Effects of the 1975 Japanese diet on the gut microbiota in younger adults

A Cohort Study of the Influence of the 12-Component Modified Japanese Diet Index on Oral and Gut Microbiota in the Japanese General Population

The Japanese diet is a healthy dietary pattern, and the oral or gut microbiota have been identified as the main factors underlying the beneficial effects of the Japanese diet. However, epidemiological studies on Japanese dietary patterns calculated from daily eating habits in the general population yielded inconsistent findings. This study aimed to determine the association between the 12-component modified Japanese Diet Index (mJDI12) and the oral and gut microbiota in the general population of a rural area in Japan. After propensity-score matching, 396 participants (198 each in the low and high mJDI12 groups) were picked out. One year after the follow up survey, we reclassified the subjects and compared the low and high mJDI12 groups again. Participants with a high mJDI12 had a higher relative abundance of butyric acid-producing bacteria in their gut microbiota. Moreover, the significantly higher dietary fiber intake in the high mJDI12 group suggested that the high intake of dietary fiber contributed to an increase in butyric acid-producing bacteria in the gut. In contrast, in individuals with a high mJDI12, only Allpprevotella was decreased in the oral microbiota. Thus, the Japanese dietary pattern can have beneficial effects by improving the oral and gut microbiota.

The Potential Use of Vitamin D3 and Phytochemicals for Their Anti-Ageing Effects

Unlike other vitamins, vitamin D3 is synthesised in skin cells in the body. Vitamin D3 has been known as a bone-related hormone. Recently, however, it has been considered as an immune vitamin. Vitamin D3 deficiency influences the onset of a variety of diseases. Vitamin D3 regulates the production of proinflammatory cytokines such as tumour necrosis factor-α (TNF-α) through binding to vitamin D receptors (VDRs) in immune cells. Since blood levels of vitamin D3 (25-OH-D3) were low in coronavirus disease 2019 (COVID-19) patients, there has been growing interest in the importance of vitamin D3 to maintaining a healthy condition. On the other hand, phytochemicals are compounds derived from plants with over 7000 varieties and have various biological activities. They mainly have health-promoting effects and are classified as terpenoids, carotenoids, flavonoids, etc. Flavonoids are known as the anti-inflammatory compounds that control TNF-α production. Chronic inflammation is induced by the continuous production of TNF-α and is the fundamental cause of diseases like obesity, dyslipidaemia, diabetes, heart and brain diseases, autoimmune diseases, Alzheimer's disease, and cancer. In addition, the ageing process is induced by chronic inflammation. This review explains the cooperative effects of vitamin D3 and phytochemicals in the suppression of inflammatory responses, how it balances the natural immune response, and its link to anti-ageing effects. In addition, vitamin D3 and phytochemicals synergistically contribute to anti-ageing by working with ageing-related genes. Furthermore, prevention of ageing processes induced by the chronic inflammation requires the maintenance of healthy gut microbiota, which is related to daily dietary habits. In this regard, supplementation of vitamin D3 and phytochemicals plays an important role. Recently, the association of the prevention of the non-disease condition called "ME-BYO" with the maintenance of a healthy condition has been an attractive regimen, and the anti-ageing effect discussed here is important for a healthy and long life.

Altered Gut Microbiota Composition Is Associated with Difficulty in Explicit Emotion Regulation in Young Children

Executive function (EF) consists of explicit emotion regulation (EER) and cognitive control (CC). Childhood EER in particular predicts mental and physical health in adulthood. Identifying factors affecting EER development has implications for lifelong physical and mental health. Gut microbiota (GM) has attracted attention as a potential biomarker for risk of physical and mental problems in adulthood. Furthermore, GM is related to brain function/structure, which plays a crucial role in emotional processing. However, little is known about how GM compositions are associated with the development of emotion regulation in early childhood. Therefore, in this study, we examined 257 children aged 3-4 to investigate links between GM and risk to EF. EF was measured using the Mother-Reported Behavior Rating Inventory of Executive Function-Preschool version. GM composition (alpha/beta diversity and genus abundance) was evaluated using 16S rRNA gene sequencing and compared between EF-risk and non-risk groups. Our results show that children with EER-risk (an index of inhibitory self-control) had a higher abundance of the genera Actinomyces and Sutterella. Although we have not established a direct link between GM and CC risk, our findings indicate that GM of preschoolers is closely associated with emotional processing and that EERrisk children have more inflammation-related bacteria.

Modulatory Effect of Fermented Black Soybean and Adlay on Gut Microbiota Contributes to Healthy Aging

SCOPE

Aging is a natural process characterized by a multifactorial, physical decline, and functional disability. Nevertheless, healthy aging can be achieved by following a multidirectional strategy. The current study aims to investigate the anti-aging potential of fermented black soybean and adlay (FBA).

METHODS AND RESULTS

FBA supplements are incorporated into a natural aging mouse model that is designed to evaluate anti-aging effects. Results show that FBA supplementation prevents muscle loss and visceral adipose tissue accumulation. FBA can also reduce aging biomarkers (including the expression of hepatic p16^INK4A and galactosidase beta-1 (GLB1). Hepatic 8-hydoxy-2'-deoxyguanosine (8-oxodG) and pro-inflammatory cytokines have been significantly reduced. Lastly, FBA supplementation improves aging-related gut microbial dysbiosis by reshaping gut microbial composition and promoting the growth of beneficial microbes such as Alistipes, Anaeroplasma, Coriobacteriaceae UCG002, and Parvibacter members in both genders of aged mice. In the functional prediction of gut microbiota, correlations to metabolic, neurodegenerative, infectious, and immune system diseases have been reduced in supplemented mice compared to aged mice. Moreover, FBA supplementation can reverse the reduced ability of microbiota in aged mice for lipid metabolism and xenobiotics biodegradation.

CONCLUSIONS

The results suggest that FBA exhibits noteworthy anti-aging effects and that it can potentially be developed into a functional food for healthy aging.

Metabolite profiling of human-originated Lachnospiraceae at the strain level

The human gastrointestinal (GI) tract harbors diverse microbes, and the family Lachnospiraceae is one of the most abundant and widely occurring bacterial groups in the human GI tract. Beneficial and adverse effects of the Lachnospiraceae on host health were reported, but the diversities at species/strain levels as well as their metabolites of Lachnospiraceae have been, so far, not well documented. In the present study, we report on the collection of 77 human-originated Lachnospiraceae species (please refer hLchsp, https://hgmb.nmdc.cn/subject/lachnospiraceae) and the in vitro metabolite profiles of 110 Lachnospiraceae strains (https://hgmb.nmdc.cn/subject/lachnospiraceae/metabolites). The Lachnospiraceae strains in hLchsp produced 242 metabolites of 17 categories. The larger categories were alcohols (89), ketones (35), pyrazines (29), short (C2-C5), and long (C > 5) chain acids (31), phenols (14), aldehydes (14), and other 30 compounds. Among them, 22 metabolites were aromatic compounds. The well-known beneficial gut microbial metabolite, butyric acid, was generally produced by many Lachnospiraceae strains, and Agathobacter rectalis strain Lach-101 and Coprococcus comes strain NSJ-173 were the top 2 butyric acid producers, as 331.5 and 310.9 mg/L of butyric acids were produced in vitro, respectively. Further analysis of the publicly available cohort-based volatile-metabolomic data sets of human feces revealed that over 30% of the prevailing volatile metabolites were covered by Lachnospiraceae metabolites identified in this study. This study provides Lachnospiraceae strain resources together with their metabolic profiles for future studies on host-microbe interactions and developments of novel probiotics or biotherapies.

Special Diets in Infants and Children and Impact on Gut Microbioma

Gut microbiota is a complex system that starts to take shape early in life. Several factors influence the rise of microbial gut colonization, such as term and mode of delivery, exposure to antibiotics, maternal diet, presence of siblings and family members, pets, genetics, local environment, and geographical location. Breastfeeding, complementary feeding, and later dietary patterns during infancy and toddlerhood are major players in the proper development of microbial communities. Nonetheless, if dysbiosis occurs, gut microbiota may remain impaired throughout life, leading to deleterious consequences, such as greater predisposition to non-communicable diseases, more susceptible immune system and altered gut–brain axis. Children with specific diseases (i.e., food allergies, inborn errors of metabolism, celiac disease) need a special formula and later a special diet, excluding certain foods or nutrients. We searched on PubMed/Medline, Scopus and Embase for relevant pediatric studies published over the last twenty years on gut microbiota dietary patterns and excluded case reports or series and letters. The aim of this review is to highlight the changes in the gut microbiota in infants and children fed with special formula or diets for therapeutic requirements and, its potential health implications, with respect to gut microbiota under standard diets.

Relationship between the Japanese-style diet, gut microbiota, and dementia: A cross-sectional study

OBJECTIVE

Previous studies have shown associations between the gut microbiota, microbial metabolites, and cognitive decline. However, the effect of the dietary composition on such associations has not been fully investigated. The aims of this study were to evaluate the relationships between adherence to a Japanese-style diet, the gut microbiota, and cognitive decline. Furthermore, we aimed to evaluate the three forms of the Japanese diet index (JDI; the conventional [JDI₉], updated [JDI₁₂], and a newly modified JDI) to determine which would show the closest relationships with cognition and the gut microbiota.

METHODS

We performed a cross-sectional subanalysis of data from a prospective hospital-based cohort study. We assessed the patients' demographic characteristics, dietary composition, risk factors, cognitive function, brain imaging, gut microbiome, and microbial metabolites. On the basis of previous studies, a nine-component traditional JDI (JDI₉), a 12-component modern JDI (JDI₁₂), and a 12-component revised JDI (rJDI₁₂), were defined. We evaluated the relationships between the JDI scores, cognitive function, and the gut microbiome and microbial metabolites using multivariable logistic regression analyses.

RESULTS

We analyzed data from 85 eligible participants (61% women; mean age: 74.6 ± 7.4 y). Compared with participants who had dementia, those without dementia were more likely to consume foods in the JDI₁₂, including fish and shellfish (64.5 versus 39.1%, P = 0.048), mushrooms (61.3 versus 30.4%, P = 0.015), soybeans and soybean-derived foods (62.9 versus 30.4%, P = 0.013), and coffee (71 versus 43.5%, P = 0.024). There were non-significant trends toward lower fecal concentrations of gut microbial metabolites in participants with a more traditional Japanese diet. Participants with dementia had lower JDI scores than those without dementia (dementia versus non-dementia, median JDI₉ score: 5 versus 7, P = 0.049; JDI₁₂: 7 versus 8, P = 0.017; and rJDI₁₂: 7 versus 9, P = 0.006, respectively).

CONCLUSIONS

Adherence to a traditional Japanese diet was found to be inversely associated with cognitive decline and tended to be associated with lower concentrations of gut microbial metabolites.

Anti-Inflammatory Properties of Diet: Role in Healthy Aging

Inflammation is a physiological process involved in the defenses of the body and the repair of tissues. It is acutely activated by infections, trauma, toxins, or allergic reactions. However, if it becomes chronic, inflammation can end up stimulating the development of diseases such as cardiovascular disease, autoimmune disease, neurological disease, or cancer. Additionally, during aging, inflammation becomes increasingly more chronic. Furthermore, we found that certain foods, such as saturated fats, have pro-inflammatory activity. Taking this into account, in this review we have discussed different diets with possible anti-inflammatory activity, the commonly ingested components of each diet and their active compounds. In addition, we have proposed some dietary guidelines, as well as a list of compounds present in foods with anti-inflammatory activity, outlining how to combine them to achieve optimal anti-inflammatory effects. Therefore, we can conclude that the compounds in our diet with anti-inflammatory activity could help alleviate the inflammatory processes derived from diseases and unhealthy diets, and thereby promote healthy aging.

Comprehensive analysis of gut microbiota of a healthy population and covariates affecting microbial variation in two large Japanese cohorts

Background

Inter-individual variations in gut microbiota composition are observed even among healthy populations. The gut microbiota may exhibit a unique composition depending on the country of origin and race of individuals. To comprehensively understand the link between healthy gut microbiota and host state, it is beneficial to conduct large-scale cohort studies. The aim of the present study was to elucidate the integrated and non-redundant factors associated with gut microbiota composition within the Japanese population by 16S rRNA sequencing of fecal samples and questionnaire-based covariate analysis.

Results

A total of 1596 healthy Japanese individuals participated in this study via two independent cohorts, NIBIOHN cohort (n=954) and MORINAGA cohort (n=642). Gut microbiota composition was described and the interaction of these microorganisms with metadata parameters such as anthropometric measurements, bowel habits, medical history, and lifestyle were obtained. Thirteen genera, including Alistipes, Anaerostipes, Bacteroides, Bifidobacterium, Blautia, Eubacterium halli group, Faecalibacterium, Fusicatenibacter, Lachnoclostridium, Parabacteroides, Prevotella_9, Roseburia, and Subdoligranulum were predominant among the two cohorts. On the basis of univariate analysis for overall microbiome variation, 18 matching variables exhibited significant association in both cohorts. A stepwise redundancy analysis revealed that there were four common covariates, Bristol Stool Scale (BSS) scores, gender, age, and defecation frequency, displaying non-redundant association with gut microbial variance.

Conclusions

We conducted a comprehensive analysis of gut microbiota in healthy Japanese individuals, based on two independent cohorts, and obtained reliable evidence that questionnaire-based covariates such as frequency of bowel movement and specific dietary habit affects the microbial composition of the gut. To our knowledge, this was the first study to investigate integrated and non-redundant factors associated with gut microbiota among Japanese populations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02215-0.

Gut Microbiota Bacterial Species Associated with Mediterranean Diet-Related Food Groups in a Northern Spanish Population

The MD (Mediterranean diet) is recognized as one of the healthiest diets worldwide and is associated with the prevention of cardiovascular and metabolic diseases. Dietary habits are considered one of the strongest modulators of gut microbiota, which seem to play a significant role in health status of the host. The purpose of the present study was to evaluate interactive associations between gut microbiota composition and habitual dietary intake in 360 Spanish adults from the Obekit cohort (normal weight, overweight, and obese participants). Dietary intake and adherence to the MD tests were administered and fecal samples were collected from each participant. Fecal 16S rRNA (ribosomal Ribonucleic Acid) gene sequencing was performed and checked against the dietary habits. MetagenomeSeq was the statistical tool applied to analyze data at the species taxonomic level. Results from this study identified several beneficial bacteria that were more abundant in the individuals with higher adherence to the MD. Bifidobacterium animalis was the species with the strongest association with the MD. Some SCFA (Short Chain Fatty Acids) -producing bacteria were also associated with MD. In conclusion, this study showed that MD, fiber, legumes, vegetable, fruit, and nut intake are associated with an increase in butyrate-producing taxa such as Roseburia faecis, Ruminococcus bromii, and Oscillospira (Flavonifractor) plautii.

Relationship between dementia and gut microbiome-associated metabolites: a cross-sectional study in Japan

Dysregulation of the gut microbiome is associated with dementia. However, the relationship between microbiome-associated metabolites and dementia has yet to be identified. Outpatients visiting a memory clinic in Japan enrolled in this cross-sectional study; 107 subjects were eligible for the study, 25 of which had dementia. We collected demographics, activities of daily living, risk factors, cognitive function, and brain imaging data. The gut microbiome was assessed using terminal restriction fragment length polymorphism analysis. Concentrations of faecal metabolite were measured. We used multivariable logistic regression analyses to identify whether metabolites were independently related to dementia. The concentrations of metabolites were significantly different between subjects with and those without dementia. Every 1 standard deviation increment in faecal ammonia concentration was associated with around a 1.6-fold risk for the presence of dementia. A higher faecal lactic acid concentration was related to a lower risk of dementia, by around 60%. A combination of higher faecal ammonia and lactic acid concentrations was indicative of the presence of dementia, and had a similar predictive value as traditional biomarkers of dementia. Thus, faecal ammonia and lactic acid are related to dementia, independently of the other risk factors for dementia and dysregulation of the gut microbiome.

The 1975 type Japanese diet improves the gut microbial flora and inhibits visceral fat accumulation in mice

In this study, the 1975 type Japanese diet was prepared and its effects and related mechanism were examined in mice. Mice were assigned to three experimental groups, the CD group fed a control diet, the MD group fed a modern Japanese diet (MD), and the JD group fed the 1975 type Japanese diet (JD) for 4 weeks. MD and JD were low protein, high fat, and high carbohydrate diets compared to the CD. Total white adipose tissue weights were significantly increased in the MD group compared to those in the CD group and were decreased in the JD group compared to those in the MD group. In the JD group, adipocyte hypertrophy was inhibited and Hsl mRNA expression was enhanced in epididymal adipose tissue and the number of bacteria associated with the production of short chain fatty acids was increased. Therefore, the JD inhibits lipid accumulation in white adipose tissue.

ABBREVIATIONS

Actb: β-actin; ALT: alanine aminotransferase; ANOVA: analyses of variance; AST: aspartate aminotransferase; Fas: fatty acid synthase; G6pdx: glucose 6-phosphate dehydrogenase; HE: hematoxylin and eosin; HOMA-IR: Homeostatic model assessment for insulin resistance; Hsl: hormone-sensitive lipase; JD: 1975 type Japanese diet; Leptin: leptin; MD: modern Japanese diet; Me: malic enzyme; NEFA: non-esterified fatty acids; PL: phospholipids; Pparδ: peroxisome proliferator-activated receptor delta; Pparγ: peroxisome proliferator-activated receptor gamma; qRT-PCR: quantitative reverse transcriptase polymerase chain reaction; SAMP8: senescence-accelerated prone 8; SEM: standard error of the mean; Srebp1c: Sterol regulatory element binding protein 1c; TBARS: thiobarbituric acid reactive substance; TC: total cholesterol; TG: Triacylglycerol; V3: variable regions 3.

Calcipotriol and iBRD9 reduce obesity in Nur77 knockout mice by regulating the gut microbiota, improving intestinal mucosal barrier function

Objective

The orphan nuclear receptor Nur77 is an important factor regulating metabolism. Nur77 knockout mice become obese with age, but the cause of obesity in these mice has not been fully ascertained. We attempted to explain the cause of obesity in Nur77 knockout mice from the perspective of the gut microbiota and to investigate the inhibitory effect of calcipotriol combined with BRD9 inhibitor (iBRD9) on obesity.

Methods

Eight-week-old wild-type mice and Nur77 knockout C57BL/6J mice were treated with calcipotriol combined with iBRD9 for 12 weeks. Mouse feces were collected and the gut microbiota was assessed by analyzing 16S rRNA gene sequences. The bacterial abundance difference was analyzed, and the intestinal mucosal tight junction protein, antimicrobial peptide, and inflammatory cytokine mRNA levels of the colon and serum LPS and inflammatory cytokine levels were measured.

Results

Calcipotriol combined with iBRD9 treatment reduced the body weight and body fat percentage in Nur77 knockout mice. In the gut microbiota of Nur77 knockout mice, the relative abundances of Lachnospiraceae and Prevotellaceae decreased, and Rikenellaceae increased; while Rikenellaceae decreased after treatment (p < 0.05). Correspondingly, the mRNA levels of intestinal mucosal tight junction proteins (occludin (Ocln), claudin3 (Cldn3)) in the colons of Nur77 knockout mice were significantly decreased, and they increased significantly after treatment (p < 0.001). The mRNA levels of inflammatory cytokines (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β)) were significantly increased in Nur77 knockout mice, and TNF-α and IL-6 levels were significantly decreased after treatment (p < 0.05, <0.01, or <0.001). The levels of serum LPS, TNF-α, and IL-1β in Nur77 knockout mice were significantly increased (p < 0.05). Serum LPS, TNF-α, and IL-6 levels were significantly decreased after treatment (p < 0.05 or <0.01).

Conclusions

Calcipotriol combined with iBRD9 can regulate the gut microbiota, improve intestinal mucosal barrier function, reduce LPS absorption into the blood, and alleviate obesity in Nur77 knockout mice.

Gut microbiota of provisioned and wild rhesus macaques (Macaca mulatta) living in a limestone forest in southwest Guangxi, China

The gut microbiota plays an important role in animal health and is strongly affected by the environment. Captivity and human source food have been shown to influence drastically the gut microbiota composition and function of wild animals. Therefore, in the present study, the gut microbiota of provisioned and wild populations of limestone‐living rhesus macaques (Macaca mulatta) were compared using high‐throughput 16S rRNA sequencing and bioinformatic analyses. The results indicated that provisioned macaques had a higher microbial richness than wild macaques, but there was no significant difference in the evenness of the gut microbiota between the two populations. Provisioned macaques also showed a higher abundance of Firmicutes and a lower abundance of Bacteroidetes than wild macaques. Functional analysis revealed that wild macaques had enriched microbial pathways involved in glycan biosynthesis and metabolism, transport and catabolism, and the digestive and endocrine systems, while provisioned macaques were richer in pathways associated with signaling molecules and interaction, neurodegenerative diseases. These differences were likely due to modification of the gut microbiota of the provisioned macaques to enable the digestion of new foods.

Carbohydrate-restricted diet alters the gut microbiota, promotes senescence and shortens the life span in senescence-accelerated prone mice

This study examined the effects of a carbohydrate-restricted diet on aging, brain function, intestinal bacteria and the life span to determine long-term carbohydrate-restriction effects on the aging process in senescence-accelerated prone mice (SAMP8). Three-week-old male SAMP8 were divided into three groups after a week of preliminary feeding. One group was given a controlled diet, while the others fed on high-fat and carbohydrate-restricted diets, respectively. The mice in each group were further divided into two subgroups, of which one was the longevity measurement group. The other groups fed ad libitum until the mice were 50 weeks old. Before the test period termination, passive avoidance test evaluated the learning and memory abilities. Following the test period, serum and various mice organs were obtained and submitted for analysis. The carbohydrate-restricted diet group exhibited significant decrease in the survival rate as compared to the other two diet groups. The passive avoidance test revealed a remarkable decrease in the learning and memory ability of carbohydrate-restricted diet group as compared to the control-diet group. Measurement of lipid peroxide level in tissues displayed a marked increase in the brain and spleen of carbohydrate-restricted diet group than the control-diet and high-fat diet groups. Furthermore, notable serum IL-6 and IL-1β level (inflammation indicators) elevations, decrease in Enterobacteria (with anti-inflammatory action), increase in inflammation-inducing Enterobacteria and lowering of short-chain fatty acids levels in cecum were observed in the carbohydrate-restricted diet group. Hence, carbohydrate-restricted diet was revealed to promote aging and shortening of life in SAMP8.

The relationship between the gut microbiome and mild cognitive impairment in patients without dementia: a cross-sectional study conducted in Japan

Recent studies have revealed an association between the dysregulation of the gut microbiome and dementia. However, whether this dysregulation is associated with mild cognitive impairment (MCI), an early stage of cognitive decline, in patients without dementia remains unclear. We performed a cross-sectional analysis to determine the association between the gut microbiome and MCI. Data, including patient demographics, risk factors, cognitive function, and brain imaging, were collected. The gut microbiome was assessed through terminal restriction fragment length polymorphism analysis. Multivariable logistic regression models were used to identify factors independently associated with MCI. Graphical modelling was used to illustrate mutual associations between MCI and identified factors. We analysed 82 patients, 61 of whom exhibited MCI. Patients with MCI had a higher prevalence of Bacteroides. Furthermore, patients with more Bacteroides were more likely to present with white matter hyperintensity and high voxel-based specific regional analysis system for Alzheimer’s Disease (VSRAD) scores, indicating cortical and hippocampal atrophy. A multivariable logistic regression analysis revealed that a greater prevalence of Bacteroides was independently associated with MCI. Graphical modelling also showed a close association between Bacteroides and MCI. In conclusion, an increased prevalence of Bacteroides is independently associated with the presence of MCI in patients without dementia.

Miso (Fermented Soybean Paste) Suppresses Visceral Fat Accumulation in Mice, Especially in Combination with Exercise

We investigated whether the difference in miso consumption between the Japanese diets of 1975 and 2010 has influenced the observed increase in diet-induced obesity. To recreate the 2010 and 1975 Japanese high-fat diets with the corresponding proportions of miso, freeze-dried miso was added to high-fat mouse feed at 1.6% and 2.6%, respectively. When 5-week-old male Institute of Cancer Research (ICR) mice were provided each of these diets ad libitum for 8 weeks, it was found that the white adipose tissue weight and adipocyte area were lower in mice receiving the 1975 diet than in those receiving the 2010 diet. Therefore, high miso consumption is one reason why the 1975 Japanese diet tended to not lead to obesity. Next, the combined effects of treadmill exercise and miso consumption were investigated. The mice were divided into three groups, which were provided either a high-fat diet (group C), a high-fat diet with exercise (group C + E), or a miso-supplemented high-fat diet with exercise (group M + E) for 8 weeks. In this experiment, the white adipose tissue weight and adipocyte area in group M + E were lower than in group C. When the mRNA expression of lipid metabolism-associated genes in adipose tissue was measured, we found that expression of Hsl (lipase, hormone sensitive), which is involved in lipolysis, and Pparγ (peroxisome proliferator activated receptor gamma), which regulates adipocyte differentiation upstream of Hsl, was increased in group M + E. These results clearly demonstrated that lipid accumulation in the adipose tissues is suppressed by miso consumption in combination with exercise.

Simultaneous Intake of Euglena gracilis and Vegetables Exerts Synergistic Anti-Obesity and Anti-Inflammatory Effects by Modulating the Gut Microbiota in Diet-Induced Obese Mice

We determined whether the anti-obesity effect provided by the consumption of Euglena gracilis (Euglena), which is rich in insoluble dietary fiber, could be enhanced by the co-consumption of vegetables with an abundance of soluble dietary fiber. Nine-week-old male C57BL/6J mice were divided into five groups as follows: group 1 received a normal diet, group 2 received a high-fat diet, and groups 3, 4, and 5 received high fat diets containing 0.3% paramylon, 1.0% Euglena, or 1.0% Euglena plus 0.3% vegetables (barley leaf, kale, and ashitaba), respectively. Mice were fed ad libitum until 18 weeks of age. Euglena intake significantly reduced visceral fat accumulation in obese mice, and co-consumption of vegetables enhanced this effect. Consumption of Euglena with vegetables reduced adipocyte area, suppressed the expression of genes related to fatty acid synthesis, upregulated genes related to adipocyte lipolysis, and suppressed serum markers of inflammation. Notably, we also observed an increase in the fraction of short-chain fatty acid-producing beneficial bacteria, a reduction in harmful bacteria that cause inflammation, and an increase in short-chain fatty acid production. Therefore, the co-consumption of vegetables enhanced the anti-obesity and anti-inflammatory effects of Euglena, likely by modulating the gut microbiota composition.