Immuno-microbiota cross and talk: the new paradigm of metabolic diseases

Role of lifestyle and glucagon-like peptide-1 receptor agonists for weight loss in obesity, type 2 diabetes and steatotic liver diseases

BACKGROUND

The current obesity pandemic has given rise to associated comorbidities and complications, including type 2 diabetes and metabolic dysfunction-associated steatotic liver disease (MASLD). During the last decade, certain glucagon-like peptide 1 receptor agonists (GLP-1RA), originally developed as antihyperglycemic drugs, also demonstrated efficacy for weight loss.

AIMS

To review shared pathophysiologic features of common metabolic diseases and compare therapeutic strategies to reduce body weight and related complications.

METHODS

We performed an extensive literature research to describe the effects of lifestyle modification, first-generation anti-obesity drugs, and GLP-1RA on weight loss in humans with obesity, type 2 diabetes and MASLD.

RESULTS

Until recently, treatment of obesity has been limited to lifestyle modification, which offer moderate degree and sustainability of weight loss. The few approved first-generation anti-obesity drugs are either limited to short term use or to certain forms of obesity. Some GLP-1RA significantly decrease caloric intake and body weight. Liraglutide and semaglutide have therefore been approved for treating people with obesity. They also lead to a reduction of hepatic fat content and inflammation in people with biopsy-confirmed MASLD. Possible limitations comprise adverse effects, treatment adherence and persistence.

CONCLUSION

Certain GLP-1RA are superior to lifestyle modification and first-generation anti-obesity drugs in inducing weight loss. They have therefore markedly changed the portfolio of obesity treatment with additional beneficial effects on steatotic liver disease.

Eating away cancer: the potential of diet and the microbiome for shaping immunotherapy outcome

The gut microbiome (GMB) plays a substantial role in human health and disease. From affecting gut barrier integrity to promoting immune cell differentiation, the GMB is capable of shaping host immunity and thus oncogenesis and anti-cancer therapeutic response, particularly with immunotherapy. Dietary patterns and components are key determinants of GMB composition, supporting the investigation of the diet-microbiome-immunity axis as a potential avenue to enhance immunotherapy response in cancer patients. As such, this review will discuss the role of the GMB and diet on anti-cancer immunity. We demonstrate that diet affects anti-cancer immunity through both GMB-independent and GMB-mediated mechanisms, and that different diet patterns mold the GMB's functional and taxonomic composition in distinctive ways. Dietary modulation therefore shows promise as an intervention for improving cancer outcome; however, further and more extensive research in human cancer populations is needed.

Clostridium butyricum inhibits the inflammation in children with primary nephrotic syndrome by regulating Th17/Tregs balance via gut-kidney axis

BACKGROUND

Primary nephrotic syndrome (PNS) is a common glomerular disease in children. Clostridium butyricum (C. butyricum), a probiotic producing butyric acid, exerts effective in regulating inflammation. This study was designed to elucidate the effect of C. butyricum on PNS inflammation through the gut-kidney axis.

METHOD

BALB/c mice were randomly divided into 4 groups: normal control group (CON), C. butyricum control group (CON+C. butyricum), PNS model group (PNS), and PNS with C. butyricum group (PNS+C. butyricum). The PNS model was established by a single injection of doxorubicin hydrochloride (DOX) through the tail vein. After 1 week of modeling, the mice were treated with C. butyricum for 6 weeks. At the end of the experiment, the mice were euthanized and associated indications were investigated.

RESULTS

Since the successful modeling of the PNS, the 24 h urine protein, blood urea nitrogen (BUN), serum creatinine (SCr), urine urea nitrogen (UUN), urine creatinine (UCr), lipopolysaccharides (LPS), pro-inflammatory interleukin (IL)-6, IL-17A were increased, the kidney pathological damage was aggravated, while a reduction of body weights of the mice and the anti-inflammatory IL-10 significantly reduced. However, these abnormalities could be dramatically reversed by C. butyricum treatment. The crucial Th17/Tregs axis in PNS inflammation also was proved to be effectively regulated by C. butyricum treatment. This probiotic intervention notably affected the expression levels of signal transducer and activator of transcription 3 (STAT3), Heme oxygenase-1 (HO-1) protein, and retinoic acid-related orphan receptor gamma t (RORγt). 16S rRNA sequencing showed that C. butyricum could regulate the composition of the intestinal microbial community and found Proteobacteria was more abundant in urine microorganisms in mice with PNS. Short-chain fatty acids (SCFAs) were measured and showed that C. butyricum treatment increased the contents of acetic acid, propionic acid, butyric acid in feces, acetic acid, and valeric acid in urine. Correlation analysis showed that there was a closely complicated correlation among inflammatory indicators, metabolic indicators, microbiota, and associated metabolic SCFAs in the gut-kidney axis.

CONCLUSION

C. butyricum regulates Th17/Tregs balance via the gut-kidney axis to suppress the immune inflammatory response in mice with PNS, which may potentially contribute to a safe and inexpensive therapeutic agent for PNS.

Analysis of immunohistomorphological changes in the colonic mucosa in a high-saturated fat and high-cholesterol fed streptozotocin/nicotinamide diabetic rat model

The mucosal surface of gastrointestinal tract is lined with epithelial cells that establish an effective barrier between the lumen and internal environment through intercellular junctions, preventing the passage of potentially harmful substances. The "intestinal barrier function" consist of a defensive system that prevent the passage of antigens, toxins, and microbial products, while maintains the correct development of the epithelial barrier, the immune system and the acquisition of tolerance toward dietary antigens and intestinal microbiota. Intestinal morphology changes subsequent to nutritional variations, stress, aging or diseases, which can also affect the composition of the microbiota, altering the homeostasis of the intestine. A growing body of evidence suggests that alterations in intestinal barrier function favor the development of exaggerated immune responses, leading to metabolic endotoxemia, which seems to be the origin of many chronic metabolic diseases such as type 2 diabetes mellitus (T2DM). Although the mechanisms are still unknown, the interaction between dietary patterns, gut microbiota, intestinal mucosa, and metabolic inflammation seems to be a key factor for the development of T2DM, among other diseases. This chapter details the different techniques that allow evaluating the morphological and molecular alterations that lead of the intestinal barrier dysfunction in a T2DM experimental model. To induce both diabetic metabolic disturbances and gut barrier disruption, Wistar rats were fed a high-saturated fat and high-cholesterol diet and received a single dose of streptozotocin/nicotinamide. This animal model may contribute to clarify the understanding of the role of intestinal barrier dysfunction on the late-stage T2DM etiology.

Microbial-Based Bioactive Compounds to Alleviate Inflammation in Obesity

The increased prevalence of obesity with several other metabolic disorders, including diabetes and non-alcoholic fatty liver disease, has reached global pandemic proportions. Lifestyle changes may result in a persistent positive energy balance, hastening the onset of these age-related disorders and consequently leading to a diminished lifespan. Although suggestions have been raised on the possible link between obesity and the gut microbiota, progress has been hampered due to the extensive diversity and complexities of the gut microbiota. Being recognized as a potential biomarker owing to its pivotal role in metabolic activities, the dysregulation of the gut microbiota can give rise to a persistent low-grade inflammatory state associated with chronic diseases during aging. This chronic inflammatory state, also known as inflammaging, induced by the chronic activation of the innate immune system via the macrophage, is controlled by the gut microbiota, which links nutrition, metabolism, and the innate immune response. Here, we present the functional roles of prebiotics, probiotics, synbiotics, and postbiotics as bioactive compounds by underscoring their putative contributions to (1) the reduction in gut hyperpermeability due to lipopolysaccharide (LPS) inactivation, (2) increased intestinal barrier function as a consequence of the upregulation of tight junction proteins, and (3) inhibition of proinflammatory pathways, overall leading to the alleviation of chronic inflammation in the management of obesity.

Resolution of inflammation in chronic disease via restoration of the heat shock response (HSR)

Effective resolution of inflammation via the heat shock response (HSR) is pivotal in averting the transition to chronic inflammatory states. This transition characterizes a spectrum of debilitating conditions, including insulin resistance, obesity, type 2 diabetes, nonalcoholic fatty liver disease, and cardiovascular ailments. This manuscript explores a range of physiological, pharmacological, and nutraceutical interventions aimed at reinstating the HSR in the context of chronic low-grade inflammation, as well as protocols to assess the HSR. Monitoring the progression or suppression of the HSR in patients and laboratory animals offers predictive insights into the organism's capacity to combat chronic inflammation, as well as the impact of exercise and hyperthermic treatments (e.g., sauna or hot tub baths) on the HSR. Interestingly, a reciprocal correlation exists between the expression of HSR components in peripheral blood leukocytes (PBL) and the extent of local tissue proinflammatory activity in individuals afflicted by chronic inflammatory disorders. Therefore, the Heck index, contrasting extracellular 70 kDa family of heat shock proteins (HSP70) (proinflammatory) and intracellular HSP70 (anti-inflammatory) in PBL, serves as a valuable metric for HSR assessment. Our laboratory has also developed straightforward protocols for evaluating HSR by subjecting whole blood samples from both rodents and human volunteers to ex vivo heat challenges. Collectively, this discussion underscores the critical role of HSR disruption in the pathogenesis of chronic inflammatory states and emphasizes the significance of simple, cost-effective tools for clinical HSR assessment. This understanding is instrumental in the development of innovative strategies for preventing and managing chronic inflammatory diseases, which continue to exert a substantial global burden on morbidity and mortality.

Postoperative Purulent Chondritis of Thyroid Cartilage in a Diabetic Patient: A Case Report

Purulent chondritis of the thyroid cartilage is a rare affliction that is not frequently observed in patients undergoing laryngeal surgery. The formation of abscesses between the inner and outer perichondria can cause constriction of the laryngeal lumen, leading to hoarseness and difficulty breathing. This report details the case of a middle-aged diabetic woman who experienced swelling in the tissue of her laryngeal cavity and destruction of her thyroid cartilage plate after undergoing laryngectomy. The pathological examination revealed evidence of inflammation, and the patient was ultimately diagnosed with purulent chondritis of the thyroid cartilage.

Insights on the role of anti-inflammatory and immunosuppressive agents in the amelioration of diabetes

Diabetes is a major health problem worldwide. It is a chronic metabolic disorder that produces overt hyperglycemic condition that occurs either when the pancreas does not produce enough insulin due to excessive destruction of pancreatic β-cells (type 1 diabetes) or due to development of insulin resistance (type 2 diabetes). An autoimmune condition known as type 1 diabetes (T1D) results in the targeted immune death of β-cells that produce insulin. The only available treatment for T1D at the moment is the lifelong use of insulin. Multiple islet autoantibody positivity is used to diagnose T1D. There are four standard autoantibodies observed whose presence shows the development of T1D: antibodies against insulin, glutamic acid decarboxylase (GAD65), zinc T8 transporter (ZnT8), and tyrosine phosphatase-like protein (ICA512). In type 2 diabetes (T2D), an inflammatory response precipitates as a consequence of the immune response to high blood glucose level along with the presence of inflammation mediators produced by macrophages and adipocytes in fat tissue. The slow and chronic inflammatory condition of adipose tissue produces insulin resistance leading to increased stress on pancreatic β-cells to produce more insulin to compensate for the insulin resistance. Thus, this stress condition exacerbates the apoptosis of β-cells leading to insufficient production of insulin, resulting in hyperglycemia which signifies late stage T2D. Therefore, the therapeutic utilization of immunosuppressive agents may be a better alternative over the use of insulin and oral hypoglycemic agents for the treatment of T1D and T2D, respectively. This review enlightens the immune intervention for the prevention and amelioration of T1D and T2D in humans with main focus on the antigen-specific immune suppressive therapy.

Past and present: a bibliometric study on polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disease that has a great impact on women's physical and mental health. It is a burden to social and patients' economy. In recent years, researchers' understanding of PCOS has reached a new level. However, many PCOS reports have different directions, and overlapping phenomena exist. Therefore, clarifying the research status of PCOS is important. This study aims to summarise the research status of PCOS and predict the hot spots of PCOS in the future by Bibliometricx.

RESULTS

The keywords of PCOS research focused on PCOS, insulin resistance (IR), obesity and metformin. Keywords plus co-occurrence network showed that PCOS, IR and prevalence were hot spots in the recent 10 years. Moreover, we found that gut microbiota may be a carrier that can be used to study hormone levels, IR-related mechanisms, prevention and treatment in the future.

CONCLUSIONS

This study is helpful for researchers to quickly grasp the current situation of PCOS research and enlighten researchers to explore new problems in PCOS.

Alterations in Gut Microbiota Composition in Patients with COVID-19: A Pilot Study of Whole Hypervariable 16S rRNA Gene Sequencing

It is crucial to consider the importance of the microbiome and the gut-lung axis in the context of SARS-CoV-2 infection. This pilot study examined the fecal microbial composition of patients with COVID-19 following a 3-month recovery. Using for the first time metagenomic analysis based on all hypervariable regions (V1-V9) of the 16S rRNA gene, we have identified 561 microbial species; however, 17 were specific only for the COVID-19 group (n = 8). The patients' cohorts revealed significantly greater alpha diversity of the gut microbiota compared to healthy controls (n = 14). This finding has been demonstrated by operational taxonomic units (OTUs) richness (p < 0.001) and Chao1 index (p < 0.01). The abundance of the phylum Verrucomicrobia was 30 times higher in COVID-19 patients compared to healthy subjects. Accordingly, this disproportion was also noted at other taxonomic levels: in the class Verrucomicrobiae, the family Verrucomicrobiaceae, and the genus Akkermansia. Elevated pathobionts such as Escherichia coli, Bilophila wadsworthia, and Parabacteroides distasonis were found in COVID-19 patients. Considering the gut microbiota's ability to disturb the immune response, our findings suggest the importance of the enteric microbiota in the course of SARS-CoV-2 infection. This pilot study shows that the composition of the microbial community may not be fully restored in individuals with SARS-CoV-2 following a 3-month recovery.

F-53B induces hepatotoxic effects and slows self-healing in ulcerative colitis in mice

Chlorinated polyfluorinated ether sulfonate (F-53 B) is a distinct substitute for perfluorooctane sulphonate. It has been reported to be biologically toxic to mammals, causing enteric toxicity, liver toxicity and neurotoxicity. However, studies about the effects of F-53 B on patients with gastrointestinal diseases such as inflammatory bowel disease are very limited. In this study, whether the toxic impacts of F-53 B on the gut and liver can be exacerbated in mice with colitis was explored. The sensitivity of mice with acute colitis caused by dextran sulfate sodium salt (DSS) to F-53 B was compared with that of healthy mice. The mice were administered water containing F-53 B at doses of 10 and 100 μg/L sequentially for two weeks, respectively. F-53 B exposure exacerbated DSS-induced colonic inflammation, including inducing shortening of colon length, inflammatory cell infiltration and more severe histopathological symptoms. In addition, F-53 B administration significantly increased the levels of inflammatory cytokines, including interleukin (IL)-1, IL-6 and tumour necrosis factor-α, in the plasma of mice with enteritis compared with control group. F-53 B impaired intestinal integrity of mice with colitis by downregulating Claudin-1 and antimicrobial peptide-related genes while elevating serum lipopolysaccharide levels. In addition, in mice with colitis, F-53 B increased the levels of serum total cholesterol, triglyceride, low-density lipoprotein cholesterol, aspartate aminotransferase, and alanine aminotransferase, resulted in more severe liver inflammation and increased the level of genes related to the Gasdermin D-mediated pyrolysis. Conclusively, our results indicated that F-53 B delayed the self-healing of ulcerative colitis (UC) and caused liver inflammation in mice. This study provided some new insights into the health risks of F-53 B and raises concerns about the health of individuals with UC.

Polystyrene microplastics aggravate inflammatory damage in mice with intestinal immune imbalance

Microplastics (MPs) have been detected in drinking water, seafood, and commodities relevant to human daily life, causing widespread concern. Although there have been studies on the health risks of MPs to mammals, the impact of MPs on populations with intestinal immune imbalance has been greatly ignored. The vulnerability of the body with intestinal immune imbalance may increase the likelihood of its response to MPs, which is in urgent need of relevant research. Here, we compared the effects of 500 μg/L polystyrene microplastics (PSMPs) on healthy mice and mice with intestinal immune imbalance through colon photographs, histopathological analysis, expression of inflammatory cytokines, PSMPs distribution, microbial community analysis, and metabolomics analysis. The results demonstrated that intestinal immune imbalance aggravated the colonic response to PSMPs. PSMPs exposure significantly increased the expression of inflammation factors (TNF-α, IL-1β and IFN-γ) in mice with intestinal immune imbalance. In addition, the exposure of PSMPs aggravated the histopathological damage of colonic mucosa in mice with intestinal immune imbalance, and exerted great disturbance on the colonic microbial community and metabolism. This may be due to the significant increase of PSMPs accumulation owing to the damage of intestinal barrier in mice with intestinal immune imbalance. In addition, the increase of several pathogenic bacteria including Bacteroides caused by intestinal immune imbalance also increased the toxicity of PSMPs. Our results highlight that individual with intestinal immune imbalance could be more sensitive to environmental pollution, which should be considered during health risk assessment.

Whole grain germinated brown rice regulates intestinal immune homeostasis and gastrointestinal hormones in type 2 diabetic patients-a randomized control trial

Background: Whole grains present distinguished benefits to a handful of metabolic syndromes (MetS). However, the preventive effects of germinated brown rice (GBR), a new type of brown rice, on patients with type 2 diabetes (T2DM) are rarely reported. Objectives: To investigate whether replacing 100 g refined white rice (RWR) with equal GBR per day is effective in T2DM and its underlying mechanisms. Methods: Ninety-nine qualified T2DM patients (64.58 ± 5.06 years old) were recruited. All patients were randomly divided into GBR group (100 g d^-1 GBR for 12 weeks) and control group (keep the regular diet). Food frequency questionnaires, and fresh stool and serum samples were collected before and after the intervention, followed by various measurements. Results: Fasting blood glucose was obviously decreased after GBR intervention with an effective rate of 62%. Glycated hemoglobin (HbA1c) levels were decreased in the GBR group with no significance. In the GBR group, the abundance of beneficial bacteria in feces was increased, while harmful bacteria were decreased. The percentage of Bacteroides (57.2%) was largely increased. In addition, three types of short-chain fatty acids (SCFAs) including acetic acid, propanoic acid, and butyric acid were increased significantly by GBR (p < 0.05). The secretion of GLP and PYY in serum, two kinds of gastrointestinal hormones downstream of SCFAs, was stimulated by GBR (p < 0.01). Meanwhile, GBR intervention could balance the ratio of Treg/Th17 immune cells in PBMCs and reduce the levels of inflammatory factors including IL-6, IL-8, and LPS in serum, which improved the permeability of intestinal mucosa. Conclusions: GBR (100 g d^-1 for 12 weeks) has positive improvement in the fasting blood glucose for T2DM patients, which attributed to the recovery of intestinal homeostasis.

Fenofibrate Ameliorated Systemic and Retinal Inflammation and Modulated Gut Microbiota in High-Fat Diet-Induced Mice

Fenofibrate, as a lipid-lowering drug, has been reported to have a protective effect on the retina independent with plasma lipid levels. This study aimed to investigate that the ameliorative effects of fenofibrate on systemic and retinal inflammation, as well as gut microbiota dysbiosis in high-fat diet (HFD)-induced mice. C57BL/6J mice were randomly allocated into four groups: standard diet (SD) group; HFD group; SD plus fenofibrate (SD_ Fe) group; HFD plus fenofibrate (HFD_ Fe) group. After successfully establishing models (5 months), indicators associated with lipid, gut barrier, inflammation and gut microbiota were investigated. Our results showed that supplementing the HFD with fenofibrate decreased body weight gain, alleviated dyslipidemia and reversed the downregulation of short-chain fatty acid (SCFAs) in serum, retina and feces. Fenofibrate ameliorated intestinal barrier function damage in HFD-induced mice. Fenofibrate coadministration inhibited the levels of inflammatory factor and lipopolysaccharide (LPS) in the serum and attenuated inflammatory response in the retina of HFD-induced mice. Systemic LPS was positively correlated with a series of inflammatory factors in serum and retina, respectively. Fenofibrate supplementation down-regulated the abundances of LPS-associated bacteria in HFD mice, including Firmicutes and Proteobacteria at the phylum level, Desulfovibrionaceae at the family level, as well as unclassified_ Desulfovibrionaceae, Acetatifactor, Flavonifractor, Oscillibacter and Anaerotruncus at the genus level. However, fenofibrate treatment up-regulated the abundances of SCFA-associated bacteria in HFD mice, including Bacteroidetes at the phylum level, Porphyromonadaceae at the family level, as well as unclassified_Porphyromonadaceae, Barnesiella, Alloprevotella and Bifidobacterium at the genus level. In conclusion, our results confirmed fenofibrate could attenuate HFD-induced systemic and retinal inflammation, accompanying with restoration of intestinal barrier damage and modulation of gut microbiota/metabolites. This work provided an explanation for the ameliorative effects of fenofibrate on HFD-induced systemic and retinal inflammation might be partially related with the modulation of gut microbiota and its metabolites.

Fecal extract from obese horses induces an inflammatory response by murine macrophages in vitro

OBJECTIVE

To compare the inflammatory response of murine macrophages exposed to the enteric microbiome of obese horses versus nonobese horses.

SAMPLE

Fecal samples from 12 obese horses (body condition score ≥ 7/9) and 12 nonobese horses (body condition score 4 to 5/9) with similar dietary management.

PROCEDURES

Fecal supernatant was prepared from frozen fecal samples. RAW 264.7 macrophage cells were exposed to the fecal extract. Inflammatory cytokine (interleukin-1β, tumor necrosis factor-α, and interleukin-6) gene expression was quantified via real-time quantitative reverse transcription PCR assay, and cytokine concentration was quantified via ELISA. Lipopolysaccharide was evaluated in fecal extract via chromo-limulus amoebocyte lysate assay.

RESULTS

Compared with fecal extracts from nonobese horses, fecal extracts from obese horses presented higher concentrations of lipopolysaccharide and induced a heightened expression of the proinflammatory cytokines interleukin-1β, tumor necrosis factor-α, and interleukin-6 from macrophages.

CLINICAL RELEVANCE

The increased levels of inflammatory markers induced in murine macrophages by the microbiome of obese horses in vitro suggested important differences in the enteric microbial composition of these horses, compared with nonobese horses. Overall, this study showed that the microbiome may play a role in mediating an inflammatory response within the gastrointestinal tract of obese horses. Mechanisms of obesity in the horse have not been fully elucidated. Improved understanding of the pathophysiology of disease will guide future research into potential diagnostic and therapeutic interventions for equine obesity.

The rationale and design of a Mediterranean diet accompanied by time restricted feeding to optimise the management of type 2 diabetes: The MedDietFast randomised controlled trial

BACKGROUND AND AIMS

Substantial scientific evidence supports the effectiveness of a Mediterranean diet (MedDiet) in managing type 2 diabetes mellitus (T2DM). Potential benefits of time restricted feeding (TRF) in T2DM are unknown. The MedDietFast trial aims to investigate the efficacy of a MedDiet with or without TRF compared to standard care diet in managing T2DM.

METHODS AND RESULTS

120 adults aged 20-75 with a body mass index (BMI) of 20-35 kg/m² and T2DM will be randomised in a 3-arm parallel design to follow an ad libitum MedDiet with or without 12-h TRF or the standard Australian Dietary Guidelines (ADG) for 24 weeks. All groups will receive dietary counselling fortnightly for 12 weeks and monthly thereafter. The primary outcome is changes in HbA1c from baseline to 12 and 24 weeks. Secondary outcomes include fasting blood glucose, insulin, blood lipids, weight loss, insulin resistance index (HOMA), Glucagon-like peptide 1 (GLP-1) and high-sensitivity C- reactive protein (hs-CRP). Data on medical history, anthropometry, wellbeing, MedDiet adherence and satiety will be measured at a private clinic via self-report questionnaires at baseline, 6, 12 and 24 weeks. Additionally, specimens (blood, urine and stool) will be collected at all time points for future omics analysis.

CONCLUSION

The MedDietFast trial will examine the feasibility and effectiveness of a MedDiet with/without TRF in T2DM patients. Potential synergistic effects of a MedDiet with TRF will be evaluated. Future studies will generate microbiomic and metabolomic data for translation of findings into simple and effective management plans for T2DM patients.

TRIAL REGISTRATION

Australia and New Zealand Clinical Trials Register, ACTRN12619000246189.

Gut Microbiota Dysbiosis and COVID-19: Possible Links

Microbiota in the gastrointestinal system is a major determinant in health and disease status with its influence on immunity. Bidirectional relationship between gut microbiota and host immune system is well balanced in healthy individuals and a disruption (dysbiosis) can lead to gastrointestinal inflammations and metabolic disorders. Growing evidence support the cross-talk between gastrointestinal microbiota and lung that maintains host homeostasis and reduces the risk of disease development. The Gut-lung axis is possibly involved in the severity of COVID-19 with the association of dysbiosis. Targeted alterations in the gut microbiota could be considered to alleviate the disease severity.

The role of Wnt pathway in obesity induced inflammation and diabetes: a review

Diabetes has become a major killer worldwide and at present, millions are affected by it. Being a chronic disease it increases the risk of other diseases ranging from pulmonary disorders to soft tissue infections. The loss of insulin-producing capacity of the pancreatic β-cells is the main reason for the development of the disease. Obesity is a major complication that can give rise to several other diseases such as cancer, diabetes, etc. Visceral adiposity is one of the major factors that play a role in the development of insulin resistance. Obesity causes a chronic low-grade inflammation in the tissues that further increases the chances of developing diabetes. Several pathways have been associated with the development of diabetes due to inflammation caused by obesity. The Wnt pathway is one such candidate pathway that is found to have a controlling effect on the development of insulin resistance. Moreover, the pathway has also been linked to obesity and inflammation. This review aims to find a connection between obesity, inflammation, and diabetes by taking the wnt pathway as the connecting link.

Chitosan-chelated zinc modulates ileal microbiota, ileal microbial metabolites, and intestinal function in weaned piglets challenged with Escherichia coli K88

This study was to investigate the effects of chitosan-chelated zinc on ileal microbiota, inflammatory response, and barrier function in weaned piglets challenged with Escherichia coli K88. Piglets of the chitosan-chelated zinc treatment (Cs-Zn; 100 mg zinc + 766 mg chitosan/kg basal diet, from chitosan-chelated zinc) and the chitosan treatment (CS, 766 mg chitosan/kg basal diet) had significantly increased ileal villus height and the ratio of villi height to crypt depth. CS-Zn group piglets had a higher abundance of Lactobacillus in the ileal digesta, while the abundance of Streptococcus, Escherichia shigella, Actinobacillus, and Clostridium sensu stricto 6 was significantly decreased. The concentrations of propionate, butyrate, and lactate in the CS-Zn group piglets were significantly increased, while the pH value was significantly decreased. Furthermore, the concentrations of IL-1β, TNF-α, MPO, and INF-γ in the ileal mucosa of the CS-Zn and the H-ZnO group (pharmacological dose of 1600 mg Zn/kg basal diet, from ZnO) were significantly lower than those of the control group fed with basal diet, and the mRNA expression of TLR4, MyD88, and NF-κB of the CS-Zn group was also reduced. In addition, the mRNA expression of IGF-1 was increased, the protein expression of occludin and claudin-1 was enhanced, while the mRNA expression of caspase 3 and caspase 8 was decreased in the CS-Zn group. These results suggest CS-Zn treatment could help modulate the composition of ileal microbiota, attenuate inflammatory response, and maintain the intestinal function in weaned piglets challenged with Escherichia coli K88. KEY POINTS: • Chitosan-chelated zinc significantly modulated ileal microbiota. • Chitosan-chelated zinc can improve ileal health. • The ileal microbiota plays an important role in host health.

CX3CR1 regulates gut microbiota and metabolism. A risk factor of type 2 diabetes

OBJECTIVE

The intestinal microbiota to immune system crosstalk is a major regulator of metabolism and hence metabolic diseases. An impairment of the chemokine receptor CX3CR1, as a key regulator shaping intestinal microbiota under normal chow feeding, could be one of the early events of dysglycemia.

METHODS

We studied the gut microbiota ecology by sequencing the gut and tissue microbiota. We studied its role in energy metabolism in CX3CR1-deficent and control mice using various bioassays notably the glycemic regulation during fasting and the respiratory quotient as two highly sensitive physiological features. We used antibiotics and prebiotics treatments, and germ free mouse colonization.

RESULTS

We identify that CX3CR1 disruption impairs gut microbiota ecology and identified a specific signature associated to the genotype. The glycemic control during fasting and the respiratory quotient throughout the day are deeply impaired. A selected four-week prebiotic treatment modifies the dysbiotic microbiota and improves the fasting state glycemic control of the CX3CR1-deficent mice and following a glucose tolerance test. A 4 week antibiotic treatment also improves the glycemic control as well. Eventually, germ free mice colonized with the microbiota from CX3CR1-deficent mice developed glucose intolerance.

CONCLUSIONS

CX3CR1 is a molecular mechanism in the control of the gut microbiota ecology ensuring the maintenance of a steady glycemia and energy metabolism. Its impairment could be an early mechanism leading to gut microbiota dysbiosis and the onset of metabolic disease.

Gut Microbiota and Cardiovascular Diseases: A Critical Review

The human intestine contains the largest and most diverse ecosystem of microbes. The main function of the intestinal bacterial flora is to limit the growth of potentially pathogenic microorganisms. However, the intestinal microbiota is increasingly emerging as a risk factor for the development of cardiovascular disease (CVD). The gut microbiota-derived metabolites, such as short-chain fatty acids, trimethylamine-N-oxide, bile acids, and polyphenols play a pivotal role in maintaining healthy cardiovascular function, and when dysregulated, can potentially lead to CVD. In particular, changes in the composition and diversity of gut microbiota, known as dysbiosis, have been associated with atherosclerosis, hypertension, and heart failure. Nonetheless, the underlying mechanisms remain yet to be fully understood. Therefore, the microbiota and its metabolites have become a new therapeutic target for the prevention and treatment of CVD. In addition to a varied and balanced diet, the use of prebiotic and probiotic treatments or selective trimethylamine-N-oxide inhibitors could play a pivotal role in the prevention of CVD, especially in patients with a high metabolic risk.

Nutritional Modulation of the Microbiome and Immune Response

The evolution of the immune system, diet, and the microbiome are interconnected. Dietary metabolites modulate the cells of the immune system both directly and indirectly via shifts in the composition of the intestinal microbiota and its products. As a result, overconsumption and malnutrition can have substantial effects on immune responses and inflammation. In resource-rich nations, diets high in processed foods, fat, and sugar can contribute to chronic inflammatory conditions, which are on the rise worldwide. Conversely, in resource-poor countries, malnutrition associated with food insecurity can lead to immunodeficiencies and shifts in the microbiome that drive intestinal inflammation. Developing a deeper understanding of the relationship between diet, microbiota, and the immune system is of huge importance, given its impact on inflammatory diseases and its potential as an easily modifiable mediator of immunomodulation.

Periodontal Pathogens and Neuropsychiatric Health

Increasing evidence incriminates low-grade inflammation in cardiovascular, metabolic diseases, and neuropsychiatric clinical conditions, all important causes of morbidity and mortality. One of the upstream and modifiable precipitants and perpetrators of inflammation is chronic periodontitis, a polymicrobial infection with Porphyromonas gingivalis (P. gingivalis) playing a central role in the disease pathogenesis. We review the association between P. gingivalis and cardiovascular, metabolic, and neuropsychiatric illness, and the molecular mechanisms potentially implicated in immune upregulation as well as downregulation induced by the pathogen. In addition to inflammation, translocation of the pathogens to the coronary and peripheral arteries, including brain vasculature, and gut and liver vasculature has important pathophysiological consequences. Distant effects via translocation rely on virulence factors of P. gingivalis such as gingipains, on its synergistic interactions with other pathogens, and on its capability to manipulate the immune system via several mechanisms, including its capacity to induce production of immune-downregulating micro-RNAs. Possible targets for intervention and drug development to manage distal consequences of infection with P. gingivalis are also reviewed.

Marine Natural Products: Promising Candidates in the Modulation of Gut-Brain Axis towards Neuroprotection

In recent decades, several neuroprotective agents have been provided in combating neuronal dysfunctions; however, no effective treatment has been found towards the complete eradication of neurodegenerative diseases. From the pathophysiological point of view, growing studies are indicating a bidirectional relationship between gut and brain termed gut-brain axis in the context of health/disease. Revealing the gut-brain axis has survived new hopes in the prevention, management, and treatment of neurodegenerative diseases. Accordingly, introducing novel alternative therapies in regulating the gut-brain axis seems to be an emerging concept to pave the road in fighting neurodegenerative diseases. Growing studies have developed marine-derived natural products as hopeful candidates in a simultaneous targeting of gut-brain dysregulated mediators towards neuroprotection. Of marine natural products, carotenoids (e.g., fucoxanthin, and astaxanthin), phytosterols (e.g., fucosterol), polysaccharides (e.g., fucoidan, chitosan, alginate, and laminarin), macrolactins (e.g., macrolactin A), diterpenes (e.g., lobocrasol, excavatolide B, and crassumol E) and sesquiterpenes (e.g., zonarol) have shown to be promising candidates in modulating gut-brain axis. The aforementioned marine natural products are potential regulators of inflammatory, apoptotic, and oxidative stress mediators towards a bidirectional regulation of the gut-brain axis. The present study aims at describing the gut-brain axis, the importance of gut microbiota in neurological diseases, as well as the modulatory role of marine natural products towards neuroprotection.

Recognizing the Benefits of Pre-/Probiotics in Metabolic Syndrome and Type 2 Diabetes Mellitus Considering the Influence of Akkermansia muciniphila as a Key Gut Bacterium

Metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM) are diseases that can be influenced by the structure of gut microbiota, whose improvement is often neglected in metabolic pathology. This review highlights the following main aspects: the relationship between probiotics/gut microbes with the pathogenesis of MetS, the particular positive roles of Akkermansia muciniphila supplementation in the onset of MetS, and the interaction between dietary polyphenols (prebiotics) with gut microbiota. Therefore, an extensive and in-depth analysis of the often-neglected correlation between gut microbiota and chronic metabolic diseases was conducted, considering that this topic continues to fascinate and stimulate researchers through the discovery of novel strains and their beneficial properties.

Ubiquitin fold modifier 1 activates NF-κB pathway by down-regulating LZAP expression in the macrophage of diabetic mouse model

Inflammatory response is closely related with the development of many serious health problems worldwide including diabetes mellitus (DM). Ubiquitin-fold modifer 1 (Ufm1) is a newly discovered ubiquitin-like protein, while its function remains poorly investigated, especially in inflammatory response and DM. In the present study, we analyzed the role of Ufm1 on inflammatory response in DM, and found that the proinflammatory cytokine levels (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-1β) and Ufm1 expression were highly increased both in the peritoneal macrophages of db/db mice and Raw264.7 cells induced by lipopolysaccharide (LPS). Western blot and luciferase reporter assay showed that NF-κB pathway was obviously activated in macrophages and the expression of LZAP, an inhibitor of NF-κB pathway, was down-regulated. With the LZAP knockdown plasmid and activation plasmid, we demonstrated that NF-κB/p65 activation was inhibited by LZAP in macrophages. The interaction of Ufm1 and LZAP was further proved with co-immunoprecipitation assay in HEK293 and Raw264.7 cells. The LZAP expression was also related with the presence of Ufm1 demonstrated by Ufm1 knockdown plasmid and activation plasmid. Besides that, we finally proved that the expression and activation of Ufm1 induced by LPS were regulated by JNK/ATF2 and JNK/c-Jun pathway with the use of SP600125. In conclusion, the present study demonstrated that Ufm 1 could activate NF-κB pathway by down-regulating LZAP in macrophage of diabetes, and its expression and activation were regulated by JNK/ATF2 and c-Jun pathway.

The Gut Microbiome in Psychosis From Mice to Men: A Systematic Review of Preclinical and Clinical Studies

The gut microbiome is rapidly becoming the focus of interest as a possible factor involved in the pathophysiology of neuropsychiatric disorders. Recent understanding of the pathophysiology of schizophrenia emphasizes the role of systemic components, including immune/inflammatory and metabolic processes, which are influenced by and interacting with the gut microbiome. Here we systematically review the current literature on the gut microbiome in schizophrenia-spectrum disorders and in their animal models. We found that the gut microbiome is altered in psychosis compared to healthy controls. Furthermore, we identified potential factors related to psychosis, which may contribute to the gut microbiome alterations. However, further research is needed to establish the disease-specificity and potential causal relationships between changes of the microbiome and disease pathophysiology. This can open up the possibility of. manipulating the gut microbiome for improved symptom control and for the development of novel therapeutic approaches in schizophrenia and related psychotic disorders.

Gut-lung axis and dysbiosis in COVID-19

COVID-19, a novel infectious disease, caused by SARS-CoV-2, affected millions of people around the world with a high mortality rate. Although SARS-CoV-2 mainly causes lung infection, gastrointestinal symptoms described in COVID-19 patients and detection of the viral RNA in feces of infected patients drove attentions to a possible fecal-oral transmission route of SARS-CoV-2. However, not only the viral RNA but also the infectious viral particles are required for the viral infection and no proof has been demonstrated the transmission of the infectious virus particles via the fecal-oral route yet. Growing evidence indicates the crosstalk between gut microbiota and lung, that maintains host homeostasis and disease development with the association of immune system. This gut-lung interaction may influence the COVID-19 severity in patients with extrapulmonary conditions. Severity of COVID-19 has mostly associated with old ages and underlying medical conditions. Since the diversity in the gut microbiota decreases during aging, dysbiosis could be the reason for older adults being at high risk for severe illness from COVID-19. We believe that gut microbiota contributes to the course of COVID-19 due to its bidirectional relationship with immune system and lung. Dysbiosis in gut microbiota results in gut permeability leading to secondary infection and multiple organ failure. Conversely, disruption of the gut barrier integrity due to dysbiosis may lead to translocation of SARS-CoV-2 from the lung into the intestinal lumen via circulatory and lymphatic system. This review points out the role of dysbiosis of the gut microbiota involving in sepsis, on the severity of SARS-CoV-2 infection. Additionally, this review aims to clarify the ambiguity in fecal-oral transmission of SARS- CoV-2.

Lycopene Alleviates DSS-Induced Colitis and Behavioral Disorders via Mediating Microbes-Gut-Brain Axis Balance

Gut microbes play significant roles in colitis development. The current study was aimed to uncover the preventive effects of lycopene (LYC), a functional carotenoid component, on colitis and the accompanied behavior disorders. The current study demonstrated that LYC treatment (50 mg/kg body weight/day) for 40 days prevented the dextran sulfate sodium (DSS)-induced gut barrier damages and inflammatory responses in male mice. LYC improved DSS-induced depression and anxiety-like behavioral disorders by suppressing neuroinflammation and prevented synaptic ultrastructure damages by upregulating the expressions of neurotrophic factor and postsynaptic-density protein. Moreover, LYC reshaped the gut microbiome in colitis mice by decreasing the relative abundance of proteobacteria and increasing the relative abundance of Bifidobacterium and Lactobacillus. LYC also elevated the generation of short-chain fatty acids and inhibited the permeability of lipopolysaccharide in colitis mice. In conclusion, LYC ameliorate DSS-induced colitis and behavioral disorders via mediating microbes-gut-brain axis balance.

Is bariatric surgery resolving NAFLD via microbiota-mediated bile acid ratio reversal? A comprehensive review

Despite the fact that there is still insufficient evidence to consider non-alcoholic fatty liver disease (NAFLD) as an stand-alone indication for bariatric surgery, many clinical and histopathological beneficial effects on both NAFLD and non-alcoholic steatohepatitis (NASH) have been shown. Although weight loss seems to be the obvious mechanism, weight-loss independent factors are also believed to be involved. Among them, changes in gut microbiota and bile acids (BA) composition may be playing an unappreciated role in the improvement of NAFLD. In this review we examine the mechanisms and interdependence of the gut microbiota and BA, and their influence on NAFLD pathogenesis and its reversal following bariatric surgery. According to the currently available evidence, gut microbiota has a major influence on BA composition. In fact, both BA and microbiome disturbances (dysbiosis) play a role in the etiopathogenesis of NAFLD and might be potential therapeutic targets. In addition, bariatric surgery can modify the intraluminal ileal environment in a way that causes significant repopulation of the gut microbiota and a reversal of the plasma primary/secondary BA ratio, which, in turn, induces weigh-independent metabolic improvements.

Effects of Dietary Grape Seed Meal Bioactive Compounds on the Colonic Microbiota of Weaned Piglets With Dextran Sodium Sulfate-Induced Colitis Used as an Inflammatory Model

Microbiota affects host health and plays an important role in dysbiosis. The study examined the effect of diet including grape seed meal (GSM) with its mixture of bioactive compounds on the large intestine microbiota and short-chain fatty acid synthesis in weaned piglets treated with dextran sodium sulfate (DSS) as a model for inflammatory bowel diseases. Twenty-two piglets were included in four experimental groups based on their diet: control, DSS (1 g/kg/b.w.+control diet), GSM (8% grape seed meal inclusion in control diet), and DSS+GSM (1 g/kg/b.w., 8% grape seed meal in control diet). After 30 days, the colon content was isolated and used for microbiota sequencing on an Illumina MiSeq platform. QIIME 1.9.1 pipeline was used to process the raw sequences. Both GSM and DSS alone and in combination affected the diversity indices and Firmicutes:Bacteroidetes ratio, with significantly higher values in the DSS-afflicted piglets for Proteobacteria phylum, Roseburia, Megasphera and CF231 genus, and lower values for Lactobacillus. GSM with high-fiber, polyphenol and polyunsaturated fatty acid (PUFA) content increased the production of butyrate and isobutyrate, stimulated the growth of beneficial genera like Prevotella and Megasphaera, while countering the relative abundance of Roseburia, reducing it to half of the DSS value and contributing to the management of the DSS effects.

RNA N6-methyladenosine: a promising molecular target in metabolic diseases

N6-methyladenosine is a prevalent and abundant transcriptome modification, and its methylation regulates the various aspects of RNAs, including transcription, translation, processing and metabolism. The methylation of N6-methyladenosine is highly associated with numerous cellular processes, which plays important roles in the development of physiological process and diseases. The high prevalence of metabolic diseases poses a serious threat to human health, but its pathological mechanisms remain poorly understood. Recent studies have reported that the progression of metabolic diseases is closely related to the expression of RNA N6-methyladenosine modification. In this review, we aim to summarize the biological and clinical significance of RNA N6-methyladenosine modification in metabolic diseases, including obesity, type 2 diabetes, non-alcoholic fatty liver disease, hypertension, cardiovascular diseases, osteoporosis and immune-related metabolic diseases.

Dietary flaxseed oil rich in omega-3 suppresses severity of type 2 diabetes mellitus via anti-inflammation and modulating gut microbiota in rats

BACKGROUND

Type 2 diabetes mellitus (T2DM) is closely associated with hyperglycemia, abnormal lipid profiles, chronic low-grade inflammation and gut dysbiosis. Dietary intervention plays a crucial role in the control of diabetes. Flaxseed oil (FO), a plant-derived omega-3 (ω-3) polyunsaturated fatty acids (PUFAs), is rich in α-linolenic acid (ALA) which has been proved to benefit for chronic metabolic disease. However, the exact effects of dietary FO on T2DM remains largely unclear.

METHODS

In the present study, SD rats were randomly allocated into four groups: pair-fed (PF) with corn oil (CO) group (PF/CO); DM with CO group (DM/CO); PF with FO group (PF/FO); DM with FO group (DM/FO). A diabetic rat model was generated by a single intraperitoneal injection of streptozotocin-nicotinamide (STZ-NA). After 5 weeks of intervention, rats were euthanized and associated indications were investigated.

RESULTS

Dietary FO significantly reduced fasting blood glucose (FBG), glycated hemoglobin (GHb), blood lipid, plasma lipopolysaccharide (LPS), interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6, IL-17A and malondialdehyde (MDA), compared to control group, respectively. Moreover, body mass (BM) and superoxide dismutase (SOD) in DM/FO group were dramatically increased respectively, compared with those in DM/CO group. But insulin (INS) and homeostasis model assessment of insulin resistance (HOMA-IR) remained no significant difference between DM/CO group and DM/FO group. Sequencing analysis of gut microbiota showed a reduction in the relative abundance of Firmicutes and Blautia, as well as a reduction in the ratio of Bacteroidetes-Firmicutes in DM/FO group compared to DM/CO group. An elevation in the relative abundance of Bacteroidetes and Alistipes were detected in DM/FO group. Acetic acid, propionic acid and butyric acid belonging to short chain fatty acids (SCFAs) as gut microbiota metabolites, were dramatically increased after FO intervention. Correlation analysis revealed that the relative abundance of Firmicutes and Blautia were positively correlated with IL-1β, TNF-α, IL-6, IL-17A or LPS, respectively. Additionally, Bacteroidetes and Alistipes were negatively correlated with LPS.

CONCLUSIONS

Taken together, dietary FO ameliorated T2DM via suppressing inflammation and modulating gut microbiota, which may potentially contribute to dietary control of diabetes.

Role of Small Intestinal Bacterial Overgrowth (SIBO) and Inflammation in Obese Children

Knowledge of the real incidence of small intestinal bacterial overgrowth (SIBO) in obese children and its role in obesity development seems essential for a more effective approach to the treatment of this condition. In this prospective, single-blind study, presence of SIBO was evaluated in a group of children with overweight/obesity. A blood sample for evaluation of cytokine profile was collected to establish the potential relationship with inflammatory condition and lactulose breath test (LBT) to diagnose SIBO was performed. A total of 36 patients with excess of adipose tissue were recruited. Among them, 16 (44.4%) were overweight and 20 (45.6%) were obese. Overall, 26 (72.2%) children had a positive LBT and were considered suffering from SIBO, 12 (75.0%) among those overweight and 14 (70.0%) among those obese. Measurement of cytokines (IL-1α, IL-1β, IL-4, IL-6, IL-7, IL-8, IL-10, IL-12p40, IL-12p70, IL-17, IFN-α2, IFN-γ, TNF-α), cytokine antagonists (IL-1ra), chemokines (IP10, MCP-1, MIP1α, MIP1β), and growth factors (EGF, G-CSF, GM-CSF, and VEGF) secreted in culture supernatants by PHA activated-PBMCs revealed that in the study population proinflammatory cytokines IL-1, IL-6, IL-8, IL-12, IFN-γ, IL-18, and TNF-α were high, whereas anti-inflammatory mediators IL-4 and IL-10 were low. However, no significance difference between children with SIBO and those without were evidenced. Evaluation of relationship of severity of SIBO showed a significant positive relationship between EGF or IFN-α2 and H2 but not CH4 levels and an inverse significant relationship with CH4 but not H2. Despite its limitations and further studies are needed, this study seems to indicate that SIBO is extremely common in overweight and obese children and can be demonstrated not only in severely obese subjects but also in moderately overweight patients. The inflammatory state seems to precede obesity development and SIBO does not seem to have relevance in obesity development, with no relationship found between severity of SIBO and inflammatory state.

Oral microbiota-induced periodontitis: a new risk factor of metabolic diseases

It has recently become evident that the periodontium (gingiva, desmodontal ligament, cementum and alveolar bone) and the associated microbiota play a pivotal role in regulating human health and diseases. The oral cavity is the second largest microbiota in the body with around 500 different bacterial species identified today. When disruption of oral cavity and dysbiosis occur, the proportion of strict anaerobic Gram-negative bacteria is then increased. Patients with periodontitis present 27 to 53% more risk to develop diabetes than the control population suggesting that periodontitis is an aggravating factor in the incidence of diabetes. Moreover, dysbiosis of oral microbiota is involved in both periodontal and metabolic disorders (cardiovascular diseases, dyslipidaemia …). The oral diabetic dysbiosis is characterized by a specific bacteria Porphyromonas, which is highly expressed in periodontal diseases and could exacerbate insulin resistance. In this review, we will address the nature of the oral microbiota and how it affects systemic pathologies with a bidirectional interaction. We also propose that using prebiotics like Akkermansia muciniphila may influence oral microbiota as novel therapeutic strategies. The discovery of the implication of oral microbiota for the control of metabolic diseases could be a new way for personalized medicine.

Resveratrol-mediated glycemic regulation is blunted by curcumin and is associated to modulation of gut microbiota

The polyphenols resveratrol (RSV) and curcumin (Cur) are phytoalexines and natural antibiotics with numerous pharmacological functions and metabolic impacts. Recent evidences show a broad control of gut microbiota by polyphenols which could influence glycemic regulation. The aim of this work is to estimate the respective effect of RSV and Cur alone or in association on the control of glycemia and on gut microbiota. A 5-week chronic treatment of hyperglycemic mice with RSV and/or Cur resulted in a differential effect on glucose tolerance test and modified gut microbiome. We precisely identified groups of bacteria representing a specific signature of the glycemic effect of RSV. Inferred metagenomic analysis and metabolic pathway prediction showed that the sulfur and branched-chain amino-acid (BCAA) metabolic activities are tightly correlated with the efficacy of RSV for the control of glycaemia. The impact on BCAA metabolism was further validated by serum metabolomics analysis. Altogether, we show that polyphenols specifically impact gut microbiota and corresponding metabolic functions which could be responsible for their therapeutic role.

Influence of a 3-month low-calorie Mediterranean diet compared to the vegetarian diet on human gut microbiota and SCFA: the CARDIVEG Study

PURPOSE

We evaluated the effect of low-calorie mediterranean (MD) and vegetarian (VD) diets on gut microbiome (GM) composition and short-chain-fatty acids (SCFA) production.

METHODS

We performed next generation sequencing (NGS) of 16S rRNA and SCFA analysis on fecal samples of 23 overweight omnivores (16 F; 7 M) with low-to-moderate cardiovascular risk. They were randomly assigned to a VD or MD, each lasting 3 months, with a crossover study design.

RESULTS

Dietary interventions did not produce significant diversity in the GM composition at higher ranks (family and above), neither between nor within MD and VD, but they did it at genus level. MD significantly changed the abundance of Enterorhabdus, Lachnoclostridium and Parabacteroides, while VD significantly affected the abundance of Anaerostipes, Streptococcus, Clostridium sensu stricto, and Odoribacter. Comparison of the mean variation of each SCFA between MD and VD showed an opposite and statistically significant trend for propionic acid (+ 10% vs - 28%, respectively, p = 0.034). In addition, variations of SCFA were negatively correlated with changes of some inflammatory cytokines such as VEGF, MCP-1, IL-17, IP-10 and IL-12, only after MD. Finally, correlation analyses showed a potential relationship-modulated by the two diets-between changes of genera and changes of clinical and biochemical parameters.

CONCLUSIONS

A short-term dietary intervention with MD or VD does not induce major change in the GM, suggesting that a diet should last longer than 3 months for scratching the microbial resilience. Changes in SCFA production support their role in modulating the inflammatory response, thus mediating the anti-inflammatory and protective properties of MD.

The Role of Inflammation in Diabetes: Current Concepts and Future Perspectives

Diabetes is a complex metabolic disorder affecting the glucose status of the human body. Chronic hyperglycaemia related to diabetes is associated with end organ failure. The clinical relationship between diabetes and atherosclerotic cardiovascular disease is well established. This makes therapeutic approaches that simultaneously target diabetes and atherosclerotic disease an attractive area for research. The majority of people with diabetes fall into two broad pathogenetic categories, type 1 or type 2 diabetes. The role of obesity, adipose tissue, gut microbiota and pancreatic beta cell function in diabetes are under intensive scrutiny with several clinical trials to have been completed while more are in development. The emerging role of inflammation in both type 1 and type 2 diabetes (T1D and T1D) pathophysiology and associated metabolic disorders, has generated increasing interest in targeting inflammation to improve prevention and control of the disease. After an extensive review of the possible mechanisms that drive the metabolic pattern in T1D and T2D and the inflammatory pathways that are involved, it becomes ever clearer that future research should focus on a model of combined suppression for various inflammatory response pathways.

The Impact of Dietary Grape Seed Meal on Healthy and Aflatoxin B1 Afflicted Microbiota of Pigs after Weaning

The study investigated the effect of grape seed (GS) meal, aflatoxin (AFB1), or their combination on the large intestine microbiota of weanling piglets. Twenty-four piglets were allocated into four groups based on diet composition: (1) Control group; (2) AFB1 (320 g/kg feed) group; (3) GS group (8% inclusion in the diet); (4) AFB1 + GS group. After 30 days of experiment, the colon content was used for microbiota analyses; after isolation of total bacterial genomic DNA, V3/V4 regions of the 16S rRNA amplicons were sequenced using the Illumina MiSeq platform. The raw sequences were analyzed using the v.1.9.1 QIIME pipeline software. 157 numbers of OTUs were identified among all four dietary groups with 26 of them being prevalent above 0.05% in the total relative abundance. GS and AFB1 increase the relative abundance of phylum Bacteroidetes and Proteobacteria, while decreasing the Firmicutes abundance in a synergic manner as compared with the individual treatments. An additive or synergistic action of the two treatments was identified for Lactobacillus, Prevotella and Campylobacter, while rather an antagonistic effect was observed on Lachnospira. The action mechanisms of aflatoxin B1 and grape seed meal that drive the large intestine microbiota to these changes are not known and need further investigations.

Current Models of Fatty Liver Disease; New Insights, Therapeutic Targets and Interventions

Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of disorders ranging from simple steatosis to steatosis with inflammation and fibrosis. NAFLD is currently the most prevalent chronic liver disease worldwide, with a global prevalence of 25%, and is soon projected to be the leading cause for liver transplantation in the US. Alarmingly, few effective pharmacotherapeutic approaches are currently available to block or attenuate development and progression of NAFLD. Preclinical models are critical for unraveling the complex and multi-factorial etiology of NAFLD and for testing potential therapeutics. Here we review preclinical models that have been instrumental in highlighting molecular and cellular mechanisms underlying the pathogenesis of NAFLD and in facilitating early proof-of-concept investigations into novel intervention strategies.

Lipoproteins and Cardiovascular Redox Signaling: Role in Atherosclerosis and Coronary Disease

SIGNIFICANCE

Lipoproteins, such as low-density lipoprotein, play a causal role in the development of atherosclerosis and coronary disease. Recent Advances: Lipoproteins can stimulate vascular production of reactive oxygen species, which act as important signaling molecules in the cardiovascular system contributing to the pathophysiology of endothelial dysfunction, hypertension, and atherosclerosis.

CRITICAL ISSUES

Modified lipoproteins have emerged as important regulators of redox signaling, such as oxidized or carbamylated low-density lipoprotein or modified high-density lipoproteins, that contain oxidized lipids, an altered protein cargo, and associated small molecules, such as symmetric dimethylarginine.

FUTURE DIRECTIONS

In this review, we provide an overview on signaling pathways stimulated by modified lipoproteins in the cardiovascular system and their potential role in cardiovascular disease development. Moreover, we highlight novel aspects of how gut microbiome-related mechanisms-a growing research field-may contribute to lipoprotein modification with subsequent impact on cardiovascular redox signaling. Antioxid. Redox Signal. 29, 337-352.

Protective role of commensal bacteria in Sjögren Syndrome

CD25 knock-out (CD25KO) mice spontaneously develop Sjögren Syndrome (SS)-like inflammation. We investigated the role of commensal bacteria by comparing CD25KO mice housed in conventional or germ-free conditions. Germ-free CD25KO mice have greater corneal barrier dysfunction, lower goblet cell density, increased total lymphocytic infiltration score, increased expression of IFN-γ, IL-12 and higher a frequency of CD4⁺IFN-γ⁺ cells than conventional mice. CD4⁺ T cells isolated from female germ-free CD25KO mice adoptively transferred to naive immunodeficient RAG1KO recipients caused more severe Sjögren-like disease than CD4⁺ T cells transferred from conventional CD25KO mice. Fecal transplant in germ-free CD25KO mice reversed the spontaneous dry eye phenotype and decreased the generation of pathogenic CD4⁺IFN-γ⁺ cells. Our studies indicate that lack of commensal bacteria accelerates the onset and severity of dacryoadenitis and generates autoreactive CD4⁺T cells with greater pathogenicity in the CD25KO model, suggesting that the commensal bacteria or their metabolites products have immunoregulatory properties that protect exocrine glands in the CD25KO SS model.

Role of innate lymphoid cells in obesity and metabolic disease (Review)

The immune system has previously been demonstrated to be associated with the pathophysiological development of metabolic abnormalities. However, the mechanisms linking immunity to metabolic disease remain to be fully elucidated. It has previously been suggested that innate lymphoid cells (ILCs) may be involved in the progression of numerous types of metabolic diseases as these cells act as suppressors and promoters for obesity and associated conditions, and are particularly involved in adipose tissue inflammation, which is a major feature of metabolic imbalance. Group 2 ILCs (ILC2s) have been revealed as anti‑obese immune regulators by secreting anti‑inflammatory cytokines and promoting the polarization of M2 macrophages, whereas group 1 ILCs (ILC1s), including natural killer cells, may promote adipose tissue inflammation via production of interferon‑γ, which in turn polarizes macrophages toward the M1 type. The majority of studies to date have demonstrated the pathological association between ILCs and obesity in the context of adipose tissue inflammation, whereas the roles of ILCs in other organs which participate in obesity development have not been fully characterized. Therefore, identifying the roles of all types of ILCs as central components mediating obesity‑associated inflammation, is of primary concern, and may lead to the discovery of novel preventative and therapeutic interventions.