Metabolic endotoxemia initiates obesity and insulin resistance

Identifying the location-dependent adipose tissue bacterial DNA signatures in obese patients that predict body weight loss

Recent sets of evidence have described profiles of 16S rDNA sequences in host tissues, notably in fat pads that are significantly overrepresented and can serve as signatures of metabolic disease. However, these recent and original observations need to be further detailed and functionally defined. Here, using state-of-the-art targeted DNA sequencing and discriminant predictive approaches, we describe, from the longitudinal FLORINASH cohort of patients who underwent bariatric surgery, visceral, and subcutaneous fat pad-specific bacterial 16SrRNA signatures. The corresponding Porphyromonadaceae, Campylobacteraceae, Prevotellaceae, Actimomycetaceae, Veillonellaceae, Anaerivoracaceae, Fusobacteriaceae, and the Clostridium family XI 16SrRNA DNA segment profiles are signatures of the subcutaneous adipose depot while Pseudomonadaceae and Micrococcacecae, 16SrRNA DNA sequence profiles characterize the visceral adipose depot. In addition, we have further identified that a specific pre-bariatric surgery adipose tissue bacterial DNA signature predicts the efficacy of body weight loss in obese patients 5-10 years after the surgery. 16SrRNA signatures discriminate (ROC ~ 1) the patients who did not maintain bodyweight loss and those who did. Second, from the 16SrRNA sequences we infer potential pathways suggestive of catabolic biochemical activities that could be signatures of subcutaneous adipose depots that predict body weight loss.

Multifunctional dietary approach reduces intestinal inflammation in relation with changes in gut microbiota composition in subjects at cardiometabolic risk: the SINFONI project

The development of cardiometabolic (CM) diseases is associated with chronic low-grade inflammation, partly linked to alterations of the gut microbiota (GM) and reduced intestinal integrity. The SINFONI project investigates a multifunctional (MF) nutritional strategy's impact combining different bioactive compounds on inflammation, GM modulation and CM profile. In this randomized crossover-controlled study, 30 subjects at CM-risk consumed MF cereal-products, enriched with polyphenols, fibers, slowly-digestible starch, omega-3 fatty acids or Control cereal-products (without bioactive compounds) for 2 months. Metabolic endotoxemia (lipopolysaccharide (LPS), lipopolysaccharide-binding protein over soluble cluster of differentiation-14 (LBP/sCD14), systemic inflammation and cardiovascular risk markers, intestinal inflammation, CM profile and response to a one-week fructose supplementation, were assessed at fasting and post mixed-meal. GM composition and metabolomic analysis were conducted. Mixed linear models were employed, integrating time (pre/post), treatment (MF/control), and sequence/period. Compared to control, MF intervention reduced intestinal inflammation (fecal calprotectin, p = 0.007) and endotoxemia (fasting LPS, p < 0.05), without alteration of systemic inflammation. MF decreased serum branched-chain amino acids compared to control (p < 0.05) and increased B.ovatus, B.uniformis, A.butyriciproducens and unclassified Christensenellaceae.CAG-74 (p < 0.05). CM markers were unchanged. A 2-month dietary intervention combining multiple bioactive compounds improved intestinal inflammation and induced GM modulation. Such strategy appears as an effective strategy to target low-grade inflammation through multi-target approach.

Obesogenic effects of six classes of emerging contaminants

There is growing concern about the concept that exposure to environmental chemicals may be contributing to the obesity epidemic. However, there is no consensus on the obesogenic effects of emerging contaminants from a toxicological and environmental perspective. The potential human exposure and experimental evidence for obesogenic effects of emerging contaminants need to be systematically discussed. The main objective of this review is to provide recommendations for further subsequent policy development following a critical analysis of the literature for humans and experimental animals exposed to emerging contaminants. This article reviews human exposure to emerging contaminants (with a focus on antimicrobials, preservatives, water and oil repellents, flame retardants, antibiotics and bisphenols) and the impact of emerging contaminants on obesity. These emerging contaminants have been widely detected in human biological samples. Epidemiological studies provide evidence linking exposure to emerging contaminants to the risks of obesity in humans. Studies based on animal models and adipose cells show the obesogenic effects of emerging contaminants and identify modes of action by which contaminants may induce changes in body fat accumulation and lipid metabolic homeostasis. Some knowledge gaps in this area and future directions for further investigation are discussed.

Gut microbial metabolites: The bridge connecting diet and atherosclerosis, and next-generation targets for dietary interventions

Mounting evidence indicates that gut microbial metabolites are central hubs linking the gut microbiota to atherosclerosis (AS). Gut microbiota enriched with pathobiont bacteria responsible for producing metabolites like trimethylamine N-oxide and phenylacetylglutamine are related to an increased risk of cardiovascular events. Furthermore, gut microbiota enriched with bacteria responsible for producing short-chain fatty acids, indole, and its derivatives, such as indole-3-propionic acid, have demonstrated AS-protective effects. This study described AS-related gut microbial composition and how microbial metabolites affect AS. Summary findings revealed gut microbiota and their metabolites-targeted diets could benefit AS treatment. In conclusion, dietary interventions centered on the gut microbiota represent a promising strategy for AS treatment, and understanding diet-microbiota interactions could potentially be devoted to developing novel anti-AS therapies.

Gut microbiome and body composition with sorbitol intake during early lifespan

OBJECTIVE

The association of sorbitol intake with maintaining healthy body weight through the gut microbiome during early life was investigated.

RESEARCH METHODS AND PROCEDURES

Sorbitol intake, body mass index (BMI), and fecal samples were collected in the total of 369 pregnant women with their infants (aged 4 months to 5 years) from the Taipei Mother-Infant Nutrition Cohort and 1946 children and adolescents (aged 6-18 years) from the Taiwan Puberty Longitudinal Study. The BMI-z score in sorbitol users was compared to that in sorbitol nonusers using generalized linear mixed model. The beta diversity of microbiome was investigated in both cohorts. The association between the richness of microbes and body composition was analyzed.

RESULTS

The children and adolescents with high sorbitol intake had lower BMI-z score at 6 to 10 and 11 to 18 years of age (P < 0.01) compared with those without sorbitol intake. The beta diversity of the microbiome differed significantly between the sorbitol users and nonusers. Bifidobacterium was higher in the gut of infants and children whose mothers were sorbitol users than that of infants and children whose mothers were sorbitol nonusers during pregnancy. Several microbes were involved in the regulation of obesity, such as Staphylococcus, Faecalibacterium, and Oscillospiraceae_UCG-005 negatively associated with anthropometric measures.

CONCLUSIONS

Sorbitol intake was associated with lower child and adolescent BMI. Sorbitol consumption could shape the composition and richness of beneficial microbiota, contributing to the maintenance of ideal body weight and metabolic homeostasis in early life.

Biomimetic nanoplatform with microbiome modulation and antioxidant functions ameliorating insulin resistance and pancreatic β-cell dysfunction for T2DM management

Insulin resistance and pancreatic β-cell dysfunction are the main pathogenesis of type 2 diabetes mellitus (T2DM). However, insulin therapy and diabetes medications do not effectively solve the two problems simultaneously. In this study, a biomimetic oral hydrogen nanogenerator that leverages the benefits of edible plant-derived exosomes and hydrogen therapy was constructed to overcome this dilemma by modulating gut microbiota and ameliorating oxidative stress and inflammatory responses. Hollow mesoporous silica (HMS) nanoparticles encapsulating ammonia borane (A) were used to overcome the inefficiency of H2 delivery in traditional hydrogen therapy, and exosomes originating from ginger (GE) were employed to enhance biocompatibility and regulate intestinal flora. Our study showed that HMS/A@GE not only considerably ameliorated insulin resistance and liver steatosis, but inhibited the dedifferentiation of islet β-cell and enhanced pancreatic β-cell proportion in T2DM model mice. In addition to its antioxidant and anti-inflammatory effects, HMS/A@GE augmented the abundance of Lactobacilli spp. and tryptophan metabolites, such as indole and indole acetic acid, which further activated the AhR/IL-22 pathway to improve intestinal-barrier function and metabolic impairments. This study offers a potentially viable strategy for addressing the current limitations of diabetes treatment by integrating gut-microbiota remodelling with antioxidant therapies.

GLP-1 and IL-6 regulates obesity in the gut and brain

Obesity is a chronic metabolic disease characterized by excessive nutrient intake leading to increased subcutaneous or visceral fat, resulting in pathological and physiological changes. The incidence rate of obesity, an important form of metabolic syndrome, is increasing worldwide. Excess appetite is a key pathogenesis of obesity, and the inflammatory response induced by obesity has received increasing attention. This review focuses on the role of appetite-regulating factor (Glucogan-like peptide 1) and inflammatory factor (Interleukin-6) in the gut and brain in individuals with obesity and draws insights from the current literature.

Multiomics of the intestine-liver-adipose axis in multiple studies unveils a consistent link of the gut microbiota and the antiviral response with systemic glucose metabolism

BACKGROUND

The microbiota is emerging as a key factor in the predisposition to insulin resistance and obesity.

OBJECTIVE

To understand the interplay among gut microbiota and insulin sensitivity in multiple tissues.

DESIGN

Integrative multiomics and multitissue approach across six studies, combining euglycaemic clamp measurements (used in four of the six studies) with other measurements of glucose metabolism and insulin resistance (glycated haemoglobin (HbA1c) and fasting glucose).

RESULTS

Several genera and species from the Proteobacteria phylum were consistently negatively associated with insulin sensitivity in four studies (ADIPOINST, n=15; IRONMET, n=121, FLORINASH, n=67 and FLOROMIDIA, n=24). Transcriptomic analysis of the jejunum, ileum and colon revealed T cell-related signatures positively linked to insulin sensitivity. Proteobacteria in the ileum and colon were positively associated with HbA1c but negatively with the number of T cells. Jejunal deoxycholic acid was negatively associated with insulin sensitivity. Transcriptomics of subcutaneous adipose tissue (ADIPOMIT, n=740) and visceral adipose tissue (VAT) (ADIPOINST, n=29) revealed T cell-related signatures linked to HbA1c and insulin sensitivity, respectively. VAT Proteobacteria were negatively associated with insulin sensitivity. Multiomics and multitissue integration in the ADIPOINST and FLORINASH studies linked faecal Proteobacteria with jejunal and liver deoxycholic acid, as well as jejunal, VAT and liver transcriptomic signatures involved in the actin cytoskeleton, insulin and T cell signalling. Fasting glucose was consistently linked to interferon-induced genes and antiviral responses in the intestine and VAT. Studies in Drosophila melanogaster validated these human insulin sensitivity-associated changes.

CONCLUSION

These data provide comprehensive insights into the microbiome-gut-adipose-liver axis and its impact on systemic insulin action, suggesting potential therapeutic targets.Cite Now.

Postbiotic Impact on Host Metabolism and Immunity Provides Therapeutic Potential in Metabolic Disease

The gut microbiota influences aspects of metabolic disease, including tissue inflammation, adiposity, blood glucose, insulin, and endocrine control of metabolism. Prebiotics or probiotics are often sought to combat metabolic disease. However, prebiotics lack specificity and can have deleterious bacterial community effects. Probiotics require live bacteria to find a colonization niche sufficient to influence host immunity or metabolism. Postbiotics encompass bacterial-derived components and molecules, which are well-positioned to alter host immunometabolism without relying on colonization efficiency or causing widespread effects on the existing microbiota. Here, we summarize the potential for beneficial and detrimental effects of specific postbiotics related to metabolic disease and the underlying mechanisms of action. Bacterial cell wall components, such as lipopolysaccharides, muropeptides, lipoteichoic acids and flagellin, have context-dependent effects on host metabolism by engaging specific immune responses. Specific types of postbiotics within broad classes of compounds, such as lipopolysaccharides and muropeptides, can have opposing effects on endocrine control of host metabolism, where certain postbiotics are insulin sensitizers and others promote insulin resistance. Bacterial metabolites, such as short-chain fatty acids, bile acids, lactate, glycerol, succinate, ethanolamine, and ethanol, can be substrates for host metabolism. Postbiotics can fuel host metabolic pathways directly or influence endocrine control of metabolism through immunomodulation or mimicking host-derived hormones. The interaction of postbiotics in the host-microbe relationship should be considered during metabolic inflammation and metabolic disease.

The oral-gut microbiota axis: a link in cardiometabolic diseases

The oral-gut microbiota axis plays a crucial role in cardiometabolic health. This review explores the interactions between these microbiomes through enteric, hematogenous, and immune pathways, resulting in disruptions in microbial balance and metabolic processes. These disruptions contribute to systemic inflammation, metabolic disorders, and endothelial dysfunction, which are closely associated with cardiometabolic diseases. Understanding these interactions provides insights for innovative therapeutic strategies to prevent and manage cardiometabolic diseases.

From Endoscopic Inspection to Gene-Expression: A Thorough Assessment of the Duodenal Mucosa After Resurfacing-A Prospective Study

AIMS

Duodenal Mucosal Resurfacing (DMR) is an endoscopic ablation technique aimed at improving glycemia in patients with type 2 diabetes mellitus (T2DM). Although the exact underlying mechanism is still unclear, it is postulated that the DMR-induced improvements are the result of changes in the duodenal mucosa. For this reason, we assessed macroscopic and microscopic changes in the duodenal mucosa induced by DMR + GLP-1RA.

METHODS

We included 16 patients with T2DM using basal insulin that received a combination treatment of a single DMR and GLP-1RA. Endoscopic evaluation was performed before the DMR procedure and 3 month after, and duodenal biopsies were obtained. Histological evaluation was performed and L and K cell density was calculated. In addition, gene-expression analysis and Western blotting was performed.

RESULTS

Endoscopic evaluation at 3 month showed duodenal mucosa with a normal appearance. In line, microscopic histological evaluation showed no signs of villous atrophy or inflammation and unchanged L and K cell density. Unbiased transcriptome profiling and western blotting revealed that PDZK1 expression was higher in responders at baseline and after DMR. GATA6 expression was significantly increased in responders after DMR compared to non-responders.

CONCLUSION

The absence of macroscopic and microscopic changes after 3 month suggest that improvements in glycemic parameters after DMR do not result from significant histological changes in duodenal mucosa. It is more likely that these improvements result from more subtle changes in enteroendocrine signaling. PDZK1 and GATA6 expression might play a role in DMR; this needs to be confirmed in pre-clinical studies.

Identifying the Involvement of Gut Microbiota in Retinal Vein Occlusion by Mendelian Randomization and Genetic Correlation Analysis

Purpose

Previous researches have suggested an important association between gut microbiota (GM) and vascular pathologies such as atherosclerosis. This study aimed to explore the association between 196 GM taxa and retinal vein occlusion (RVO).

Methods

This study used Mendelian randomization (MR), linkage disequilibrium score regression (LDSC), and polygenic overlap analysis. Genome-wide association study (GWAS) data associated with 196 GM taxa was obtained from the MiBioGen consortium, involving a large number of European-ancestry participants. GWAS data of RVO was obtained from the FinnGen consortium and another study that also involved European-ancestry participants. Inverse-variance weighted was used as the primary approach for MR estimation. Moreover, LDSC and polygenic overlap analyses were performed to evaluate the genetic correlation between GM taxa and RVO.

Results

The MR results identified the association of six GM taxa, including class Bacilli, order Lactobacillales, family Streptococcaceae, genus Clostridium innocuum group, genus Family XIII AD3011 group, and genus Subdoligranulum with the development of RVO. In addition, the polygenic overlap analysis supported the genetic association between GM and RVO.

Conclusions

Our findings confirmed the association between six GM taxa and the development of RVO, thereby highlighting the effects of GM on retinal vascular health.

Translational Relevance

The results may provide the rationale for developing GM-based strategies for preventing the onset of RVO.

Dietary ω-3 Fatty Acids Mitigate Intestinal Barrier Integrity Alterations in Mice Fed a High-Fat Diet: Implications for Pancreatic Carcinogenesis

BACKGROUND

Although body fatness is a recognized risk factor for pancreatic ductal adenocarcinoma (PDAC), the underlying mechanisms of how fat composition affects pancreatic carcinogenesis are poorly understood. High-fat diets (HFDs) can disrupt intestinal barrier function, potentially accelerating carcinogenesis. Omega-3 (ω-3) polyunsaturated fatty acids (FAs) have anti-inflammatory properties and help preserve intestinal integrity.

OBJECTIVE

The objective of this study was to evaluate how ω-3 FAs affect the colonic barrier in the context of HFD-induced changes, in a mouse model of PDAC [p48-Cre; LSL-KrasG12D (KC)].

METHODS

Male and female KC mice were randomly assigned into 1 of the following 4 groups: 1) a control diet containing ∼11% total calories from fat with an ω-6:ω-3 FA ratio of 10:1 (C), 2) the control diet with high concentrations of ω-3 FA with an ω-6:ω-3 FA ratio of 1:1 (Cω3), 3) an HFD containing 60% total calories from fat with an ω-6:ω-3 FA ratio of approximately 10:1 (HF), and 4) an HFD with high concentrations of ω-3 FA with an ω-6:ω-3 FA ratio of 1:1 (HFω3).

RESULTS

Consumption of an HFD for 8 wk caused: 1) disruption of tight junction structure and function; 2) decreased goblet cell number; 3) higher colonic Toll-like receptor 4 (TLR4) and NADPH oxidase 1 expression; 4) activation of TLR4-triggered pathways, that is, NF-κB, c-Jun N-terminal kinase; 5) elevated plasma lipopolysaccharide concentrations; and 6) higher pancreatic TLR4 expression, and 7) accelerated acinar-to-ductal metaplasia. All of these events were mitigated in mice fed the HFω3.

CONCLUSIONS

Our findings support the concept that, in the context of obesity, ω-3 FAs have protective effects during early-stage pancreatic carcinogenesis through the regulation of intestinal permeability and endotoxemia.

The Role of the Neural Exposome as a Novel Strategy to Identify and Mitigate Health Inequities in Alzheimer's Disease and Related Dementias

With the continuous increase of the elderly population, there is an urgency to understand and develop relevant treatments for Alzheimer's disease and related dementias (ADRD). In tandem with this, the prevalence of health inequities continues to rise as disadvantaged communities fail to be included in mainstream research. The neural exposome poses as a relevant mechanistic approach and tool for investigating ADRD onset, progression, and pathology as it accounts for several different factors: exogenous, endogenous, and behavioral. Consequently, through the neural exposome, health inequities can be addressed in ADRD research. In this paper, we address how the neural exposome relates to ADRD by contributing to the discourse through defining how the neural exposome can be developed as a tool in accordance with machine learning. Through this, machine learning can allow for developing a greater insight into the application of transferring and making sense of experimental mouse models exposed to health inequities and potentially relate it to humans. The overall goal moving beyond this paper is to define a multitude of potential factors that can increase the risk of ADRD onset and integrate them to create an interdisciplinary approach to the study of ADRD and subsequently translate the findings to clinical research.

Targeting the NLRP3 inflammasome-IL-1β pathway in type 2 diabetes and obesity

Increased activity of the NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome-IL-1β pathway is observed in obesity and contributes to the development of type 2 diabetes and its complications. In this review, we describe the pathological activation of IL-1β by metabolic stress, ageing and the microbiome and present data on the role of IL-1β in metabolism. We explore the physiological role of the IL-1β pathway in insulin secretion and the relationship between circulating levels of IL-1β and the development of diabetes and associated diseases. We highlight the paradoxical nature of IL-1β as both a friend and a foe in glucose regulation and provide details on clinical translation, including the glucose-lowering effects of IL-1 antagonism and its impact on disease modification. We also discuss the potential role of IL-1β in obesity, Alzheimer's disease, fatigue, gonadal dysfunction and related disorders such as rheumatoid arthritis and gout. Finally, we address the safety of NLRP3 inhibition and IL-1 antagonists and the prospect of using this therapeutic approach for the treatment of type 2 diabetes and its comorbidities.

Rebalancing immune homeostasis in combating disease: The impact of medicine food homology plants and gut microbiome

BACKGROUND

Gut microbiota plays an important role in multiple human physiological processes and an imbalance in it, including the species, abundance, and metabolites can lead to diseases. These enteric microorganisms modulate immune homeostasis by presenting a myriad of antigenic determinants and microbial metabolites. Medicinal and food homologous (MFH) plants, edible herbal materials for both medicine and food, are important parts of Traditional Chinese Medicine (TCM). MFH plants have drawn much attention due to their strong biological activity and low toxicity. However, the interplay of MFH and gut microbiota in rebalancing the immune homeostasis in combating diseases needs systematic illumination.

PURPOSE

The review discusses the interaction between MFH and gut microbiota, including the effect of MFH on the major group of gut microbiota and the metabolic effect of gut microbiota on MFH. Moreover, how gut microbiota influences the immune system in terms of innate and adaptive immunity is addressed. Finally, the immunoregulatory mechanisms of MFH in regulation of host pathophysiology via gut microbiota are summarized.

METHODS

Literature was searched, analyzed, and collected using databases, including PubMed, Web of Science, and Google Scholar using relevant keywords. The obtained articles were screened and summarized by the research content of MFH and gut microbiota in immune regulation.

RESULTS

The review demonstrates the interaction between MFH and gut microbiota in disease prevention and treatment. Not only do the intestinal microorganisms and intestinal mucosa constitute an important immune barrier of the human body, but also lymphoid tissue and diffused immune cells within the mucosa participate in the response of innate immunity and adaptive immunity. MFH modulates immune regulation by affecting intestinal flora, helps maintain the balance of the immune system and interfere with the occurrence and development of a broad category of diseases.

CONCLUSION

Being absorbed from the gastrointestinal tract, MFH can have profound effects on gut microbiota. In turn, the gut microbiota also actively participate in the bioconversion of complex constituents from MFH, which could further influence their physiological and pharmacological properties. The review deepens the understanding of the relationship among MFH, gut microbiota, immune system, and human diseases and further promotes the progression of additional relevant research.

R. Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) in People Living With HIV Attending Centre of Excellence in HIV Care at a Tertiary Level Teaching Hospital in North India-A Pilot Study

With the availability of free antiretroviral therapy (ART) across India, HIV in adults has become a chronic disease with prolonged survival. The emergence of various non-communicable diseases in these prolonged survivors is a cause of concern. Metabolic dysfunction-associated steatotic liver disease (MASLD) in adults with HIV infection in India has not been explored to date. In this study, we attempted to assess the existence of MASLD in thirty adults registered at the Centre of Excellence in ART Care at a tertiary teaching hospital in New Delhi. This center provides free first-line, second-line, and third-line ART to patients as well as comprehensive HIV care including counseling, nutritional advice, and inpatient admissions for intercurrent illnesses. A total of 30 subjects were enrolled in the study to assess the occurrence of MASLD among people living with HIV (PLHIV) and its risk factors and to assess hepatic fibrosis in the subjects with MASLD using transient elastography and clinical fibrosis scores. The study population included 13 subjects on ART (43.3%) and 17 ART-naïve subjects (56.6%). All the study subjects underwent ultrasonography (USG) for the identification of the development of MASLD in them. Steatosis was identified as an increase in the echogenicity of the liver seen as an increase in the hepatorenal contrast and was further graded into the 3 grades of fatty liver. Out of the 30 subjects, 16.6% (5 out of 30) were found to have MASLD on USG, with grade 1 fatty changes seen in 4 (13.3%) and grade 2 fatty changes seen in 1 out of 30 subjects (3.3%). A majority (40%) of the subjects were underweight (body mass index [BMI] < 18.5). 22.7% of the male subjects included in the study had MASLD whereas none of the females had fatty changes in the liver on USG. Out of the study subjects, MASLD was detected in 17.6% of ART-naïve subjects while it was detected in 15.4% of subjects on ART. Although no statistically significant association was seen with any of these parameters, a few important trends were observed. These might be statistically significant in a higher power study with a larger sample size. Higher BMI (mean difference [MD] = 3.25, P = .09), waist circumference (MD = 3.84, P = .15), hip circumference (MD = 4.36, P = .14), and older age (MD = 6.56, P = .07) were observed to be associated with MASLD in our study, whereas the biochemical parameters and HIV-related factors were not seen to have any particular trend of association in our study. However, a higher median CD4 count was associated with MASLD as compared to the group without fatty changes on USG. On FibroScan, all 5 subjects with fatty changes in our study were found to have liver stiffness less than 7 kPa which corresponds to F0-F1 stage of fibrosis. Using the nonalcoholic fatty liver disease score, 2 subjects had scores corresponding to F0-F2 stage of fibrosis (as per METAVIR score) while the rest (3 out of 5) had indeterminate values. While on FIB4 scoring, 4 subjects had scores suggesting stage 0-1 fibrosis while 1 had a score suggestive of stage 4-6 fibrosis as per Ishak Fibrosis staging. As PLHIV with known diabetes mellitus, obesity, and hypothyroidism were excluded from our study, the prevalence of MASLD observed in our study underestimates the real prevalence of MASLD in this specific population. No significant association was observed between ART status or ART regimen and MASLD in our study subjects. However, in light of the existing evidence of association of dolutegravir (DTG) with significant weight gain, and the recent inclusion of DTG in the first-line ART regimen nationally in India, robust surveillance and large-scale studies are recommended to study the contribution of DTG to MASLD in PLHIV, if any.

Collection and Processing of Samples for Next-Generation Sequencing to Study the Gut Microbiome

16S rRNA gene sequencing is commonly used for identification and quantitation of microorganisms in complex biological mixtures, such as the human gut microbiome. The 16S rRNA gene is an excellent target gene for sequencing DNA in a heterogenous sample, as it is a highly conserved part of the transcriptional machinery. Universal PCR primers are used to amplify the conserved regions of 16S. Thus, it is possible to amplify the gene in a wide range of different microorganisms from a single sample. As the 16S rRNA gene consists of both conserved and variable regions, sequencing of the variable regions can be used to differentiate between different bacterial species.

A low-dose prebiotic fiber supplement reduces lipopolysaccharide-binding protein concentrations in a subgroup of young, healthy adults consuming low-fiber diets

Although the beneficial effects of fiber supplementation on overall health and the gut microbiome are well-known, it is not clear whether fiber supplementation can also alter the concentrations of lipopolysaccharide-binding protein (LBP), a marker of intestinal permeability. A secondary analysis of a previously conducted study was performed. In the randomized-order, placebo-controlled, double-blinded, cross-over study 20 healthy, young participants consuming a low-fiber diet at baseline were administered a daily dose of 12 g of prebiotic fiber compared with a placebo over a period of 4 weeks with a 4-week washout between arms. In this secondary analysis, we hypothesized that the fiber supplement would reduce LBP concentration. We further hypothesized that lecithin cholesterol acyltransferase activity, a measure of high-density lipoprotein functional capacity, would be altered. Fiber supplementation did not significantly alter LBP concentration or lecithin cholesterol acyltransferase activity in the overall cohort. However, in a subgroup of individuals with elevated baseline LBP concentrations, fiber supplementation significantly reduced LBP from 9.27 ± 3.52 to 7.02 ± 2.32 µg/mL (P = .003). Exploratory analyses found positive correlations between microbial genes involved in lipopolysaccharide synthesis and conversely negative correlations with genes involved in antibiotic synthesis and LBP. Positive correlations between LBP and multiple sulfated molecules including sulfated bile acids and perfluorooctanesulfonate, and ibuprofen metabolites were also found. These findings highlight multiple environmental and lifestyle factors such as exposure to industrial chemicals and medication intake, in addition to diet, which may influence the association between the gut microbiome and gut barrier function.

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.

Understanding the complex function of gut microbiota: its impact on the pathogenesis of obesity and beyond: a comprehensive review

Obesity is a multifactorial condition influenced by genetic, environmental, and microbiome-related factors. The gut microbiome plays a vital role in maintaining intestinal health, increasing mucus creation, helping the intestinal epithelium mend, and regulating short-chain fatty acid (SCFA) production. These tasks are vital for managing metabolism and maintaining energy balance. Dysbiosis-an imbalance in the microbiome-leads to increased appetite and the rise of metabolic disorders, both fuel obesity and its issues. Furthermore, childhood obesity connects with unique shifts in gut microbiota makeup. For instance, there is a surge in pro-inflammatory bacteria compared to children who are not obese. Considering the intricate nature and variety of the gut microbiota, additional investigations are necessary to clarify its exact involvement in the beginnings and advancement of obesity and related metabolic dilemmas. Currently, therapeutic methods like probiotics, prebiotics, synbiotics, fecal microbiota transplantation (FMT), dietary interventions like Mediterranean and ketogenic diets, and physical activity show potential in adjusting the gut microbiome to fight obesity and aid weight loss. Furthermore, the review underscores the integration of microbial metabolites with pharmacological agents such as orlistat and semaglutide in restoring microbial homeostasis. However, more clinical tests are essential to refine the doses, frequency, and lasting effectiveness of these treatments. This narrative overview compiles the existing knowledge on the multifaceted role of gut microbiota in obesity and much more, showcasing possible treatment strategies for addressing these health challenges.

Exploring the effects of probiotics on olanzapine-induced metabolic syndrome through the gut microbiota

BACKGROUND

Maintaining gut microbial homeostasis is crucial for human health, as imbalances in the gut microbiota (GM) can lead to various diseases, including metabolic syndrome (MS), exacerbated by the use of antipsychotic medications such as olanzapine (OLZ). Understanding the role of the GM in OLZ-induced MS could lead to new therapeutic strategies. This study used metagenomic analysis to explore the impact of OLZ on the GM composition and examined how probiotics can mitigate its adverse effects in a rat model. Changes in weight, blood pressure, and lipid levels, which are key parameters defining MS, were assessed. Additionally, this study investigated serotonin, dopamine, and histopathological changes to explore their possible link with the microbiota-gut-brain axis (MGBA).

RESULTS

OLZ had an antagonistic effect on serotonin and dopamine receptors, and it was consistently found to alter the composition of the GM, with an increase in the relative abundance (RA) of the Firmicutes/Bacteroidetes phyla ratio and TM7 genera, indicating that the anticommonsal action of OLZ affects appetite and energy expenditure, contributing to obesity, dyslipidemia and increased blood pressure, which are core components of MS. Hepatic steatosis and intestinal damage in OLZ-treated rat tissues further indicate its role in MS. Conversely, the administration of probiotics, either alone or in combination with OLZ, was found to mitigate these OLZ-induced symptoms of MS by altering the GM composition. These alterations included increases in the abundances of the taxa Bacteroidetes, Actinobacteria, Prevotella, Blautia, Bacteroides, Bacteroidales, and Ruminococcaceae and a decrease in Firmicute abundance. These changes helped maintain gut barrier integrity and modulated neurotransmitter levels, suggesting that probiotics can counteract the adverse metabolic effects of OLZ by restoring the GM balance. Moreover, this study highlights the modulation of the MGBA by OLZ as a potential mechanism through which probiotics modulate serotonin and dopamine levels, influencing metabolic health.

CONCLUSION

These findings emphasise the significant impact of OLZ on the GM and its contribution to MS. These findings suggest that interventions targeting the GM, such as probiotics, could mitigate the metabolic side effects of OLZ. Future research should focus on developing integrative treatment approaches that consider the health of the gut microbiome in managing antipsychotic-induced adverse effects.

Omega-3 Fatty Acid and Vitamin D Supplementations Partially Reversed Metabolic Disorders and Restored Gut Microbiota in Obese Wistar Rats

Obesity is a global public health issue linked to various comorbidities in both humans and animals. This study investigated the effects of vitamin D (VD) and omega-3 fatty acids (ω3FA) on obesity, gut dysbiosis, and metabolic alterations in Wistar rats. After 13 weeks on a standard (S) or High-Fat, High-Sugar (HFHS) diet, the rats received VD, ω3FA, a combination (VD/ω3), or a control (C) for another 13 weeks. The HFHS diet led to increased weight gain, abdominal circumference, glucose intolerance, insulin resistance, and gut dysbiosis. VD supplementation improved their fasting blood glucose and reduced liver damage, while ω3FA slowed BMI progression, reduced abdominal fat, liver damage, and intestinal permeability, and modulated the gut microbiota. The combination of VD/ω3 prevented weight gain, decreased abdominal circumference, improved glucose tolerance, and reduced triglycerides. This study demonstrates that VD and ω3FA, alone or combined, offer significant benefits in preventing obesity, gut dysbiosis, and metabolic alterations, with the VD/ω3 combination showing the most promise. Further research is needed to explore the mechanisms behind these effects and their long-term potential in both animal and human obesity management.

Protective effects of Mycobacterium vaccae ATCC 15483 against "Western"-style diet-induced weight gain and visceral adiposity in adolescent male mice

The prevalence of noncommunicable inflammatory disease is increasing in modern urban societies, posing significant challenges to public health. Novel prevention and therapeutic strategies are needed to effectively deal with this issue. One promising approach is leveraging microorganisms such as Mycobacterium vaccae ATCC 15483, known for its anti-inflammatory, immunoregulatory, and stress-resilience properties. This study aimed to assess whether weekly subcutaneous administrations of a whole-cell, heat-killed preparation of M. vaccae ATCC 15483 (eleven injections initiated one week before the onset of the diet intervention), relative to vehicle injections, in adolescent male C57BL/6N mice can mitigate inflammation associated with Western-style diet-induced obesity, which is considered a risk factor for a number of metabolic and inflammatory diseases. Our results show that treatment with M. vaccae ATCC 15483 prevented Western-style diet-induced excessive weight gain, visceral adipose tissue accumulation, and elevated plasma leptin concentrations. The Western-style diet, relative to a control diet condition, decreased alpha diversity and altered the community composition of the gut microbiome, increasing the Bacillota to Bacteroidota ratio (formerly referred to as the Firmicutes to Bacteroidetes ratio). Despite the finding that M. vaccae ATCC 15483 prevented Western-style diet-induced excessive weight gain, visceral adipose tissue accumulation, and elevated plasma leptin concentrations, it had no effect on the diversity or community composition of the gut microbiome, suggesting that it acts downstream of the gut microbiome to alter immunometabolic signaling. M. vaccae ATCC 15483 reduced baseline levels of biomarkers of hippocampal neuroinflammation and microglial priming, such as Nfkbia and Nlrp3, and notably decreased anxiety-like defensive behavioral responses. The current findings provide compelling evidence supporting the potential for M. vaccae ATCC 15483 as a promising intervention for prevention or treatment of adverse immunometabolic outcomes linked to the consumption of a Western-style diet and the associated dysbiosis of the gut microbiome.

The role of reproductive tract microbiota in gynecological health and diseases

The reproductive tract, as a lumen connected to the outside world, its microbial community is influenced by various factors. The changes in its microbiome are closely related to women's health. The destruction of the micro ecological environment will lead to various infections, such as Bacterial vaginosis, sexually transmitted infections, adverse pregnancy outcomes, infertility and tumors. In recent years, with the continuous development and progress of molecular biology, research on reproductive tract microbiota has become a clinical hotspot. The reproductive tract microbiota is closely related to the occurrence and development of female reproductive tract diseases such as vaginitis, pelvic inflammation, PCOS, cervical lesions, and malignant tumors. This article reviews the research on the relationship between vaginal microbiota and female reproductive tract diseases, in order to provide theoretical basis for the prevention and treatment of female reproductive tract diseases.

Gut microbiota dysbiosis in Alzheimer's disease (AD): Insights from human clinical studies and the mouse AD models

Alzheimer's Disease (AD) is a debilitating neurocognitive disorder with an unclear underlying mechanism. Recent studies have implicated gut microbiota dysbiosis with the onset and progression of AD. The connection between gut microbiota and AD can significantly affect the prevention and treatment of AD patients. This systematic review summarizes primary outcomes of human and mouse AD models concerning gut microbiota alterations. A systematic literature search in February through March 2023 was conducted on PubMed, Embase, and Web of Science. We identified 711 as potential manuscripts of which 672 were excluded because of irrelevance to the identified search criteria. Primary outcomes include microbiota compositions of control and AD models in humans and mice. In total, 39 studies were included (19 mouse and 20 human studies), published between 2017 and 2023. We included studies involving well-established mice models of AD (5xFAD, 3xTg-AD, APP/PS1, Tg2576, and APPPS2) which harbor mutations and genes that drive the formation of Aß plaques. All human studies were included on those with AD or mild cognitive impairment. Among alterations in gut microbiota, most studies found a decreased abundance of the phyla Firmicutes and Bifidobacteria, a genus of the phylum Actinomycetota. An increased abundance of the phyla Bacteroidetes and Proteobacteria were identified in animal and human studies. Studies indicated that gut microbiota alter the pathogenesis of AD through its impact on neuroinflammation and permeability of the gastrointestinal tract. The ensuing increase in blood-brain barrier permeability may accelerate Aβ penetrance and formation of neuritic plaques that align with the amyloid hypothesis of AD pathogenesis. Further studies should assess the relationship between gut microbiota and AD progression and therapy preserving beneficial gut microbiota.

Evaluating the Effects of Sugar Shift® Symbiotic on Microbiome Composition and LPS Regulation: A Double-Blind, Placebo-Controlled Study

(1) Background: This study evaluated the effects of BiotiQuest® Sugar Shift®, a novel probiotic formulation, for its impact on gut microbiome composition and metabolic health in type 2 diabetes mellitus (T2D). T2D is characterized by chronic inflammation and gut microbiome imbalances, yet the therapeutic potential of targeted probiotics remains underexplored. (2) Methods: In a 12-week randomized, double-blind, placebo-controlled trial, 64 adults with T2D received either Sugar Shift or placebo capsules twice daily. Each dose provided 18 billion CFU of eight GRAS-certified bacterial strains and prebiotics. Clinical samples were analyzed for metabolic markers, and microbiome changes were assessed using 16S rRNA sequencing and metagenomics. (3) Results: Sugar Shift significantly reduced serum lipopolysaccharide (LPS) levels, improved insulin sensitivity (lower HOMA-IR scores), and increased short-chain fatty acid (SCFA)-producing genera, including Bifidobacterium, Faecalibacterium, Fusicatenibacter, and Roseburia. Pro-inflammatory taxa like Enterobacteriaceae decreased, with reduced LPS biosynthesis genes and increased SCFA production genes. The Lachnospiraceae:Enterobactericeae ratio emerged as a biomarker of reduced inflammation. (4) Conclusions: These findings demonstrate the potential of Sugar Shift to restore gut homeostasis, reduce inflammation, and improve metabolic health in T2D. Further studies are warranted to explore its long-term efficacy and broader application in metabolic disease management.

Six-month randomized, placebo controlled trial of synbiotic supplementation in women with polycystic ovary syndrome undergoing lifestyle modifications

PURPOSE

To determine whether long-term administration of synbiotics affects clinical, endocrine and metabolic aspects of polycystic ovary syndrome (PCOS) in overweight and obese subjects undergoing intensive lifestyle modifications.

METHODS

During six-month trial, all subjects underwent intensive lifestyle modifications (diet and exercise). The subjects were randomized (1:1) to receive synbiotic supplementation (Synbiotic Group) or placebo (Placebo Group).

RESULTS

Subjects in the Placebo Group and the Synbiotic Group experienced significant reduction of BMI (- 8% and - 11%, respectively; both at P < 0.0001) and body fat percentage (- 11% and - 14%, respectively; both at P < 0.0001). These effects were statistically comparable for both groups. Total testosterone was not significantly changed in the Placebo Group (- 5%, P = 0.41) while it greatly declined in the Synbiotic Group (- 40%; P < 0.0001); the difference between these groups was significant (P = 0.0002). Synbiotic supplementation was superior to placebo in reducing LH (- 21%; P = 0.047), total cholesterol (- 6%; P = 0.002), low-density lipoprotein cholesterol (- 6%; P = 0.044), triglycerides (- 29%; P = 0.049), LPS (- 23%; P = 0.001) and LPS-binding protein (- 21%; P = 0.001).

CONCLUSIONS

Synbiotic supplementation led to a marked improvement of several key clinical and laboratory aspects of PCOS including an improvement of hyperandrogenism, lipid profile, and markers of endotoxemia.

TRIAL REGISTRATION

Clinical Trial Registration Number: NCT03325023 (URL, clinicaltrials.gov; date of registration 10/26/2017).

CD14loCD301b+ macrophages gathering as a proangiogenic marker in adipose tissues

The role of the monocyte marker CD14 in the regulation of obesity is increasingly recognized. Our observations indicated that Cd14-/- mice exhibited a leaner body shape compared to their wild-type (WT) counterparts. And the loss of CD14 alleviated high-fat diet-induced obesity in mice. In human subjects, CD14 level was tested to be positively correlated with overweight and obesity. However, the relationship between CD14 and the development of obesity remains only partially understood. To investigate the underlying mechanisms, adipose tissues (ATs) from Cd14-/- and WT mice were subjected to deep RNA sequencing. Gene Ontology enrichment analysis revealed a significant enhancement of angiogenesis-related function in the Cd14-/- epididymal adipose tissues compared to WT counterpart, which was accompanied by an upregulation of Cd301b. Subsequent assays confirmed the enhanced angiogenesis and more accumulation of CD301b+ macrophages in Cd14-/- epididymal adipose tissues. Because Igf1 expression has been suggested to be associated with Cd301b expression through pseudotime analysis, we found it was insulin-like growth factor 1 secreted from Cd14-/- macrophages that mediated the angiogenesis enhancement. Collectively, our findings indicate that CD14 deficiency increased the accumulation of CD14loCD301b+ macrophages in ATs, which may serve as a proangiogenic marker, providing novel insights into the relationship between CD14 and obesity development.

Intestine epithelial-specific hypoxia-inducible factor-1α overexpression ameliorates western diet-induced MASLD

BACKGROUND

Intestine epithelial hypoxia-inducible factor-1α (HIF-1α) plays a critical role in maintaining gut barrier function. The aim of this study was to determine whether pharmacological or genetic activation of intestinal HIF-1α ameliorates western diet-induced metabolic dysfunction-associated steatotic liver disease.

METHODS

Metabolic effects of pharmacological activation of HIF-1α by dimethyloxalylglycine were evaluated in HIF-α luciferase reporter (ODD-luc) mice. Male and/or female intestinal epithelial-specific Hif1α overexpression mice (Hif1αLSL/LSL;VilERcre) and wild-type littermates (Hif1αLSL/LSL) were fed with regular chow diet, high fructose (HFr) or high-fat (60% Kcal) high-fructose diet (HFHFr) for 8 weeks. Metabolic phenotypes were profiled.

RESULTS

Dimethyloxalylglycine treatment led to increased intestine HIF-α luciferase activity and decreased blood glucose levels in HFr diet-fed male ODD-luc mice. Male Hif1αLSL/LSL;VilERcre mice exhibited markedly improved glucose tolerance compared to Hif1αLSL/LSL mice in response to HFr diet. Eight weeks HFHFr feeding led to obesity in both Hif1αLSL/LSL;VilERcre and Hif1αLSL/LSL mice. However, male Hif1αLSL/LSL;VilERcre mice exhibited markedly attenuated hepatic steatosis along with reduced liver size and liver weight compared to male Hif1αLSL/LSL mice. Moreover, HFHFr-induced systemic inflammatory responses were mitigated in male Hif1αLSL/LSL;VilERcre mice compared to male Hif1αLSL/LSL mice, and those responses were not evident in female mice. Ileum RNA-seq analysis revealed that glycolysis/gluconeogenesis was up in male Hif1αLSL/LSL;VilERcre mice, accompanied by increased epithelial cell proliferation. Moreover, an in vitro study showed that HIF stabilization enhances glycolysis in intestine organoids.

CONCLUSIONS

Our data provide evidence that pharmacological or genetic activation of intestinal HIF-1α markedly ameliorates western diet-induced metabolic dysfunction-associated steatotic liver disease in a sex-dependent manner. The underlying mechanism is likely attributed to HIF-1α activation-induced upregulation of glycolysis, which, in turn, leads to enhanced epithelial cell proliferation and augmented gut barrier function.

Gut microbiota and fecal volatilome profile inspection in metabolically healthy and unhealthy obesity phenotypes

BACKGROUND

People with metabolically healthy (MHO) and metabolically unhealthy obesity (MUO) differ for the presence or absence of cardio-metabolic complications, respectively.

OBJECTIVE

Based on these differences, we are interested in deepening whether these obesity phenotypes could be linked to changes in microbiota and metabolome profiles. In this respect, the overt role of microbiota taxa composition and relative metabolic profiles is not completely understood. At this aim, biochemical and nutritional parameters, fecal microbiota, metabolome and SCFA compositions were inspected in patients with MHO and MUO under a restrictive diet regimen with a daily intake ranging from 800 to 1200 kcal.

METHODS

Blood, fecal samples and food questionnaires were collected from healthy controls (HC), and an obese cohort composed of both MHO and MUO patients. Most impacting biochemical/anthropometric variables from an a priori sample stratification were detected by applying a robust statistics approach useful in lowering the background noise. Bacterial taxa and volatile metabolites were assessed by qPCR and gas chromatography coupled with mass spectrometry, respectively. A targeted GC-MS analyses on SCFAs was also performed.

RESULTS

Instructed to follow a controlled and restricted daily calorie intake, MHO and MUO patients showed differences in metabolic, gut microbial and volatilome signatures. Our data revealed higher quantities of specific pro-inflammatory taxa (i.e., Desulfovibrio and Prevotella genera) and lower quantities of Clostridium coccoides group in MUO subset. Higher abundances in alkane, ketone, aldehyde, and indole VOC classes together with a lower amount of butanoic acid marked the faecal MUO metabolome.

CONCLUSIONS

Compared to MHO, MUO subset symptom picture is featured by specific differences in gut pro-inflammatory taxa and metabolites that could have a role in the progression to metabolically unhealthy status and developing of obesity-related cardiometabolic diseases. The approach is suitable to better explain the crosstalk existing among dysmetabolism-related inflammation, nutrient intake, lifestyle, and gut dysbiosis.

Gut microbiota mediate the alleviation effect of Xiehuo-Guzheng granules on β cell dedifferentiation in type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a worldwide public health problem characterized by a progressive decline in β cell function. In traditional Chinese medicine (TCM) theory, 'fire' and 'healthy qi deficiency' are important pathogeneses of T2DM, and purging 'fire' and reinforcing the 'healthy qi' (Pinyin name: Xiehuo-Guzheng, XHGZ) are important method of treatment. Over the years, we have observed its benefit for diabetes. However, the underlying mechanisms remain unclear.

PURPOSE

To investigate the mechanism of XHGZ granules against β cell dedifferentiation in T2DM based on gut microbiota.

METHODS

Rats with T2DM, induced by intraperitoneal injection of streptozotocin after eight weeks of high-fat diet, were randomly allocated to receive XHGZ granules, metformin, or distilled water for eight consecutive weeks. Changes in metabolic parameters, β cell dedifferentiation, inflammatory cytokines, gut microbiota, and microbial metabolites (lipopolysaccharide (LPS) and short-chain fatty acids (SCFAs)), were detected. Furthermore, faecal microbiota transplantation (FMT) was performed to confirm the anti-diabetic effect of XHGZ granule-regulated gut microbiota in pseudo-germ-free T2DM rats.

RESULTS

XHGZ granules significantly ameliorated hyperglycaemia, improved islet function and pathology, and reduced β cell dedifferentiation and pro-inflammatory cytokines in T2DM rats. 16S rRNA sequencing revealed that XHGZ granules decreased the LPS-containing microbiota (e.g., Colidextribacter, Desulfovibrionaceae, and Morganella) and increased the SCFAs-producing bacteria (e.g., Prevotella, Alloprevotella, and Muribaculaceae) and Lactobacillus_intestinalis. Correspondingly, it strengthened intestinal barrier, lowered LPS, and elevated acetic and butyric acids. Tax4Fun analysis indicated that XHGZ granules restored abnormal metabolism, lipopolysaccharide biosynthesis, and pantothenate and CoA biosynthesis. Moreover, the XHGZ granule-regulated microbiota also exhibited the effects of anti-diabetes, anti-β cell dedifferentiation, and anti-inflammation along with the reduction of LPS and the increase of SCFAs in pseudo-germ-free T2DM rats.

CONCLUSION

Our results show that XHGZ granules alleviate β cell dedifferentiation via regulating gut microbiota and their metabolites in T2DM, suggesting its potential as a promising complementary treatment for T2DM. As far as we know, there are very few studies on the alleviation of β cell dedifferentiation by TCM, and investigations into the mechanism from the perspective of intestinal flora and microbial metabolites are yet to be reported.

Targeting microbiota-immune-synaptic plasticity to explore the effect of tea polyphenols on improving memory in the aged type 2 diabetic rat model

OBJECTIVES

The study aimed to explore whether TP could improve memory in the aged type 2 diabetic rat model by regulating microbiota-immune-synaptic plasticity axis.

METHODS

The experiment was divided into two parts. Firstly, to investigate the effects of TP on the physiopathology of the aged T2DM model rats, rats were randomly divided into the Normal control group, the aged group, the Aged T2DM model group, the TP 75, 150, 300 mg/kg groups, the 150 mg/kg Piracetam group and the 3 mg/kg Rosiglitazone group. Then, to further verify whether TP improved memory in aged T2DM rat model by regulating intestinal flora, the fecal microbiota transplantation (FMT) from the rats in the 300 mg/kg TP group into the rats in the aged T2DM model group was carried out. Effects on gut microbiota, colonic integrity (epithelial tight junction proteins), and endotoxemia (serum LPS) were examined, along with synaptic structure, synaptic plasticity-related structural proteins and inflammation signaling of the hippocampus in our study.

RESULTS

Our results demonstrated that TP alleviated memory impairments in the aged T2DM rat model. The specific outcomes were as follows: TP 300 mg/kg corrected the gut dysbacteriosis, alleviated intestinal permeability reduction and peripheral/central inflammation, inhibited the TLR4/NF-κB signaling pathway. Meanwhile, TP improved the synaptic plasticity in the hippocampus of the aged T2DM model rats, whose expressions of SYN, PSD 95, NMDAR1 and GluR1 in hippocampus were significantly up-regulated. Surprisingly, rats of the FMT group displayed the same changes.

DISCUSSION

TP improves the memory in aged T2DM rat model. The mechanism may be related to the alteration of gut flora, which can inhibit hippocampal TLR4/NF-κB signaling to attenuate neuroinflammation, then improve synaptic plasticity. The study proposes that TP interventions aimed at manipulating the gut microbiota may hold great potential as an effective approach for preventing and treating this disease.

The dynamic distribution of the rectal microbiota in Holstein dairy calves provides a framework for understanding early-life gut health

The posterior intestinal microbiota plays a vital role in the growth and health of Holstein dairy calves. However, its establishment and dynamic changes during early development remain unclear. The aim of this study was to investigate microbial colonization and development in the rectum of calves within the first 70 d after birth. Here, 96 rectal content samples were collected from 8 Holstein dairy calves at 12 time points and analyzed using 16S rRNA gene sequencing. The microbial alpha diversity increased with age. The bacterial community displayed a distinct dynamic distribution. The phylum Proteobacteria was replaced by Firmicutes and Bacteroidetes after d 3. The colonization process of bacterial genera in the rectum of neonatal calves can be divided into 2 periods: the colonization period (stage 1: d 1 and stage 2: d 3) and the stable period (stage 3: d 7-14, stage 4: d 21-42, and stage 5: d 49-70). The fermentation pattern and metabolic function changed from propionate fermentation dominated by Shigella to lactic acid fermentation dominated by Lactobacillus, Blautia, and Oscillospira. The stable period was more comprehensive and complete than the colonization period. This study revealed the dynamic changes in the posterior intestinal microbiota of Holstein dairy calves during early development. The transition period (d 7-14) was identified as a key stage for early nutritional intervention, as the abundance of Lactobacillus increased and the abundance of harmful bacteria (such as Proteobacteria and Shigella) decreased. This study provides a framework for understanding early-life gut health and offers theoretical guidance for future research on host-microbe interactions and early nutritional interventions. It is suggested that nutritional interventions based on microbial characteristics at different stages be implemented to improve calf growth performance and immune function, which may contribute to the reduction of diarrhea and other gastrointestinal disorders during dairy production.

Regulation of lipid storage and inflammation in the liver by CEACAM1

This review focuses on a special aspect of hepatic lipid storage and inflammation that occurs during nutritional excess in obesity. Mounting evidence supports that prolonged excess fatty acid (FA) uptake in the liver is strongly associated with hepatic lipid storage and inflammation and that the two processes are closely linked by a homeostatic mechanism. There is also strong evidence that bacterial lipids may enter the gut by a common mechanism with lipid absorption and that there is a set point to determine when their uptake triggers an inflammatory response in the liver. In fact, the progression from high uptake of FAs in the liver resulting in Metabolic dysfunction-associated steatotic liver disease (MASLD) to the development of the more serious Metabolic dysfunction-associated steatohepatitis (MASH) depends on the degree of inflammation and its progression from an acute to a chronic state. Thus, MASLD/MASH implicates both excess fatty acids and progressive inflammation in the aetiology of liver disease. We start the discussion by introduction of CD36, a major player in FA and lipopolysaccharide (LPS) uptake in the duodenum, liver and adipose tissue. We will then introduce CEACAM1, a major player in the regulation of hepatic de novo lipogenesis and the inflammatory response in the liver, and its dual association with CD36 in enterocytes and hepatocytes. We conclude that CEACAM1 and CD36 together regulate lipid droplet formation and inflammation in the liver.

Relevance of Indian Traditional Herbal Brews for Gut Microbiota Balance

The considerable changes in lifestyle patterns primarily affect the human gut microbiota and result in obesity, diabetes, dyslipidemia, renal complications, etc. though there are few traditional safeguards such as herbal brews to maintain the ecological stability under intestinal dysbiosis. The present article is designed to collect all the scientific facts in a place to decipher the role of the Indian traditional herbal brews used to balance gut health for centuries. Computerized databases, commercial search engines, research papers, articles, and books were used to search by using different keywords to select the most appropriate published articles from 2000 onward to September 2023. A total of 1907 articles were scrutinized, 46 articles were finally selected from the 254 screened, and targeted information was compiled. Interaction of herbal brews to the gut microflora and resulting metabolites act as prebiotics due to antimicrobial, anti-inflammatory, and antioxidant properties, and modulate the pH of the gut. The effect of brews on gut microbiota has a drastic impact on various gut-related diseases and has gained popularity as an alternative to antibiotics against bacteria, fungi, viruses, parasites, and boosting the immune system and strengthening the intestinal barrier. Berberine, kaempferol, piperine, and quercetin have been found in more than one brew discussed in the present article. Practically, these brews balance the gut microbiota, prevent chronic and degenerative diseases, and reduce organ inflammation, though, there is a knowledge gap on the molecular mechanism to explain their efficacy. Indian traditional herbal brews used to reboot and heal the gut microbiota since centuries-old practice with successful history without toxicity. The systematic consumption of these brews under specific dietary prescriptions has a hope of arrays for a healthy human gut microbiome in the present hasty lifestyle with overall health and well-being.

Graphical Abstract

Adipose Tissue-Resident Sphingomonas Paucimobilis Suppresses Adaptive Thermogenesis by Reducing 15-HETE Production and Inhibiting AMPK Pathway

Obesity represents a low-grade chronic inflammation status, which is associated with compromised adaptive thermogenesis. However, the mechanisms underlying the defective activation of thermogenesis in chronic inflammation remain unclear. Here, a chronic inflammatory model is first estabolished by injecting mice with low-dose lipopolysaccharide (LPS) before cold exposure, and then it is verified that LPS treatment can decrease the core body temperature of mice and alter the microbial distribution in epididymal white adipose tissue (eWAT). An adipose tissue-resident bacterium Sphingomonas paucimobilis is identified as a potential inhibitor on the activation of brown fat and browning of inguinal WAT, resulting in defective adaptive thermogenesis. Mechanically, LPS and S. paucimobilis inhibit the production and release of 15-HETE by suppressing its main metabolic enzyme 12 lipoxygenase (12-LOX) and 15- Hydroxyeicosatetraenoic acid (15-HETE) rescues the impaired thermogenesis. Interestingly, 15-HETE directly binds to AMP-activated protein kinase α (AMPKα) and elevates the phosphorylation of AMPK, leading to the activation of uncoupling protein 1 (UCP1) and mitochondrial oxidative phosphorylation (OXPHOS) complexes. Further analysis with human obesity subjects reveals that individuals with high body mass index displayed lower 15-HETE levels. Taken together, this work improves the understanding of how chronic inflammation impairs adaptive thermogenesis and provides novel targets for alleviating obesity.

Exploring the hypothetical links between environmental pollutants, diet, and the gut-testis axis: The potential role of microbes in male reproductive health

The gut system, commonly referred to as one of the principal organs of the human "superorganism," is a home to trillions of bacteria and serves an essential physiological function in male reproductive failures or infertility. The interaction of the endocrine-immune system and the microbiome facilitates reproduction as a multi-network system. Some recent studies that link gut microbiota to male infertility are questionable. Is the gut-testis axis (GTA) real, and does it affect male infertility? As a result, this review emphasizes the interconnected links between gut health and male reproductive function via changes in gut microbiota. However, a variety of harmful (endocrine disruptors, heavy metals, pollutants, and antibiotics) and favorable (a healthy diet, supplements, and phytoconstituents) elements promote microbiota by causing dysbiosis and symbiosis, respectively, which eventually modify the activities of male reproductive organs and their hormones. The findings of preclinical and clinical studies on the direct and indirect effects of microbiota changes on testicular functions have revealed a viable strategy for exploring the GTA-axis. Although the GTA axis is poorly understood, it may have potential ties to reproductive issues that can be used for therapeutic purposes in the future.

Metabolic dysfunction-associated steatotic liver disease: A superior predictor for incident type 2 diabetes over traditional criteria - NAGALA study

AIMS/INTRODUCTION

The 2023 Delphi consensus recommended the use of new term, metabolic dysfunction-associated steatotic liver disease (MASLD), aiming conceptual shift from the conventional non-alcoholic fatty liver disease (NAFLD). The association between NAFLD and type 2 diabetes mellitus (T2DM) development is well known. This study aimed to examine the correlation between MASLD and T2DM development, comparing their utility as predictors.

MATERIALS AND METHODS

This retrospective cohort study obtained data from a medical health checkup program conducted at Asahi University Hospital, Japan, between 2004 and 2021. Logistic regression analysis was used to assess the association between MASLD and incident T2DM over 5 years. To compare the predictive utility of NAFLD and MASLD, receiver operating characteristic curves were drawn, followed by area under the curve (AUC) comparisons.

RESULTS

In total, 15,039 participants (59.6% males; median [interquartile range {IQR}] age, 44 [38, 50] years) were included. Out of 2,682 participants meeting the criteria for MASLD, 234 individuals (8.7%) developed T2DM. Multivariate analysis revealed a significantly elevated risk of T2DM in MASLD compared with the reference healthy group (without steatotic liver disease or cardiometabolic risk), presenting an OR of 127.00 (95% CI 40.40-399.00, P < 0.001). The concordance rate of diagnosis between NAFLD and MASLD was 98.7%. The AUC values were 0.799 for NAFLD and 0.807 for MASLD, respectively. Comparative analysis of the AUC showed a statistical difference between NAFLD and MASLD (P < 0.001).

CONCLUSIONS

MASLD was shown to be a significant risk factor for incident T2DM, exhibiting a potentially higher predictive capacity than conventional NAFLD.

The Role of the Gut Microbiome in the Development and Progression of Type 2 Diabetes and Liver Disease

Type 2 diabetes mellitus (T2DM) and progressive liver disease are 2 of the most significant global health concerns, and they have alarming and ever-increasing prevalence. A growing body of literature has demonstrated a potential multilateral link between gut microbiome dysbiosis and the development and progression of the above-mentioned conditions. Modulation of gut microbial composition from the norm is due to changes in diet allied with external factors such as age, genetics, and environmental changes. In this comprehensive review, we recapitulate the research to date investigating the links between gut microbiome dysbiosis and T2DM or liver disease, with special attention to the importance of diet. Additionally, we review the most commonly used tools and methodologies of investigating changes in the gut microbiome, highlighting the advantages and limitations of each strategy, before introducing a novel in vitro approach to the problem. Finally, the review offers recommendations for future research in this field that will allow better understanding of how the gut microbiota affects disease progression and of the prospects for intestinal microbiota-based therapeutic options.

Gut microbiota and mycobiota change with feeding duration in mice on a high-fat and high-fructose diet

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD), formerly known as nonalcoholic fatty liver disease (NAFLD), is becoming the most common chronic liver disease. The gut microbiome is regarded to play a crucial role in MAFLD, but the specific changes of gut microbiome, especially fungi, in different stages of MAFLD are not well understood. This study aimed to observe the longitudinal changes of colon bacteria and fungi of mice at different feeding duration of a high-fat and high-fructose diet (HFHFD), and explore the association between the changes and the progression of MAFLD.

METHODS

Twenty-eight male C57BL6J mice were randomly assigned to the normal diet (ND) group and HFHFD group. At the 8th and 16th weeks, mice were sacrificed to compare the diversity, composition, and co-abundance network of bacteria and fungi in colon contents among groups.

RESULTS

HFHFD-8W mice exhibited increases in Candida and Dorea, and decreases in Oscillospira and Prevotella in comparison to ND-8W mice, HFHFD-16W mice had increases in Bacteroides, Candida, Desulfovibrio, Dorea, Lactobacillus, and Rhodotorula, and decreases in Akkermansia, Aspergillus, Sterigmatomyces, and Vishniacozyma in comparison to ND-16W mice. And compared to HFHFD-8W mice, HFHFD-16W mice had increases in Desulfovibrio, Lactobacillus, Penicillium, and Rhodotorula, and decreases in Talaromyces and Wallemia. Spearman and GEE correlation analysis revealed that Bacteroides, Candida, Desulfovibrio, and Lactobacillus positively correlated with NAFLD activity score (NAS).

CONCLUSION

Gut microbiota and mycobiota undergo diverse changes at different stages of MAFLD.

CLINICAL TRIAL NUMBER

Not applicable.

The Interactions Between Diet and Gut Microbiota in Preventing Gestational Diabetes Mellitus: A Narrative Review

Recent studies have revealed that dysbiosis, defined as alterations in gut microbiota, plays an important role in the development and the progression of many non-communicable diseases, including metabolic disorders, such as type 2 diabetes mellitus and gestational diabetes mellitus (GDM). The high frequency of GDM makes this disorder an important public health issue, which needs to be addressed in order to reduce both the maternal and fetal complications that are frequently associated with this disease. The studies regarding the connections between gut dysbiosis and GDM are still in their early days, with new research continuously emerging. This narrative review seeks to outline the mechanisms through which a healthy diet that protects the gut microbiota is able to prevent the occurrence of GDM, thus providing medical nutritional therapeutic perspectives for the management of GDM.

Protective Effects of Spirulina Against Lipid Micelles and Lipopolysaccharide-Induced Intestinal Epithelium Disruption in Caco-2 Cells: In Silico Molecular Docking Analysis of Phycocyanobilin

Damage to intestinal epithelial cells is present in obesity and other diseases because of inflammatory and oxidative processes. This damage compromises the gastrointestinal barrier, killing enterocytes, altering intestinal permeability, and eliciting abnormal immune responses that promote chronic inflammation. Recent evidence shows that spirulina is a potent natural agent with antioxidant and anti-inflammatory properties.

OBJECTIVES

This study was conducted to evaluate the effect of spirulina aqueous extract (SPAE) on the alterations of the intestinal epithelium induced by lipid micelles (LMs) and/or inflammation induced by lipopolysaccharides (LPSs) in the Caco-2 cell line.

METHODS

In the current research, we assessed the protective actions of SPAE against cytotoxicity, oxidative stress, inflammation, and epithelial barrier perturbation by using an in vitro model, the intestinal Caco-2 cells, treated with LPSs and/or LMs. We also performed an in silico molecular docking analysis with spirulina's bioactive compound, phycocyanobilin.

RESULTS

Our results showed that SPAE has no cytotoxic effect on Caco-2 cells. On the contrary, it improved cell viability and exhibited anti-inflammatory and antioxidant actions. SPAE also protected against endoplasmic reticulum stress and tight junction proteins, thus improving the epithelial barrier. The in silico study revealed a strong binding affinity of the phycocyanobilin compound with human SOD and NADPH oxidase and a good binding affinity towards COX-2 and iNOS.

CONCLUSIONS

Taken together, these findings demonstrate the beneficial actions of SPAE on Caco-2 cells, suggesting it may be useful in preserving the epithelial intestinal barrier in human conditions involving oxidative stress and inflammation such as obesity.

TLR4-dependent neuroinflammation mediates LPS-driven food-reward alterations during high-fat exposure

BACKGROUND

Obesity has become a global pandemic, marked by significant shifts in both the homeostatic and hedonic/reward aspects of food consumption. While the precise causes are still under investigation, recent studies have identified the role of gut microbes in dysregulating the reward system within the context of obesity. Unravelling these gut-brain connections is crucial for developing effective interventions against eating and metabolic disorders, particularly in the context of obesity. This study explores the causal role of LPS, as a key relay of microbiota component-induced neuroinflammation in the dysregulation of the reward system following exposure to high-fat diet (HFD).

METHODS

Through a series of behavioural paradigms related to food-reward events and the use of pharmacological agents targeting the dopamine circuit, we investigated the mechanisms associated with the development of reward dysregulation during HFD-feeding in male mice. A Toll-like receptor 4 (TLR4) full knockout model and intraventricular lipopolysaccharide (LPS) diffusion at low doses, which mimics the obesity-associated neuroinflammatory phenotype, were used to investigate the causal roles of gut microbiota-derived components in neuroinflammation and reward dysregulation.

RESULTS

Our study revealed that short term exposure to HFD (24 h) tended to affect food-seeking behaviour, and this effect became significant after 1 week of HFD. Moreover, we found that deletion of TLR4 induced a partial protection against HFD-induced neuroinflammation and reward dysregulation. Finally, chronic brain diffusion of LPS recapitulated, at least in part, HFD-induced molecular and behavioural dysfunctions within the reward system.

CONCLUSIONS

These findings highlight a link between the neuroinflammatory processes triggered by the gut microbiota components LPS and the dysregulation of the reward system during HFD-induced obesity through the TLR4 pathway, thus paving the way for future therapeutic approaches.

Review of the Relationships Between Human Gut Microbiome, Diet, and Obesity

Obesity is a complex disease that increases the risk of other pathologies. Its prevention and long-term weight loss maintenance are problematic. Gut microbiome is considered a potential obesity modulator. The objective of the present study was to summarize recent findings regarding the relationships between obesity, gut microbiota, and diet (vegetable/animal proteins, high-fat diets, restriction of carbohydrates), with an emphasis on dietary fiber and resistant starch. The composition of the human gut microbiome and the methods of its quantification are described. Products of the gut microbiome metabolism, such as short-chain fatty acids and secondary bile acids, and their effects on the gut microbiota, intestinal barrier function and immune homeostasis are discussed in the context of obesity. The importance of dietary fiber and resistant starch is emphasized as far as effects of the host diet on the composition and function of the gut microbiome are concerned. The complex relationships between human gut microbiome and obesity are finally summarized.

High-fat diet stimulated butyric acid metabolism dysbiosis, altered microbiota, and aggravated inflammatory response in collagen-induced arthritis rats

BACKGROUND

Research has demonstrated that obesity may be associated with rheumatoid arthritis (RA). In addition, Dysbiosis of intestinal microbiota and their metabolites has been linked to the occurrence and development of RA and obesity. However, the mechanism by which obesity affects RA remains unclear.In this study, we explored the impact of high fat diet(HFD) on collagen-induced arthritis (CIA) rats and revealed its mechanisms based on gut microbiota and metabolomics.

METHODS

Based on diet and modeling, rats were divided into normal group (Con), CIA model group, HFD group (HFD), and HFD + CIA group (HCIA). The effect of HFD on arthritis in CIA rats were investigated based on the arthritis index (AI), weight, blood lipid levels, and inflammatory cytokines. Moreover, HE staining and micro-CT were performed to evaluated the effect of HFD on the pathology of joints and synovial tissues in CIA rats.16S rRNA amplicon sequencing and liquid chromatography-mass spectrometry (LC-MS) were employed to explore changes in gut microbiota and short-chain fatty acids (SCFAs).

RESULTS

The AI scores, inflammatory cytokines and bone destruction parameters in the HCIA group were significantly higher than those in the other three groups. The results of 16S rRNA amplicon sequencing and metabolomics showed that compared with the other three groups, the expression of g_Muribaculaceae and butyric acid were reduced in the HCIA group. Spearman and linear correlation analyses revealed a positive correlation between g_Muribaculaceae abundance and butyric acid levels.

CONCLUSIONS

HFD stimulated butyric acid metabolism dysbiosis, altered microbiota, and aggravated inflammatory response in CIA rats.

Intestinal fatty acid binding protein is associated with coronary artery disease in long-term type 1 diabetes-the Dialong study

BACKGROUND

Individuals with type 1 diabetes are at increased risk of accelerated atherosclerosis, causing coronary artery disease (CAD). The underlying mechanisms remain unclear, but new theories proposed are damage of gut mucosa causing leakage and translocation of gut microbiota products into the circulation, leading to inflammatory responses and atherosclerosis. We therefore aimed to study the associations between gut related inflammatory biomarkers and coronary atherosclerosis in individuals with long-term type 1 diabetes.

METHODS

In this cross-sectional, controlled study of 102 participants with type 1 diabetes and 63 control subjects, we measured circulating levels of intestinal fatty acid binding protein (I-FABP), soluble cluster of differentiation 14 (sCD14), lipopolysaccharide binding protein (LBP) and interleukin 18 (IL-18) by enzyme-linked immunosorbent assay (ELISA), and further gene expression of CD14 and toll-like receptor 4 (TLR4) by real time PCR in circulating leukocytes and peripheral blood mononuclear cells (PBMCs). The participants had either established coronary heart disease (CHD) or underwent computed tomography coronary angiography (CTCA) to assess for coronary atherosclerosis, including total, calcified and soft/mixed plaque volumes.

RESULTS

In the diabetes group, the levels of I-FABP were significantly higher in participants with established CHD or significant stenosis on CTCA compared to the participants with normal arteries or non-significant stenosis, with median 1.67 ng/ml (interquartile range [IQR] 1.02-2.32) vs. median 1.09 ng/ml (IQR 0.82-1.58), p = 0.003. I-FABP was associated with significant coronary artery stenosis by CTCA (> 50%) or previously established CHD in the adjusted analysis (odds ratio [OR] = 2.32, 95% confidence interval [CI]: 1.09-4.95; p = 0.029). The levels of I-FABP correlated also to total coronary plaque volume (r = 0.22, p < 0.05). This association remained significant after adjusting for age, sex, persistent albuminuria, eGFR, statin treatment, diabetes duration and mean time-weighted variables; HbA1c, LDL-cholesterol and systolic blood pressure (OR = 1.97, 95% CI: 1.28-3.01; p = 0.002).

CONCLUSIONS

In this cohort of individuals with long-term type 1 diabetes I-FABP associated significantly with coronary artery stenosis, suggesting a potential role of gut mucosa damage in the process of atherosclerosis in type 1 diabetes.

Paederia foetida Ameliorates Diabetic Cardiomyopathy in Rats Models by Suppressing Apoptosis

Diabetes mellitus is one of the most prevalent global public health issues associated with a higher risk of cardiovascular diseases, contributing to morbidity and mortality. Research has demonstrated that elevated reactive oxygen species (ROS) generation in diabetes can trigger apoptosis, exacerbating diabetic cardiomyopathy (DCM). This study investigates the cardioprotective effects of Paederia foetida in rats’ models of type 2 diabetes induced by a high-fat diet (HFD) and streptozotocin (STZ) treatment. The diabetic model was established in Sprague Dawley rats by intraperitoneal injection of streptozotocin (STZ, 40 mg/kg). Sprague Dawley rats were treated with varied concentrations of standardized extract of P. foetida (50 mg/kg and 100 mg/kg), administered orally once daily for four weeks. Standardized extract from P. foetida has a range of therapeutic potential, including anti-inflammatory, antioxidant, and anti-diabetic properties. The common metabolic disorder indices and myocardial apoptosis were investigated. The findings from this study demonstrated increased expression of Bcl-2 and decreased expression of Bcl-2 Associated X-protein BAX as indicated by IRS scoring in cardiomyocytes, suggesting that P. foetida has a significant protective effect on diabetic cardiomyopathy by decreasing apoptosis. Increased Bcl-2 and decreased BAX levels may be related to regulating oxidative stress and mitochondrial pathways involving myocardial apoptosis. P. foetida extract could be a potential intervention for attenuating cardiomyopathy in diabetes mellitus.