Unkeito Suppresses RANKL-Mediated Osteoclastogenesis via the Blimp1-Bcl6 and NF-κB Signaling Pathways and Enhancing Osteoclast Apoptosis.

Osteoporosis is a common bone disease, particularly in menopausal women. Herein, we screened four Kampo medicines (Unkeito (UKT), Kamishoyosan (KSS), Kamikihito (KKT), and Ninjinyoeito (NYT)), frequently used to treat menopausal syndromes, for their effects on receptor activator of nuclear factor-kappaB ligand (RANKL)-induced osteoclast differentiation in RAW 264 cells. Considering that UKT exhibited the most potent effect, we examined its effect on RANKL-induced osteoclastogenesis, the induction of osteoclast apoptosis, and the mechanisms underlying its effects. UKT inhibits RANKL-induced osteoclast differentiation in the early stage and decreases osteoclast-related genes, including tartrate-resistant acid phosphatase (Trap), dendritic cell-specific transmembrane protein (Dcstamp), matrix metalloproteinase-9 (Mmp9), and cathepsin K (Ctsk). Specifically, UKT inhibits the nuclear factor of activated T cells 1 (NFATc1), which is essential for osteoclastogenesis. UKT increases Bcl6, which antagonizes NFATc1 and Dc-stamp, thereby blocking the progression of osteoclasts to maturation. UKT also decreased nuclear translocation by downregulating the activity of p65/NF-κB. In addition, UKT enhances mononuclear osteoclast apoptosis via activation of caspase-3. Herein, we demonstrate that UKT suppresses RANKL-mediated osteoclastogenesis via the Blimp1-Bcl6 and NF-κB signaling pathways and enhances mononuclear osteoclast apoptosis. Furthermore, UKT prevents bone loss in OVX mice. Thus, UKT might be a potential therapeutic agent for postmenopausal osteoporosis.

Induction of γδT cells from HSC-enriched BMCs co-cultured with iPSC-derived thymic epithelial cells.

T cells bearing γδ antigen receptors have been investigated as potential treatments for several diseases, including malignant tumours. However, the clinical application of γδT cells has been hampered by their relatively low abundance in vivo and the technical difficulty of inducing their differentiation from hematopoietic stem cells (HSCs) in vitro. Here, we describe a novel method for generating mouse γδT cells by co-culturing HSC-enriched bone marrow cells (HSC-eBMCs) with induced thymic epithelial cells (iTECs) derived from induced pluripotent stem cells (iPSCs). We used BMCs from CD45.1 congenic C57BL/6 mice to distinguish them from iPSCs, which expressed CD45.2. We showed that HSC-eBMCs and iTECs cultured with IL-2 + IL-7 for up to 21 days induced CD45.1+ γδT cells that expressed a broad repertoire of Vγ and Vδ T-cell receptors. Notably, the induced lymphocytes contained few or no αßT cells, NK1.1+ natural killer cells, or B220+ B cells. Adoptive transfer of the induced γδT cells to leukemia-bearing mice significantly reduced tumour growth and prolonged mouse survival with no obvious side effects, such as tumorigenesis and autoimmune diseases. This new method suggests that it could also be used to produce human γδT cells for clinical applications.

Association between household solid fuel use and tuberculosis: cross-sectional data from the Mongolian National Tuberculosis Prevalence Survey.

BACKGROUND: Tuberculosis (TB) and indoor air pollution (IAP) are equally critical public health issues in the developing world. Mongolia is experiencing the double burden of TB and IAP due to solid fuel combustion. However, no study has assessed the relationship between household solid fuel use and TB in Mongolia. The present study aimed to assess the association between household solid fuel use and TB based on data from the Mongolian National Tuberculosis Prevalence Survey (MNTP Survey). METHOD: The MNTP Survey was a nationally representative population-based cross-sectional survey targeting households in Mongolia from 2014 to 2015, with the aim of evaluating the prevalence of TB. The survey adopted a multistage cluster sampling design in accordance with the World Health Organization prevalence survey guidelines. Clusters with at least 500 residents were selected by random sampling. A sample size of 98 clusters with 54,100 participants was estimated to be required for the survey, and 41,450 participants were included in the final analysis of the present study. A structured questionnaire was used to collect information on environmental and individual factors related to TB. Physical examination, chest X-ray, and sputum examinations were also performed to diagnose TB. RESULTS: The use of solid fuels for heating (adjusted odds ratio (aOR): 1.5; 95% confidence interval (CI): 1.1-2.1), male gender (aOR: 2.2; 95% CI: 1.6-3.2), divorced or widowed (aOR: 2.6; 95% CI: 1.7-3.8), daily smoker (aOR: 1.8; 95% CI: 1.3-2.5), contact with an active TB case (aOR: 1.7; 95% CI: 1.2-2.3), being underweight (aOR: 3.7; 95% CI: 2.4-5.7), and previous history of TB (aOR: 4.3; 95% CI: 3.0-6.1) were significantly associated with bacteriologically confirmed TB after adjusting for confounding variables. CONCLUSION: The use of solid fuels for heating was significantly associated with active TB in Mongolian adults. Increased public awareness is needed on the use of household solid fuels, a source of IAP.

Trends in Serum Lipid Levels of a 10- and 13-Year-Old Population in Fukuroi City, Japan (2007-2017).

BACKGROUND: Current trends in serum lipid levels among children are likely to be important predictors of future cardiovascular disease prevalence. However, no studies have examined trends in low-density lipoprotein cholesterol (LDL-C) levels in Japanese children. METHODS: We investigated trends in LDL-C levels from 2008 through 2017 and HDL-C levels from 2007 through 2017 in a population of 10- and 13-year-old children in Fukuroi City, Japan. We analyzed 17,838 children, accounting for 93.8% of all fifth and eighth graders in the entire city. Adverse lipid levels were defined as follows: 130 mg/dL or higher for LDL-C, and lower than 40 mg/dL for HDL-C. The Jonckheere-Terpstra and Cochran-Armitage tests were used to evaluate secular trends in mean serum lipid levels and prevalence of dyslipidemia, respectively. RESULTS: There were no significant trends in BMI during the study period. In children aged 10 years, serum levels of LDL-C and HDL-C showed significant positive associations with calendar year during the study period for both sexes. A significant increase in HDL-C levels was observed in girls aged 13 years. On the other hand, no significant trends were observed in the prevalence of high LDL-C or low HDL-C regardless of sex or age, while the prevalence of high non-HDL-C showed a significant increase in boys. CONCLUSIONS: In the Fukuroi population, serum levels of LDL-C and HDL-C slightly increased in both boys and girls aged 10 years, and HDL-C levels slightly increased in girls aged 13 years, during the past decade.

Trunk-to-peripheral fat ratio predicts a subsequent blood pressure in normal-weight pubertal boys: a 3-year follow-up of the Kitakata Kids Health Study.

BACKGROUND: Limited evidence exists regarding the relationship between central-to-peripheral fat ratio measured by dual-energy X-ray absorptiometry (DXA) and subsequent cardiometabolic risk in both pediatric and adult populations. METHODS: The present cohort study investigated the relationship between DXA-measured body fat distribution and cardiometabolic parameters. The source population was 275 4th-6th graders (aged 9.6-12.6 years) in the northeast region of Japan (Shiokawa area in Kitakata). A 3-year follow-up was conducted to obtain complete information from 155 normal-weight children (87 boys and 68 girls). Normal-weight children were identified using sex- and age-specific international cut-offs for body mass index (BMI) based on adult BMI values of 25 kg/m2 and 18.5 kg/m2, respectively. Body fat distribution was assessed using the trunk-to-appendicular fat ratio (TAR) and trunk-to-leg fat ratio (TLR) measured by DXA. RESULTS: In boys, systolic blood pressure (SBP) at follow-up showed a significant relationship with TAR at baseline after adjusting for age, height, pubic hair appearance, SBP, and whole body fat at baseline (ß = 0.24, P < 0.05), and SBP also showed a significant relationship with TLR after adjusting for confounding factors including whole body fat (ß = 0.25, P < 0.05). In girls, there were no significant relationships between blood pressure and TAR/TLR. CONCLUSION: Body fat distribution in normal-weight boys predicted subsequent blood pressure levels in adolescence. The relationship between fat distribution and blood pressure was independent of fat volume.

Coal burning-derived SO2 and traffic-derived NO2 are associated with persistent cough and current wheezing symptoms among schoolchildren in Ulaanbaatar, Mongolia.

BACKGROUND: Children in Ulaanbaatar are exposed to air pollution, but few epidemiological studies have been conducted on the effects of environmental risk factors on children's health. Also, no studies have yet examined the prevalence of respiratory symptoms in children in suburban areas, where air quality-monitoring stations have not yet been installed. This cross-sectional study evaluated the associations between outdoor air pollution and respiratory symptoms among schoolchildren in urban and suburban districts of Ulaanbaatar. METHODS: The ATS-DLD-78 C questionnaire was used to investigate the respiratory symptoms of schoolchildren aged 6-12 years (n = 1190) who lived in one of three urban districts or a suburban district of Ulaanbaatar. In each district, the outdoor concentrations of nitrogen dioxide (NO2) and sulfur dioxide (SO2) were measured at two sites (at ≤100 m and > 100 m from the nearest major road) in the 2-year period from 2015 to 2016. The associations between health outcomes and exposure to air pollutants were estimated using the multinomial logistic regression method. RESULTS: The outdoor concentration of SO2 was significantly associated with persistent cough symptom (OR = 1.12, 95% CI 1.04-1.22). Furthermore, the outdoor concentration of NO2 was significantly associated with the current wheezing symptom (OR = 1.33, 95% CI 1.01-1.75) among children in urban and suburban. CONCLUSIONS: The prevalence of persistent cough symptom was markedly high among the schoolchildren in urban/suburban districts of Ulaanbaatar. Overall, the increases in the prevalence of respiratory symptoms among children might be associated with ambient air pollution in Ulaanbaatar.

The in vitro estrogenic activity of the crude drugs found in Japanese herbal medicines prescribed for menopausal syndrome was enhanced by combining them.

BACKGROUND: Japanese herbal medicines can be used as alternatives to estrogen therapy and are sometimes prescribed for menopausal syndrome because they have fewer side effects and are associated with better compliance than estrogen therapy, but little is known about the pharmacological mechanisms of such treatments. This study aimed to explore the mechanisms responsible for the estrogen-like effects of five widely prescribed Japanese herbal medicines (unkeito, kamishoyosan, nyoshinsan, keishibukuryogan, and tokishakuyakusan). METHODS: We evaluated the estrogenic activity of these five Japanese herbal medicines and their metabolites using an estrogen receptor (ER)-dependent cell proliferation bioassay and an ER-dependent reporter assay. We also investigated the estrogenic activity of the crude drugs within the medicines and attempted to detect inter-crude drug synergistic effects using the ER-dependent reporter assay. RESULTS: We found that unkeito, kamishoyosan, and nyoshinsan exhibited estrogenic activity, and they displayed stronger estrogenic activity after being metabolized. Then, we focused on investigating the estrogenic activity of the crude drugs present within unkeito. We found that glycyrrhizae radix, cinnamomi cortex, evodiae fructus, and zingiberis rhizoma demonstrated ERß-dependent estrogenic activity. The combined use of evodiae fructus and glycyrrhizae radix, or evodiae fructus and cinnamomi cortex produced synergistic ERß-dependent estrogenic activity. CONCLUSION: It was suggested that unkeito, kamishoyosan, and nyoshinsan exert estrogenic activity, and hence, might be useful for treating menopausal syndrome. Furthermore, synergistic estrogenic effects were detected between some of the crude drugs present within unkeito.

A modified seated side tapping test in which the arms are crossed also reflects gait function in community-dwelling elderly.

[Purpose] Seated side tapping test (SST) performance is associated with mobility impairment in the elderly. Although this test was developed to assess trunk function, interpretation of its results may be confounded by the upper-limb movements in its protocol. Here, this study aimed to validate the association between trunk function and gait function by means of the Arms Crossed SST (AC-SST), a modified version of the SST in which the arms are crossed over the chest, to exclude the effects of the upper limbs. [Subjects and Methods] A total of 116 community-dwelling elderly people were enrolled in the study (mean age: 75.1 ± 5.5 yrs). Measurement categories were gait function (gait speed and TUG), lower extremity strength (knee extension and flexion strength), trunk muscle endurance (trunk extension and flexion endurance), and trunk function (SST and AC-SST). [Results] AC-SST performance significantly correlated with gait function items, as did SST performance. Moreover, AC-SST was one of the significant predictor variables of gait function selected in stepwise multiple regressions. [Conclusion] Gait function associated with performance on the AC-SST, a test of trunk function in which the effects of upper limb function were excluded, reinforcing the importance of trunk function to elderly mobility.

Effect of combination of dietary fish protein and fish oil on lipid metabolism in rats.

This study examined the effects of fish protein in combination with fish oil on rat lipid metabolism. Male Wistar rats were divided into four groups and fed an AIN93G-based diet with casein (20%) + soybean oil (7%), casein (10%) + fish protein (10%) + soybean oil (7%), casein (20%) + soybean oil (5%) + fish oil (2%), and casein (10%) + fish protein (10%) + soybean oil (5%) + fish oil (2%) for 4 weeks. The dietary combination of fish protein and fish oil decreased the contents of serum triacylglycerol, serum cholesterol, liver triacylglycerol and liver cholesterol in addition to altering liver lipid fatty acid composition. These effects are partly due to the increase in fecal cholesterol, bile acid excretion, and increased enzyme activities of fatty acid ß-oxidation in the liver. These data suggest that combined intake of fish protein and fish oil lead to both hypocholesterolemic and hypotriglyceridemic in serum and the liver, while sole intake of fish protein or fish oil decrease only cholesterol and triglyceride levels, respectively. These results suggest that combined intake of fish protein and fish oil may play beneficial roles in the prevention of lifestyle-related diseases as compared with sole fish protein intake.

Similarities and discrepancies between commercially available bioelectrical impedance analysis system and dual-energy X-ray absorptiometry for body composition assessment in 10-14-year-old children.

A variety of easy-to-use commercial bioelectrical impedance appliances are available. The aim of this study was to examine the usefulness of a commercially available body composition meter using bioelectrical impedance analysis (BIA) by comparing its measurement results with those obtained from dual-energy X-ray absorptiometry (DXA). The participants were 443 children aged from 10 to 14 years (226 boys and 217 girls). Fat mass, fat-free mass, lean body mass, percentage of body fat, and bone mineral contents were evaluated for all participants using BIA and DXA. The agreement in the anthropometric data obtained from both devices was analyzed using correlation analysis, intraclass correlation coefficient (ICC), Lin's concordance correlation coefficient (CCC), Bland-Altman plots, and ordinary least products regression analysis. Equivalence between both devices was tested by two one-sided t-test. All measured indicators showed strong linear correlations between the two measurement systems (r, 0.853-1.000). Fat mass, fat-free mass, and lean body mass showed absolute concordance (ICC, 0.902-0.972; Lin's CCC, 0.902-0.972). BIA overestimated bone mineral content (62.7-66.5%) and underestimated percentage of body fat (- 8.9 to - 0.8%), lean body mass (- 3.5 to - 1.8%), and body mass (- 0.8 to - 0.5%). For fat mass and fat-free mass, the overestimate or underestimate varied according to the sex and statistical analysis test. Bland-Altman analysis and ordinary least products analysis showed fixed bias and proportional bias in all indicators. Results according to quartiles of body mass index showed poor agreement for fat mass and percentage of body fat in both boys and girls in the lowest body mass index quartile. The present results revealed strong linear correlations between BIA and DXA, which confirmed the validity of the present single-frequency BIA-derived parameters. Our results suggest that BIA cannot provide the exact same values as DXA for some body composition parameters, but that performance is sufficient for longitudinal use within an individual for daily health management and monitoring.

Maternal Inflammation with Elevated Kynurenine Metabolites Is Related to the Risk of Abnormal Brain Development and Behavioral Changes in Autism Spectrum Disorder.

Several studies show that genetic and environmental factors contribute to the onset and progression of neurodevelopmental disorders. Maternal immune activation (MIA) during gestation is considered one of the major environmental factors driving this process. The kynurenine pathway (KP) is a major route of the essential amino acid L-tryptophan (Trp) catabolism in mammalian cells. Activation of the KP following neuro-inflammation can generate various endogenous neuroactive metabolites that may impact brain functions and behaviors. Additionally, neurotoxic metabolites and excitotoxicity cause long-term changes in the trophic support, glutamatergic system, and synaptic function following KP activation. Therefore, investigating the role of KP metabolites during neurodevelopment will likely promote further understanding of additional pathophysiology of neurodevelopmental disorders, including autism spectrum disorder (ASD). In this review, we describe the changes in KP metabolism in the brain during pregnancy and represent how maternal inflammation and genetic factors influence the KP during development. We overview the patients with ASD clinical data and animal models designed to verify the role of perinatal KP elevation in long-lasting biochemical, neuropathological, and behavioral deficits later in life. Our review will help shed light on new therapeutic strategies and interventions targeting the KP for neurodevelopmental disorders.

Diagnosis of active tuberculosis using MPB64, a specific antigen of Mycobacterium bovis.

Because the incidence of tuberculosis (TB) is still high in developing countries, an inexpensive and rapid diagnostic test for this infection is needed. To develop a screening test for TB, MPB64 antigen was produced by recombinant technology and purified with a polyhistidine tag. Next, serum and urine samples from patients with TB and uninfected individuals were examined by the dot-blot assay method using this purified antigen. Serum samples from patients with TB reacted more strongly with MPB64 antigen than did those from uninfected individuals. In addition, serum samples from TB patients with active infection reacted more strongly with the antigen than did samples from patients with inactive TB. When urine samples were assessed using this assay, similar results were obtained. Correlations between the data obtained from serum and urine samples were analyzed for all subjects, including uninfected individuals, and a strong positive correlation between the results of serum and urine tests (n = 36, r = 0.672) was found. The sensitivity and specificity of this assay for serum samples was 85.7 % and 85.0 %, and for urine samples 75.0 % and 85.0 %, respectively. These results suggest that dot-blot assay with MPB64 antigen could be a useful screening test for active TB. Because urine samples can be obtained more easily than serum samples and because urine is less contagious, urine testing should probably be employed for screening purposes.

Body weight at 1.5- and 3-year health checks and body fat at 14 years of age: a population-based retrospective cohort study using dual-energy X-ray absorptiometry.

BACKGROUND: In Japan, height and weight measurements, taken for all children at birth and 1.5- and 3-year health checks, are recorded in the Mother and Child Health (MCH) Handbook, as required by the law. The present population-based retrospective cohort study aimed to evaluate the diagnostic performance of height and weight records in the Handbook for predicting excessive adiposity in adolescents. METHODS: The source population consisted of 8th grade students (800 students aged 14 years) registered at two public junior high schools. Of these, we excluded students who were born at a gestational age < 37 weeks or > 42 weeks. The present analyses included 435 participants who provided complete information. Body mass index (BMI) was calculated using height and weight records. Body fat mass at 14 years of age was measured by dual-energy X-ray absorptiometry (DXA). Diagnostic performance of BMI calculated from the MCH Handbook records to discriminate between the presence and absence of excessive adiposity at 14 years of age was evaluated using receiver operating characteristic (ROC) curve analysis. The area under the ROC curve (AUC) was used to quantify the diagnostic accuracy of BMI. RESULTS: With regard to the prediction of excessive fat at 14 years of age, AUCs and 95% confidence intervals for BMI at 1.5 and 3 years of age were greater than 0.5. Meanwhile, the AUC of BMI at birth was not significantly greater than 0.5. CONCLUSION: The present study findings indicate that BMI values calculated using MCH Handbook data have potential ability to distinguish between the presence and absence of excessive fat at 14 years of age.

Dietary Alaska Pollock Protein Attenuates the Experimental Colitis Induced by Dextran Sulfate Sodium via Regulation of Gut Microbiota and Its Metabolites in Mice.

Protein derived from fish has not only nutritional properties but also health-promoting properties. Few studies have examined the effect of dietary Alaska pollock protein (APP) on the anticolitis effect reported to be associated with metabolic syndrome (MetS). This study investigated the effect of APP intake on colitis symptoms, gut microbiota, and its metabolites in the experimental colitis mouse model induced by dextran sulfate sodium (DSS). Male C57BL/6J mice were divided into three groups: (1) DSS-untreated mice fed an American Institute of Nutrition (AIN) 93G diet (protein source is casein), (2) DSS-treated mice fed an AIN93G diet, and (3) DSS-treated mice fed an APP diet. After the mice were fed the diets for 21 days, experimental colitis was induced by three cycles of 2% DSS administration for 5 days followed by washouts over the course of 5 days. APP-reduced body weight loss increased the disease activity index, and elevated spleen weight and alleviated colon length shortening and colonic tissue damage. Furthermore, APP altered the structure and composition of the microbiota and short-chain fatty acids in feces. Since APP intake alleviates experimental colitis induced by DSS administration through alterations in the gut microbiota and its metabolites, we deduced that APP would inhibit MetS progression via colitis suppression.

Reduction in Anti-Dengue Virus IgG Antibody Levels with the Use of a Larvicide for Vector Control in Rural Lao People's Democratic Republic.

The Lao People's Democratic Republic is an endemic area of dengue, with cases reported in urban and rural areas every year. In this study, we indirectly evaluated the efficacy of a larvicide (SumiLarvTM 2MR discs) that was used for vector control against Aedes mosquitoes. Villages in a rural area of Lao PDR were selected as study areas, non-intervention and intervention villages. At the intervention village, the larvicide was used to treat refillable water containers for 27 months (October 2017 to February 2020), while at the non-intervention villages were no treatment. The serum samples of villagers from both villages were randomized to collect in the pre-intervention and in post-intervention periods. An enzyme-linked immunosorbent assay (ELISA) was used to examine anti-dengue virus (DENV) IgG antibody levels in serum samples. Recombinant DENV serotype 2 non-structural protein1 was used as an antigen for the ELISA, the optical density (OD) values were analyzed for comparison. The results showed that the OD values decreased significantly (p < 0.01) between the pre-intervention and post-intervention periods at the intervention site. The treatment of water storage containers in rural areas with SumiLarvTM 2MR discs may help to protect residents from Aedes mosquito bites, and hence, reduce DENV infections.

Protective Effects of Fish (Alaska Pollock) Protein Intake against Short-Term Memory Decline in Senescence-Accelerated Mice.

Dietary fish intake has proven to have health benefits in humans. n-3 polyunsaturated fatty acids (PUFAs) in fish oil (FO), especially, may provide protection against age-related cognitive disorders. Owing to the unique benefits of n-3 PUFAs, other nutrients, such as fish protein (FP), have not been well studied. To clarify the effects of FO and FP on brain function, we investigated whether FO or FP feeding can prevent age-related cognitive dysfunction in senescence-accelerated mouse-prone 10 (SAMP10) mice. The FP group maintained a better working memory compared to the control and FO groups in the Y-maze test, but not episodic memory in the novel object recognition test. To evaluate demyelination levels, we measured neurofilament H (NfH) and myelin basic protein (MBP) immunoreactivity in the hippocampus (Hipp). Axon morphology was maintained in the FP group, but not in the control and FO groups. Additionally, the percentage of positive area for double-staining with NfH/MPB was significantly higher in the Hipp of FP-fed mice than in the control (p < 0.05). These results suggest that FP intake prevents age-related cognitive dysfunction by maintaining axonal morphology in the Hipp of SAMP10 mice.

Dietary Oyster (Crassostrea gigas) Extract Ameliorates Dextran Sulfate Sodium-Induced Chronic Experimental Colitis by Improving the Composition of Gut Microbiota in Mice.

Previously, we have reported that the intake of oyster extract (OE), prepared from Pacific oysters (Crassostrea gigas), can attenuate symptoms of dextran sulfate sodium (DSS)-induced acute experimental colitis in mice. Herein, we aimed to evaluate whether OE intake ameliorates chronic experimental colitis induced by repeated DSS administration in mice. Male C57BL/6J (4-week-old) mice were fed either the standard diet AIN93G (control diet) or the control diet containing 5.0% (w/w) OE (OE diet). After 21 days of diet feeding, chronic experimental colitis was induced by three cycles of 2.0% (w/w) DSS solution administration (5 days), followed by distilled water (5 days). Mice fed OE alleviated the shortened colonic length, increased the relative weight of the spleen, colonic histopathological score (regeneration), and blood in the stool score compared with mice fed control diet. A tendency to improve the α-diversity of fecal microbiota, which was exacerbated by colitis, was observed in mice fed OE. Correlation analysis suggested that the anti-colitis effect of OE intake could be related to the valeric acid content and relative abundances of Ruminococcus and Enterococcus in the feces. In conclusion, OE could ameliorate DSS-induced chronic experimental colitis by improving the gut environment, including the microbiota community and SCFA composition.

Oyster (Crassostrea gigas) Extract Attenuates Dextran Sulfate Sodium-Induced Acute Experimental Colitis by Improving Gut Microbiota and Short-Chain Fatty Acids Compositions in Mice.

Drugs for inflammatory bowel diseases can be associated with serious side effects, and the development of alternative candidate resources derived from natural products has attracted considerable attention. Oyster extract (OE) derived from Crassostrea gigas contains glycogen, taurine, and amino acids, and has been assigned diverse health-promoting properties. This study investigated the anti-colitis effect of OE intake on fecal microbiota and its metabolites of acute experimental colitis mouse model induced by dextran sulfate sodium (DSS). C57BL/6J mice (male) were divided into three groups: (1) American Institute of Nutrition (AIN) 93G diet + DSS-untreated, (2) AIN93G diet + DSS-treated, and (3) 5% OE diet + DSS-treated. Mice were fed each diet for 21 days, and then administered 2.5% DSS solution to induce acute colitis for 7 days. In DSS-induced colitis mice, OE decreased body weight loss and increased disease activity index during the DSS-induced period. In addition, OE tended to decrease the colon length shortening and the relative spleen weight and alleviated colonic tissue damage. Moreover, OE improved fecal short-chain fatty acids compositions and altered the structure of fecal microbiota. These results provide insight into the health-promoting property of OE in alleviating DSS-induced acute colitis, providing a basis for the development and use of functional foods.