Emerging concepts in intestinal immune control of obesity-related metabolic disease

Microbial succinate promotes the response to metformin by upregulating secretory immunoglobulin a in intestinal immunity

Metformin is the first-line pharmacotherapy for type 2 diabetes mellitus; however, many patients respond poorly to this drug in clinical practice. The potential involvement of microbiota-mediated intestinal immunity and related signals in metformin responsiveness has not been previously investigated. In this study, we successfully constructed a humanized mouse model by fecal transplantation of the gut microbiota from clinical metformin-treated - responders and non-responders, and reproduced the difference in clinical phenotypes of responsiveness to metformin. The abundance of Bacteroides thetaiotaomicron, considered a representative differential bacterium of metformin responsiveness, and the level of secretory immunoglobulin A (SIgA) in intestinal immunity increased significantly in responder recipient mice following metformin treatment. In contrast, no significant alterations in B. thetaiotaomicron and SIgA were observed in non-responder recipient mice. The study of IgA-/- mice confirmed that downregulated expression or deficiency of SIgA resulted in non-response to metformin, meaning that metformin was unable to improve dysfunctional glucose metabolism and reduce intestinal and adipose tissue inflammation, ultimately leading to systemic insulin resistance. Furthermore, supplementation with succinate, a microbial product of B. thetaiotaomicron, potentially reversed the non-response to metformin by inducing the production of SIgA. In conclusion, we demonstrated that upregulated SIgA, which could be regulated by succinate, was functionally involved in metformin response through its influence on immune cell-mediated inflammation and insulin resistance. Conversely, an inability to regulate SIgA may result in a lack of response to metformin.

Immunometabolic Interactions in Obesity: Implications for Therapeutic Strategies

Obesity is characterized by excessive fat accumulation that triggers chronic low-grade inflammation and systemic immune dysregulation, significantly increasing the risk of metabolic disorders including insulin resistance, type 2 diabetes, and cardiovascular disease. This review examines the bidirectional relationship between obesity and immune dysfunction, focusing on how immune cell infiltration in adipose tissue drives inflammatory processes. We highlight the phenotypic shifts in key immune populations-macrophages polarized toward proinflammatory M1 phenotypes, T cell exhaustion occurrs, and alterations appear in B cells, natural killer (NK) cells, and dendritic cells-that collectively contribute to metabolic deterioration. The gut microbiome emerged as a critical mediator in this relationship, influencing both immune responses and metabolic regulation through gut-liver and gut-brain axes. We explore emerging immunomodulatory therapeutic strategies, including anti-inflammatory agents, microbiota interventions, and targeted immune therapies such as innovative nanomedicine approaches. The review also addresses the challenges of immunotherapy in obesity, particularly the paradoxical effects observed in cancer immunotherapy outcomes and the need for personalized treatment approaches. Artificial intelligence is highlighted as a potential tool to enhance patient stratification and treatment optimization in future immunomodulatory interventions. Understanding these immunometabolic interactions provides a foundation for developing more effective therapeutic strategies that could transform obesity management and reduce the burden of obesity-related metabolic diseases.

Gut microbiota-derived metabolite phenylacetylglutamine in cardiovascular and metabolic disease

The aging of population coupled with unhealthy dietary habits among residents has led to a rise in the incidence of cardiovascular and metabolic diseases (CVMDs). Extensive research has highlighted the role of gut microbiota-derived metabolites in CVMDs. Among these metabolites, phenylacetylglutamine (PAGln), a meta-organismal prothrombotic metabolite, has been proved to promote the progression of CVMDs. This bacterial derived metabolite is a byproduct of amino acid comes from phenylalanine (Phe) in the diet. There are increasing evidence showing that the level of PAGln is associated with the risk of developing CVMDs. To provide a comprehensive understanding of the role of PAGln in CVMDs, this review delves into the production and metabolic pathways of PAGln and discusses the links of PAGln and the pathogenesis of CVMDs.

Gut commensal Phascolarctobacterium faecium retunes innate immunity to mitigate obesity and metabolic disease in mice

The gut microbiota may protect against obesity and chronic metabolic conditions by regulating the immune response to dietary triggers. Yet the specific bacteria that control the overactivation of the immune system in obesity and their mode of action remain largely unknown. Here we surveyed 7,569 human metagenomes and observed an association between the gut symbiont Phascolarctobacterium faecium and non-obese adults regardless of nationality, sex or age. In a mouse model of diet-induced obesity, we confirmed the specificity of P. faecium DSM 32890 anti-obesogenic properties compared with other species of the same genus. P. faecium reversed the inflammatory phenotype associated with obesity. Specifically, P. faecium promoted polarization of alternatively activated macrophages (M2), which reversed the obesity-induced increase in gut-resident type 1 innate lymphoid cells. This resulted in mitigation of glucose intolerance, adiposity and body weight gain irrespective of treatment with live or pasteurized bacteria. The metabolic benefits were independent of the adaptive immune system, but they were abolished by an inhibitor of M2 polarization in mice. P. faecium directly promoted M2-macrophage polarization through TLR2 signalling and these effects seemed to be independent of gut microbiota changes. Overall, we identify a previously undescribed gut commensal bacterium that could help mitigate obesity and metabolic comorbidities by retuning the innate immune response to hypercaloric diets.

Immunological biomarkers of aging

The immune system has long been recognized for its critical role in the elimination of pathogens and the development of autoimmune diseases, but recent evidence demonstrates that it also contributes to noncommunicable diseases associated with biological aging processes, such as cancer, cardiovascular disease, neurodegeneration, and frailty. This review examines immunological biomarkers of aging, focusing on how the immune system evolves with age and its impact on health and disease. It discusses the historical development of immunological assessments, technological advancements, and the creation of novel biomarkers and models to study immune aging. We also explore the clinical implications of immune aging, such as increased susceptibility to infectious diseases, poor vaccine responses, and a higher incidence of noncommunicable diseases. In summary, we provide a comprehensive overview of current research, highlight the clinical relevance of immune aging, and identify gaps in knowledge that require further investigation.

Carotid baroreceptor stimulation attenuates obesity-related hypertension through sympathetic-driven IL- 22 restoration of intestinal homeostasis

BACKGROUND

Gut microbiota and its metabolites, as well as the intestinal barrier, play important roles in the development of obesity-related hypertension. Sympathetic nerves are critical for intestinal homeostasis. Carotid baroreceptor stimulation (CBS) has been shown to exert protective effects against hypertension via sympathetic tone reduction. This study aimed to reveal the effects of CBS treatment on intestinal homeostasis and its underlying mechanisms in obesity-related hypertension.

METHODS

An animal model of obesity-related hypertension was established with Sprague-Dawley rats by a high-fat diet and 10% fructose solution for 13 weeks. CBS devices were implanted at the 5 th week. The effects of CBS on body weight, blood pressure, gut microbiota, intestinal autonomic nerve, intestinal barrier, and type 3 innate lymphoid cells (ILC3 s) were investigated.

RESULTS

CBS treatment significantly reduced blood pressure and body weight in rats with obesity-related hypertension. In addition, CBS obviously improved gut microbial dysbiosis and intestinal barrier damage. Interestingly, after an 8-week CBS intervention, the obesity-related hypertensive rats exhibited a dramatic decrease in sympathetic nerve distribution and norepinephrine concentration, as well as an increase in IL- 22 production by ILC3 s in the intestine.

CONCLUSIONS

CBS increased IL- 22 production in ILC3 s to alleviate gut microbial dysbiosis and intestinal barrier destruction, thus improving obesity-related hypertension in rats.

Obesity and the gut microbiota: implications of neuroendocrine and immune signaling

Obesity is a major health challenge due to its high prevalence and associated comorbidities. The excessive intake of a diet rich in fat and sugars leads to a persistent imbalance between energy intake and energy expenditure, which increases adiposity. Here, we provide an update on relevant diet-microbe-host interactions contributing to or protecting from obesity. In particular, we focus on how unhealthy diets shape the gut microbiota and thus impact crucial intestinal neuroendocrine and immune system functions. We describe how these interactions promote dysfunction in gut-to-brain neuroendocrine pathways involved in food intake control and postprandial metabolism and elevate the intestinal proinflammatory tone, promoting obesity and metabolic complications. In addition, we provide examples of how this knowledge may inspire microbiome-based interventions, such as fecal microbiota transplants, probiotics, and biotherapeutics, to effectively combat obesity-related disorders. We also discuss the current limitations and gaps in knowledge of gut microbiota research in obesity.

Evaluation of antiobesogenic properties of fermented foods: In silico insights

Obesity prevalence has steadily increased over the past decades. Standard approaches, such as increased energy expenditure, lifestyle changes, a balanced diet, and the use of specific drugs, are the conventional strategies for preventing or treating the disease and its associated complications. Fermented foods and their subsequent bioactive constituents are now believed to be a novel strategy that can complement already existing approaches for managing and preventing this disease. Recent developments in systems biology and bioinformatics have made it possible to model and simulate compounds and disease interactions. The adoption of such in silico models has contributed to the discovery of novel fermented product targets and helped in testing hypotheses regarding the mechanistic impact and underlying functions of fermented food components. From the studies explored, key findings suggest that fermented foods affect adipogenesis, lipid metabolism, appetite regulation, gut microbiota composition, insulin resistance, and inflammation related to obesity, which could lead to new ways to treat these conditions. These outcomes were linked to probiotics, prebiotics, metabolites, and complex bioactive substances produced during fermentation. Overall, fermented foods and their bioactive compounds show promise as innovative tools for obesity management by influencing metabolic pathways and overall gut health.

Necroptosis in obesity: a complex cell death event

Obesity is an exceedingly prevalent and frequent health issue in today's society. Fat deposition is accompanied by low-grade inflammation in fat tissue and throughout the body, leading to metabolic disorders that ultimately promote the onset of obesity-related diseases. The development of obesity is accompanied by cell death events such as apoptosis as well as pyroptosis, however, the role of necroptosis in obesity has been widely reported in recent years. Necroptosis, a mode of cell death distinct from apoptosis and necrosis, is associated with developing many inflammatory conditions and their associated diseases. It also exhibits modulation of apoptosis and pyroptosis. It is morphologically similar to necroptosis, characterized by the inhibition of caspase-8, the formation of membrane pores, and the subsequent rupture of the plasma membrane. This paper focuses on the key pathways and molecules of necroptosis, exploring its connections with apoptosis and pyroptosis, and its implications in obesity. This paper posits that the modulation of necroptosis-related targets may represent a novel potential therapeutic avenue for the prevention and treatment of obesity-induced systemic inflammatory responses, and provides a synopsis of potential molecular targets that may prove beneficial in obesity-associated inflammatory diseases.

Portulaca oleracea L. (purslane) extract ameliorates intestinal inflammation in diet-induced obese mice by inhibiting the TLR4/NF-κB signaling pathway

Background

Portulaca oleracea L. (purslane) is a dietary plant and a botanical drug with antioxidant, antidiabetic, and anti-inflammatory activities. However, the effects of purslane against intestinal-inflammation-associated obesity are yet to be studied. In the present study, we hypothesized that purslane extract could reduce intestinal inflammation associated with metabolic disorder.

Results

Male C57BL/6J mice were fed a high-fat diet (HFD, 60% kcal% of fat) for a total duration of 14 weeks to establish an obesity model; further, the treatment group was orally administered purslane extract (200 mg/kg/day) during the last 4 weeks. Then, intestinal tissues were detached from the mice for detecting protein expressions through Western blot and immunohistochemical analyses. Pro-inflammatory cytokines were determined using ELISA kits, whereas the components of purslane extract were detected by ultra performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry. Chronic oral administration of purslane extract ameliorated colon shortening syndrome and reduced bowel inflammation in HFD-induced obese mice through suppression of the toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) signaling pathway to downregulate TLR4, myeloid differentiation factor 88 (MyD88), Ser32 phosphorylation of NF-κB inhibitor alpha (IκBα), and Ser536 phosphorylation of NF-κB p65 expression levels, thereby inhibiting the pro-inflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-6 levels.

Conclusion

The present study supports the anti-inflammatory potential of purslane extract for modulating bowel inflammation under obesity through inhibition of the TLR4/NF-κB signaling pathway.

Adipose tissue macrophages-derived exosomal MiR-500a-5p under high glucose promotes adipocytes inflammation by suppressing Nrf2 expression

BACKGROUND

Type 2 diabetes (T2DM) is a chronic metabolic disorder characterized by insulin resistance and chronic inflammation. Adipose tissue macrophages (ATMs), central players in mediating pro-inflammatory responses within adipose tissue, have been shown to influence insulin sensitivity through exosome secretion. While the role of macrophages-derived exosomal miRNA has been studied in various diseases, their pathogenic roles in T2DM, particularly ATMs-derived exosomal miRNA in adipose tissue inflammation, remain underexplored.

OBJECTIVES

This study focuses specifically on T2DM, investigating the role of ATM-derived exosomal miRNAs in adipose tissue inflammation, a critical factor in the pathogenesis of T2DM.

METHODS

ATM were isolated from visceral adipose tissues in patients with or without diabetes. Differentially expressed miRNAs in ATM-derived exosomes were predicted by high-throughput RNA sequencing. The RAW264.7 macrophages and 3T3-L1 preadipocytes was selected as a model system. Quantitative RT-PCR was used to assess miR-500a-5p expression. The direct binding of miR-500a-5p to Nrf2 mRNA 3' UTR was verified by dual luciferase assay.

RESULTS

MiR-500a-5p was also enriched in the exosomes of high-glucose-treated macrophages. Furthermore, these exosomes induced high expression of miR-500a-5p and activation of the NLRP3 inflammasome in adipocytes when co-cultured with them. Additionally, the reduction of miR-500a-5p expression in macrophages by using a miR-500a-5p inhibitor ameliorated the pro-inflammatory properties of the exosomes, and co-culturing these exosomes with adipocytes resulted in decreased expression of NLRP3 inflammasome-associated proteins in adipocytes. In contrast, induction of miR-500a-5p expression led to the opposite results. Moreover, the dual-luciferase assay confirmed that miR-500a-5p directly targeted the 3' UTR of Nrf2 mRNA. Unlike miR-500a-5p, Nrf2 exhibited an anti-inflammatory response.

CONCLUSION

The results indicate that ATM-derived exosomal miR-500a-5p promotes NLRP3 inflammasome activation and adipose tissue inflammation through down-regulation of Nrf2 in adipocytes.

Enteric glial NLRP3 inflammasome contributes to gut mucosal barrier alterations in a mouse model of diet-induced obesity

AIM

In the present study, we investigated the involvement of NLRP3 inflammasome in the intestinal epithelial barrier (IEB) changes associated with obesity, and its role in the interplay between enteric glia and intestinal epithelial cells (IECs).

METHODS

Wild-type C57BL/6J and NLRP3-KO (-/-) mice were fed with high-fat diet (HFD) or standard diet for 8 weeks. Colonic IEB integrity and inflammasome activation were assessed. Immunolocalization of colonic mucosal GFAP- and NLRP3-positive cells along with in vitro coculture experiments with enteric glial cells (EGCs) and IECs allowed to investigate the potential link between altered IEB, enteric gliosis, and NLRP3 activation.

RESULTS

HFD mice showed increased body weight, altered IEB integrity, increased GFAP-positive glial cells, and NLRP3 inflammasome hyperactivation. HFD-NLRP3-/- mice showed a lower increase in body weight, an improvement in IEB integrity and an absence of enteric gliosis. Coculture experiments showed that palmitate and lipopolysaccharide contribute to IEB damage and promote enteric gliosis with consequent hyperactivation of enteric glial NLRP3/caspase-1/IL-1β signaling. Enteric glial-derived IL-1β release exacerbates the IEB alterations. Such an effect was abrogated upon incubation with anakinra (IL-1β receptor antagonist) and with conditioned medium derived from silenced-NLRP3 glial cells.

CONCLUSION

HFD intake elicits mucosal enteric gliotic processes characterized by a hyperactivation of NLRP3/caspase-1/IL-1β signaling pathway, that contributes to further exacerbate the disruption of intestinal mucosal barrier integrity. However, we cannot rule out the contribution of NLRP3 inflammasome activation from other cells, such as immune cells, in IEB alterations associated with obesity. Overall, our results suggest that enteric glial NLRP3 inflammasome might represent an interesting molecular target for the development of novel pharmacological approaches aimed at managing the enteric inflammation and intestinal mucosal dysfunctions associated with obesity.

Brd4 modulates metabolic endotoxemia-induced inflammation by regulating colonic macrophage infiltration in high-fat diet-fed mice

High-fat diet (HFD) induces low-grade chronic inflammation, contributing to obesity and insulin resistance. However, the precise mechanisms triggering obesity-associated metabolic inflammation remain elusive. In this study, we identified epigenetic factor Brd4 as a key player in this process by regulating the expression of Ccr2/Ccr5 in colonic macrophage. Upon 4-week HFD, myeloid-lineage-specific Brd4 deletion (Brd4-CKO) mice showed reduced colonic inflammation and macrophage infiltration with decreased expression of Ccr2 and Ccr5. Mechanistically, Brd4 was recruited by NF-κB to the enhancer regions of Ccr2 and Ccr5, promoting enhancer RNA expression, which facilitated Ccr2/Ccr5 expression and macrophage migration. Furthermore, decreased infiltration of Ccr2/Ccr5-positive colonic macrophages in Brd4-CKO mice altered gut microbiota composition and reduced intestinal permeability, thereby lowering metabolic endotoxemia. Finally, Brd4-CKO mice subjected to a 4-week LPS infusion exhibited restored susceptibility to HFD-induced obesity and insulin resistance. This study identifies Brd4 as a critical initiator of colonic macrophage-mediated inflammation and metabolic endotoxemia upon HFD, suggesting Brd4 as a potential target for mitigating HFD-induced inflammation, obesity, and its metabolic complications.

Immunological mechanisms in steatotic liver diseases: An overview and clinical perspectives

Steatotic liver diseases (SLD) are the principal worldwide cause of cirrhosis and end-stage liver cancer, affecting nearly a quarter of the global population. SLD includes metabolic dysfunction-associated alcoholic liver disease (MetALD) and metabolic dysfunction-associated steatotic liver disease (MASLD), resulting in asymptomatic liver steatosis, fibrosis, cirrhosis and associated complications. The immune processes include gut dysbiosis, adiposeliver organ crosstalk, hepatocyte death and immune cell-mediated inflammatory processes. Notably, various immune cells such as B cells, plasma cells, dendritic cells, conventional CD4+ and CD8+ T cells, innate-like T cells, platelets, neutrophils and macrophages play vital roles in the development of MetALD and MASLD. Immunological modulations targeting hepatocyte death, inflammatory reactions and gut microbiome include N-acetylcysteine, selonsertib, F-652, prednisone, pentoxifylline, anakinra, JKB-121, HA35, obeticholic acid, probiotics, prebiotics, antibiotics and fecal microbiota transplantation. Understanding the immunological mechanisms underlying SLD is crucial for advancing clinical therapeutic strategies.

The therapeutic effect and possible mechanisms of alginate oligosaccharide on metabolic syndrome by regulating gut microbiota

Metabolic syndrome (MetS) is a disease condition incorporating the abnormal accumulation of various metabolic components, including overweight or abdominal obesity, insulin resistance and abnormal glucose tolerance, hypertension, atherosclerosis, or dyslipidemia. It has been proved that the gut microbiota and microbial-derived products play an important role in regulating lipid metabolism and thus the onset and development of MetS. Previous studies have demonstrated that oligosaccharides with prebiotic effects, such as chitosan oligosaccharides, can regulate the structure of the microbial community and its derived products to control weight and reduce MetS associated with obesity. Alginate oligosaccharides (AOS), natural products extracted from degraded alginate salts with high solubility and extensive biological activity, have also been found to modulate gut microbiota. This review aims to summarize experimental evidence on the positive effects of AOS on different types of MetS while providing insights into mechanisms through which AOS regulates gut microbiota for preventing and treating MetS.

Yoyo Dieting, Post-Obesity Weight Loss, and Their Relationship with Gut Health

Excessive body weight is associated with many chronic metabolic diseases and weight loss, so far, remains the gold standard treatment. However, despite tremendous efforts exploring optimal treatments for obesity, many individuals find losing weight and maintaining a healthy body weight difficult. Weight loss is often not sustainable resulting in weight regain and subsequent efforts to lose weight. This cyclic pattern of weight loss and regain is termed "yoyo dieting" and predisposes individuals to obesity and metabolic comorbidities. How yoyo dieting might worsen obesity complications during the weight recurrence phase remains unclear. In particular, there is limited data on the role of the gut microbiome in yoyo dieting. Gut health distress, especially gut inflammation and microbiome perturbation, is strongly associated with metabolic dysfunction and disturbance of energy homeostasis in obesity. In this review, we summarise current evidence of the crosstalk between the gastrointestinal system and energy balance, and the effects of yoyo dieting on gut inflammation and gut microbiota reshaping. Finally, we focus on the potential effects of post-dieting weight loss in improving gut health and identify current knowledge gaps within the field, including gut-derived peptide hormones and their potential suitability as targets to combat weight regain, and how yoyo dieting and associated changes in the microbiome affect the gut barrier and the enteric nervous system, which largely remain to be determined.

Comparison of the effects of three sourdough postbiotics on high-fat diet-induced intestinal damage

There is significant interest in using postbiotics as an intervention strategy to address obesity. This study assesses the efficacy of postbiotics derived from different sourdough strains (Lactiplantibacillus plantarum LP1, LP25, and Pediococcus pentosaceus PP18) in mitigating intestinal injury in zebrafish fed on a high-fat diet. We screened postbiotics for their anti-colon cancer cell effects and compared various preparation methods applied to live bacterial strains, including heat-killing at different temperatures, pH adjustments, and ultraviolet radiation exposure. Heat-killing at 120 °C proved to be the most effective preparation method. A marked variation in health effects was observed in the heat-killed microbial cells, as evidenced by their hydrophobicity and self-aggregation ability. A five-week high-fat dietary intervention study in zebrafish demonstrated that diets supplemented with 108 CFU g-1 K-LP25 significantly attenuated weight gain and body fat, along with reductions in FASN, Leptin, and SREBF1 mRNA expression. However, diets supplemented with 107 CFU g-1 K-PP18 only reduced Leptin and SREBF1 mRNA expression. K-PP18 was more effective at mitigating gut barrier damage, promoting colonic Occludin, ZO-1, and Claudin-1 levels. Additionally, K-LP25 supplementation markedly downregulated the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β, reducing intestinal inflammation. Supplementation with K-LP1 and K-PP18 increased the abundance of Acinetobacter spp., whereas K-LP25 increased the abundance of Cetobacterium and Plesiomonas. Collectively, these findings suggest that inactivated strains confer protective effects against high-fat diet-induced intestinal damage in zebrafish, with variation observed across different species. Studying the effects of sourdough-derived postbiotics on gut health may open new avenues for dietary interventions to manage gut-related diseases.

Beneficial effects of Dendrobium officinale National Herbal Drink on metabolic immune crosstalk via regulate SCFAs-Th17/Treg

BACKGROUND

The development of gut-liver axis metabolic immune crosstalk is intimately associated with intestinal barrier disorder, intestinal SCFAs-Th17/Treg immunological imbalance, and disorders of the gut microbiota. Prior research has discovered that Dendrobium officinale National Herbal Drink (NHD), a traditional Chinese medicine drink with enhanced immunity, may enhance the immunological response in animals with impaired immune systems brought on by cyclophosphamide by repairing intestinal barrier function and controlling turbulence in the gut microbiota. However, whether NHD can further improve the gut-liver axis metabolic immune crosstalk and its related mechanisms need to be systematically studied.

OBJECTIVES

The purpose of this study is to clarify the function and mechanism of NHD in enhancing the gut-liver axis metabolic immunological crosstalk brought on by excessive alcohol intake.

METHODS

In this work, we set up a mouse model to analyze the metabolic and immunological crosstalk involving the gut-liver axis across 7 weeks of continuous, excessive drinking. At the same time, high and low doses (20,10 ml/kg) of NHD were given by gavage. The effect of NHD on improving the metabolism of gut-liver axis was evaluated by blood lipid, liver lipid deposition, liver function and intestinal pathophysiology. By measuring serum immunological indices, intestinal barrier, and intestinal immune barrier, the impact of NHD on enhancing immune and intestinal barrier function was assessed. Furthermore, immunohistochemistry, immunofluorescence, 16S rRNA, Western blot, q-PCR and other methods were used to detect gut microbiota, SCFAs-GPR41/43 pathway, intestinal Th17/Treg immune cells and PPAR-α-NPC1L1/SREBP1 pathway to elucidate the mechanism by which NHD enhances the gut-liver axis' metabolic immune crosstalk.

RESULTS

Our study demonstrated that NHD has the potential to improve the pathophysiological damage caused by gut-liver axis in model mice. NHD also ameliorated the disorder of lipid metabolism. In addition, it regulated the levels of peripheral blood T cell immunity and serum immune factors. And NHD can restore intestinal mechanical and immune barrier damage. NHD has a favorable impact on the quantity of beneficial bacteria, including uncultured_bacterium_g__norank_f__muribaculacea and uncultured_bacterium_g__Turicibacter. Additionally, it raised the model mice's levels of SCFAs (n-butyric acid, isovaleric acid, etc.). This resulted in the promotion of intestinal GPR41/43-ERK1/2 expression and the reshaping of intestinal CD4+T cell Th17/Treg homeostasis. As a consequence, colon IL-22 and IL-10 levels increased, while colon IL-17A levels decreased. Lastly, NHD raised the amount of intestinal IAP/LPS, regulated the development of PPAR-α-NPC1L1/SREBP1 pathway in gut-liver axis, and improve lipid metabolism disorder.

CONCLUSIONS

Our study found that NHD can improve the gut-liver axis metabolic immune crosstalk in model mice caused by excessive drinking. The mechanism might be connected to how NHD controls gut microbiota disorders in model mice, the activation of intestinal SCFAs-GPR41/43 pathway, the remodeling of Th17/Treg immune homeostasis of intestinal CD4+T cells, the improvement of IAP/LPS abnormality, and further mediating the PPAR-α-NPC1L1/SREBP1 pathway of lipid metabolism in gut-liver axis.

Role of gut microbiota in Crohn's disease pathogenesis: Insights from fecal microbiota transplantation in mouse model

BACKGROUND

Inflammatory bowel disease, particularly Crohn's disease (CD), has been associated with alterations in mesenteric adipose tissue (MAT) and the phenomenon termed "creeping fat". Histopathological evaluations showed that MAT and intestinal tissues were significantly altered in patients with CD, with these tissues characterized by inflammation and fibrosis.

AIM

To evaluate the complex interplay among MAT, creeping fat, inflammation, and gut microbiota in CD.

METHODS

Intestinal tissue and MAT were collected from 12 patients with CD. Histological manifestations and protein expression levels were analyzed to determine lesion characteristics. Fecal samples were collected from five recently treated CD patients and five control subjects and transplanted into mice. The intestinal and mesenteric lesions in these mice, as well as their systemic inflammatory status, were assessed and compared in mice transplanted with fecal samples from CD patients and control subjects.

RESULTS

Pathological examination of MAT showed significant differences between CD-affected and unaffected colons, including significant differences in gut microbiota structure. Fetal microbiota transplantation (FMT) from clinically healthy donors into mice with 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced CD ameliorated CD symptoms, whereas FMT from CD patients into these mice exacerbated CD symptoms. Notably, FMT influenced intestinal permeability, barrier function, and levels of proinflammatory factors and adipokines. Furthermore, FMT from CD patients intensified fibrotic changes in the colon tissues of mice with TNBS-induced CD.

CONCLUSION

Gut microbiota play a critical role in the histopathology of CD. Targeting MAT and creeping fat may therefore have potential in the treatment of patients with CD.

Gubra Amylin-NASH Diet Induced Nonalcoholic Fatty Liver Disease Associated with Histological Damage, Oxidative Stress, Immune Disorders, Gut Microbiota, and Its Metabolic Dysbiosis in Colon

SCOPE

The overall changes of colon under nonalcoholic fatty liver disease (NAFLD) remain to be further elucidated.

METHODS AND RESULTS

This study establishes a mouse model of NAFLD through a long-term Gubra Amylin-nonalcoholic steatohepatitis (NASH) diet (GAN diet). The results show that GAN diet significantly induces weight gain, liver steatosis, colonic oxidative stress, and lipid accumulation in blood, liver, and adipose tissue in mice. GAN feeding reduces the diversity of the gut microbiota, alters the composition and abundance of the gut microbiota, and leads to an increase in microbial metabolites such as long-chain fatty acids (LCFAs) and secondary bile acids (BAs), as well as a decrease in short-chain fatty acids (SCFAs). The RNA-seq and immunofluorescence results reveal that the GAN diet alters the expression of proteins and their coding genes involved in oxidative stress, immune response, and barrier function in colon tissue, such as lipocalin-2 (Lcn2, p < 0.05), heme oxygenase-1 (HO-1/Hmox1, p < 0.05), interferon-gamma (IFN-γ), and claudin-3/7. In addition, correlation analysis indicates a strong correlation between the changes in gut microbiota and lipid biomarkers. Additionally, the expression of immune related genes in colon tissue is related to the LCFAs produced by microbial metabolism.

CONCLUSION

GAN-induced NAFLD is related to microbiota and its metabolic imbalance, oxidative stress, immune disorders, and impaired barrier function in colon.

Obesity-associated inflammation countered by a Mediterranean diet: the role of gut-derived metabolites

The prevalence of obesity has increased dramatically worldwide and has become a critical public health priority. Obesity is associated with many co-morbid conditions, including hypertension, diabetes, and cardiovascular disease. Although the physiology of obesity is complex, a healthy diet and sufficient exercise are two elements known to be critical to combating this condition. Years of research on the Mediterranean diet, which is high in fresh fruits and vegetables, nuts, fish, and olive oil, have demonstrated a reduction in numerous non-communicable chronic diseases associated with this diet. There is strong evidence to support an anti-inflammatory effect of the diet, and inflammation is a key driver of obesity. Changes in diet alter the gut microbiota which are intricately intertwined with human physiology, as gut microbiota-derived metabolites play a key role in biological pathways throughout the body. This review will summarize recent published studies that examine the potential role of gut metabolites, including short-chain fatty acids, bile acids, trimethylamine-N-oxide, and lipopolysaccharide, in modulating inflammation after consumption of a Mediterranean-like diet. These metabolites modulate pathways of inflammation through the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, toll-like receptor 4 signaling, and macrophage driven effects in adipocytes, among other mechanisms.

Bacteroides uniformis CECT 7771 requires adaptive immunity to improve glucose tolerance but not to prevent body weight gain in diet-induced obese mice

BACKGROUND

The metabolic disturbances of obesity can be mitigated by strategies modulating the gut microbiota. In this study, we sought to identify whether innate or adaptive immunity mediates the beneficial metabolic effects of the human intestinal bacterium Bacteroides uniformis CECT 7771 in obesity.

METHODS

We evaluated the effects of orally administered B. uniformis on energy homeostasis, intestinal immunity, hormone levels, and gut microbiota in wild-type and Rag1-deficient mice with diet-induced obesity. We also assessed whether B. uniformis needed to be viable to exert its beneficial effects in obesity and to directly induce immunoregulatory effects.

RESULTS

The administration of B. uniformis to obese mice improved glucose tolerance and insulin secretion, restored the caloric intake suppression after an oral glucose challenge, and reduced hyperglycemia. The pre- and post-prandial glucose-related benefits were associated with restoration of the anti-inflammatory tone mediated by type 2 macrophages and regulatory T cells (Tregs) in the lamina propria of the small intestine. Contrastingly, B. uniformis administration failed to improve glucose tolerance in obese Rag1-/- mice, but prevented the increased body weight gain and adiposity. Overall, the beneficial effects seemed to be independent of enteroendocrine effects and of major changes in gut microbiota composition. B. uniformis directly induced Tregs generation from naïve CD4+ T cells in vitro and was not required to be viable to improve glucose homeostasis but its viability was necessary to prevent body weight gain in diet-induced obese wild-type mice.

CONCLUSIONS

Here we demonstrate that B. uniformis modulates the energy homeostasis in diet-induced obese mice through different mechanisms. The bacterium improves oral glucose tolerance by adaptive immunity-dependent mechanisms that do not require cell viability and prevents body weight gain by adaptive immunity-independent mechanisms which require cell viability. Video Abstract.

The endoplasmic reticulum stress protein GRP94 modulates cathepsin L activity in M2 macrophages in conditions of obesity-associated inflammation and contributes to their pro-inflammatory profile

BACKGROUND/OBJECTIVES

Adipose tissue macrophages (ATM) are key actors in the pathophysiology of obesity-related diseases. They have a unique intermediate M2-M1 phenotype which has been linked to endoplasmic reticulum (ER) stress. We previously reported that human M2 macrophages treated with the ER stress inducer thapsigargin switched to a pro-inflammatory phenotype that depended on the stress protein GRP94. In these conditions, GRP94 promoted cathepsin L secretion and was co-secreted with complement C3. As cathepsin L and complement C3 have been reported to play a role in the pathophysiology of obesity, in this work we studied the involvement of GRP94 in the pro-inflammatory phenotype of ATM.

METHODS

GRP94, cathepsin L and C3 expression were analyzed in CD206 + ATM from mice, WT or obesity-resistant transgenic fat-1, fed a high-fat diet (HFD) or a standard diet. GRP94 colocalization with cathepsin L and C3 and its effects were analyzed in human primary macrophages using thapsigargin as a control to induce ER stress and palmitic acid (PA) as a driver of metabolic activation.

RESULTS

In WT, but not in fat-1 mice, fed a HFD, we observed an increase in crown-like structures consisting of CD206 + pSTAT1+ macrophages showing high expression of GRP94 that colocalized with cathepsin L and C3. In vitro experiments showed that PA favored a M2-M1 switch depending on GRP94. This switch was prevented by omega-3 fatty acids. PA-induced GRP94-cathepsin L colocalization and a decrease in cathepsin L enzymatic activity within the cells (while the enzymatic activity in the extracellular medium was increased). These effects were prevented by the GRP94 inhibitor PU-WS13.

CONCLUSIONS

GRP94 is overexpressed in macrophages both in in vivo and in vitro conditions of obesity-associated inflammation and is involved in changing their profile towards a more pro-inflammatory profile. It colocalizes with complement C3 and cathepsin L and modulates cathepsin L activity.

The effects of inulin on solubilizing and improving anti-obesity activity of high polymerization persimmon tannin

High polymerization persimmon tannin has been reported to have lipid-lowering effects. Unfortunately, the poor solubility restricts its application. This research aimed to investigate the effect and mechanism of inulin on solubilizing of persimmon tannin. Furthermore, we examined whether the addition of inulin would affect the attenuated obesity effect of persimmon tannin. Transmission electron microscope (TEM), Isothermal titration calorimetry (ITC) and Fourier transform infrared spectroscopy (FT-IR) results demonstrated that inulin formed a gel-like network structure, which enabled the encapsulation of persimmon tannin through hydrophobic and hydrogen bond interactions, thereby inhibiting the self-aggregation of persimmon tannin. The turbidity of the persimmon tannin solution decreased by 56.2 %, while the polyphenol content in the supernatant increased by 60.0 %. Furthermore, biochemical analysis and 16s rRNA gene sequencing technology demonstrated that persimmon tannin had a significant anti-obesity effect and improved intestinal health in HFD-fed mice. Moreover, inulin was found to have a positive effect on enhancing the health benefits of persimmon tannin, including improving hepatic steatosis and gut microbiota dysbiosis. it enhanced the abundance of beneficial core microbes while decreasing the abundance of harmful bacteria. Our findings expand the applications of persimmon tannin in the food and medical sectors.

Uncovering the key pharmacodynamic material basis and possible molecular mechanism of Xiaoke formulation improve insulin resistant through a comprehensive investigation

ETHNOPHARMACOLOGICAL RELEVANCE

Xiaoke formulation (XKF) has been utilized in clinical practice for decades in China as a treatment option for mild to moderate type 2 diabetes. However, there is still a need for systematic research to uncover the key pharmacodynamic material basis and mechanism of XKF.

AIM OF THE STUDY

Aim of to investigate the distribution and metabolism of XKF in normal and insulin resistant (IR) mice were different, and elucidate its key pharmacodynamic material basis and mechanism of action.

MATERIALS AND METHODS

Ultra performance liquid chromatography/time of flight mass spectrometry technology was employed to investigate the differences in XKF absorption, distribution, and metabolism between normal and IR mice across blood, liver, feces, and urine samples. Further, network pharmacology was used to predict target proteins and their associated signaling pathways. Then, molecular docking was utilized to validate the activity of key pharmacodynamic components and targets. Finally, IR HepG2 cells were used to detect the glucose consumption under the action of key pharmacodynamic material basis. In addition, the expression of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT) and phospho-protein kinase B (p-AKT) was determined using western blotting.

RESULTS

The study demonstrates significant distinctions in plasma and liver number and abundance of alkaloids, organic acids, flavonoids, iridoids and saponins between normal and IR mice when XKF was administered. Further analysis has shown that the representative components of XKF, including berberine, chlorogenic acid, calycosin, swertiamarin and astragaloside IV have significantly different metabolic pathways in plasma and liver. Prototypes and metabolites of these components were rarely detected in the urine and feces of mice. According to the network pharmacological analysis, these differential components are predicted to improve IR by targeting key factors such as SRC, JUN, HRAS, NOS3, FGF2, etc. Additionally, the signaling pathways involved in this process include PI3K-AKT pathway, GnRH signaling pathway, and T cell receptor signaling pathway. In addition, in vitro experiments indicate that berberine and its metabolites (berberine and demethyleneberine), chlorogenic acid and its metabolites (3-O-ferulic quinic acid and 5-O-ferulic quinic acid), calycosin and swertiamarin could improve IR in IR-HepG2 cells by elevating the expression of PI3K and AKT, leading to an increase in glucose consumption.

CONCLUSION

The key pharmacodynamic material basis of XKF, such as berberine and its metabolites (berberrubine and demethyleneberberine), chlorogenic acid and its metabolites (3-O-feruloylquinic acid and 5-O-feruloylquinic acid), calycosin and swertiamarin influence the glucose metabolism disorder of IR-HepG2 cells by regulating the PI3K/AKT signalling pathway, leading to an improvement in IR.

Lab-on-chip technologies for exploring the gut-immune axis in metabolic disease

The continued rise in metabolic diseases such as obesity and type 2 diabetes mellitus poses a global health burden, necessitating further research into factors implicated in the onset and progression of these diseases. Recently, the gut-immune axis, with diet as a main regulator, has been identified as a possible role player in their development. Translation of conventional 2D in vitro and animal models is however limited, while human studies are expensive and preclude individual mechanisms from being investigated. Lab-on-chip technology therefore offers an attractive new avenue to study gut-immune interactions. This review provides an overview of the influence of diet on gut-immune interactions in metabolic diseases and a critical analysis of the current state of lab-on-chip technology to study this axis. While there has been progress in the development of "immuno-competent" intestinal lab-on-chip models, with studies showing the ability of the technology to provide mechanical cues, support longer-term co-culture of microbiota and maintain in vivo-like oxygen gradients, platforms which combine all three and include intestinal and immune cells are still lacking. Further, immune cell types and inclusion of microenvironment conditions which enable in vivo-like immune cell dynamics as well as host-microbiome interactions are limited. Future model development should focus on combining these conditions to create an environment capable of hosting more complex microbiota and immune cells to allow further study into the effects of diet and related metabolites on the gut-immune ecosystem and their role in the prevention and development of metabolic diseases in humans.

Unleashing the potential of adipose organoids: A revolutionary approach to combat obesity-related metabolic diseases

Obesity-related metabolic diseases, including obesity, diabetes, hyperlipidemia, and non-alcoholic fatty liver diseases pose a significant threat to health. However, comprehensive pathogenesis exploration and effective therapy development are impeded by the limited availability of human models. Notably, advances in organoid technology enable the generation of adipose organoids that recapitulate structures and functions of native human adipose tissues to investigate mechanisms and develop corresponding treatments for obesity-related metabolic diseases. Here, we review the general principles, sources, and three-dimensional techniques for engineering adipose organoids, along with strategies to promote maturation. We also outline the application of white adipose organoids, primarily for disease modeling and drug screening, and highlight the therapeutic potential of thermogenic beige and brown adipose organoids in promoting weight loss and glucose and lipid metabolic homeostasis. We also discuss the challenges and prospects in the establishment and bench-to-bedside of adipose organoids, as well as their potential applications.

Human intestinal organoids: Modeling gastrointestinal physiology and immunopathology - current applications and limitations

Human intestinal organoids are an ideal model system for studying gastrointestinal physiology and immunopathology. Altered physiology and mucosal immune response are hallmarks of numerous intestinal functional and inflammatory diseases, including inflammatory bowel disease (IBD), coeliac disease, irritable bowel syndrome (IBS), and obesity. These conditions impact the normal epithelial functions of the intestine, such as absorption, barrier function, secretion, and host-microbiome communication. They are accompanied by characteristic intestinal symptoms and have significant societal, economic, and healthcare burdens. To develop new treatment options, cutting-edge research is required to investigate their etiology and pathology. Human intestinal organoids derived from patient tissue recapitulate the key physiological and immunopathological aspects of these conditions, providing a promising platform for elucidating disease mechanisms. This review will summarize recent reports on patient-derived human small intestinal and colonic organoids and highlight how these models have been used to study intestinal epithelial functions in the context of inflammation, altered physiology, and immune response. Furthermore, it will elaborate on the various organoid systems in use and the techniques/assays currently available to study epithelial functions. Finally, it will conclude by discussing the limitations and future perspectives of organoid technology.

Gut microbes in metabolic disturbances. Promising role for therapeutic manipulations?

The prevalence of overweight, obesity, type 2 diabetes, metabolic syndrome and steatotic liver disease is rapidly increasing worldwide with a huge economic burden in terms of morbidity and mortality. Several genetic and environmental factors are involved in the onset and development of metabolic disorders and related complications. A critical role also exists for the gut microbiota, a complex polymicrobial ecology at the interface of the internal and external environment. The gut microbiota contributes to food digestion and transformation, caloric intake, and immune response of the host, keeping the homeostatic control in health. Mechanisms of disease include enhanced energy extraction from the non-digestible dietary carbohydrates, increased gut permeability and translocation of bacterial metabolites which activate a chronic low-grade systemic inflammation and insulin resistance, as precursors of tangible metabolic disorders involving glucose and lipid homeostasis. The ultimate causative role of gut microbiota in this respect remains to be elucidated, as well as the therapeutic value of manipulating the gut microbiota by diet, pre- and pro- synbiotics, or fecal microbial transplantation.

Obesity alters immunopathology in cancers and inflammatory diseases

Obesity is characterized by chronic low-grade inflammation and is strongly associated with multiple immunological diseases, including cancer and inflammatory diseases. Recent animal studies revealed that obesity-induced immunological changes worsen immune-driven diseases and cause resistance to immunotherapy. Here, we discuss the role of obesity in the immunopathology and treatment responses of cancers, respiratory and allergic diseases, and IL-17-mediated inflammatory diseases. We summarize the unique features of the inflammatory state of these diseases, which are orchestrated by obesity. In particular, obesity alters the immune landscape in cancers with a reprogrammed metabolic profile of tumor-infiltrating immune cells. Obesity exacerbates airway inflammation by dysregulating multiple immune-cell subsets. Obesity also dysregulates Th17, IL-17-producing mucosal-associated invariant T (MAIT), and γδ T cells, which contribute to IL-17-mediated inflammatory response in multiple sclerosis, inflammatory bowel disease, psoriasis, atopic dermatitis, and rheumatoid arthritis. By identifying the effects of obesity on immunological diseases, new strategies could be devised to target immune dysregulation caused by obesity.

Anti-A and anti-B titers, age, gender, biochemical parameters, and body mass index in Japanese blood donors

It has been reported that anti-A and anti-B (ABO antibody) titers decrease with age, but little is known about the association between ABO antibody titers and physiologic/biochemical parameters such as body mass index (BMI), gamma-glutamyl transpeptidase (GGT), and total cholesterol (T-Cho). We investigated the present situation of ABO antibody titers among healthy blood donors in Japan and the physiologic/biochemical factors that may be associated with changes in ABO antibody titers. Plasma from 7450 Japanese blood donors was tested for ABO antibody titers using ABO reverse typing reagents by an automated microplate system; donor samples were classified into low, middle, and high titers according to the agglutination results obtained with diluted plasma samples. Multivariate regression analysis was performed to analyze the association between ABO antibody titers and age, gender, biochemical parameters (alanine transaminase [ALT], GGT, globulin, T-Cho, and glycosylated albumin [GA]), and BMI according to the ABO blood groups. A significant correlation between ABO antibody titers and age/gender, except for gender in anti-A of blood group B donors, was observed. BMI showed significant but negative correlations with anti-A and anti-B (β = -0.085 and -0.062, respectively; p < 0.01) in blood group O donors. In addition, significant but negative correlations between GGT and T-Cho with anti-B of blood group A donors (β = -0.055 and -0.047, respectively; p < 0.05) were observed. Although differences existed among the ABO blood groups, ABO antibody titers seem to be associated with physiologic and biochemical parameters of healthy individuals.

Arctium lappa L. roots inhibit the intestinal inflammation of dietary obese rats through TLR4/NF-κB pathway

Long-term consumption of Arctium lappa L. roots can lead to weight loss. To explore the relationship between anti-obesity and anti-inflammation, the effects and mechanism of A. lappa L. root powder (ARP) on intestinal inflammation in obese rats were investigated. Dietary obese rats were successfully established by feeding a high-fat and high-sugar diet. The control group (n = 6) consumed a normal diet. The intestines were compared among the groups (each n = 6) with and without the administration of ARP (intragastric 7.5 g/kg·bw/d). Real-time quantitative reverse transcription-polymerase chain reaction and western blotting analysis revealed that ARP effectively inhibited the expression of pro-inflammatory and inflammatory cytokines in the colons of obese rats. These cytokines included interleukin (IL)-1β, IL-8, IL-6, tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1. The inhibition rates for all these cytokines exceeded 88 %. Moreover, ARP demonstrated the ability to down-regulate key genes involved in Toll-like receptor 4 (TLR4) complexes, namely Tlr4, myeloid differentiation protein-2 (Md2), and myeloid differentiation factor 88 (Myd88), along with downstream signaling molecules such as tumor necrosis factor receptor associated factor 6 (TRAF6) and nuclear factor-κB (NF-κB), with inhibition rates over 81 %. Additionally, ARP was observed to inhibit protein levels of TLR4, NF-κB, IL-1β, and TNF-α in the colons of obese rats, with inhibition rates of 65.6 ± 10.9 %, 84.4 ± 19.9 %, 80.8 ± 14.4 %, and 68.4 ± 17.5 %, respectively. This study confirmed the effectiveness of ARP in inhibiting intestinal inflammation through the blockade of the TLR4/NF-κB signaling pathway. It also suggested that ARP holds potential in improving intestinal health in the context of obesity, implying its possible application in the prevention and treatment of obesity and related metabolic diseases.

Gut microbiota and microbiota-derived metabolites in cardiovascular diseases

Cardiovascular diseases, including heart failure, coronary artery disease, atherosclerosis, aneurysm, thrombosis, and hypertension, are a great economic burden and threat to human health and are the major cause of death worldwide. Recently, researchers have begun to appreciate the role of microbial ecosystems within the human body in contributing to metabolic and cardiovascular disorders. Accumulating evidence has demonstrated that the gut microbiota is closely associated with the occurrence and development of cardiovascular diseases. The gut microbiota functions as an endocrine organ that secretes bioactive metabolites that participate in the maintenance of cardiovascular homeostasis, and their dysfunction can directly influence the progression of cardiovascular disease. This review summarizes the current literature demonstrating the role of the gut microbiota in the development of cardiovascular diseases. We also highlight the mechanism by which well-documented gut microbiota-derived metabolites, especially trimethylamine N-oxide, short-chain fatty acids, and phenylacetylglutamine, promote or inhibit the pathogenesis of cardiovascular diseases. We also discuss the therapeutic potential of altering the gut microbiota and microbiota-derived metabolites to improve or prevent cardiovascular diseases.

The interconnection between obesity and executive function in adolescence: The role of the gut microbiome

In the United States, adolescent obesity is a growing epidemic associated with maladaptive executive functioning. Likewise, data link the microbiome to obesity. Emerging microbiome research has demonstrated an interconnection between the gut microbiome and the brain, indicating a bidirectional communication system within the gut-microbiome-brain axis in the pathophysiology of obesity. This narrative review identifies and summarizes relevant research connecting adolescent obesity as it relates to three core domains of executive functioning and the contribution of the gut microbiome in the relationship between obesity and executive functions in adolescence. The review suggests that (1) the interconnection between obesity, executive function, and the gut microbiome is a bidirectional connection, and (2) the gut microbiome may mediate the neurobiological pathways between obesity and executive function deficits. The findings of this review provide valuable insights into obesity-associated executive function deficits and elucidate the possible mediation role of the gut microbiome.

Unveiling the hidden world of gut health: Exploring cutting-edge research through visualizing randomized controlled trials on the gut microbiota

BACKGROUND

The gut microbiota plays a crucial role in gastrointestinal and overall health. Randomized clinical trials (RCTs) play a crucial role in advancing our knowledge and evaluating the efficacy of therapeutic interventions targeting the gut microbiota.

AIM

To conduct a comprehensive bibliometric analysis of the literature on RCTs involving the gut microbiota.

METHODS

Using bibliometric tools, a descriptive cross-sectional investigation was conducted on scholarly publications concentrated on RCTs related to gut microbiota, spanning the years 2003 to 2022. The study used VOSviewer version 1.6.9 to examine collaboration networks between different countries and evaluate the frequently employed terms in the titles and abstracts of the retrieved publications. The primary objective of this analysis was to identify key research areas and focal points associated with RCTs involving the gut microbiota.

RESULTS

A total of 1061 relevant articles were identified from the 24758 research articles published between 2003 and 2022. The number of publications showed a notable increase over time, with a positive correlation (R2 = 0.978, P < 0.001). China (n = 276, 26.01%), the United States (n = 254, 23.94%), and the United Kingdom (n = 97, 9.14%) were the leading contributing countries. Københavns Universitet (n = 38, 3.58%) and Dankook University (n = 35, 3.30%) were the top active institutions. The co-occurrence analysis shows current gut microbiota research trends and important topics, such as obesity interventions targeting the gut microbiota, the efficacy and safety of fecal microbiota transplantation, and the effects of dietary interventions on humans.

CONCLUSION

The study highlights the rapid growth and importance of research on RCTs that involve the gut microbiota. This study provides valuable insight into research trends, identifies key players, and outlines potential future directions in this field. Additionally, the co-occurrence analysis identified important topics that play a critical role in the advancement of science and provided insights into future research directions in this field.

Water-Insoluble Polysaccharide Extracted from Poria cocos Alleviates Antibiotic-Associated Diarrhea Based on Regulating the Gut Microbiota in Mice

Antibiotics are very effective in treating a variety of bacterial infections, while clinical overuse of antibiotics can lead to diseases such as antibiotic-associated diarrhea. Numerous studies have shown that natural polysaccharides can be used as prebiotics to alleviate antibiotic-associated diarrhea (AAD). Poria cocos is a medicinal and edible mushroom widely used for thousands of years in China, and our former study demonstrated that water-insoluble polysaccharide (PCY) has the potential prebiotic function. Therefore, we simulated the digestion and fermentation of PCY using feces from volunteers, and then administered it to C57BL/6 mice with AAD to study its effects on the gut microbiota and metabolites. The results indicated that PCY effectively alleviated the symptoms of AAD in mice, restored the intestinal barrier function, improved the content of short-chain fatty acids (SCFAs), decreased the level of inflammatory cytokines, and changed the structure of gut microbiota by increasing the relative abundance of norank_f__Muribaculaceae and unclassified_f__Lachnospiraceae, and decreasing that of Escherichia-Shigella, Staphylococcus and Acinetobacter. This study further demonstrated that PCY is an effective functional prebiotic for improving AAD disease, and provided a new avenue and insight for developing PCY as a functional food or prebiotic for alleviating gastrointestinal diseases.

Targeted Application of Functional Foods as Immune Fitness Boosters in the Defense against Viral Infection

In recent times, the emergence of viral infections, including the SARS-CoV-2 virus, the monkeypox virus, and, most recently, the Langya virus, has highlighted the devastating effects of viral infection on human life. There has been significant progress in the development of efficacious vaccines for the prevention and control of viruses; however, the high rates of viral mutation and transmission necessitate the need for novel methods of control, management, and prevention. In recent years, there has been a shift in public awareness on health and wellbeing, with consumers making significant dietary changes to improve their immunity and overall health. This rising health awareness is driving a global increase in the consumption of functional foods. This review delves into the benefits of functional foods as potential natural means to modulate the host immune system to enhance defense against viral infections. We provide an overview of the functional food market in Europe and discuss the benefits of enhancing immune fitness in high-risk groups, including the elderly, those with obesity, and people with underlying chronic conditions. We also discuss the immunomodulatory mechanisms of key functional foods, including dairy proteins and hydrolysates, plant-based functional foods, fermentates, and foods enriched with vitamin D, zinc, and selenium. Our findings reveal four key immunity boosting mechanisms by functional foods, including inhibition of viral proliferation and binding to host cells, modulation of the innate immune response in macrophages and dendritic cells, enhancement of specific immune responses in T cells and B cells, and promotion of the intestinal barrier function. Overall, this review demonstrates that diet-derived nutrients and functional foods show immense potential to boost viral immunity in high-risk individuals and can be an important approach to improving overall immune health.

Hydrochlorothiazide-induced glucose metabolism disorder is mediated by the gut microbiota via LPS-TLR4-related macrophage polarization

Hydrochlorothiazide (HCTZ) is reported to impair glucose tolerance and may induce new onset of diabetes, but the pharmacomicrobiomics of the adverse effect for HCTZ remains unknown. Mice-fed HCTZ exhibited insulin resistance and impaired glucose tolerance. By using FMT and antibiotic cocktail models, we found that HCTZ-induced metabolic disorder was mediated by commensal microbiota. HCTZ consumption disturbed the structure of the intestinal microbiota, causing abnormal elevation of Gram-negative Enterobacteriaceae and lipopolysaccharide (LPS) then leading to intestinal barrier dysfunction. Additionally, HCTZ activated TLR4 signaling and induced macrophage polarization and inflammation in the liver. Furthermore, HCTZ-induced macrophage polarization and metabolic disorder were abrogated by blocking TLR4 signaling. HCTZ consumption caused a significant increase in Gram-negative Enterobacteriaceae, which elevated the levels of LPS, thereby activating LPS/TLR4 pathway, promoting inflammation and macrophage polarization, and resulting in metabolic disorders. These findings revealed that the gut microbiome is the key medium underlying HCTZ-induced metabolic disorder.

Diesel Exhaust Particle (DEP)-induced glucose intolerance is driven by an intestinal innate immune response and NLRP3 activation in mice

BACKGROUND

We previously found that air pollution particles reaching the gastrointestinal tract elicit gut inflammation as shown by up-regulated gene expression of pro-inflammatory cytokines and monocyte/macrophage markers. This inflammatory response was associated with beta-cell dysfunction and glucose intolerance. So far, it remains unclear whether gut inflammatory changes upon oral air pollution exposure are causally linked to the development of diabetes. Hence, our aim was to assess the role of immune cells in mediating glucose intolerance instigated by orally administered air pollutants.

METHODS

To assess immune-mediated mechanisms underlying air pollution-induced glucose intolerance, we administered diesel exhaust particles (DEP; NIST 1650b, 12 µg five days/week) or phosphate-buffered saline (PBS) via gavage for up to 10 months to wild-type mice and mice with genetic or pharmacological depletion of innate or adaptive immune cells. We performed unbiased RNA-sequencing of intestinal macrophages to elucidate signaling pathways that could be pharmacologically targeted and applied an in vitro approach to confirm these pathways.

RESULTS

Oral exposure to air pollution particles induced an interferon and inflammatory signature in colon macrophages together with a decrease of CCR2^- anti-inflammatory/resident macrophages. Depletion of macrophages, NLRP3 or IL-1β protected mice from air pollution-induced glucose intolerance. On the contrary, Rag2-/- mice lacking adaptive immune cells developed pronounced gut inflammation and glucose intolerance upon oral DEP exposure.

CONCLUSION

In mice, oral exposure to air pollution particles triggers an immune-mediated response in intestinal macrophages that contributes to the development of a diabetes-like phenotype. These findings point towards new pharmacologic targets in diabetes instigated by air pollution particles.

NAD+ Precursors and Intestinal Inflammation: Therapeutic Insights Involving Gut Microbiota

The oxidized form of nicotinamide adenine dinucleotide (NAD+) is a critical metabolite for living cells. NAD+ may act either as a cofactor for many cellular reactions as well as a coenzyme for different NAD+-consuming enzymes involved in the physiological homeostasis of different organs and systems. In mammals, NAD+ is synthesized from either tryptophan or other vitamin B3 intermediates that act as NAD+ precursors. Recent research suggests that NAD+ precursors play a crucial role in maintaining the integrity of the gut barrier. Indeed, its deficiency has been associated with enhanced gut inflammation and leakage, and dysbiosis. Conversely, NAD+-increasing therapies may confer protection against intestinal inflammation in experimental conditions and human patients, with accumulating evidence indicating that such favorable effects could be, at least in part, mediated by concomitant changes in the composition of intestinal microbiota. However, the mechanisms by which NAD+-based treatments affect the microbiota are still poorly understood. In this context, we have focused specifically on the impact of NAD+ deficiency on intestinal inflammation and dysbiosis in animal and human models. We have further explored the relationship between NAD+ and improved host intestinal metabolism and immunity and the composition of microbiota in vivo. Overall, this comprehensive review aims to provide a new perspective on the effect of NAD+-increasing strategies on host intestinal physiology.

Early infancy dysbiosis in food protein-induced enterocolitis syndrome: A prospective cohort study

BACKGROUND

The microbiome associations of food protein-induced enterocolitis syndrome (FPIES) are understudied. We sought to prospectively define the clinical features of FPIES in a birth cohort, and investigate for the evidence of gut dysbiosis.

METHODS

We identified children diagnosed with FPIES in the Gastrointestinal Microbiome and Allergic Proctocolitis Study, a healthy infant cohort. Children were assessed and stools were collected at each well child visit. The clinical features of the children with FPIES were summarized. Stool microbiome was analyzed using 16S rRNA sequencing comparing children with and without FPIES.

RESULTS

Of the 874 children followed up for 3 years, 8 FPIES cases (4 male) were identified, yielding a cumulative incidence of 0.92%. The most common triggers were oat and rice (n = 3, each) followed by milk (n = 2). The children with FPIES were more likely to have family history of food allergy (50% vs. 15.9% among unaffected, p = .03). The average age of disease presentation was 6 months old. During the first 6 months of life, stool from children with FPIES contained significantly less Bifidobacterium adolescentis, but more pathobionts, including Bacteroides spp. (especially Bacteroides fragilis), Holdemania spp., Lachnobacterium spp., and Acinetobacter lwoffii. The short-chain fatty acid (SCFA)-producing Bifidobacterium shunt was expressed significantly less in the stool from FPIES children.

CONCLUSIONS

In this cohort, the cumulative incidence over the 3-year study period was 0.92%. During the first 6 months of life, children with FPIES had evidence of dysbiosis and SCFA production pathway was expressed less in their stool, which may play an important role in the pathogenesis of FPIES.

Circulating sepsis-related metabolite sphinganine could protect against intestinal damage during sepsis

Introduction

Sepsis is intricately linked to intestinal damage and barrier dysfunction. At present times, there is a growing interest in a metabolite-based therapy for multiple diseases.

Methods

Serum samples from septic patients and healthy individuals were collected and their metabonomics profiling assessed using Ultra-Performance Liquid Chromatography-Time of Flight Mass Spectrometry (UPLC-TOFMS). The eXtreme Gradient Boosting algorithms (XGBOOST) method was used to screen essential metabolites associated with sepsis, and five machine learning models, including Logistic Regression, XGBoost, GaussianNB(GNB), upport vector machines(SVM) and RandomForest were constructed to distinguish sepsis including a training set (75%) and validation set(25%). The area under the receiver-operating characteristic curve (AUROC) and Brier scores were used to compare the prediction performances of different models. Pearson analysis was used to analysis the relationship between the metabolites and the severity of sepsis. Both cellular and animal models were used to HYPERLINK "javascript:;" assess the function of the metabolites.

Results

The occurrence of sepsis involve metabolite dysregulation. The metabolites mannose-6-phosphate and sphinganine as the optimal sepsis-related variables screened by XGBOOST algorithm. The XGBoost model (AUROC=0.956) has the most stable performance to establish diagnostic model among the five machine learning methods. The SHapley Additive exPlanations (SHAP) package was used to interpret the XGBOOST model. Pearson analysis reinforced the expression of Sphinganine, Mannose 6-phosphate were positively associated with the APACHE-II, PCT, WBC, CRP, and IL-6. We also demonstrated that sphinganine strongly diminished the LDH content in LPS-treated Caco-2 cells. In addition, using both in vitro and in vivo examination, we revealed that sphinganine strongly protects against sepsis-induced intestinal barrier injury.

Discussion

These findings highlighted the potential diagnostic value of the ML, and also provided new insight into enhanced therapy and/or preventative measures against sepsis.

Mitochondria: It is all about energy

Mitochondria play a key role in both health and disease. Their function is not limited to energy production but serves multiple mechanisms varying from iron and calcium homeostasis to the production of hormones and neurotransmitters, such as melatonin. They enable and influence communication at all physical levels through interaction with other organelles, the nucleus, and the outside environment. The literature suggests crosstalk mechanisms between mitochondria and circadian clocks, the gut microbiota, and the immune system. They might even be the hub supporting and integrating activity across all these domains. Hence, they might be the (missing) link in both health and disease. Mitochondrial dysfunction is related to metabolic syndrome, neuronal diseases, cancer, cardiovascular and infectious diseases, and inflammatory disorders. In this regard, diseases such as cancer, Alzheimer's, Parkinson's, amyotrophic lateral sclerosis (ALS), chronic fatigue syndrome (CFS), and chronic pain are discussed. This review focuses on understanding the mitochondrial mechanisms of action that allow for the maintenance of mitochondrial health and the pathways toward dysregulated mechanisms. Although mitochondria have allowed us to adapt to changes over the course of evolution, in turn, evolution has shaped mitochondria. Each evolution-based intervention influences mitochondria in its own way. The use of physiological stress triggers tolerance to the stressor, achieving adaptability and resistance. This review describes strategies that could recover mitochondrial functioning in multiple diseases, providing a comprehensive, root-cause-focused, integrative approach to recovering health and treating people suffering from chronic diseases.

The association between the body roundness index and the risk of colorectal cancer: a cross-sectional study

BACKGROUND

Colorectal cancer (CRC), has a link between obesity, especially visceral fat. The body roundness index (BRI) can more accurately assess body fat and visceral fat levels. It is, however, unknown whether BRI is associated with CRC risk.

METHODS

53,766 participants were enrolled from the National Health and Nutrition Examination Survey (NHANES). Analysing the corelation between BRI and CRC risk was performed using logistic regression. Stratified analyses revealed the association based on the population type. Receiver operating characteristic curve (ROC) was performed for predicting CRC risk using different anthropometric indices.

RESULTS

The risk of CRC mounting apparently with elevated BRI for participants with CRC compared to normal participants (P-trend < 0.001). The association persisted even after adjusting for all covariates (P-trend = 0.017). In stratified analyses, CRC risk increased with increasing BRI, especially among those who were inactive (OR (95% CI): Q3 3.761 (2.139, 6.610), P < 0.05, Q4 5.972 (3.347, 8.470), P < 0.01), overweight (OR (95% CI): Q3 2.573 (1.012, 7.431), P < 0.05, Q4 3.318 (1.221, 9.020), P < 0.05) or obese (OR (95% CI): Q3 3.889 (1.829, 8.266), P < 0.001, Q4 4.920 (2.349, 10.308), P < 0.001). ROC curve showed that BRI had a better ability in forecasting the risk of CRC than other anthropometric indices such as body weight etc. (all P < 0.05).

CONCLUSIONS

CRC risk and BRI have a positive and significant relationship, particularly in inactive participants with BMI ≥ 25 kg/m². It is hoped that these results will raise awareness of the importance of reducing visceral fat deposition.

Current progress of mesenchymal stem cell membrane-camouflaged nanoparticles for targeted therapy

Nanodrug delivery systems have been widely used in disease treatment. However, weak drug targeting, easy to be cleared by the immune system, and low biocompatibility are great obstacles for drug delivery. As an important part of cell information transmission and behavior regulation, cell membrane can be used as drug coating material which represents a promising strategy and can overcome these limitations. Mesenchymal stem cell (MSC) membrane, as a new carrier, has the characteristics of active targeting and immune escape of MSC, and has broad application potential in tumor treatment, inflammatory disease, tissue regeneration and other fields. Here, we review recent progress on the use of MSC membrane-coated nanoparticles for therapy and drug delivery, aiming to provide guidance for the design and clinical application of membrane carrier in the future.

Gut Enterobacteriaceae and uraemic toxins - Perpetrators for ageing

Ageing is a complex process that is associated with changes in the composition and functions of gut microbiota. Reduction of gut commensals is the hallmarks of ageing, which favours the expansion of pathogens even in healthy centenarians. Interestingly, gut Enterobacteriaceae have been found to be increased with age and also consistently observed in the patients with metabolic diseases. Thus, they are associated with all-cause mortality, regardless of genetic origin, lifestyle, and fatality rate. Moreover, Enterobacteriaceae are also implicated in accelerating the ageing process through telomere attrition, cellular senescence, inflammasome activation and impairing the functions of mitochondria. However, acceleration of ageing is likely to be determined by intrinsic interactions between Enterobacteriaceae and other associated gut bacteria. Several studies suggested that Enterobacteriaceae possess genes for the synthesis of uraemic toxins. In addition to intestine, Enterobacteriaceae and their toxic metabolites have also been found in other organs, such as adipose tissue and liver and that are implicated in multiorgan dysfunction and age-related diseases. Therefore, targeting Enterobacteriaceae is a nuance approach for reducing inflammaging and enhancing the longevity of older people. This review is intended to highlight the current knowledge of Enterobacteriaceae-mediated acceleration of ageing process.

Psyllium Fiber Protects Against Colitis Via Activation of Bile Acid Sensor Farnesoid X Receptor

BACKGROUND & AIMS

Fiber-rich foods promote health, but mechanisms by which they do so remain poorly defined. Screening fiber types, in mice, revealed psyllium had unique ability to ameliorate 2 chronic inflammatory states, namely, metabolic syndrome and colitis. We sought to determine the mechanism of action of the latter.

METHODS

Mice were fed grain-based chow, which is naturally rich in fiber or compositionally defined diets enriched with semi-purified fibers. Mice were studied basally and in models of chemical-induced and T-cell transfer colitis.

RESULTS

Relative to all diets tested, mice consuming psyllium-enriched compositionally defined diets were markedly protected against both dextran sulfate sodium- and T-cell transfer-induced colitis, as revealed by clinical-type, histopathologic, morphologic, and immunologic parameters. Such protection associated with stark basal changes in the gut microbiome but was independent of fermentation and, moreover, maintained in mice harboring a minimal microbiota (ie, Altered Schaedler Flora). Transcriptomic analysis revealed psyllium induced expression of genes mediating bile acids (BA) secretion, suggesting that psyllium's known ability to bind BA might contribute to its ability to prevent colitis. As expected, psyllium resulted in elevated level of fecal BA, reflecting their removal from enterohepatic circulation but, in stark contrast to the BA sequestrant cholestyramine, increased serum BA levels. Moreover, the use of BA mimetics that activate the farnesoid X receptor (FXR), as well as the use of FXR-knockout mice, suggested that activation of FXR plays a central role in psyllium's protection against colitis.

CONCLUSIONS

Psyllium protects against colitis via altering BA metabolism resulting in activation of FXR, which suppresses pro-inflammatory signaling.

Weight cycling based on altered immune microenvironment as a result of metaflammation

As a result of the obesity epidemic, more people are concerned about losing weight; however, weight regain is common, leading to repeated weight loss and weight cycling. The health benefits of early weight loss are nullified by weight regain after weight cycling, which has much more severe metabolic consequences. Weight cycling alters body composition, resulting in faster fat recovery and slower muscle reconstruction. This evident fat accumulation, muscle loss, and ectopic fat deposition destroy the intestinal barrier, increase the permeability of the small intestinal epithelium, and cause the lipotoxicity of lipid metabolites and toxins to leak into extraintestinal tissues and circulation. It causes oxidative stress and hypoxia in local tissues and immune cell infiltration in various tissues, all contributing to the adaptation to this metabolic change. Immune cells transmit inflammatory responses in adipose and skeletal muscle tissue by secreting cytokines and adipokines, which mediate immune cell pathways and cause metaflammation and inefficient metabolic degradation. In this review, we focus on the regulatory function of the immunological microenvironment in the final metabolic outcome, with a particular emphasis on the cellular and molecular processes of local and systemic metaflammation induced by weight cycling-induced changes in body composition. Metaflammation in adipose and muscle tissues that is difficult to relieve may cause weight cycling. As this chronic low-grade inflammation spreads throughout the body, metabolic complications associated with weight cycling are triggered. Inhibiting the onset and progression of metabolic inflammation and enhancing the immune microenvironment of adipose and muscle tissues may be the first step in addressing weight cycling.

Nicotinamide mononucleotide alters body composition and ameliorates metabolic disorders induced by a high-fat diet

Obesity is caused by an imbalance between calorie intake and energy expenditure, leading to excessive adipose tissue accumulation. Nicotinamide adenine dinucleotide (NAD⁺ ) is an important molecule in energy and signal transduction, and NAD⁺ supplementation therapy is a new treatment for obesity in recent years. Liver kinase B1 (LKB1) is an energy metabolism regulator. The relationship between NAD⁺ and LKB1 has only been studied in the heart and has not yet been reported in obesity. Nicotinamide mononucleotide (NMN), as a direct precursor of NAD⁺ , can effectively enhance the level of NAD⁺ . In the current study, we showed that NMN intervention altered body composition in obese mice, characterized by a reduction in fat mass and an increase in lean mass. NMN reversed high-fat diet-induced blood lipid levels then contributed to reducing hepatic steatosis. NMN also improved glucose tolerance and alleviated adipose tissue inflammation. Moreover, our data suggested that NMN supplementation may be depends on the NAD⁺ /SIRT6/LKB1 pathway to regulate brown adipose metabolism. These results provided new evidence for NMN in obesity treatment.