Gastrointestinal Barrier Breakdown and Adipose Tissue Inflammation

Cross-talk between adipose tissue and microbiota-gut-brain-axis in brain development and neurological disorder

The gut microbiota is an important factor responsible for the physiological processes as well as pathogenesis of host. The communication between central nervous system (CNS) and microbiota occurs by different pathways i.e., chemical, neural, immune, and endocrine. Alteration in gut microbiota i.e., gut dysbiosis causes alteration in the bidirectional communication between CNS and gut microbiota and linked to the pathogenesis of neurological and neurodevelopmental disorder. Therefore, now-a-days microbiota-gut-brain-axis (MGBA) has emerged as therapeutic target for the treatment of metabolic disorder. But, experimental data available on MGBA from basic research has limited application in clinical study. In present study we first summarized molecular mechanism of microbiota interaction with brain physiology and pathogenesis via collecting data from different sources i.e., PubMed, Scopus, Web of Science. Furthermore, evidence shows that adipose tissue (AT) is active during metabolic activities and may also interact with MGBA. Hence, in present study we have focused on the relationship among MGBA, brown adipose tissue, and white adipose tissue. Along with this, we have also studied functional specificity of AT, and understanding heterogeneity among MGBA and different types of AT. Therefore, molecular interaction among them may provide therapeutic target for the treatment of neurological disorder.

Tongxieyaofang Decotion Alleviates IBS by Modulating CHRM3 and Gut Barrier

Purpose

Through network pharmacology combined with molecular docking and in vivo validation, the study examines the unexplored molecular mechanisms of Tongxieyaofang (TXYF) in the treatment of irritable bowel syndrome (IBS). In particular, the potential pharmacological mechanism of TXYF alleviating IBS by regulating CHRM3 and intestinal barrier has not been studied.

Patients and Methods

LC-MS technique and TCMSP database were used in combination to identify the potential effective components and target sites of TXYF. Potential targets for IBS were obtained from Genecards and OMIM databases. PPI and cytoHub analysis for targets. Molecular docking was used to validate the binding energy of effective components with related targets and for visualization. GO and KEGG analysis were employed to identify target functions and signaling pathways. In the in vivo validation, wrap restraint stress-induced IBS model was employed to verify the change for cytoHub genes and CHRM3 expression. Furthermore, inflammatory changes of colon were observed by HE staining. The changes of Ach were verified by ELISA. IHC and WB validated CHRM3 and GNAQ/PLC/MLCK channel variations. AB-PAS test and WB test confirmed the protection of TXYF on gut barrier. The NF-κB/MLCK pathway was also verified.

Results

In TXYF decoction, LC-MS identified 559 chemical components, with 23 remaining effective components after screening in TCMSP. KEGG analysis indicated that calcium plays a crucial role in TXYF treated for IBS. Molecular docking validated the binding capacity of the effective components Naringenin and Nobiletin with cytoHub-gene and CHRM3. In vivo validation demonstrated that TXYF inhibits the activation of Ach and CHRM3 in IBS, and inhibits for the GNAQ/PLC/MLCK axis. Additionally, TXYF downregulates TNF-α, MMP9, and NF-κB/MLCK, while modulating goblet cell secretion to protect gut barrier.

Conclusion

TXYF inhibits Ach and CHRM3 expression, regulating the relaxation of intestinal smooth muscle via GNAQ/PLC/MLCK. Additionally, TXYF inhibits NF-κB/MLCK activated and goblet cell secretion to protect gut barrier.

Decreased expression of the NLRP6 inflammasome is associated with increased intestinal permeability and inflammation in obesity with type 2 diabetes

BACKGROUND

Obesity-associated dysfunctional intestinal permeability contributes to systemic chronic inflammation leading to the development of metabolic diseases. The inflammasomes constitute essential components in the regulation of intestinal homeostasis. We aimed to determine the impact of the inflammasomes in the regulation of gut barrier dysfunction and metabolic inflammation in the context of obesity and type 2 diabetes (T2D).

METHODS

Blood samples obtained from 80 volunteers (n = 20 normal weight, n = 21 OB without T2D, n = 39 OB with T2D) and a subgroup of jejunum samples were used in a case-control study. Circulating levels of intestinal damage markers and expression levels of inflammasomes as well as their main effectors (IL-1β and IL-18) and key inflammation-related genes were analyzed. The impact of inflammation-related factors, different metabolites and Akkermansia muciniphila in the regulation of inflammasomes and intestinal integrity genes was evaluated. The effect of blocking NLRP6 by using siRNA in inflammation was also studied.

RESULTS

Increased circulating levels (P < 0.01) of the intestinal damage markers endotoxin, LBP, and zonulin in patients with obesity decreased (P < 0.05) after weight loss. Patients with obesity and T2D exhibited decreased (P < 0.05) jejunum gene expression levels of NLRP6 and its main effector IL18 together with increased (P < 0.05) mRNA levels of inflammatory markers. We further showed that while NLRP6 was primarily localized in goblet cells, NLRP3 was localized in the intestinal epithelial cells. Additionally, decreased (P < 0.05) mRNA levels of Nlrp1, Nlrp3 and Nlrp6 in the small intestinal tract obtained from rats with diet-induced obesity were found. NLRP6 expression was regulated by taurine, parthenolide and A. muciniphila in the human enterocyte cell line CCL-241. Finally, a significant decrease (P < 0.01) in the expression and release of MUC2 after the knockdown of NLRP6 was observed.

CONCLUSIONS

The increased levels of intestinal damage markers together with the downregulation of NLRP6 and IL18 in the jejunum in obesity-associated T2D suggest a defective inflammasome sensing, driving to an impaired epithelial intestinal barrier that may regulate the progression of multiple obesity-associated comorbidities.

New Insights and Potential Therapeutic Interventions in Metabolic Diseases

Endocrine homeostasis and metabolic diseases have been the subject of extensive research in recent years. The development of new techniques and insights has led to a deeper understanding of the mechanisms underlying these conditions and opened up new avenues for diagnosis and treatment. In this review, we discussed the rise of metabolic diseases, especially in Western countries, the genetical, psychological, and behavioral basis of metabolic diseases, the role of nutrition and physical activity in the development of metabolic diseases, the role of single-cell transcriptomics, gut microbiota, epigenetics, advanced imaging techniques, and cell-based therapies in metabolic diseases. Finally, practical applications derived from this information are made.

Extra virgin coconut oil (Cocos nucifera L.) intake shows neurobehavioural and intestinal health effects in obesity-induced rats

The present study aimed to evaluate the effect of E-VCO on the neurobehaviour and intestinal health parameters of obesity-induced rats, focusing on food consumption, body composition, bacterial and faecal organic acids and histological analyses in the hippocampus and colon. A total of 32 male Wistar rats were randomized into healthy (HG, n = 16) and obese groups (OG, n = 16), which consumed a control or cafeteria diet for eight weeks, respectively. After this period, they were subdivided into four groups: healthy (HG, n = 8); healthy treated with E-VCO (HGCO, n = 8); obese (OG, n = 8); obese treated with E-VCO (OGCO, n = 8), continuing for another eight weeks with their respective diets. The treated groups received 3000 mg kg^-1 of E-VCO and control groups received water via gavage. Food preference, body weight gain, body composition, anxiety- and depression-like behaviour were evaluated. Bacteria and organic acids were evaluated in faeces, and histological analyses of the hippocampus and M1 and M2 macrophages in the colon were performed. E-VCO reduced energy intake (16.68%) and body weight gain (16%), although it did not reduce the fat mass of obese rats. E-VCO showed an antidepressant effect, increased lactic acid bacteria counts and modulated organic acids in obese rats. Furthermore, E-VCO protected the hippocampus from neuronal degeneration caused by the obesogenic diet, decreased the M1 macrophage and increased the M2 macrophage population in the gut. The results suggest neurobehavioural modulation and improved gut health by E-VCO, with promising effects against obesity-related comorbidities.

Taiwanese green propolis ameliorates metabolic syndrome via remodeling of white adipose tissue and modulation of gut microbiota in diet-induced obese mice

Excessive energy intake leads to dysbiosis of intestinal microbiota and puts surrounding tissues under oxidative stress and inflammation, contributing to the development of metabolic syndrome. Taiwanese green propolis (TGP) exhibits a broad spectrum of biological activities, including anti-bacterial, anti-inflammatory, and antioxidant properties. However, the benefits of TGP on metabolic syndrome have not been explained in detail. In this study, we examined the preventive effects of TGP on high-fat diet (HFD)-induced obesity. The results showed that TGP supplementation at 1000 ppm improved condition such as hyperlipidemia, fat accumulation, liver steatosis, and whitening of brown adipose tissue (BAT) in mice. In addition, we observed more cold-induced non-shivering thermogenesis by BAT in TGP treatment with 1000 ppm group. At lower dose of 500 ppm, TGP improved glucose intolerance and insulin insensitivity in HFD mice and restructured the composition of gut microbiota to reduce dysbiosis, which involved an increase in the abundance of metabolism-related bacteria such as Lachnospiraceae NK4A136 group and the decrease in Desulfovibrio. The change of dominant microbiota was associated with the homeostasis of blood glucose and lipid. Transcriptome and micro-western array analysis revealed that TGP supplementation at 500 ppm promoted the browning and adipogenesis in white adipose tissue (WAT), blocked inflammation signaling and attenuated reactive oxygen species, contributing to healthy WAT remodeling and offsetting negative metabolic effects of obesity. We concluded that TGP modulated the function of BAT, WAT, and gut microbiota, bringing a balance to the glucose and lipid homeostasis in the body.

Influence of the gut microbiota on satiety signaling

Recent studies show a link between the gut microbiota and the regulation of satiety and energy intake, processes that contribute to the development and pathophysiology of metabolic diseases. However, this link is predominantly established in animal and in vitro studies, whereas human intervention studies are scarce. In this review we focus on recent evidence linking satiety and the gut microbiome, with specific emphasis on gut microbial short-chain fatty acids (SCFAs). Based on a systematic search we provide an overview of human studies linking the intake of prebiotics with gut microbial alterations and satiety signaling. Our outcomes highlight the importance of in-depth examination of the gut microbiota in relation to satiety and provide insights into recent and future studies in this field.

Exercise Restores Hypothalamic Health in Obesity by Reshaping the Inflammatory Network

Obesity and overnutrition induce inflammation, leptin-, and insulin resistance in the hypothalamus. The mediobasal hypothalamus responds to exercise enabling critical adaptions at molecular and cellular level that positively impact local inflammation. This review discusses the positive effect of exercise on obesity-induced hypothalamic dysfunction, highlighting the mechanistic aspects related to the anti-inflammatory effects of exercise. In HFD-fed animals, both acute and chronic moderate-intensity exercise mitigate microgliosis and lower inflammation in the arcuate nucleus (ARC). Notably, this associates with restored leptin sensitivity and lower food intake. Exercise-induced cytokines IL-6 and IL-10 mediate part of these positive effect on the ARC in obese animals. The reduction of obesity-associated pro-inflammatory mediators (e.g., FFAs, TNFα, resistin, and AGEs), and the improvement in the gut-brain axis represent alternative paths through which regular exercise can mitigate hypothalamic inflammation. These findings suggest that the regular practice of exercise can restore a proper functionality in the hypothalamus in obesity. Further analysis investigating the crosstalk muscle-hypothalamus would help toward a deeper comprehension of the subject.

The mitigative effect of isorhamnetin against type 2 diabetes via gut microbiota regulation in mice

In order to demonstrate the effects of isorhamnetin (IH) on the symptoms of type 2 diabetes mellitus (T2DM) and the role of gut microbiota in this process, an T2DM mouse model was established via a high-fat diet and streptozotocin. After 6 weeks of IH intervention and diabetes phenotype monitoring, the mice were dissected. We detected blood indicators and visceral pathology. Contents of the cecum were collected for 16S rRNA sequencing and short chain fatty acid (SCFAs) detection. The results showed that after IH intervention, the body weight of type 2 diabetic mice was gradually stabilized, fasting blood glucose was significantly decreased, and food intake was reduced (P < 0.05). Isorhamnetin significantly increased the level of SCFAs and decreased the levels of blood lipids and inflammatory factors in mice (P < 0.05). 16S rRNA sequencing results showed that Lactobacillus were significantly decreased and Bacteroidales S24-7 group_norank were significantly increased (P < 0.05). Interestingly, gut microbiota was significantly correlated with inflammatory factors, blood lipids, and SCFAs (P < 0.05). Taken together, our data demonstrated that isorhamnetin could improve the diabetic effects in T2DM mice, which might be mediated by gut microbiota.

Casein Lactose-Glycation of the Maillard-Type Attenuates the Anti-Inflammatory Potential of Casein Hydrolysate to IEC-6 Cells with Lipopolysaccharide Stimulation

During the thermal processing of dairy products, the Maillard reaction occurs between milk proteins and lactose, resulting in the formation of various products including glycated proteins. In this study, lactose-glycated casein was generated through the Maillard reaction between casein and lactose and then hydrolyzed by a trypsin preparation. The anti-inflammatory effect of the resultant glycated casein hydrolysate (GCH) was investigated using the lipopolysaccharide (LPS)-sitmulated rat intestinal epithelial (IEC-6) cells as a cell model and corresponding casein hydrolysate (CH) as a control. The results indicated that the preformed glycation enabled lactose conjugation to casein, which endowed GCH with a lactose content of 12.61 g/kg protein together with a lower activity than CH to enhance the viability value of the IEC-6 cells. The cells with LPS stimulation showed significant inflammatory responses, while a pre-treatment of the cells with GCH before LPS stimulation consistently led to a decreased secretion of three pro-inflammatory mediators, namely, IL-6, IL-1β and tumor necrosis factor-α (TNF-α) but an increased secretion of two anti-inflammatory mediators, including IL-10 and transforming growth factor-β (TGF-β), demonstrating the anti-inflammatory potential of GCH in LPS-stimulated cells. In addition, GCH up-regulated the expression of TLR4, p-p38, and p-p65 proteins in the stimulated cells, resulting in the suppression of NF-κB and MAPK signaling pathways. Collectively, GCH was mostly less efficient than CH to exert these assessed anti-inflammatory activities in the cells and more importantly, GCH also showed an ability to cause cell inflammation by promoting IL-6 secretion and up-regulating the expression of TLR4 and p-p65. The casein lactose-glycation of the Maillard-type was thereby concluded to attenuate the anti-inflammatory potential of the resultant casein hydrolysate. It is highlighted that the casein lactose-glycation of the Maillard-type might cause a negative impact on the bioactivity of casein in the intestine, because the glycated casein after digestion could release GCH with reduced anti-inflammatory activity.

Enterorenal crosstalks in diabetic nephropathy and novel therapeutics targeting the gut microbiota

The role of gut-kidney crosstalk in the progression of diabetic nephropathy (DN) is receiving increasing concern. On one hand, the decline in renal function increases circulating uremic toxins and affects the composition and function of gut microbiota. On the other hand, intestinal dysbiosis destroys the epithelial barrier, leading to increased exposure to endotoxins, thereby exacerbating kidney damage by inducing systemic inflammation. Dietary inventions, such as higher fiber intake, prebiotics, probiotics, postbiotics, fecal microbial transplantation (FMT), and engineering bacteria and phages, are potential microbiota-based therapies for DN. Furthermore, novel diabetic agents, such as glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 (DPP-4) inhibitors, and sodium-dependent glucose transporter-2 (SGLT-2) inhibitors, may affect the progression of DN partly through gut microbiota. In the current review, we mainly summarize the evidence concerning the gut-kidney axis in the advancement of DN and discuss therapies targeting the gut microbiota, expecting to provide new insight into the clinical treatment of DN.

Hemp seed significantly modulates the endocannabinoidome and produces beneficial metabolic effects with improved intestinal barrier function and decreased inflammation in mice under a high-fat, high-sucrose diet as compared with linseed

Omega-3 fatty acids support cardiometabolic health and reduce chronic low-grade inflammation. These fatty acids may impart their health benefits partly by modulating the endocannabinoidome and the gut microbiome, both of which are key regulators of metabolism and the inflammatory response. Whole hemp seeds (Cannabis sativa) are of exceptional nutritional value, being rich in omega-3 fatty acids. We assessed the effects of dietary substitution (equivalent to about 2 tablespoons of seeds a day for humans) of whole hemp seeds in comparison with whole linseeds in a diet-induced obesity mouse model and determined their effects on obesity and the gut microbiome-endocannabinoidome axis. We show that whole hemp seed substitution did not affect weigh gain, adiposity, or food intake, whereas linseed substitution did, in association with higher fasting glucose levels, greater insulin release during an oral glucose tolerance test, and higher levels of liver triglycerides than controls. Furthermore, hemp seed substitution mitigated diet-induced obesity-associated increases in intestinal permeability and circulating PAI-1 levels, while having no effects on markers of inflammation in epididymal adipose tissue, which were, however, increased in mice fed linseeds. Both hemp seeds and linseeds were able to modify the expression of several endocannabinoidome genes and markedly increased the levels of several omega-3 fatty acid–derived endocannabinoidome bioactive lipids with previously suggested anti-inflammatory actions in a tissue specific manner, despite the relatively low level of seed substitution. While neither diet markedly modified the gut microbiome, mice on the hemp seed diet had higher abundance of Clostridiaceae 1 and Rikenellaceae than mice fed linseed or control diet, respectively. Thus, hemp seed-containing foods might represent a source of healthy fats that are not likely to exacerbate the metabolic consequences of obesogenic diets while producing intestinal permeability protective effects and some anti-inflammatory actions.

Pre-Digested Protein Enteral Nutritional Supplementation Enhances Recovery of CD4+ T Cells and Repair of Intestinal Barrier in HIV-Infected Immunological Non-Responders

AIDS patients with immune non-response are prone to malnutrition, intestinal barrier damage, thus aggravating chronic immune activation and inflammation. However, nutritional interventions targeting malnutrition may be beneficial to restore immune function, improve clinical outcomes, and reduce mortality remains largely unclear. This work aimed to evaluate the efficacy of a nutritional supplement in HIV-infected immune non-responders (INRs). The subjects received oral supplementation of a pre-digested protein nutrition formula for three months. We show that the CD4⁺ T and CD8⁺ T cell counts were significantly increased after supplementation of the pre-digested enteral nutritional supplement. Among all pro-inflammatory cytokines in the serum, only IL-1β level was significantly decreased, while TNF-β was significantly increased (P < 0.05). The levels of intestinal mucosal damage markers, diamine oxidase (DAO), D-lactic acid (D-lactate), and lipopolysaccharide (LPS), decreased significantly (P < 0.05) after the nutritional intervention. Moreover, at month 3 after the intervention, the body weight, body mass index, albumin, and hemoglobin of all subjects were significantly increased (P < 0.05). The correlation analysis demonstrated a significantly negative correlation of CD4⁺ T cell count with levels of DAO (r = -0.343, P = 0.004), D-lactate (r = -0.250, P = 0.037), respectively, and a significantly positive correlation of IL-1β level with levels of DAO (r = 0.445, P < 0.001), D-lactate (r = 0.523, P < 0.001), and LPS (r = 0.622, P < 0.001). We conclude that the pre-digested enteral nutrition supplement is effective for HIV-infected INRs.

Effects of Docetaxel Injection and Docetaxel Micelles on the Intestinal Barrier and Intestinal Microbiota

Increasing evidence has suggested that chemotherapeutics affect the integrity of the intestinal barrier and alter the intestinal microbiota, thus limiting the therapeutic outcomes of cancer chemotherapy. Docetaxel (DTX) is used for breast cancer treatment and has gastrointestinal side effects, but the influence of DTX formulations on the intestinal barrier and intestinal microbiota remains unknown. Therefore, in this work, the influence of DTX injection (free DTX, commercial formulation) and DTX/methoxy poly(ethylene glycol)-block-poly(D,L-lactide) (mPEG-PDLLA) (DTX micelles, nanoformulation) on the integrity of the intestinal barrier and the intestinal microbiota is investigated. It is found that the free DTX causes significantly greater intestinal barrier damage than the DTX micelles. The diversity of the intestinal microbiota, and the relative abundance of Akkermansia muciniphila and Ruminococcus gnavus in the DTX micelle-treated group is significantly higher than that in the free DTX-treated group. Moreover, the tumor growth rate is elevated in antibiotic mixture-pretreated mice, demonstrating that the diversity and composition of the intestinal microbiota may be associated with tumor progression. This work demonstrates that different formulations of chemotherapeutics have different effects on the integrity of the intestinal barrier and the intestinal microbiota.

Bifidobacterium animalis subsp. lactis lkm512 Attenuates Obesity-Associated Inflammation and Insulin Resistance Through the Modification of Gut Microbiota in High-Fat Diet-Induced Obese Mice

SCOPE

The impacts of longevity-promoting probiotic Bifidobacterium animalis subsp. lactis LKM512 (LKM512) on metabolic disease remain unclear. Here, the authors aim to explore the potential of LKM512 on the host physiological function and gut microbiota in high-fat diet-induced obese mice.

METHODS AND RESULTS

LKM512 are orally administrated for 12 weeks, and the effects of LKM 512 on systemic inflammation and insulin resistance, as well as gut microbiota, are investigated in high-fat (HF) diet-induced obese mice. LKM512 supplementation ameliorates hepatic lipid accumulation, attenuates hepatic and adipose tissue inflammation, and improves intestinal barrier function. These results are associated with improved insulin sensitivity and metabolic endotoxemia. Furthermore, the colonization of LKM512 induces an increase in polyamine metabolism and production, together with significant alternations in the composition and function of gut microbiota in obese mice, which are correlated with these improved metabolic phenotypes in the host.

CONCLUSION

The probiotic strain LKM512 may become a promising strategy to improve obesity and related metabolic disorders.

The Protective Effects of Live and Pasteurized Akkermansia muciniphila and Its Extracellular Vesicles against HFD/CCl4-Induced Liver Injury

Akkermansia muciniphila, as a member of the gut microbiota, has been proposed as a next-generation probiotic. Liver fibrosis is the main determinant of liver dysfunction and mortality in patients with chronic liver disease. In this study, we aimed to determine the beneficial effects of live and pasteurized A. muciniphila and its extracellular vesicles (EVs) on the prevention of liver fibrosis. The response of hepatic stellate cells (HSCs) to live and pasteurized A. muciniphila and its EVs was examined in quiescent, lipopolysaccharide (LPS)-activated LX-2 cells. Liver fibrosis was induced in 8-week-old C57BL/6 mice, using a high-fat diet (HFD) and carbon tetrachloride (CCl4) administration for 4 weeks. The mice were concomitantly treated via oral gavage with three forms of bacteria. The relative expression of different fibrosis and inflammatory markers was assessed in the tissues. Histological markers, serum biochemical parameters, and cytokine production were also analyzed, and their correlations with the relative abundance of targeted fecal bacteria were examined. All A. muciniphila preparations exhibited protective effects against HSC activation; however, EVs showed the greatest activity in HSC regression. Oral gavage with A. muciniphila ameliorated the serum biochemical and inflammatory cytokines and improved liver and colon histopathological damages. The relative expression of fibrosis and inflammatory biomarkers was substantially attenuated in the tissues of all treated mice. The composition of targeted stool bacteria in the live A. muciniphila group was clearly different from that in the fibrosis group. This study indicated that A. muciniphila and its derivatives could successfully protect against HFD/CCl4-induced liver injury. However, further studies are needed to prove the beneficial effects of A. muciniphila on the liver. IMPORTANCE Akkermansia muciniphila, as a member of the gut microbiota, has been proposed as a next-generation probiotic. Liver fibrosis is the main determinant of liver dysfunction and mortality in patients with chronic liver disease. In this study, we aimed to determine the beneficial effects of live and pasteurized A. muciniphila and its extracellular vesicles (EVs) on the prevention of liver fibrosis. The results of the present study indicated that oral administration of live and pasteurized A. muciniphila and its EVs could normalize the fecal targeted bacteria composition, improve the intestinal permeability, modulate inflammatory responses, and subsequently prevent liver injury in HFD/CCl4-administered mice. Following the improvement of intestinal and liver histopathology, HFD/CCl4-induced kidney damage and adipose tissue inflammation were also ameliorated by different A. muciniphila treatments.

DNA Damage-Regulated Autophagy Modulator 1 (DRAM1) Mediates Autophagy and Apoptosis of Intestinal Epithelial Cells in Inflammatory Bowel Disease

BACKGROUND AND AIMS

DNA damage-regulated autophagy modulator 1 (DRAM1) is required for induction of autophagy and apoptosis. However, the influence of DRAM1 on the pathogenesis of inflammatory bowel disease (IBD) has not been explored.

METHODS

DRAM1 expression was examined in the intestinal mucosa of patients with IBD and colons of colitis mice. We used a recombinant adeno-associated virus carrying small hairpain DRAM1 to knock down the DRAM1 gene to treat colitis in the mice. The effect of DRAM1 on autophagy and apoptosis of intestinal epithelial cells was explored. DRAM1-mediated interaction with the c-Jun N-terminal kinase (JNK) pathway was also examined.

RESULTS

DRAM1 expression in the intestinal mucosa of the IBD patients was higher than that in the control participates. DRAM1 expression in the inflammatory cells in patients with Crohn's disease (CD) was lower than that in patients with ulcerative colitis (UC). Additionally, DRAM1 expression was correlated with the Simple Endoscopic Score for CD and the Mayo endoscopic score for UC. Serum levels of DRAM1 in the IBD group were substantially higher than those in the normal group. The knockdown of DRAM1 could alleviate colitis symptoms in mice. In in vitro experiments, knocking down DRAM1 could reduce autophagy and apoptosis levels. Mechanistically, DRAM1 may participate in the regulation of these two processes by positively regulating JNK activation.

CONCLUSIONS

During intestinal inflammation, the upregulation of DRAM1 may promote the activation of JNK and further aggravate intestinal epithelium damage.

Exercise tolls the bell for key mediators of low-grade inflammation in dysmetabolic conditions

Metabolic conditions share a common low-grade inflammatory milieu, which represents a key-factor for their ignition and maintenance. Exercise is instrumental for warranting systemic cardio-metabolic balance, owing to its regulatory effect on inflammation. This review explores the effect of physical activity in the modulation of sub-inflammatory framework characterizing dysmetabolic conditions. Regular exercise suppresses plasma levels of TNFα, IL-1β, FFAs and MCP-1, in dysmetabolic subjects. In addition, a single session of training increases the anti-inflammatory IL-10, IL-1 receptor antagonist (IL-1ra), and muscle-derived IL-6, mitigating low-grade inflammation. Resting IL-6 levels are decreased in trained-dysmetabolic subjects, compared to sedentary. On the other hand, the acute release of muscle-IL-6, after exercise, seems to exert a regulatory effect on the metabolic and inflammatory balance. In fact, muscle-released IL-6 is presumably implicated in fat loss and boosts plasma levels of IL-10 and IL-1ra. The improvement of adipose tissue functionality, following regular exercise, is also critical for the mitigation of sub-inflammation. This effect is likely mediated by muscle-released IL-15 and IL-6 and partly relies on the brown-shifting of white adipocytes, induced by exercise. In obese-dysmetabolic subjects, moderate training is shown to restore gut-microbiota health, and this mitigates the translocation of bacterial-LPS into bloodstream. Finally, regular exercise can lower plasma advanced glycated endproducts. The articulated physiology of circulating mediators and the modulating effect of the pathophysiological background, render the comprehension of the exercise-regulatory effect on sub-inflammation a key issue, in dysmetabolism.

Maintaining Digestive Health in Diabetes: The Role of the Gut Microbiome and the Challenge of Functional Foods

Over the last decades, the incidence of diabetes has increased in developed countries and beyond the genetic impact, environmental factors, which can trigger the activation of the gut immune system, seem to affect the induction of the disease process. Since the composition of the gut microbiome might disturb the normal interaction with the immune system and contribute to altered immune responses, the restoration of normal microbiota composition constitutes a new target for the prevention and treatment of diabetes. Thus, the interaction of gut microbiome and diabetes, focusing on mechanisms connecting gut microbiota with the occurrence of the disorder, is discussed in the present review. Finally, the challenge of functional food diet on maintaining intestinal health and microbial flora diversity and functionality, as a potential tool for the onset inhibition and management of the disease, is highlighted by reporting key animal studies and clinical trials. Early onset of the disease in the oral cavity is an important factor for the incorporation of a functional food diet in daily routine.

The Interrelationships between Intestinal Permeability and Phlegm Syndrome and Therapeutic Potential of Some Medicinal Herbs

The gastrointestinal (GI) tract has an intriguing and critical role beyond digestion in both modern and complementary and alternative medicine (CAM), as demonstrated by its link with the immune system. In this review, we attempted to explore the interrelationships between increased GI permeability and phlegm, an important pathological factor in CAM, syndrome, and therapeutic herbs for two disorders. The leaky gut and phlegm syndromes look considerably similar with respect to related symptoms, diseases, and suitable herbal treatment agents, including phytochemicals even though limitations to compare exist. Phlegm may be spread throughout the body along with other pathogens via the disruption of the GI barrier to cause several diseases sharing some parts of symptoms, diseases, and mechanisms with leaky gut syndrome. Both syndromes are related to inflammation and gut microbiota compositions. Well-designed future research should be conducted to verify the interrelationships for evidence based integrative medicine to contribute to the promotion of public health. In addition, systems biology approaches should be adopted to explore the complex synergistic effects of herbal medicine and phytochemicals on conditions associated with phlegm and leaky gut syndromes.

Spermidine ameliorates high-fat diet-induced hepatic steatosis and adipose tissue inflammation in preexisting obese mice

AIMS

The therapeutic effects of spermidine on preexisting obese mice have been not fully elucidated. In this study, we assessed the anti-obesity impact of spermidine on high-fat diet (HFD)-induced obese mice.

MAIN METHODS

C57BL/6J mice were fed a HFD for 16 weeks to induce obesity, and then treated with or without spermidine via drinking water for additional 8 weeks. The contributions of spermidine in regulating obesity phenotypes and metabolic syndrome were further evaluated.

KEY FINDINGS

Spermidine administration lowered fat mass and plasma lipid profile in HFD-induced obese mice without affecting body weight. In addition, spermidine attenuated hepatic steatosis by regulating lipid metabolism and enhancing antioxidant capacity. Moreover, spermidine reduced adipose tissue inflammation by decreasing inflammatory cytokine and chemokines expression, and these results might contributed to the enhanced thermogenic gene expression in brown adipose tissue. Furthermore, spermidine treatment enhanced gut barrier function by up-regulating tight junction- and mucin-related gene expression.

SIGNIFICANCE

Spermidine-mediated protective impacts involve the regulation of lipid metabolism, inflammation response, gut barrier function and thermogenesis. These findings demonstrate that spermidine has potentials in treating obesity.

Direct and indirect modulation of LPS-induced cytokine production by insulin in human macrophages

Overweight and obesity are accompanied by insulin resistance, impaired intestinal barrier function resulting in increased lipopolysaccharide (LPS) levels, and a low-grade chronic inflammation that results in macrophage activation. Macrophages produce a range of interleukins as well as prostaglandin E₂ (PGE₂). To cope with insulin resistance, hyperinsulinemia develops. The purpose of the study was to elucidate how LPS, insulin and PGE₂ might interact to modulate the inflammatory response in macrophages. Human macrophages were either derived by differentiation from U937 cells or isolated from blood mononuclear cells. The macrophages were stimulated with LPS, insulin and PGE₂. Insulin significantly enhanced the LPS-dependent expression of interleukin-1β and interleukin-8 on both the mRNA and protein levels. Additionally, insulin increased the LPS-dependent induction of enzymes involved in the PGE₂-synthesis and the production of PGE₂ by macrophages. PGE₂ in turn further enhanced the LPS-dependent expression of cytokines via its G_s-coupled receptors EP2 and EP4, the latter of which appeared to be more relevant. The combination of all three stimuli resulted in an even higher induction than the combination of LPS plus insulin or LPS plus PGE₂. Thus, the compensatory hyperinsulinemia might directly and indirectly enhance the LPS-dependent cytokine production in obese individuals.

Evaluation of the Probiotic Properties and the Capacity to Form Biofilms of Various Lactobacillus Strains

Over the last 20 years, Lactobacillus species inhabiting the gastrointestinal tract (GIT) have received much attention, and their health-promoting properties are now well-described. Probiotic effects cannot be generalized, and their uses cover a wide range of applications. It is thus important to proceed to an accurate selection and evaluation of probiotic candidates. We evaluate the probiotic potential of six strains of Lactobacillus in different in vitro models representing critical factors of either survival, efficacy, or both. We characterized the strains for their ability to (i) modulate intestinal permeability using transepithelial electrical resistance (TEER), (ii) form biofilms and resist stressful conditions, and (iii) produce beneficial host and/or bacteria metabolites. Our data reveal the specificity of Lactobacillus strains to modulate intestinal permeability depending on the cell type. The six isolates were able to form spatially organized biofilms, and we provide evidence that the biofilm form is beneficial in a strongly acidic environment. Finally, we demonstrated the ability of the strains to produce γ-aminobutyric acid (GABA) that is involved in the gut-brain axis and beneficial enzymes that promote the bacterial tolerance to bile salts. Overall, our study highlights the specific properties of Lactobacillus strains and their possible applications as biofilms.

Role of ROCK/NF‑κB/AQP8 signaling in ethanol‑induced intestinal epithelial barrier dysfunction

The present study aimed to investigate the signaling pathways and the underlying molecular mechanisms involved in ethanol-induced intestinal epithelial barrier (IEB) dysfunction. Therefore, an in vitro experimental model of IEB was established using an ethanol-treated Caco-2 intestinal epithelial cell monolayer. The results confirmed that Rho-associated kinases (ROCKs), namely ROCK1 and ROCK2, were involved in the underlying pathway of ethanol-induced IEB dysfunction. Ethanol exposure significantly increased the expression of both ROCK isoforms and the activity of nuclear factor κB (NF-κB). Furthermore, ROCK1- and ROCK2-specific small interfering RNAs (siRNAs), and the NF-κB inhibitor ammonium pyrrolidine dithiocarbamate partially inhibited transepithelial electrical resistance in Caco-2 cells in an in vitro IEB model. In addition, ROCK1- and ROCK2-specific siRNAs inhibited the activity of NF-κB, thereby downregulating the expression of aquaporin 8 (AQP8). Taken together, the results of the present study suggested that ROCK1/ROCK2-mediated activation of NF-κB and upregulation of AQP8 expression levels may represent a novel mechanism of ethanol-induced impairment of IEB function.

Trained Immunity: Linking Obesity and Cardiovascular Disease across the Life-Course?

Obesity, a chronic inflammatory disease, is the most prevalent modifiable risk factor for cardiovascular disease. The mechanisms underlying inflammation in obesity are incompletely understood. Recent developments have challenged the dogma of immunological memory occurring exclusively in the adaptive immune system and show that the innate immune system has potential to be reprogrammed. This innate immune memory (trained immunity) is characterized by epigenetic and metabolic reprogramming of myeloid cells following endogenous or exogenous stimulation, resulting in enhanced inflammation to subsequent stimuli. Trained immunity phenotypes have now been reported for other immune and non-immune cells. Here, we provide a novel perspective on the putative role of trained immunity in mediating the adverse cardiovascular effects of obesity and highlight potential translational pathways.

Effect of probiotics on obesity-related markers per enterotype: a double-blind, placebo-controlled, randomized clinical trial

Background

Prevention and improvement of disease symptoms are important issues, and probiotics are suggested as a good treatment for controlling the obesity. Human gut microbiota has different community structures. Because gut microbial composition is assumed to be linked to probiotic function, this study evaluated the efficacy of probiotics on obesity-related clinical markers according to gut microbial enterotype.

Methods

Fifty subjects with body mass index over 25 kg/m² were randomly assigned to either the probiotic or placebo group. Each group received either unlabeled placebo or probiotic capsules for 12 weeks. Body weight, waist circumference, and body composition were measured every 3 weeks. Using computed tomography, total abdominal fat area and visceral fat area were measured. Blood and fecal samples were collected before and after the intervention for biochemical parameters and gut microbial compositions analysis.

Results

Gut microbial compositions of all the subjects were classified into two enterotypes according to Prevotella/Bacteroides ratio. The fat percentage, blood glucose, and insulin significantly increased in the Prevotella-rich enterotype of the placebo group. The obesity-related markers, such as waist circumference, total fat area, visceral fat, and ratio of visceral to subcutaneous fat area, were significantly reduced in the probiotic group. The decrease of obesity-related markers was greater in the Prevotella-rich enterotype than in the Bacteroides-rich enterotype.

Conclusion

Administration of probiotics improved obesity-related markers in obese people, and the efficacy of probiotics differed per gut microbial enterotype and greater responses were observed in the Prevotella-dominant enterotype.

miRNA-Gene Regulatory Network in Gnotobiotic Mice Stimulated by Dysbiotic Gut Microbiota Transplanted From a Genetically Obese Child

Gut microbiota (GM) dysbiosis has been considered a pathogenic origin of many chronic diseases. In our previous trial, a shift in GM structure caused by a complex fiber-rich diet was associated with the health improvement of obese Prader-Willi syndrome (PWS) children. The pre- and post-intervention GMs (pre- and post-group, respectively) from one child were then transplanted into gnotobiotic mice, which resulted in significantly different physiological phenotypes, each of which was similar to the phenotype of the corresponding GM donor. This study was designed to investigate the miRNA-gene regulatory networks involved in causing these phenotypic differences. Using the post-group as a reference, we systematically identified and annotated the differentially expressed (DE) miRNAs and genes in the colon and liver of the pre-group in the second and fourth weeks after GM inoculation. Most of the significantly enriched GO terms and KEGG pathways were observed in the liver and were in the second week after GM transplantation. We screened 23 key genes along with their 73 miRNA regulators relevant to the host phenotype changes and constructed a network. The network contained 92 miRNA-gene regulation relationships, 51 of which were positive, and 41 of which were negative. Both the colon and liver had upregulated pro-inflammatory genes, and genes involved in fatty acid oxidation, lipolysis, and plasma cholesterol clearance were downregulated in only the liver. These changes were consistent with lipid and cholesterol accumulation in the host and with a high inflammation level. In addition, the colon showed an impacted glucagon-like peptide 1 (GLP-1) signaling pathway, while the liver displayed decreased insulin receptor signaling pathway activity. These molecular changes were mainly found in the second week, 2 weeks before changes in body fat occurred. This time lag indicated that GM dysbiosis might initially induce cholesterol and lipid metabolism-related miRNA and gene expression disorder and then lead to lipid accumulation and obesity development, which implicates a causative role of GM dysbiosis in obesity development rather than a result of obesity. This study provides fundamental molecular information that elucidates how dysbiotic GM increases host inflammation and disturbs host lipid and glucose metabolism.