Differing Effects of Body Size on Circulating Lipid Concentrations and Hemoglobin A1c Levels in Young and Middle-Aged Japanese Women

The condition of being underweight is a social problem in Japan among women. However, there is a lack of evidence for dietary guidance for underweight women because there has been no comparison of lipids or HbA1c among underweight, normal weight, and overweight women in different age groups. We analyzed the effect of body size and age on the serum lipid and hemoglobin A1c levels in Japanese women in a cross-sectional study. A total of 26,118 women aged >20-65 years underwent physical examinations between 2012 and 2022. Seventeen percent of women aged >20-29 years were underweight, and 8% of those aged 50-65 years were underweight. Total cholesterol and non-HDL-C concentrations increased with age, but the difference between underweight and overweight individuals was lowest among women aged 50-65 years. On the other hand, the differences in HDL-C, TG, and HbA1c levels between underweight and overweight subjects were greatest in the 50-65 age group, but the differences between underweight and normal weight subjects were much smaller. Considering that, unlike HDL-C, TG, and HbA1c, TC and non-HDL-C increase to levels comparable to overweight levels in underweight women in aged 50-65 years, educating people about a diet that lowers non-HDL-C is necessary even in young underweight women.

Young Japanese Underweight Women with "Cinderella Weight" Are Prone to Malnutrition, including Vitamin Deficiencies

Undernutrition among young women at "Cinderella weight" is socially important in Japan. To determine the nutritional status of Cinderella-weight women, we conducted an exploratory cross-sectional study on the health examination results of employees aged 20 to 39 (n = 1457 and 643 for women and men, respectively). The percentage of underweight women was found to be much higher than that of men (16.8% vs. 4.5%, respectively). In underweight women (n = 245), handgrip strength (22.82 ± 5.55 vs. 25.73 ± 5.81 kg, p < 0.001), cholesterol level (177.8 ± 25.2 vs. 194.7 ± 31.2 mg/dL, p < 0.05), and lymphocyte count (1883 ± 503 vs. 2148 ± 765/μL, p < 0.001) were significantly lower than in overweight women (n = 116). Then, the BMI < 17.5 group (n = 44) was referred to the outpatient nutrition evaluation clinic. Lower prealbumin, cholesterol, and lymphocyte levels were also observed in 34%, 59%, and 32% of the patients, respectively. Regarding dietary characteristics, 32% of the underweight women in this study skipped breakfast, and 50% had low dietary diversity scores. Lower total energy intake, carbohydrate and fiber intake, and Ca and Fe intake were also observed in 90% of the patients. Deficiencies in vitamin B₁, B₁₂, D, and folate were diagnosed in 4.6%, 25%, 14%, and 98% of the patients, respectively. Thus, young underweight women may be prone to malnutrition.

Host metabolic benefits of prebiotic exopolysaccharides produced by Leuconostoc mesenteroides

Fermented foods demonstrate remarkable health benefits owing to probiotic bacteria or microproducts produced via bacterial fermentation. Fermented foods are produced by the fermentative action of several lactic acid bacteria, including Leuconostoc mesenteroides; however, the exact mechanism of action of these foods remains unclear. Here, we observed that prebiotics associated with L. mesenteroides-produced exopolysaccharides (EPS) demonstrate substantial host metabolic benefits. L. mesenteroides-produced EPS is an indigestible α-glucan, and intake of the purified form of EPS improved glucose metabolism and energy homeostasis through EPS-derived gut microbial short-chain fatty acids, and changed gut microbial composition. Our findings reveal an important mechanism that accounts for the effects of diet, prebiotics, and probiotics on energy homeostasis and suggests an approach for preventing lifestyle-related diseases by targeting bacterial EPS.

Lycopene intake induces colonic regulatory T cells in mice and suppresses food allergy symptoms

BACKGROUND

Food allergy (FA) is a common disease in children; thus, a high level of safety is required for its prevention and treatment. Colonic regulatory T cells (Tregs) have been suggested to attenuate FA. We investigated the Treg-inducing ability and anti-FA effects of carotenoids, a pigment contained in vegetables and fruits.

METHODS

C57BL/6N mice were fed a diet containing 0.01% (w/w) of lycopene, β-carotene, astaxanthin or lutein for 4 weeks, and the population of colonic Tregs was assessed. Subsequently, to evaluate the Treg-inducing ability of lycopene, splenic naïve CD4⁺ T cells from BALB/c mice were cultured with anti-CD3/CD28 antibody, TGF-β and lycopene, and the frequencies of Tregs were examined. The effect of 0.1% (w/w) lycopene containing diet on FA was investigated in OVA-induced FA model BALB/c mice.

RESULTS

In screening, only lycopene significantly increased the frequency and number of colonic Tregs. Lycopene also increased Treg differentiation in splenic naïve CD4⁺ T cells. In FA mice, lycopene feeding significantly increased the number of colonic Tregs and attenuated allergic symptoms. The expression levels of IL-4, IL-9 and IL-13 mRNA in colonic mucosa were also significantly reduced by lycopene. IL-9 is known to induce proliferation of mast cells, and we found that lycopene feeding significantly reduced the number of mast cells in the colonic mucosa of FA mice.

CONCLUSION

Our results suggest that lycopene, a carotenoid present in many common foods on the market, may have the potential to induce colonic Tregs and suppress FA symptoms.

High-Fat Diet Causes Constipation in Mice via Decreasing Colonic Mucus

BACKGROUND

Constipation is one of the most common gastrointestinal complaints. Although the causes of constipation are varied, dietary habits have a significant influence. Excessive fat intake is suggested as one of the main causes of constipation; however, the exact mechanism is unknown.

AIMS

To investigate whether a high-fat diet (HFD) causes constipation in mice and to clarify the underlying mechanism, focusing on the amount of colonic mucus.

METHODS

Six-week-old male C57BL/6 mice were randomly divided into two groups: mice fed with HFD and those with normal chow diet (NCD). Fecal weight, water content, total gastrointestinal transit time, and colon transit time were measured to determine whether the mice were constipated. The colonic mucus was evaluated by immunostaining and quantified by spectrometry. Malondialdehyde (MDA) was measured using the thiobarbituric acid (TBA) test as a marker for oxidative stress.

RESULTS

Compared to the NCD group, the weight of feces was less in the HFD group. In the functional experiment, the total gastrointestinal transit time and colon transit time were longer in the HFD group. Furthermore, HFD significantly reduced the amount of colonic mucus. In addition, the reduction in colonic mucus caused by surfactant resulted in constipation in the NCD group.

CONCLUSIONS

HFD causes constipation with delayed colon transit time possibly via the reduction in colonic mucus in mice.

Promotion of wound healing by acetate in murine colonic epithelial cell via c-Jun N-terminal kinase activation

BACKGROUND AND AIM

Mucosal healing is an important clinical goal in patients with inflammatory bowel disease. Recently, short-chain fatty acids (SCFAs) have been reported to have multifaceted effects to host. However, the effects of SCFAs on wound healing in intestinal epithelial cells are unclear. In the present study, we investigated the effects of acetate, one of the major SCFAs, on the wound healing of murine colonic epithelial cells.

METHODS

Young adult mouse colonic epithelial cells were used to determine the effect of acetate using wound healing assay. Mitogen-activated protein kinase and Rho kinase inhibitor were used to elucidate intracellular signal of wound healing treated with acetate. Meanwhile, Rho activation assays were utilized to measure Rho activation levels. To assess in vivo effects, C57B6 mice with dextran sodium sulfate for 7 days were treated with enema administration of acetate for 7 days. Body weight, disease activity index, colon length, and mucosal break ratio in histology were examined.

RESULTS

Acetate enhanced wound healing and fluorescence intensity of actin stress fiber compared with control. These effects were canceled with pretreatment of c-Jun N-terminal kinase (JNK) inhibitor or Rho kinase inhibitor. Furthermore, JNK inhibitor reduced the activation of Rho induced by acetate. In the dextran sodium sulfate-induced colitis model, the mice with enema treatment of acetate significantly exhibited recovery.

CONCLUSIONS

In this study, we demonstrated that acetate promoted murine colonic epithelial cell wound healing via activation of JNK and Rho signaling pathways. These findings suggested that acetate could have applications as a therapeutic agent for patients with intestinal mucosal damage, such as inflammatory bowel disease.

Epigallocatechin-3-gallate (EGCG) attenuates non-alcoholic fatty liver disease via modulating the interaction between gut microbiota and bile acids

The spectrum of non-alcoholic fatty liver disease (NAFLD) ranges from simple hepatic steatosis commonly associated with obesity, to non-alcoholic steatohepatitis, which can progress to fibrosis, cirrhosis and hepatocellular carcinoma. Recent reports have indicated the crucial role of gut microbiota and their metabolites in the progression of NAFLD. In the present review, we demonstrated the influence of oral administration of (-)-epigallocatechin-3-gallate (EGCG) on the gut microbiota, serum bile acid profile, and gene expression in the liver in mice fed a high-fat diet (HFD). EGCG significantly inhibited the increase in histological fatty deposit and triglyceride accumulation in the liver induced by HFD, and improved intestinal dysbiosis. One of important findings is that the abundance of Proteobacteria and Defferibacteres phylums increased markedly in the HFD group, and this increase was significantly suppressed in the EGCG group. Interestingly, taurine-conjugated cholic acid (TCA) increased in the HFD group, like the mirror image against a marked decrease in the cholic acid (CA) value, and this increase was markedly inhibited in the EGCG group. TCA is not a simple serum biomarker for liver injury but TCA may be a causal factor to disturb lipid metabolism. The distribution of correlation coefficients by Heatmap analysis showed that the abundance of Akkermansia and Parabacteroides genus showed a positive correlation with CA and a negative correlation with TCA, and significantly increased in the EGCG group as compared with the HFD group. In addition, nutrigenomics approaches demonstrated that sirtuin signaling, EIF2 pathway and circadian clock are involved in the anti-steatotic effects of EGCG. In the present paper, we summarized recent update data of EGCG function focusing on intestinal microbiota and their interaction with host cells.

Dietary short-chain fatty acid intake improves the hepatic metabolic condition via FFAR3

Fermented foods represent a significant portion of human diets with several beneficial effects. Foods produced by bacterial fermentation are enriched in short-chain fatty acids (SCFAs), which are functional products of dietary fibers via gut microbial fermentation. In addition to energy sources, SCFAs also act as signaling molecules via G-protein coupled receptors such as FFAR2 and FFAR3. Hence, dietary SCFAs in fermented foods may have a direct influence on metabolic functions. However, the detailed mechanism by dietary SCFAs remains unclear. Here, we show that dietary SCFAs protected against high-fat diet-induced obesity in mice in parallel with increased plasma SCFAs without changing cecal SCFA or gut microbial composition. Dietary SCFAs suppressed hepatic weight and lipid synthesis. These effects were abolished in FFAR3-deficient mice but not FFAR2-deficient. Thus, SCFAs supplementation improved hepatic metabolic functions via FFAR3 without influencing intestinal environment. These findings could help to promote the development of functional foods using SCFAs.

Ginsenoside Rb1 promotes intestinal epithelial wound healing through extracellular signal-regulated kinase and Rho signaling

BACKGROUND AND AIM

Daikenchuto, a traditional Japanese herbal medicine, has been reported to exhibit anti-inflammatory effects against intestinal inflammation. However, whether daikenchuto has a therapeutic effect against intestinal mucosal injuries remains unclear. Thus, the aim of this study was to determine the effect of daikenchuto on intestinal mucosal healing.

METHODS

Colitis was induced in male Wistar rats by using trinitrobenzenesulfonic acid. Daikenchuto (900 mg/kg/day) was administered for 7 days after the induction of colitis. Thereafter, intestinal mucosal injuries were evaluated by determining the colonic epithelial regeneration ratio ([area of epithelial regeneration/area of ulcer] × 100). Restoration of rat intestinal epithelial cells treated with daikenchuto and its constituent herbs (Zanthoxylum fruit, processed ginger, and ginseng) and ginsenoside Rb1, which is a ginseng ingredient, was evaluated using a wound-healing assay.

RESULTS

The colon epithelial regeneration ratio in the daikenchuto-treated rats was significantly higher than that in the control rats. Daikenchuto, ginseng, and ginsenoside Rb1 enhanced wound healing, and the ginsenoside Rb1-induced enhancement was inhibited by extracellular signal-regulated kinase and Rho inhibitors.

CONCLUSIONS

Daikenchuto and its constituent, ginsenoside Rb1, promoted wound healing. Because mucosal healing is one of the most important therapeutic targets in patients with inflammatory bowel disease, ginsenoside Rb1 may be a novel therapeutic agent against intestinal mucosal damage such as that occurring in intestinal bowel disease.

Green tea polyphenol (epigallocatechin-3-gallate) improves gut dysbiosis and serum bile acids dysregulation in high-fat diet-fed mice

Gut microbiota have profound effects on bile acid metabolism by promoting deconjugation, dehydrogenation, and dehydroxylation of primary bile acids in the distal small intestine and colon. High-fat diet-induced dysbiosis of gut microbiota and bile acid dysregulation may be involved in the pathology of steatosis in patients with non-alcoholic fatty liver disease. Epigallocatechin-3-gallate (EGCG), the most abundant polyphenolic catechin in green tea, has been widely investigated for its inhibitory or preventive effects against fatty liver. The aim of the present study was to investigate the effects of EGCG on the abundance of gut microbiota and the composition of serum bile acids in high-fat diet-fed mice and determine the specific bacterial genera that can improve the serum bile acid dysregulation associated with EGCG anti-hepatic steatosis action. Male C57BL/6N mice were fed with the control diet, high-fat diet, or high-fat diet + EGCG at a concentration of 0.32% for 8 weeks. EGCG significantly inhibited the increases in weight, the area of fatty lesions, and the triglyceride content in the liver induced by the high-fat diet. Principal coordinate analysis revealed significant differences in microbial structure among the groups. At the genus level, EGCG induced changes in the microbiota composition in high-fat diet-fed mice, showing a significantly higher abundance of Adlercreutzia, Akkermansia, Allobaculum and a significantly lower abundance of Desulfovibrionaceae. EGCG significantly reversed the decreased population of serum primary cholic acid and β-muricholic acid as well as the increased population of taurine-conjugated cholic acid, β-muricholic acid and deoxycholic acid in high-fat diet-fed mice. Finally, the correlation analysis between bile acid profiles and gut microbiota demonstrated the contribution of Akkermansia and Desulfovibrionaceae in the improvement of bile acid dysregulation in high-fat diet-fed mice by treatment with EGCG. In conclusion, the present study suggests that EGCG could alter bile acid metabolism, especially taurine deconjugation, and suppress fatty liver disease by improving the intestinal luminal environment.

Carbon monoxide ameliorates murine T-cell-dependent colitis through the inhibition of Th17 differentiation

Recent studies have identified carbon monoxide (CO) as a potential therapeutic molecule for the treatment of inflammatory diseases including intestinal inflammation. In the present study, we explored the efficacy and the mechanisms of action of CO-releasing molecule (CORM)-A1 in T-cell transfer induced colitis model in mice. In addition, the impact of CORM-A1 on the T helper (Th) cell differentiation was evaluated using naïve CD4⁺ T cells isolated from the spleens in Balb/c mice. The results showed that CORM-A1 conferred protection against the development of intestinal inflammation and attenuated Th17 cell differentiation. Hence, the observed immunomodulatory effects of CORM-A1 could be useful for developing novel therapeutic approaches for managing intestinal inflammation through the regulation of Th17 differentiation.

Effects of molecular hydrogen-dissolved alkaline electrolyzed water on intestinal environment in mice

Increasing evidence indicates that molecular hydrogen-dissolved alkaline electrolyzed water (AEW) has various physiological activities such as antioxidative activity. Gut microbiota are deeply associated with our health through a symbiotic relationship. Recent reports have described that most gastrointestinal microbial species encode the genetic capacity to metabolize molecular hydrogen, meaning that molecular hydrogen might affect the gut microbial composition. Nevertheless, AEW effects on gut microbiota remain unknown. This study investigated AEW effects on the intestinal environment in mice, including microbial composition and short-chain fatty acid contents. After mice were administered AEW for 4 weeks, 16S rRNA gene sequencing analyses revealed their fecal microbiota profiles. Organic acid concentrations in cecal contents were measured using an HPLC system. Compared to the control group, AEW administration mice had significantly lower serum low-density lipoprotein cholesterol level and alanine aminotransferase activity. Organic acid concentrations of propionic, isobutyric, and isovaleric acids were higher in AEW-administered mice. Results of 16S rRNA gene sequencing analyses showed that the relative abundances of 20 taxa differed significantly in AEW-administered mice. Although the definitive role of gut microbes of AEW-administered mice remains unknown, our data demonstrate the possibility that AEW administration affects the gut microbial composition and that it has beneficial health effects in terms of cholesterol metabolism and liver protection.

Secreted protein acidic and rich in cysteine functions in colitis via IL17A regulation in mucosal CD4+ T cells

BACKGROUND AND AIM

Secreted protein acidic and rich in cysteine (SPARC) is a matricellular glycol that regulates cell proliferation, tissue repair, and tumorigenesis. Despite evidence linking SPARC to inflammation, the mechanisms are unclear. Accordingly, the role of SPARC in intestinal inflammation was investigated.

METHODS

Colitis was induced in wild-type (WT) and SPARC knockout (KO) mice using trinitrobenzene sulfonic acid (TNBS). Colons were assessed for damage; leukocyte infiltration; Tnf, Ifng, Il17a, and Il10 mRNA expression; and histology. Cytokine profiling of colonic lamina propria mononuclear cells (LPMCs) was performed by flow cytometry. Naïve CD4⁺ T cells were isolated from WT and SPARC KO mouse spleens, and the effect of SPARC on Th17 cell differentiation was examined. Recombination activating gene 1 knockout (RAG1 KO) mice reconstituted with T cells from either WT or SPARC KO mice were investigated.

RESULTS

Trinitrobenzene sulfonic acid exposure significantly reduced bodyweight and increased mucosal inflammation, leukocyte infiltration, and Il17a mRNA expression in WT relative to SPARC KO mice. The percentage of IL17A-producing CD4⁺ T cells among LPMCs from KO mice was lower than that in WT mice when both groups were exposed to TNBS. Th17 cell differentiation was suppressed in cells from SPARC KO mice. In the T cell transfer colitis model, RAG1 KO mice receiving T cells from WT mice were more severely affected than those reconstituted with cells from SPARC KO mice.

CONCLUSIONS

Secreted protein acidic and rich in cysteine accelerates colonic mucosal inflammation via modulation of IL17A-producing CD4⁺ T cells. SPARC is a potential therapeutic target for conditions involving intestinal inflammation.

Rebamipide upregulates mucin secretion of intestinal goblet cells via Akt phosphorylation

Mucin is produced and secreted by epithelial goblet cells and is a key component of the innate immune system, acting as a barrier in the intestinal tract. However, no studies have been conducted investigating the increase in mucin secretion to enhance the intestinal barrier function. The present study investigated whether rebamipide (Reb) acts as a secretagogue of intestinal mucin and the underlying mechanisms involved, thereby focusing on the effect on goblet cells. The LS174T cell line was used as goblet cell‑like cells. Using Reb‑treated LS174T cells, the level of mucin content was assessed by periodic acid‑Schiff (PAS) staining, and mucin 2, oligomeric mucus/gel‑forming (MUC2) mRNA expression was assessed using quantitative polymerase chain reaction (PCR). Furthermore, MUC2 secretion in the supernatant was quantified by the dot blot method. The present study additionally investigated the involvement of the epidermal growth factor receptor/Akt serine/threonine kinase 1 (Akt) pathway in mucin secretion by western blotting. The results suggested that Reb strongly enhanced the positivity of PAS staining in LS174T cells, thereby suggesting increased intracellular mucin production. The PCR results indicated that Reb significantly increased MUC2 mRNA in whole cell lysate of LS174T cells. In order to assess the subsequent secretion of mucin by LS174T, MUC2 protein expression in the supernatant was assessed using the dot blot method and it was demonstrated that Reb significantly increased the secretion of MUC2 in a concentration‑dependent manner. The p‑Akt was significantly increased by Reb treatment, and an Akt inhibitor specifically suppressed MUC2 secretion. Overall, Reb increased mucin secretion directly via p‑Akt. Reb‑increased mucin may act as a strong non‑specific barrier against pathogenic stimulants in various intestinal diseases.

Protective effect of agaro-oligosaccharides on gut dysbiosis and colon tumorigenesis in high-fat diet-fed mice

High-fat diet (HFD)-induced alteration in the gut microbial composition, known as dysbiosis, is increasingly recognized as a major risk factor for various diseases, including colon cancer. This report describes a comprehensive investigation of the effect of agaro-oligosaccharides (AGO) on HFD-induced gut dysbiosis, including alterations in short-chain fatty acid contents and bile acid metabolism in mice. C57BL/6N mice were fed a control diet or HFD, with or without AGO. Terminal restriction fragment-length polymorphism (T-RFLP) analysis produced their fecal microbiota profiles. Profiles of cecal organic acids and serum bile acids were determined, respectively, using HPLC and liquid chromatography-tandem mass spectrometry systems. T-RFLP analyses showed that an HFD changed the gut microbiota significantly. Changes in the microbiota composition induced by an HFD were characterized by a decrease in the order Lactobacillales and by an increase in the Clostridium subcluster XIVa. These changes of the microbiota community generated by HFD treatment were suppressed by AGO supplementation. As supported by the data of the proportion of Lactobacillales order, the concentration of lactic acid increased in the HFD + AGO group. Data from the serum bile acid profile showed that the level of deoxycholic acid, a carcinogenic secondary bile acid produced by gut bacteria, was increased in HFD-receiving mice. The upregulation tended to be suppressed by AGO supplementation. Finally, results show that AGO supplementation suppressed the azoxymethane-induced generation of aberrant crypt foci in the colon derived from HFD-treated mice. Our results suggest that oral intake of AGO prevents HFD-induced gut dysbiosis, thereby inhibiting colon carcinogenesis.