Positive influence of gut microbiota on the effects of Korean red ginseng in metabolic syndrome: a randomized, double-blind, placebo-controlled clinical trial

Background

Ginseng, a traditional herbal medicine, has been used for thousands of years to treat various diseases including metabolic syndrome (MS). However, the underlying mechanism(s) of such beneficial actions of ginseng against MS is poorly understood. Emerging evidence indicates a close association of the host gut microbiota with MS. The present study was conducted to examine, whether the beneficial effects of Korean red ginseng (KRG) against MS could be influenced by gut microbial population and whether gut microbial profile could be considered a valuable biomarker for targeted treatment strategy for MS in compliance with the predictive, preventive, and personalized medicine (PPPM / 3PM).

Methods

This clinical study was a randomized, double-blind, placebo-controlled trial evaluating the effects of KRG treatment for 8 weeks on patients with MS. The anthropometric parameters, vital signs, metabolic biomarkers, and gut microbial composition through 16S rRNA gene sequencing were assessed at the baseline and endpoint. The impact of KRG was also evaluated after categorizing the subjects into responders and non-responders, as well as enterotypes 1 and 2 based on their gut microbial profile at the baseline.

Results

Fifty out of 60 subjects who meet the MS criteria completed the trial without showing adverse reactions. The KRG treatment caused a significant decrease in systolic blood pressure (SBP). Microbial analysis revealed a decrease in Firmicutes, Proteobacteria, and an increase in Bacteroidetes in response to KRG. In patient stratification analysis, the responders showing marked improvement in the serum levels of lipid metabolic biomarkers TC and LDL due to the KRG treatment exhibited higher population of both the family Lachnospiraceae and order Clostridiales compared to the non-responders. The homeostasis model assessment-insulin resistance (HOMA-IR) and insulin level were decreased in enterotype 1 (Bacteroides-abundant group) and increased in enterotype 2 (prevotella-abundant group) following the KRG treatment.

Conclusion

In this study, the effects of KRG on the glucose metabolism in MS patients were influenced by the relative abundances of gut microbial population and differed according to the individual enterotype. Therefore, the analysis of enterotype categories is considered to be helpful in predicting the effectiveness of KRG on glucose homeostasis of MS patients individually. This will further help to decide on the appropriate treatment strategy for MS, in compliance with the perspective of PPPM.

Nocardioides luti sp. nov., belonging to the family Nocardioidaceae isolated from kaolinite, exhibiting the biosynthesis potential of alkylresorcinol

A novel Gram-staining-positive, short rod-shaped, non-motile, and non-pigmented actinobacterial strain (KIGAM211^T) was isolated from kaolinite, a soft white clay mineral, collected from Sancheong in the Republic of Korea. On the basis of 16S rRNA gene sequence analysis, strain KIGAM211^T was determined to belong to the genus Nocardioides and was most closely related to N. ungokensis UKS-03^T (97.5% similarity). Cells could grow between 4 and 35 °C (optimum 30 °C), 0-3% (w/v) NaCl concentration (optimum 0%) and pH 5.5-8.5 (optimum 7.0) on R2A agar. Morphological appearance of colonies was cream-white, arranged singly or in groups. Biochemical characterization of strain KAGAM211^T indicated that it could hydrolyze casein, gelatin, Tweens 40 and tyrosine. Furthermore, the strain was positive for both oxidase and catalase activity. Strain KIGAM211^T was characterized chemotaxonomically by MK-8 (H₄) as the predominant menaquinone and phosphatidylglycerol (PG) and phosphatidylinositol (PI) as the major polar lipids. Major fatty acids were iso-C_16:0 and C_18:1 ω9c. The Ortholog average nucleotide identity (OrthoANI) and in silico DNA-DNA hybridization (isDDH) values between strain KIGAM211T and its most closely related strains of the Nocardioides genus were < 82% and < 24%, respectively, suggesting that strain KIGAM211^T represent a novel species. The whole genome size of KIGAM211^T was 4.52 Mb, comprising a total of 4,294 genes with DNA G + C content of 72.3 mol%. The genome of strain KIGAM211^T also comprises the biosynthetic gene cluster for alkylresorcinol as secondary metabolite. The results of physiological, taxonomical, phylogenetic, and whole genome analyses allowed for differentiation of strain KIGAM211^T from the recognized Nocardioides species. Therefore, strain KIGAM211^T is considered to represent a novel species, for which the name Nocardioides luti sp. nov. (type strain KIGAM211^T = KCTC 49364^T = JCM 33859^T) is proposed.

Association Between Gut Microbiome and Frailty in the Older Adult Population in Korea

Frailty is a common geriatric syndrome associated with the risk of adverse health outcomes. Recently, 2 key pathophysiological characteristics of frailty, altered energy metabolism and dysregulated immunity, have been reported to be associated with gut microbiome dysbiosis, indicating that the gut microbiome plays a role in frailty. However, few studies have directly examined the relationship between the gut microbiome and frailty. Here, we investigated the association of frailty measures with the gut microbiome using 16S rRNA gene sequencing data obtained from the fecal samples of 176 Korean older adults. Overall frailty was scored using the Korean Frailty Index (FI). Grip strength and Geriatric Depression Scale (GDS) scores were used as physical and mental frailty measures, respectively. In contrast to age, metabolic, and inflammatory biomarkers, the frailty measures were associated with interindividual variations in microbial composition (false discovery rate [FDR] < 0.2). Both FI and GDS scores were negatively associated with microbial diversity (FDR < 0.2). Frailty measures showed distinct associations with specific microbial taxa and metabolic functions. Particularly, the Bacteroides enterotype was found only in subjects categorized in the frail group. Moreover, we observed that the abundance of beneficial taxa, such as Prevotella copri and Coprococcus eutactus, was reduced in frailer individuals, whereas that of detrimental taxa, such as Bacteroides fragilis and Clostridium hathewayi, was increased (FDR < 0.2). Our findings suggest that the gut microbiome can be used an indicator of an increased risk of frailty or a target for improving health in frail older adults.

Beneficial Effects of Newly Isolated Akkermansia muciniphila Strains from the Human Gut on Obesity and Metabolic Dysregulation

The identification of new probiotics with anti-obesity properties has attracted considerable interest. In the present study, the anti-obesity activities of Akkermansia muciniphila (A. muciniphila) strains isolated from human stool samples and their relationship with the gut microbiota were evaluated using a high fat-diet (HFD)-fed mice model. Three strains of A. muciniphila were chosen from 27 isolates selected based on their anti-lipogenic activity in 3T3-L1 cells. The anti-lipogenic, anti-adipogenic and anti-obesity properties of these three strains were evaluated further in HFD-induced obese mice. The animals were administered these strains six times per week for 12 weeks. The treatment improved the HFD-induced metabolic disorders in mice in terms of the prevention of body weight gain, caloric intake and reduction in the weights of the major adipose tissues and total fat. In addition, it improved glucose homeostasis and insulin sensitivity. These effects were also associated with the inhibition of low-grade intestinal inflammation and restoration of damaged gut integrity, prevention of liver steatosis and improvement of hepatic function. These results revealed a difference in the distribution pattern of the gut microbial communities between groups. Therefore, the gut microbial population modulation, at least in part, might contribute to the beneficial impact of the selected A. muciniphila strains against metabolic disorders.

The human gut archaeome: identification of diverse haloarchaea in Korean subjects

BACKGROUND

Archaea are one of the least-studied members of the gut-dwelling autochthonous microbiota. Few studies have reported the dominance of methanogens in the archaeal microbiome (archaeome) of the human gut, although limited information regarding the diversity and abundance of other archaeal phylotypes is available.

RESULTS

We surveyed the archaeome of faecal samples collected from 897 East Asian subjects living in South Korea. In total, 42.47% faecal samples were positive for archaeal colonisation; these were subsequently subjected to archaeal 16S rRNA gene deep sequencing and real-time quantitative polymerase chain reaction-based abundance estimation. The mean archaeal relative abundance was 10.24 ± 4.58% of the total bacterial and archaeal abundance. We observed extensive colonisation of haloarchaea (95.54%) in the archaea-positive faecal samples, with 9.63% mean relative abundance in archaeal communities. Haloarchaea were relatively more abundant than methanogens in some samples. The presence of haloarchaea was also verified by fluorescence in situ hybridisation analysis. Owing to large inter-individual variations, we categorised the human gut archaeome into four archaeal enterotypes.

CONCLUSIONS

The study demonstrated that the human gut archaeome is indigenous, responsive, and functional, expanding our understanding of the archaeal signature in the gut of human individuals. Video Abstract.

Evaluation of fecal DNA extraction protocols for human gut microbiome studies

BACKGROUND

DNA extraction is an important factor influencing the microbiome profile in fecal samples. Considering that the QIAamp DNA Stool Mini Kit, one of the most commonly used DNA extraction kits, is no longer manufactured, this study aimed to investigate whether a new commercially available kit, the QIAamp PowerFecal Pro DNA Kit, yields comparable microbiome profiles with those previously obtained using the QIAamp DNA Stool Mini Kit.

RESULTS

We extracted DNA from fecal samples of 10 individuals using three protocols (protocol P of the QIAamp PowerFecal Pro DNA Kit, and protocols SB and S of the QIAamp DNA Stool Mini Kit with and without an additional bead-beating step, respectively) in triplicate. Ninety extracted DNA samples were subjected to 16S rRNA gene sequencing. DNA quality measured by 260/280 absorbance ratios was found to be optimal in protocol P. Additionally, the DNA quantity and microbiome diversity obtained using protocol P were significantly higher than those of protocol S, however, did not differ significantly from those of protocol SB. Based on the overall microbiome profiles, variations between protocol P and protocol SB or S were significantly less than between-individual variations. Furthermore, most genera were not differentially abundant in protocol P compared to the other protocols, and the number of differentially abundant genera, as well as the degree of fold-changes were smaller between protocols P and SB than between protocols P and S.

CONCLUSIONS

The QIAamp PowerFecal Pro DNA Kit exhibited microbiome analysis results that were comparable with those of the QIAamp DNA Stool Mini Kit with a bead-beating step. These results will prove useful for researchers investigating the gut microbiome in selecting an alternative protocol to the widely used but discontinued kit.

The Effect of Lactobacillus acidophilus YT1 (MENOLACTO) on Improving Menopausal Symptoms: A Randomized, Double-Blinded, Placebo-Controlled Clinical Trial

This study evaluated the efficacy of Lactobacillus acidophilus YT1 (MENOLACTO) for alleviating menopausal symptoms. This study was a multi-center, randomized, double-blinded, placebo-controlled clinical trial involving female subjects (ages: 40-60 years) with menopausal symptoms and a Kupperman index (KMI) score ≥ 20. Subjects were administered 1 × 108 CFU/day MENOLACTO or placebo, with the primary endpoint being total KMI score, and the effect of secondary endpoints on alleviating menopausal symptoms according to individual categories of the modified KMI, as well as a quality of life questionnaire (MENQOL questionnaire). After 12 weeks, total KMI scores decreased significantly, demonstrating improved menopausal symptoms relative to placebo along with improved modified KMI scores. Additionally, quality of life, according to the MENQOL questionnaire, significantly improved in all four symptoms-physical, psychosocial, vasomotor, and sexual symptoms. Moreover, we observed no significant difference between the two groups or significant changes in blood follicle-stimulating hormone and estradiol levels or endometrial thickness. These results demonstrated that MENOLACTO alleviated menopausal symptoms without notable side effects and improved quality of life, suggesting its efficacy as an alternative supplement to alleviate menopausal symptoms in women ineligible for hormonal therapy.

Chemically or surgically induced thyroid dysfunction altered gut microbiota in rat models

Thyroid hormones are essential for the regulation of energy homeostasis and metabolic processes. However, the relationship between thyroid function and host gut microbial communities is not properly understood. To determine whether and how gut microbiota is associated with thyroid function, metagenomics analysis of the bacterial population in fecal samples of rat models of hyperthyroidism (induced by levothyroxine) and hypothyroidism (induced by propylthiouracil or thyroidectomy) was conducted through 16S rRNA gene sequencing. Our results revealed that all thyroid dysfunction models were definitely established and gut microbial composition varied according to different thyroid functional status. The relative abundance of Ruminococcus was significantly higher in the hyperthyroidism group (HE) vs both the normal and hypothyroidism groups (HO) while S24-7 was significantly higher in the HO group. The population of Prevotellaceae and Prevotella were significantly lower in the HO group vs the normal. Firmicutes and Oscillospira were significantly higher in the SHO (surgery-induced hypothyroidism) group, while Prevotellaceae and Prevotella showed lower abundance in the SHO group than the SHAM group. Present results suggest that thyroid functions may have the potential to influence the profile of gut microbiota and could be used as foundation to investigate interaction mechanism between thyroid and gut microbiome.

Gut Microbiome Composition Is Associated with a Pathologic Response After Preoperative Chemoradiation in Patients with Rectal Cancer

PURPOSE

There are ongoing investigations to find promising biomarkers for predicting a complete response (CR) after concurrent chemoradiation (CCRT) in rectal cancer. We aimed to find the predictive value in the gut microbiome in terms of response after preoperative CCRT.

METHODS AND MATERIALS

We collected a total of 45 fecal samples from patients with rectal cancer before CCRT. Tumor response after CCRT was assessed according to the American Joint Committee on Cancer tumor regression grading system. Analysis of linear discriminant analysis effect size and MetaCyc pathway abundance predictions were performed to compare composition and metabolic function of microbiome between patients with and without CR. We also established a Bayesian network model to identify microbial networks and species to be related with CCRT response.

RESULTS

Seven patients (15.6%) demonstrated pathologically CR, and 38 patients (84.4%) showed non-CR after preoperative CCRT. Between CR and non-CR patients, there was a significant difference in terms of β-diversity (P = .028), but no difference in α-diversity was found. Bacteroidales (Bacteroidaceae, Rikenellaceae, Bacteroides) were relatively more abundant in patients with non-CR than those with CR. Pathways related to anabolic function predominated in CR patients. According to Bayesian network analysis, Duodenibacillus massiliensis was linked with the improved CR rate.

CONCLUSIONS

From the fecal microbiome using samples obtained before preoperative CCRT, differences in microbial community composition and functions were observed between patients with and without CR in rectal cancer. However, the finding that a specific taxon may be linked with the improved therapeutic response should be verified in a prospective setting.

Changes in microbiome and metabolomic profiles of fecal samples stored with stabilizing solution at room temperature: a pilot study

The gut microbiome is related to various host health conditions through metabolites produced by microbiota. Investigating their relationships involves association analysis of the population-level microbiome and metabolome data, which requires the appropriate collection, handling, and storage of specimens. Simplification of the specimen handling processes will facilitate such investigations. As a pilot study for population-level studies, we collected the fecal samples from three volunteers and tested whether a single sample collection procedure, particularly using OMNIgene-GUT, can be used to reliably obtain both microbiome and metabolome data. We collected fecal samples from three young and healthy Korean adults, stored them at room temperature with and without OMNIgene-GUT solution up to three weeks, and analyzed their microbiome and metabolite profiles. We found that the microbiome profiles were stably maintained in OMNIgene-GUT solution for 21 days, and the abundance relationships among metabolites were well preserved, although their absolute abundances slightly varied over time. Our results show that a single sampling procedure suffices to obtain a fecal sample for collecting gut microbiome and gut metabolome data of an individual. We expect that the health effects of gut microbiome via fecal metabolites can be further understood by increasing the sampling size to the population level.

Lactate-Fortified Puerariae Radix Fermented by Bifidobacterium breve Improved Diet-Induced Metabolic Dysregulation via Alteration of Gut Microbial Communities

BACKGROUND

Puerariae Radix (PR), the dried root of Pueraria lobata, is reported to possess therapeutic efficacies against various diseases including obesity, diabetes, and hypertension. Fermentation-driven bioactivation of herbal medicines can result in improved therapeutic potencies and efficacies.

METHODS

C57BL/6J mice were fed a high-fat diet and fructose in water with PR (400 mg/kg) or PR fermented by Bifidobacterium breve (400 mg/kg) for 10 weeks. Histological staining, qPCR, Western blot, and 16s rRNA sequencing were used to determine the protective effects of PR and fermented PR (fPR) against metabolic dysfunction.

RESULTS

Treatment with both PR and fPR for 10 weeks resulted in a reduction in body weight gain with a more significant reduction in the latter group. Lactate, important for energy metabolism and homeostasis, was increased during fermentation. Both PR and fPR caused significant down-regulation of the intestinal expression of the MCP-1, IL-6, and TNF-α genes. However, for the IL-6 and TNF-α gene expressions, the inhibitory effect of fPR was more pronounced (p < 0.01) than that of PR (p < 0.05). Oral glucose tolerance test results showed that both PR and fPR treatments improved glucose homeostasis. In addition, there was a significant reduction in the expression of hepatic gene PPARγ, a key regulator of lipid and glucose metabolism, following fPR but not PR treatment. Activation of hepatic AMPK phosphorylation was significantly enhanced by both PR and fPR treatment. In addition, both PR and fPR reduced adipocyte size in highly significant manners (p < 0.001). Treatment by fPR but not PR significantly reduced the expression of PPARγ and low-density lipoproteins in adipose tissue.

CONCLUSION

Treatment with fPR appears to be more potent than that of PR in improving the pathways related to glucose and lipid metabolism in high-fat diet (HFD)+fructose-fed animals. The results revealed that the process of fermentation of PR enhanced lactate and facilitated the enrichment of certain microbial communities that contribute to anti-obesity and anti-inflammatory activities.

Age-related compositional and functional changes in micro-pig gut microbiome

Age-related changes in human gut microbiota composition have been reported, and such changes might be influenced by the intake of nutrients or diets. To investigate the effects of aging on the gut microbiota independent of nutrient effects, we analyzed the gut microbiomes of 126 micro-pigs at a wide range of ages from newborns to 10 years old. The micro-pigs were reared in a constantly controlled environment. The diversity of the gut microbiome was found to continuously change with age. We also found associations between age and specific members and functions of the gut microbiome. Consistent with previous studies on the human gut microbiome, beneficial microbes including probiotic bacteria and short-chain fatty acid-producers decreased in older pigs, whereas Bacteroides increased with age. Based on the correlation network, Bacteroides seemed to have an important role in determining the relative abundances of other beneficial microbes. Our results suggest that maintaining beneficial gut microbes at a specific ratio corresponding to a certain age might contribute to a younger gut microbiome-age. Furthermore, due to similarities with the human system, micro-pigs are a useful animal model to elucidate the links between aging and the microbiome.

Paenibacillus lutimineralis sp. nov., Isolated From Bentonite

Strain MBLB1234^T was isolated from bentonite samples collected at Guryong mining area located in Pohang, Republic of Korea and was taxonomically characterized by a polyphasic approach. This strain was a Gram-stain-negative, motile, endospore-forming, facultative anaerobic, catalase-positive, oxidase-negative, and rod-shaped bacterium. Strain MBLB1234^T was able to grow at 20‒45 °C (optimum, 37 °C), pH 6.0‒10.0 (optimum, 7.0-8.0), and 0‒5.0% (w/v) NaCl (optimum, 0.5%). Genome size was 6,497,679 bp with a G + C content of 46.4 mol %. The genome was predicted to contain 5233 protein-coding genes, and 135 rRNA genes consisted of 10 5S rRNAs, 10 16S rRNAs, 10 23S rRNAs, and 105 tRNAs. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain MBLB1234^T clustered with Paenibacillus motobuensis JCM 12774^T and P. aceti JCM 31170^T with 98.3-98.5% and 97.2-97.4% sequencing similarity, respectively. The major fatty acids of strain MBLB1234^T were anteiso-C_15:0 (35.7%), anteiso-C_17:0 (17.8%), iso-C_17:0 (14.5%), and C_16:0 (11.0%). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, and one unidentified phospholipid, six unidentified aminophospholipids, and one unidentified lipid. The predominant isoprenoid quinone was menaquinone-7. DNA-DNA hybridization values between strain MBLB1234^T and P. motobuensis JCM 12774^T and P. aceti JCM 31170^T were 34 and 38%, respectively. Average nucleotide identity value between strains MBLB1234^T and P. aceti L14^T was 82.3%. Based on characteristics of genomic, phenotypic, chemotaxonomic, and phylogenetic analyses, strain MBLB1234^T represents a novel species of the genus P. , for which the name P. lutimineralis sp. nov. is proposed. The type strain is MBLB1234^T (= JCM 32684^T = KCTC 33978^T).

Diet Control More Intensively Disturbs Gut Microbiota Than Genetic Background in Wild Type and ob/ob Mice

Changes in environmental and genetic factors are vital to development of obesity and its complications. Induction of obesity and type 2 diabetes by both leptin deficiency (ob/ob) and high fat diet (HFD) has been verified in animal models. In the present experiment, three types of diets (normal diet; ND, HFD and high sucrose diet; HSD) and two types of genetic mice (Wild type: WT and ob/ob) were used to explore the relationship among diet supplements, gut microbiota, host genetics and metabolic status. HFD increased the body, fat and liver weight of both ob/ob and WT mice, but HSD did not. HFD also resulted in dyslipidemia, as well as increased serum transaminases and fasting glucose in ob/ob mice but not in WT mice, while HSD did not. Moreover, HFD led to brain BDNF elevation in WT mice and reduction in ob/ob mice, whereas HSD did not. Both HFD and HSD had a greater influence on gut microbiota than host genotypes. In detail, both of HFD and HSD alteration elucidated the majority (≥63%) of the whole structural variation in gut microbiota, however, host genetic mutation accounted for the minority (≤11%). Overall, diets more intensively disturbed the structure of gut microbiota in excess of genetic change, particularly under leptin deficient conditions. Different responses of host genotypes may contribute to the development of metabolic disorder phenotypes linked with gut microbiota alterations.

Attenuating Effects of Lactobacillus Acidophilus YT1 on Menopausal Symptoms in Ovariectomized Rats (P20-014-19)

Objectives

Menopause is a natural process, where ovaries produce less reproductive hormones, which degrades the quality of life. Hormone replacement therapy was used primarily to reduce menopausal symptoms but new therapies are needed because they have a risk in long-term use. Probiotics are well known for their beneficial effects on bowel health, obesity, and immunity, and they have been reported to have useful effects on menopause in recent years. This study examined the effects of Lactobacillus acidophilus YT1 on menopausal symptoms in ovariectomized (OVX) rats.

Methods

Twelve weeks-old female SD rats were divided into five groups: (1) sham + DW, (2) OVX + DW, (3) OVX + estradiol, (4) OVX + L. acidophilus YT1, and (5) OVX + Lactobacillus reuteri that were treated once daily for 12 weeks after OVX.

Results

Pain sensitivity, depression-related behavior, and fat mass were significantly increased at 12 weeks after OVX and the bone mineral density was decreased. These menopause symptoms were significantly recovered by a daily oral treatment of L. acidophilus YT1 for 12 weeks. In addition, L. acidophilus YT1 enhanced intestinal barrier function by up-regulation tight junction expression in Caco-2 cell monolayers.

Conclusions

The treatment of L. acidophilus YT1 could alleviate menopausal symptoms, such as increased pain sensitivity, depression, body fat, and bone loss in menopausal women, which suggests it could be developed as a functional food and probiotics for elderly women health.

Funding Sources

This research was supported by the main research Program (E0164502-03) of the Korea Food Research Institute funded by the Minstry of Science and ICT.

Probiotics in human health and disease: from nutribiotics to pharmabiotics

Probiotics are the most useful tools for balancing the gut microbiota and thereby influencing human health and disease. Probiotics have a range of effects, from those on nutritional status to medical conditions throughout the body from the gut to non-intestinal body sites such as the brain and skin. Research interest in probiotics with nutritive claims (categorized as nutribiotics) has evolved into interest in therapeutic and pharmacological probiotics with health claims (pharmabiotics). The concept of pharmabiotics emerged only two decades ago, and the new categorization of probiotics to nutribiotics and pharmabiotics was recently suggested, which are under the different regulation depending on that they are food or drug. Information of the gut microbiome has been continuously accumulating, which will make possible the gut microbiome-based healthcare in the future, when nutribiotics show potential for maintaining health while pharmabiotics are effective therapeutic tools for human diseases. This review describes the current understanding in the conceptualization and classification of probiotics. Here, we reviewed probiotics as nutribiotics with nutritional functions and pharmabiotics with pharmaceutic functions in different diseases.

Comparative evaluation of spoilage-related bacterial diversity and metabolite profiles in chilled beef stored under air and vacuum packaging

Microbial spoilage is a complex event to which different bacterial populations and metabolites can contribute depending on the storage conditions. This study explored the evolution of spoilage and related volatile organic compounds (VOCs) in chilled beef under air and vacuum packaging (VP). The results suggested that different storage conditions affected changes in bacterial communities and metabolites in beef and consequently affected the odor properties of the stored beef, thereby leading to spoilage. Bacterial species belonging to Pseudomonadaceae (Pseudomonas spp.) and lactic acid bacteria (Lactobacillus sp.) dominated the bacterial communities in beef stored under air and VP, respectively, with several VOCs associated with off-odors of the stored beef and most likely produced by both bacteria. Our results suggested several microbial VOCs that could be used as potential spoilage indicators, including acetic acid, butanoic acid, and 2-butanone in VP-stored beef and 3-methylbutan-1-ol, ethyl acetate, acetoin, 2-butanone, and diacetyl in air-stored beef. These findings might provide valuable information regarding the quality monitoring of beef during storage.

Immune-Enhancing Effect of Nanometric Lactobacillus plantarum nF1 (nLp-nF1) in a Mouse Model of Cyclophosphamide-Induced Immunosuppression

Nanometric Lactobacillus plantarum nF1 (nLp-nF1) is a biogenics consisting of dead L. plantarum cells pretreated with heat and a nanodispersion process. In this study, we investigated the immune-enhancing effects of nLp-nF1 in vivo and in vitro. To evaluate the immunostimulatory effects of nLp-nF1, mice immunosuppressed by cyclophosphamide (CPP) treatment were administered with nLp-nF1. As expected, CPP restricted the immune response of mice, whereas oral administration of nLp-nF1 significantly increased the total IgG in the serum, and cytokine production (interleukin-12 (IL-12) and tumor necrosis factor alpha (TNF-α)) in bone marrow cells. Furthermore, nLp-nF1 enhanced the production of splenic cytokines such as IL-12, TNF-α, and interferon gamma (IFN-γ). In vitro, nLp-nF1 stimulated the immune response by enhancing the production of cytokines such as IL-12, TNF-α, and IFN-γ. Moreover, nLp-nF1 given a food additive enhanced the immune responses when combined with various food materials in vitro. These results suggest that nLp-nF1 could be used to strengthen the immune system and recover normal immunity in people with a weak immune system, such as children, the elderly, and patients.

Bacterial community analysis in three types of the fermented seafood, jeotgal, produced in South Korea

Jeotgal is a traditional Korean seafood fermented by indigenous microbes. The bacterial community in five myeolchi-jeot (Engraulis japonica), five meongge-jeot (Halocynthia roretzi), and six saeu-jeot (Acetes japonicas) produced in South Korea was analyzed by barcoded pyrosequencing targeting the V1/V2 hyper-variable regions of the 16S rRNA gene. All samples were dominated by the phyla Firmicutes, which represented 67.7% (SD = 27.2%) of the population. Tetragenococcus halophilus and Tetragenococcus muriaticus were the predominant species in myeolchi-jeot. The LABs, Lactobacillus sakei, Lactobacillus curvatus, and Weissella koreensis were the predominant species in meongge-jeot. In myeolchi-jeot and meongge-jeot, the bacterial communities within samples were consistent in their predominance, however each of saeu-jeot samples had inter-individual variety in the bacterial community leading to the difficulties of standardization for the commercial production of saeu-jeot. The results of this study will conclusively help to expand our basic knowledge of jeotgal and the related microorganisms involved in food fermentation.