruginosa and methicillin-resistant S. aureus (MRSA), causing membrane disruption and inhibiting adhesion ability to human skin HaCaT cells. Moreover, CYLB30 and CYLB47 BLIS rescued the larvae after being infected with P. aeruginosa and MRSA infections. In conclusion, CYLB30 and CYLB47 BLIS may be potential alternative treatment for multidrug-resistant bacteria infections.

Genomic characterization and probiotic potential assessment of an exopolysaccharide-producing strain Pediococcus pentosaceus LL-07 isolated from fermented meat.

BACKGROUND: The genomic information available for Pediococcus pentosaceus is primarily derived from fermented fruits and vegetables, with less information available from fermented meat. P. pentosaceus LL-07, a strain isolated from fermented meat, has the capability of producing exopolysaccharides (EPS). To assess the probiotic attributes of P. pentosaceus LL-07, we conducted whole-genome sequencing (WGS) using the PacBio SequelIIe and Illumina MiSeq platforms, followed by in vitro experiments to explore its probiotic potential. RESULTS: The genome size of P. pentosaceus LL-07 is 1,782,685 bp, comprising a circular chromosome and a circular plasmid. Our investigation revealed the absence of a CRISPR/Cas system. Sugar fermentation experiments demonstrated the characteristics of carbohydrate metabolism. P. pentosaceus LL-07 contains an EPS synthesis gene cluster consisting of 13 genes, which is different from the currently known gene cluster structure. NO genes associated with hemolysis or toxin synthesis were detected. Additionally, eighty-six genes related to antibiotic resistance were identified but not present in the prophage, transposon or plasmid. In vitro experiments demonstrated that P. pentosaceus LL-07 was comparable to the reference strain P. pentosaceus ATCC25745 in terms of tolerance to artificial digestive juice and bile, autoaggregation and antioxidation, and provided corresponding genomic evidence. CONCLUSION: This study confirmed the safety and probiotic properties of P. pentosaceus LL-07 via complete genome and phenotype analysis, supporting its characterization as a potential probiotic candidate.

Evaluation of probiotic efficacy of indigenous yeast strain, Saccharomyces cerevisiae Y-89 isolated from a traditional fermented beverage of West Bengal, India having protective effect against DSS-induced colitis in experimental mice.

Increasing awareness regarding health promotion and disease prevention has driven inclusion of fermented foods and beverages in the daily diet. These are the enormous sources of beneficial microbes, probiotics. This study aims to isolate yeast strains having probiotic potential and effectivity against colitis. Initially, ninety-two yeast strains were isolated from Haria, an ethnic fermented beverage of West Bengal, India. Primary screening was done by their acid (pH 4) and bile salt (0.3%) tolerance ability. Four potent isolates were selected and found effective against Entamoeba histolytica, as this human pathogen is responsible to cause colitis. They were identified as Saccharomyces cerevisiae. They showed luxurious growth even at 37 oC, tolerance up to 5% of NaCl, resistance to gastric juice and high bile salt (2.0%) and oro-gastrointestinal transit tolerance. They exhibited good auto-aggregation and co-aggregation ability and strong hydrophobicity. Finally, heat map and principal component analysis revealed that strain Y-89 was the best candidate. It was further characterised and found to have significant protective effects against DSS-induced colitis in experimental mice model. It includes improvement in colon length, body weight and organ indices; reduction in disease activity index; reduction in cholesterol, LDL, SGPT, SGOT, urea and creatinine levels; improvement in HDL, ALP, total protein and albumin levels; decrease in coliform count and restoration of tissue damage. This study demonstrates that the S. cerevisiae strain Y-89 possesses remarkable probiotic traits and can be used as a potential bio-therapeutic candidate for the prevention of colitis.

Genome mining and physiological analyses uncover adaptation strategies and biotechnological potential of Virgibacillus dokdonensis T4.6 isolated from high-salt shrimp paste.

Virgibacillus spp. stand out as a potent starter culture for accelerating the fermention of fish sauces and shrimp pastes. However, the underlying molecular mechanisms responsible for their adaptation and biotechnological potential remain elusive. Therefore, the present study focuses on phenotypic and genomic analyses of a halophilic bacterium Virgibacillus dokdonensis T4.6, derived from Vietnamese high-salt fermented shrimp paste. The draft genome contained 4,096,868 bp with 3780 predicted coding sequences. Genome mining revealed the presence of 143 genes involved in osmotic adaptation explaining its resistant phenotype to 24% (w/v) NaCl. Among them, 37 genes making up the complete ectoine metabolism pathway, confirmed its ability to produce 4.38 ± 0.29 wt% ectoine under 12.5% NaCl stress. A significant finding was the identification of 39 genes responsible for an entire degradation pathway of the toxic biogenic amine histamine, which was in agreement with its histamine degradation rate of 42.7 ± 2.1% in the HA medium containing 5 mM histamine within 10 days at 37 °C. Furthermore, 114 proteolytic and 19 lipolytic genes were detected which might contribute to its survival as well as the nutrient quality and flavor of shrimp paste. Of note, a putative gene vdo2592 was found as a possible novel lipase/esterase due to its unique Glycine-Aspartate-Serine-Leucine (GDSL) sequence motif. This is the first report to reveal the adaptative strategies and related biotechnological potential of Virgibacillus associated with femented foods. Our findings indicated that V. dokdonensis T4.6 is a promising starter culture for the production of fermented shrimp paste products.

Lactobacillus juensis sp. nov. and Lactobacillus rizhaonensis sp. nov., isolated from the gut of honeybee (Apis mellifera).

Four lactic acid bacteria, designated F690T, F697, F790T and F769-2, were isolated from the gut of honeybee (Apis mellifera). Results of 16S rRNA gene sequence analysis indicated that strains F690T and F697 were phylogenetically related to the type strains of Lactobacillus kimbladii, Lactobacillus laiwuensis, Lactobacillus kullabergensis and Lactobacillus huangpiensis, having 99.1-99.6 % 16S rRNA gene sequence similarities; and that strains F790T and F769-2 were most closely related to the type strain of Lactobacillus melliventris, having 99.2-99.3 % 16S rRNA gene sequence similarities. The phylogenies based on concatenated pheS, rpoA, gyrB, hsp60, recA, rpoB and tuf sequences and based on whole genome sequences were identical to that based on 16S rRNA gene sequences. Strains F690T and F697 exhibited the highest average nucleotide identity (ANI; 92.1-93.2 %), digital DNA-DNA hybridization (dDDH; 50-50.1 %) and average amino acid identity (AAI; 94.9-95.1 %) values with L. kimbladii Hma2NT. Strains F790T and F769-2 had the highest ANI (93.1-94 %), dDDH (54.4 %) and AAI (94.4-94.7 %) values with L. melliventris Hma8NT. Based upon the data obtained in the present study, two novel species, Lactobacillus juensis sp. nov. and Lactobacillus rizhaonensis sp. nov., are proposed and the type strains are F690T (=JCM 36259T=CCTCC AB 2023131T) and F790T (=JCM 36260T=CCTCC AB 2023132T), respectively.

Lactiplantibacillus paraxiangfangensis sp. nov., isolated from traditional Chinese pickle.

Three Gram-stain-positive bacterial strains (designated 231-9T, 142-6 and 463-4) were isolated from traditional Chinese pickle, and were characterized using a polyphasic taxonomic approach. Results of 16S rRNA gene sequence analysis indicated that strains 231-9T, 142-6 and 463-4 were phylogenetically related to the type strains of Lactiplantibacillus xiangfangensis, Lactiplantibacillus garii, Lactiplantibacillus carotarum, Lactiplantibacillus plajomi and Lactiplantibacillus modestisalitolerans, having 98.6-99.9 % 16S rRNA gene sequence similarities. Strains 231-9T, 142-6 and 463-4 were most closely related to the type strain of L. xiangfangensis, having 99.9 % 16S rRNA gene, 95.6 % pheS, 99.4 % rpoA and 98.2 % concatenated pheS and rpoA sequence similarities. Relatively low pheS (95.6 %) sequence similarity indicated that strain 231-9T should be further identified. Strain 231-9T shared 99.7-99.9 % average nucleotide identity (ANI) and 98.8-98.9 % digital DNA-DNA hybridization (dDDH) values with strains 142-6 and 463-4, indicating that they belonged to the same species. The ANI and dDDH values between strain 231-9T and L. xiangfangensis LMG 26013T were 92.4-92.9 and 49.6 %, respectively, less than the threshold for species demarcation (95-96% ANI and 70 % dDDH values, respectively), indicating that strains 231-9T, 142-6 and 463-4 represented a novel species within the genus Lactiplantibacillus. Acid production from d-ribose, d-adonitol, d-galactose and lactose, activity of ß-galactosidase and ß-glucosidase, Voges-Proskauer reaction, hydrolysis of hippurate, resistance to 5 µg ml-1 erythromycin, 100 µg ml-1 tetracycline hydrochloride, 50 µg ml-1 bacitracin, 300 µg ml-1 each of gentamicin sulphate, streptomycin sulphate and neomycin sulphate, tolerance to 6 % NaCl could distinguish strains 231-9T, 142-6 and 463-4 from L. xiangfangensis 3.1.1T. Based upon the data of polyphasic characterization obtained in the present study, a novel species, Lactiplantibacillus paraxiangfangensis sp. nov., is proposed and the type strain is 231-9T (=JCM 36258T=CCTCC AB 2023133T).

Leuconostoc koreense sp. nov., isolated from kimchi, a fermented vegetable.

The novel strain CBA3628T was isolated from kimchi, a Korean fermented vegetable. CBA3628T is a cocci-shaped, Gram-stain-positive, catalase- and oxidase-negative and facultatively anaerobic bacterium. The results of phylogenetic analysis based on 16S rRNA gene sequencing indicated that CBA3628T represented a member of the genus Leuconostoc of the family Leuconostocaceae. CBA3628T has a circular chromosomal genome and three plasmids of 1 864 558 bp (37% DNA G+C content), containing 1,887 genes, 1,762 predicted protein-coding genes, 4 complete rRNA loci and 70 tRNA genes. The cells were non-haemolytic, non-motile and non-spore forming. The optimal growth of CBA3628T occurred at 30 °C, pH 6.0 and with 0-2% (w/v) NaCl. The major polar lipids of CBA3628T were diphosphatidylglycerol and phosphatidylglycerol. The major fatty acids (>10%) of CBA3628T were C16  :  0, C20  :  0 and C19 : 0 cyclo ω8c. CBA3628T contained A3α-type peptidoglycans. CBA3628T was most closely related to Leuconostoc mesenteroides subsp. mesenteroides ATCC 8293T, L. mesenteroides subsp. dextranicum DSM 20484T and L. suionicum DSM 20241T with 99.52% 16S rRNA gene sequence similarity. However, the average nucleotide identities of 91.9%, 91.7% and 91.1% and the digital DNA-DNA hybridisation values of 45.6%, 45.4% and 45.4% indicated that the novel isolate represented a distinct species. Phylogenetic analyses of both the 16S rRNA gene and genome sequences revealed that CBA3628T formed a distinct phylogenetic lineage within the genus Leuconostoc and was most closely related to Leuconostoc litchii MB7T. The ANI and dDDH values between CBA3628T and L. litchii MB7T were 84.9 and 22.8%, respectively. Functional genes belonging to COG categories E, J and K were enriched in the genome of CBA3628T (>7.9%). On the basis of its physiological, chemotaxonomic, phylogenetic and genomic properties, strain CBA3628T represents a novel species from the genus Leuconostoc, for which we propose the name Leuconostoc koreense sp. nov., with the type strain CBA3628T (= KACC 23049T = DSM 116836T).

Vagococcus jeotgali sp. nov., isolated from cutlassfish jeotgal, a traditional Korean fermented seafood.

A novel, Gram-positive, facultatively anaerobic, and non-motile bacterial strain, designated B2T-5T, was isolated from jeotgal, a traditional Korean fermented seafood. Colonies grown on gifu anaerobic medium agar plates were cream-coloured, irregular, and umbonate with curled margins. Optimal growth of strain B2T-5T occurred at 20 °C, pH 8.0, and in the presence of 1% (w/v) NaCl. Strain B2T-5T was negative for oxidase and catalase activity. Hippurate was not hydrolysed and acetoin was not produced. The major cellular fatty acids were C18 : 1 ω9c and C16 : 0. The cell-wall peptidoglycan was of the A4α type containing l-Lys-d-Asp. The predominant respiratory quinone was menaquinone 7. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylcholine. According to the phylogenetic analysis based on 16S rRNA gene sequences, strain B2T-5T was most closely related to Vagococcus teuberi DSM 21459T, showing 98.2% sequence similarity. Genome sequencing of strain B2T-5T revealed a genome size of 2.0 Mbp and a G+C content of 33.8 mol%. The average nucleotide identities of strain B2T-5T with Vagococcus teuberi DSM 21459T, Vagococcus bubulae SS1994T, and Vagococcus martis D7T301T were 75.0, 74.7, and 75.1%, respectively. Based on the phenotypic, chemotaxonomic, and genotypic data, strain B2T-5T represents a novel species of the genus Vagococcus, for which the name Vagococcus jeotgali sp. nov. is proposed. The type strain is B2T-5T (=KCTC 21223T=JCM 35937T).

Effects of gnotobiotic fermentation on global gene expression of germ-free vegetables.

Existing research has underscored the vital interplay between host organisms and their associated microbiomes, which affects health and function. In both plants and animals, host factors critically shape microbial communities and influence growth, health, and immunity. Post-harvest plants, such as those used in kimchi, a traditional Korean dish, offer a unique avenue for exploring host-microbe dynamics during fermentation. Despite the emphasis on lactic acid bacteria (LAB) in fermentation studies, the roles of host factors remain unclear. This study aimed to investigate the influence of these factors on plant transcriptomes during kimchi fermentation. We individually inoculated nine LAB strains into germ-free kimchi to generate LAB-mono-associated gnotobiotic kimchi and performed RNA-sequencing analysis for the host vegetables during fermentation. The transcriptomes of post-harvest vegetables in kimchi change over time, and microbes affect the transcriptome profiles of vegetables. Differentially expressed gene analyses revealed that microbes affected the temporal expression profiles of several genes in the plant transcriptomes in unique directions depending on the introduced LAB strains. Cluster analysis with other publicly available transcriptomes of post-harvest vegetables and fruits further revealed that the plant transcriptome is more profoundly influenced by the environment harboring the host than by host phylogeny. Our results bridge the gap in understanding the bidirectional relationship between host vegetables and microbes during food fermentation, illuminating the complex interplay between vegetable transcriptomes, fermentative microbes, and the fermentation process in food production. The different transcriptomic responses elicited by specific LAB strains suggest the possibility of microbial manipulation to achieve the desired fermentation outcomes.

Association between traditional Korean fermented vegetables (kimchi) intake and serum lipid profile: using the Korean Genome and Epidemiology Study (KoGES) cohort.

PURPOSE: Dyslipidemia is a major health issue worldwide. There is growing interest in understanding the potential role of kimchi consumption on serum lipid profiles. However, there are limited epidemiological studies available on this topic. Therefore, this study aims to investigate the association between kimchi intake and serum lipid profiles. METHODS: We conducted an epidemiological study on participants (aged 40-69 years old) selected from the Health Examinees (HEXA) cohort study (n = 61,761). Four types of kimchi, including Baechu kimchi (cabbage kimchi), Kkakdugi (radish kimchi), Nabak kimchi/Dongchimi (a type of water kimchi made with fermented vegetables), and other kimchi, were assessed by a 106-food item semi-quantitative validated food frequency questionnaire (FFQ). Each kimchi intake is the average value calculated from the FFQ of the baseline and follow-up surveys. Fasting blood data were obtained at baseline and follow-up visits. Linear regression was used to examine the relationship between the intake of kimchi and the change in serum lipid profiles. RESULTS: The mean years between the baseline survey and a follow-up survey was 4.97 years. In this study, compared to the lowest category (< 1 serving/day), Baechu kimchi intake (2- < 3 servings/day) had more negative correlations with the change in values of total cholesterol (ß: -1.600, 95% confidence interval [CI, -2.744, -0.456]), triglycerides (ß: -3.372, 95% CI [-5.414, -1.330]), and low-density lipoprotein cholesterol (ß: -1.155, 95% CI [-2.214, -0.095]) in women. In men, Baechu kimchi intake (2- < 3 servings/day) had a more positive correlation associated with the changes in values of high-density lipoprotein cholesterol (ß: 0.049, 95% CI [0.031, 0.907]) compared to the lowest intake category (< 1 serving/day). CONCLUSIONS: Among Korean adults, consumption of kimchi, particularly Baechu kimchi, was found to be associated with improvements in serum lipid profiles. Further studies are required to conduct additional interventions to confirm the association between kimchi and serum lipid profiles.

Analysis of ester-producing performance in high-yield ethyl hexanoate yeast and the effect on metabolites in bio- enhanced Daqu, the starter for Baijiu and other traditional fermented foods.

AIMS: Ethyl hexanoate, one of the key flavor compounds in strong-flavor Baijiu. To improve the content of ethyl hexanoate in strong-flavor Baijiu, a functional strain with high yield of ethyl hexanoate was screened and its ester-producing performance was studied. METHODS AND RESULTS: Upon identification, the strain was classified as Candida sp. and designated as ZY002. Under optimal fermentation conditions, the content of ethyl hexanoate synthesized by ZY002 can be as high as 170.56 mg L-1. A fermentation test was carried out using the ZY002 strain bioaugmented Daqu to verify the role of the strain applied to Baijiu brewing. It was found that strain ZY002 could not only improve the moisture and alcohol contents of fermented grains but also diminish the presence of reducing sugar and crude starch. Furthermore, it notably amplified the abundance of flavor compounds. CONCLUSION: In this study, Candida sp. ZY002 with a high yield of ethyl hexanoate provided high-quality strain resources for the actual industrial production of Baijiu.

Conversion of notoginsenoside R1 to 3ß,12ß-dihydroxydammar-(E)-20(22),24-diene-6-O-ß-D-xylopyranosyl-(1→2)-ß-D-glucopyranoside by Lactiplantibacillus plantarum S165 enhanced protective effects of LPS-induced intestinal epithelial barrier injury in Caco-2 cells.

AIMS: Microbial transformation to modify saponins and enhance their biological activities has received increasing attention in recent years. This study aimed to screen the strain that can biotransform notoginsenoside R1, identify the product and study its biological activity. METHODS AND RESULTS: A lactic acid bacteria strain S165 with glycosidase-producing activity was isolated from traditional Chinese fermented foods, which was identified and grouped according to API 50 CHL kit and 16S rDNA sequence analysis. Subsequently, notoginsenoside R1 underwent a 30-day fermentation period by the strain S165, and the resulting products were analyzed using High-performance liquid chromatography (HPLC), Ultra-performance liquid chromatography (UPLC)-mass spectrometry (MS)/MS, and 13C-Nuclear magnetic resonance (NMR) techniques. Employing a model of Lipopolysaccharide (LPS)-induced damage to Caco-2 cells, the damage of Caco-2 cells was detected by Hoechst 33 258 staining, and the activity of notoginsenoside R1 biotransformation product was investigated by CCK-8 and western blotting assay. The strain S165 was identified as Lactiplantibacillus plantarum and was used to biotransform notoginsenoside R1. Through a 30-day biotransformation, L. plantarum S165 predominantly converts notoginsenoside R1 into 3ß,12ß-dihydroxydammar-(E)-20(22),24-diene-6-O-ß-D-xylopyranosyl-(1→2)-ß-D-glucopyranoside, temporarily named notoginsenoside T6 (NGT6) according to HPLC, UPLC-MS/MS, and 13C-NMR analysis. Results from CCK-8 and Hoechst 33258 staining indicated that the ability notoginsenoside T6 to alleviate the intestinal injury induced by LPS in the Caco-2 cell was stronger than that of notoginsenoside R1. In addition, Western blotting result showed that notoginsenoside T6 could prevent intestinal injury by protecting tight junction proteins (Claudin-1, Occludin, and ZO-1). CONCLUSION: Notoginsenoside R1 was biotransformed into the notoginsenoside T6 by L. plantarum S165, and the biotransformed product showed an enhanced intestinal protective effect in vitro.

Design and rationale for an open-label, randomized, controlled pilot trial to evaluate the changes in blood uremic toxins in patients with chronic kidney disease by dietary therapy with sake lees.

BACKGROUND: Patients with chronic kidney disease (CKD) reportedly show dysbiosis, which is the imbalance of gut microbiome. Dysbiosis increases the uremic toxin level in the intestine, and uremic toxins transfer into the blood, causing CKD progression. Sake lees, a traditional Japanese fermented food, may help reduce uremic toxins by altering the gut microbiome. Additionally, D-alanine, which is present in sake lees, may have a renoprotective effect. The present pilot study aims to evaluate the effect of adding sake lees to the standard CKD dietary therapy in reducing blood uremic toxins. METHODS: This pilot study is a single-center, open-label, randomized controlled trial. Twenty-four patients with CKD will be enrolled and allocated 1:1 to the intervention and control groups. The intervention group will receive standard CKD dietary therapy with an additional intake of 50 g of sake lees per day for 8 weeks, whereas the control group will only receive standard CKD dietary therapy. The primary endpoint is the change in serum indoxyl sulfate after 8 weeks. The secondary endpoint is the plasma D-alanine and fecal microbiome changes. CONCLUSION: This pilot study provides insight into the development of a new diet focused on gut microbiome and D-amino acids in patients with CKD. CLINICAL TRIAL REGISTRATION: This protocol was approved by the Clinical Trial Review Board of Kanazawa University Hospital on October 27, 2022 (2022-001 [6139]) and available to the public on the website of the Japan Registry of Clinical Trials on November 22, 2022 (jRCT1040220095).

Identification and estimation of the intake of fermented foods and their contribution to energy and nutrients among Japanese adults.

OBJECTIVE: Few studies have reported intakes of fermented foods with their clear definitions. This study aimed to identify fermented foods and beverages consumed in Japan based on international definitions and to estimate their intake and contribution to energy and nutrients. DESIGN: Data from a 16-d (four non-consecutive days within each season at 3-month intervals) semi-weighted dietary records (DR) were used. To identify 'entirely fermented foods' and 'partially fermented foods', a literature search on food processing and ingredients was conducted for all foods that appeared in the DR. For 'partially fermented foods', only the weight of the fermented food component was included in the estimation of total fermented food intake. SETTING: Four regions in Japan: Osaka, Nagano, Tottori and Okinawa. PARTICIPANTS: Two-hundred forty-two apparently healthy Japanese adults aged 31-81 years. RESULTS: Of the 1396 kinds of unique foods that appeared in the DR, 101 were 'entirely fermented foods' and 104 were 'partially fermented foods'. The mean intake of fermented foods was 438 g/d per person (17 % of the total weight). They were mainly derived from beer, coffee, bread and yogurt. The mean contribution of fermented foods to the total energy intake was 18 %. For nutrients, the contribution to total intake was high to Na (46 %), Mg (22 %) and Ca (20 %). CONCLUSIONS: Fermented foods account for approximately one-fifth of the total weight and energy of dietary intake and are important contributors to some nutrients in Japanese adults.