Gut Microbiota as a Trigger for Metabolic Inflammation in Obesity and Type 2 Diabetes

The effects of Mitragyna speciosa extracts on intestinal microbiota and their metabolites in vitro fecal fermentation

BACKGROUND

Kratom (Mitragyna speciosa) has a long history of traditional use. It contains various alkaloids and polyphenols. The properties of kratom's alkaloids have been well-documented. However, the property of kratom's polyphenols in water-soluble phase have been less frequently reported. This study assessed the effects of water-soluble Mitragyna speciosa (kratom) extract (MSE) on gut microbiota and their metabolite production in fecal batch culture.

RESULTS

The water-soluble kratom extract (MSE0) and the water-soluble kratom extract after partial sugar removal (MSE50) both contained polyphenols, with total phenolic levels of 2037.91 ± 51.13 and 3997.95 ± 27.90 mg GAE/g extract, respectively and total flavonoids of 81.10 ± 1.00 and 84.60 ± 1.43 mg CEQ/g extract. The gut microbiota in fecal batch culture was identified by 16S rRNA gene sequencing at 0 and 24 h of fermentation. After fermentation, MSE50 stimulated the growth of Bifidobacterium more than MSE0. MSE0 gave the highest total fatty acids level among the treatments. The phenolic metabolites produced by some intestinal microbiota during fecal fermentation at 24 h were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The major metabolite of biotransformation of both water-soluble MSEs by intestinal microbiota was pyrocatechol (9.85-11.53%).

CONCLUSION

The water-soluble MSEs and their produced metabolites could potentially be used as ingredients for functional and medicinal food production that supports specific gut microbiota. © 2024 Society of Chemical Industry.

Jianpi-Huatan-Huoxue-Anshen formula ameliorates gastrointestinal inflammation and microecological imbalance in chemotherapy-treated mice transplanted with H22 hepatocellular carcinoma

BACKGROUND

Jianpi-Huatan-Huoxue-Anshen formula [Tzu-Chi cancer-antagonizing & life-protecting II decoction (TCCL)] is a Chinese medical formula that has been clinically shown to reduce the gastrointestinal side effects of chemotherapy in cancer patients and improve their quality of life. However, its effect and mechanism on the intestinal microecology after chemotherapy are not yet clear.

AIM

To discover the potential mechanisms of TCCL on gastrointestinal inflammation and microecological imbalance in chemotherapy-treated mice transplanted with hepatocellular carcinoma (HCC).

METHODS

Ninety-six mice were inoculated subcutaneously with HCC cells. One week later, the mice received a large dose of 5-fluorouracil by intraperitoneal injection to establish a HCC chemotherapy model. Thirty-six mice were randomly selected before administration, and feces, ileal tissue, and ileal contents were collected from each mouse. The remaining mice were randomized into normal saline, continuous chemotherapy, Yangzheng Xiaoji capsules-treated, and three TCCL-treated groups. After treatment, feces, tumors, liver, spleen, thymus, stomach, jejunum, ileum, and colon tissues, and ileal contents were collected. Morphological changes, serum levels of IL-1β, IL-6, IL-8, IL-10, IL-22, TNF-α, and TGF-β, intestinal SIgA, and protein and mRNA expression of ZO-1, NF-κB, Occludin, MUC-2, Claudin-1, and IκB-α in colon tissues were documented. The effect of TCCL on the abundance and diversity of intestinal flora was analyzed using 16S rDNA sequencing.

RESULTS

TCCL treatment improved thymus and spleen weight, thymus and spleen indexes, and body weight, decreased tumor volumes and tumor tissue cell density, and alleviated injury to gastric, ileal, and colonic mucosal tissues. Among proteins and genes associated with inflammation, IL-10, TGF-β, SIgA, ZO-1, MUC-2, and Occludin were upregulated, whereas NF-κB, IL-1β, IL-6, TNF-α, IL-22, IL-8, and IκB-α were downregulated. Additionally, TCCL increased the proportions of fecal Actinobacteria, AF12, Adlercreutzia, Clostridium, Coriobacteriaceae, and Paraprevotella in the intermediate stage of treatment, decreased the proportions of Mucipirillum, Odoribacter, RF32, YS2, and Rikenellaceae but increased the proportions of p_Deferribacteres and Lactobacillus at the end of treatment. Studies on ileal mucosal microbiota showed similar findings. Moreover, TCCL improved community richness, evenness, and the diversity of fecal and ileal mucosal flora.

CONCLUSION

TCCL relieves pathological changes in tumor tissue and chemotherapy-induced gastrointestinal injury, potentially by reducing the release of pro-inflammatory factors to repair the gastrointestinal mucosa, enhancing intestinal barrier function, and maintaining gastrointestinal microecological balance. Hence, TCCL is a very effective adjuvant to chemotherapy.

Exploring the Gut Microbiota: Key Insights Into Its Role in Obesity, Metabolic Syndrome, and Type 2 Diabetes

The gut microbiota (GM), comprising trillions of microorganisms in the gastrointestinal tract, is a key player in the development of obesity and related metabolic disorders, such as type 2 diabetes (T2D), metabolic syndrome (MS), and cardiovascular diseases. This mini-review delves into the intricate roles and mechanisms of the GM in these conditions, offering insights into potential therapeutic strategies targeting the microbiota. The review elucidates the diversity and development of the human GM, highlighting its pivotal functions in host physiology, including nutrient absorption, immune regulation, and energy metabolism. Studies show that GM dysbiosis is linked to increased energy extraction, altered metabolic pathways, and inflammation, contributing to obesity, MS, and T2D. The interplay between dietary habits and GM composition is explored, underscoring the influence of diet on microbial diversity and metabolic functions. Additionally, the review addresses the impact of common medications and therapeutic interventions like fecal microbiota transplantation on GM composition. The evidence so far advocates for further research to delineate the therapeutic potential of GM modulation in mitigating obesity and metabolic diseases, emphasizing the necessity of clinical trials to establish effective and sustainable treatment protocols.

Microbiome-derived metabolites in early to mid-pregnancy and risk of gestational diabetes: a metabolome-wide association study

BACKGROUND

Pre-diagnostic disturbances in the microbiome-derived metabolome have been associated with an increased risk of diabetes in non-pregnant populations. However, the roles of microbiome-derived metabolites, the end-products of microbial metabolism, in gestational diabetes (GDM) remain understudied. We examined the prospective association of microbiome-derived metabolites in early to mid-pregnancy with GDM risk in a diverse population.

METHODS

We conducted a prospective discovery and validation study, including a case-control sample of 91 GDM and 180 non-GDM individuals within the multi-racial/ethnic The Pregnancy Environment and Lifestyle Study (PETALS) as the discovery set, a random sample from the PETALS (42 GDM, 372 non-GDM) as validation set 1, and a case-control sample (35 GDM, 70 non-GDM) from the Gestational Weight Gain and Optimal Wellness randomized controlled trial as validation set 2. We measured untargeted fasting serum metabolomics at gestational weeks (GW) 10-13 and 16-19 by gas chromatography/time-of-flight mass spectrometry (TOF-MS), liquid chromatography (LC)/quadrupole TOF-MS, and hydrophilic interaction LC/quadrupole TOF-MS. GDM was diagnosed using the 3-h, 100-g oral glucose tolerance test according to the Carpenter-Coustan criteria around GW 24-28.

RESULTS

Among 1362 annotated compounds, we identified 140 of gut microbiome metabolism origin. Multivariate enrichment analysis illustrated that carbocyclic acids and branched-chain amino acid clusters at GW 10-13 and the unsaturated fatty acids cluster at GW 16-19 were positively associated with GDM risk (FDR < 0.05). At GW 10-13, the prediction model that combined conventional risk factors and LASSO-selected microbiome-derived metabolites significantly outperformed the model with only conventional risk factors including fasting glucose (discovery AUC: 0.884 vs. 0.691; validation 1: 0.945 vs. 0.731; validation 2: 0.987 vs. 0.717; all P < 0.01). At GW 16-19, similar results were observed (discovery AUC: 0.802 vs. 0.691, P < 0.01; validation 1: 0.826 vs. 0.780; P = 0.10).

CONCLUSIONS

Dysbiosis in microbiome-derived metabolites is present early in pregnancy among individuals progressing to GDM.

Porous starch microspheres loaded with luteolin exhibit hypoglycemic activities and alter gut microbial communities in type 2 diabetes mellitus mice

Luteolin (LUT), a natural flavonoid known for its hypoglycemic properties, is primarily sourced from vegetables such as celery and broccoli. However, its poor stability and low bioavailability in the upper digestive tract hinder its application in the functional food industry. To address these challenges, this study employed porous starch (PS) as a carrier to develop PS microspheres loaded with luteolin (PSLUT), simulating its release in vitro. The research assessed the hypoglycemic effects of LUT in type 2 diabetes mellitus (T2DM) mice both before and after PS treatment. In vitro findings demonstrated that PS improved LUT's stability in simulated gastric fluids and enhanced its in vivo bioavailability, aligning with experimental outcomes. PSLUT administration significantly improved body weight, fasting blood glucose (FBG), oral glucose tolerance test (OGTT), pancreatic islet function, and other relevant indicators in T2DM mice. Moreover, PSLUT alleviated abnormal liver biochemical indicators and liver tissue injury caused by T2DM. The underlying hypoglycemic mechanism of PSLUT is thought to involve the regulation of protein kinase B (AKT-1) and glucose transporter 2 (GLUT-2). After four weeks of intervention, various PSLUT doses significantly reduced the Firmicutes to Bacteroidetes ratio at the phylum level and decreased the relative abundance of harmful bacteria at the genus level, including Acetatifactor, Candidatus-Arthromitus, and Turicibacter. This microbial shift was associated with improvements in hyperglycemia-related indicators such as FBG, the area under the curve (AUC) of OGTT, and homeostasis model assessment of insulin resistance (HOMA-IR), which are closely linked to these bacterial genera. Additionally, Lachnoclostridium, Parasutterella, Turicibacter, and Papillibacter were identified as key intestinal marker genera involved in T2DM progression through Spearman correlation analysis. In conclusion, PS enhanced LUT's hypoglycemic efficacy by modulating the transcription and protein expression levels of AKT-1 and GLUT-2, as well as the relative abundance of potential gut pathogens in T2DM mice. These results provide a theoretical foundation for advancing luteolin's application in the functional food industry and further investigating its hypoglycemic potential.

Protective effects of puerarin on metabolic diseases: Emphasis on the therapeutical effects and the underlying molecular mechanisms

Metabolic diseases (MetD) such as diabetes mellitus, obesity, and hyperlipidemia have become global health challenges. As a naturally occurring plant component, puerarin has been verified to possess a wide range of pharmacological effects including lowering blood glucose, improving insulin resistance, and regulating lipid metabolism, which has attracted extensive attention in recent years, and its potential in the treatment of MetD has been highly acclaimed. In addition, puerarin has exhibited antioxidant, anti-inflammatory, and cardiovascular protective effects, which are of great significance in the prevention and treatment of MetD. This article comprehensively summarizes the research progress of puerarin in the treatment of MetD and explores its pharmacological mechanisms, clinical applications, and future perspectives. More importantly, this review provided a list of the involved molecular mechanims in treating MetD of puerarin. Taking into account these conclusions, it may provide a strong foundation for the optimized use of puerarin in the treatment of patients suffering from MetD.

Intestinal permeability disturbances: causes, diseases and therapy

Nowadays, a pathological increase in the permeability of the intestinal barrier (the so-called leaky gut) is increasingly being diagnosed. This condition can be caused by various factors, mainly from the external environment. Damage to the intestinal barrier entails a number of adverse phenomena: dysbiosis, translocation of microorganisms deep into the intestinal tissue, immune response, development of chronic inflammation. These phenomena can ultimately lead to a vicious cycle that promotes the development of inflammation and further damage to the barrier. Activated immune cells in mucosal tissues with broken barriers can migrate to other organs and negatively affect their functioning. Damaged intestinal barrier can facilitate the development of local diseases such as irritable bowel disease, inflammatory bowel disease or celiac disease, but also the development of systemic inflammatory diseases such as rheumatoid arthritis, ankylosing spondylitis, hepatitis, and lupus erythematosus, neurodegenerative or psychiatric conditions, or metabolic diseases such as diabetes or obesity. However, it must be emphasized that the causal links between a leaky gut barrier and the onset of certain diseases often remain unclear and require in-depth research. In light of recent research, it becomes crucial to prevent damage to the intestinal barrier, as well as to develop therapies for the barrier when it is damaged. This paper presents the current state of knowledge on the causes, health consequences and attempts to treat excessive permeability of the intestinal barrier.

Exploring the associations between gut microbiota composition and SARS-CoV-2 inactivated vaccine response in mice with type 2 diabetes mellitus

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination is crucial for protecting vulnerable individuals, yet individuals with type 2 diabetes mellitus (T2DM) often exhibit impaired vaccine responses. Emerging evidence suggests that the composition of the host microbiota, crucial in immune regulation and development, influences vaccine efficacy. This study aimed to characterize the relationships between the SARS-CoV-2 inactivated vaccine and the host microbiota (specifically, gut and lung microbiota) of C57BL/6 mice with T2DM. Employing 16S rRNA metagenomic sequencing and ultra-high-performance liquid chromatography-mass spectrometry, we observed lower alpha diversity and distinct beta diversity in fecal microbiota before vaccination and in gut microbiota 28 days post-vaccination between T2DM mice and healthy mice. Compared with healthy mice, T2DM mice showed a higher Firmicutes/Bacteroidetes ratio 28 days post-vaccination. Significant alterations in gut microbiota composition were detected following vaccination, while lung microbiota remained unchanged. T2DM was associated with a diminished initial IgG antibody response against the spike protein, which subsequently normalized after 28 days. Notably, the initial IgG response positively correlated with fecal microbiota alpha diversity pre-vaccination. Furthermore, after 28 days, increased relative abundance of gut probiotics (Bifidobacterium and Lactobacillus) and higher levels of the gut bacterial tryptophan metabolite, indole acrylic acid, were positively associated with IgG levels. These findings suggest a potential link between vaccine efficacy and gut microbiota composition. Nonetheless, further research is warranted to elucidate the precise mechanisms underlying the impact of the gut microbiome on vaccine response. Overall, this study enhances our understanding of the intricate relationships among host microbiota, SARS-CoV-2 vaccination, and T2DM, with potential implications for improving vaccine efficacy.

IMPORTANCE

Over 7 million deaths attributed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by 6 May 2024 underscore the urgent need for effective vaccination strategies. However, individuals with type 2 diabetes mellitus (T2DM) have been identified as particularly vulnerable and display compromised immune responses to vaccines. Concurrently, increasing evidence suggests that the composition and diversity of gut microbiota, crucial regulators of immune function, may influence the efficacy of vaccines. Against this backdrop, our study explores the complex interplay among SARS-CoV-2 inactivated vaccination, T2DM, and host microbiota. We discover that T2DM compromises the initial immune response to the SARS-CoV-2 inactivated vaccine, and this response is positively correlated with specific features of the gut microbiota, such as alpha diversity. We also demonstrate that the vaccination itself induces alterations in the composition and structure of the gut microbiota. These findings illuminate potential links between the gut microbiota and vaccine efficacy in individuals with T2DM, offering valuable insights that could enhance vaccine responses in this high-risk population.

The complex link between the gut microbiome and obesity-associated metabolic disorders: Mechanisms and therapeutic opportunities

Microbial interactions are widespread and important processes that support the link between disease and microbial ecology. The gut microbiota is a major source of microbial stimuli that can have detrimental or beneficial effects on human health. It is also an endocrine organ that maintains energy homeostasis and host immunity. Obesity is a highly and increasingly prevalent metabolic disease and the leading cause of preventable death worldwide. An imbalance in the gut microbiome is associated with several diseases including obesity-related metabolic disorders. This review summarizes the complex association between the gut microbiome and obesity-associated metabolic diseases and validates the role and mechanisms of ecological dysregulation in the gut in obesity-associated metabolic disorders. Therapies that could potentially alleviate obesity-associated metabolic diseases by modulating the gut microbiota are discussed.

Associations of circulating total p-cresylsulfate and indoxyl sulfate concentrations with central obesity in patients with stable coronary artery disease: sex-specific insights

BACKGROUND/AIMS

Elevated systemic inflammation, common in obesity, increases cardiovascular disease risk. Obesity is linked to a pro-inflammatory gut microbiota that releases uremic toxins like p-cresylsulfate (PCS) and indoxyl sulfate (IS), which are implicated in coronary atherosclerosis, insulin resistance, and chronic kidney disease. This study examines the relationship between total PCS and IS levels and central obesity in patients with stable coronary artery disease (CAD).

METHODS

A cross-sectional study was conducted on 373 consecutive patients with stable CAD from a single center. Serum levels of total PCS and IS were measured using an Ultra Performance LC System. Central obesity was evaluated using a body shape index (ABSI) and conicity index (CI). Six obesity-related proteins were also analyzed. Structural equation modeling (SEM) assessed direct and indirect effects of total PCS, IS, and the six obesity-related proteins on central obesity.

RESULTS

Significant positive correlations were found between total PCS and IS with waist-to-hip ratio (WHR) (r = 0.174, p = 0.005 for total PCS; r = 0.144, p = 0.021 for IS), CI (r = 0.273, p < 0.0001 for total PCS; r = 0.260, p < 0.0001 for IS), and ABSI (r = 0.297, p < 0.0001 for total PCS; r = 0.285, p < 0.0001 for IS) in male patients, but not in female patients. Multivariate analysis showed higher odds ratios (ORs) for elevated CI (OR = 3.18, 95% CI: 1.54-6.75, p = 0.002) and ABSI (OR = 3.28, 95% CI: 1.54-7.24, p = 0.002) in patients with high PCS levels, and elevated CI (OR = 2.30, 95% CI: 1.15-4.66, p = 0.018) and ABSI (OR = 2.22, 95% CI: 1.07-4.72, p = 0.033) in those with high IS levels, compared to those with low toxin levels. SEM analysis indicated that total PCS and IS directly impacted central obesity indices and indirectly influenced central adiposity measures like WHR through high sensitivity C-reactive protein (hs-CRP) (β = 0.252, p < 0.001).

CONCLUSIONS

Circulating total PCS and IS contribute to central obesity in male patients with stable CAD, partially mediated by hs-CRP.

Probiotics for pancreatic β-cell function: from possible mechanism of action to assessment of effectiveness

Type 2 diabetes (T2D) is a metabolic disease characterized by chronic hyperglycemia because of insulin resistance (IR) and\or pancreatic β-cell dysfunction. Last century research showed that gut microbiota has a direct effect on metabolism and metabolic diseases. New studies into the human microbiome and its connection with the host is making it possible to develop new therapies for a wide variety of diseases. Inflammation is a well-known precursor to metabolic syndrome, which increases the risk of hypertension, visceral obesity, and dyslipidemia, which can lead to T2D through the damage of pancreatic β-cell and reduce insulin secretion. Current understanding for beneficial effects of probiotics in T2D strictly rely on both animal and clinical data, which mostly focused on their impact on IR, anthropometric parameters, glycemic control and markers of chronic systemic inflammation. From the other hand, there is a lack of evidence-based probiotic efficacy on pancreatic β-cell function in terms of T2D and related metabolic disorders. Therefore, current review will focus on the efficacy of probiotics for the protection of β-cells damage and it`s mechanism in patients with T2D.

Nut consumption, gut microbiota, and body fat distribution: results of a large, community-based population study

OBJECTIVE

We aimed to investigate the relationships among nut consumption, gut microbiota, and body fat distribution.

METHODS

We studied 2255 Chinese adults in the Lanxi Cohort living in urban areas in Lanxi City, China. Fat distribution was assessed by dual-energy x-ray absorptiometry, and nut consumption was assessed using food frequency questionnaires. 16S ribosomal RNA (rRNA) sequencing was performed on stool samples from 1724 participants. Linear regression and Spearman correlation were used in all analyses. A validation study was performed using 1274 participants in the Lanxi Cohort living in rural areas.

RESULTS

Nut consumption was beneficially associated with regional fat accumulation. Gut microbial analysis suggested that a high intake of nuts was associated with greater microbial α diversity. Six genera were found to be associated with nut consumption, and the abundance of genera Anaerobutyricum, Anaerotaenia, and Fusobacterium was significantly associated with fat distribution. Favorable relationships between α diversity and fat distribution were also observed. Similar relationships between gut microbiota and fat distribution were obtained in the validation analysis.

CONCLUSIONS

We have shown that nut consumption is beneficially associated with body fat distribution and gut microbiota diversity and taxonomy. Furthermore, the microbial features related to high nut intake are associated with a favorable pattern of fat distribution.

Associations of gut microbiota features and circulating metabolites with systemic inflammation in children

OBJECTIVE

Gut microbes and microbe-dependent metabolites (eg, tryptophan-kynurenine-serotonin pathway metabolites) have been linked to systemic inflammation, but the microbiota-metabolite-inflammation axis remains uncharacterised in children. Here we investigated whether gut microbiota features and circulating metabolites (both microbe-dependent and non-microbe-dependent metabolites) associated with circulating inflammation markers in children.

METHODS

We studied children from the prospective Gen3G birth cohort who had data on untargeted plasma metabolome (n=321 children; Metabolon platform), gut microbiota (n=147; 16S rRNA sequencing), and inflammation markers (plasminogen activator inhibitor-1 (PAI-1), monocyte chemoattractant protein-1, and tumour necrosis factor-α) measured at 5-7 years. We examined associations of microbial taxa and metabolites-examining microbe-dependent and non-microbe-dependent metabolites separately-with each inflammatory marker and with an overall inflammation score (InfSc), adjusting for key confounders and correcting for multiple comparisons. We also compared the proportion of significantly associated microbe-dependent versus non-microbe-dependent metabolites, identified a priori (Human Microbial Metabolome Database), with each inflammation marker.

RESULTS

Of 335 taxa tested, 149 were associated (qFDR<0.05) with at least one inflammatory marker; 10 of these were robust to pseudocount choice. Several bacterial taxa involved in tryptophan metabolism were associated with inflammation, including kynurenine-degrading Ruminococcus, which was inversely associated with all inflammation markers. Of 1037 metabolites tested, 315 were previously identified as microbe dependent and were more frequently associated with PAI-1 and the InfSc than non-microbe dependent metabolites. In total, 87 metabolites were associated (qFDR<0.05) with at least one inflammation marker, including kynurenine (positively), serotonin (positively), and tryptophan (inversely).

CONCLUSION

A distinct set of gut microbes and microbe-dependent metabolites, including those involved in the tryptophan-kynurenine-serotonin pathway, may be implicated in inflammatory pathways in childhood.

Oral Microbiome: A Review of Its Impact on Oral and Systemic Health

PURPOSE OF REVIEW

This review investigates the oral microbiome's composition, functions, influencing factors, connections to oral and systemic diseases, and personalized oral care strategies.

RECENT FINDINGS

The oral microbiome is a complex ecosystem consisting of bacteria, fungi, archaea, and viruses that contribute to oral health. Various factors, such as diet, smoking, alcohol consumption, lifestyle choices, and medical conditions, can affect the balance of the oral microbiome and lead to dysbiosis, which can result in oral health issues like dental caries, gingivitis, periodontitis, oral candidiasis, and halitosis. Importantly, our review explores novel associations between the oral microbiome and systemic diseases including gastrointestinal, cardiovascular, endocrinal, and neurological conditions, autoimmune diseases, and cancer. We comprehensively review the efficacy of interventions like dental probiotics, xylitol, oral rinses, fluoride, essential oils, oil pulling, and peptides in promoting oral health by modulating the oral microbiome.

SUMMARY

This review emphasizes the critical functions of the oral microbiota in dental and overall health, providing insights into the effects of microbial imbalances on various diseases. It underlines the significant connection between the oral microbiota and general health. Furthermore, it explores the advantages of probiotics and other dental care ingredients in promoting oral health and addressing common oral issues, offering a comprehensive strategy for personalized oral care.

Causal relationships between gut microbiome and obstructive sleep apnea: a bi-directional Mendelian randomization

Background

Previous studies have identified a clinical association between gut microbiota and Obstructive sleep apnea (OSA), but the potential causal relationship between the two has not been determined. Therefore, we aim to utilize Mendelian randomization (MR) to investigate the potential causal effects of gut microbiota on OSA and the impact of OSA on altering the composition of gut microbiota.

Methods

Bi-directional MR and replicated validation were utilized. Summary-level genetic data of gut microbiota were derived from the MiBioGen consortium and the Dutch Microbiome Project (DMP). Summary statistics of OSA were drawn from FinnGen Consortium and Million Veteran Program (MVP). Inverse-variance-weighted (IVW), weighted median, MR-Egger, Simple Mode, and Weighted Mode methods were used to evaluate the potential causal link between gut microbiota and OSA.

Results

We identified potential causal associations between 23 gut microbiota and OSA. Among them, genus Eubacterium xylanophilum group (OR = 0.86; p = 0.00013), Bifidobacterium longum (OR = 0.90; p = 0.0090), Parabacteroides merdae (OR = 0.85; p = 0.00016) retained a strong negative association with OSA after the Bonferroni correction. Reverse MR analyses indicated that OSA was associated with 20 gut microbiota, among them, a strong inverse association between OSA and genus Anaerostipes (beta = -0.35; p = 0.00032) was identified after Bonferroni correction.

Conclusion

Our study implicates the potential bi-directional causal effects of the gut microbiota on OSA, potentially providing new insights into the prevention and treatment of OSA through specific gut microbiota.

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.

Relationship between changes in the triglyceride glucose-body mass index and frail development trajectory and incidence in middle-aged and elderly individuals: a national cohort study

BACKGROUND

Insulin resistance is linked to an increased risk of frailty, yet the comprehensive relationship between the triglyceride glucose-body mass index (TyG-BMI), which reflects weight, and frailty, remains unclear. This relationship is investigated in this study.

METHODS

Data from 9135 participants in the China Health and Retirement Longitudinal Study (2011-2020) were analysed. Baseline TyG-BMI, changes in the TyG-BMI and cumulative TyG-BMI between baseline and 2015, along with the frailty index (FI) over nine years, were calculated. Participants were grouped into different categories based on TyG-BMI changes using K-means clustering. FI trajectories were assessed using a group-based trajectory model. Logistic and Cox regression models were used to analyse the associations between the TyG-BMI and FI trajectory and frail incidence. Nonlinear relationships were explored using restricted cubic splines, and a linear mixed-effects model was used to evaluate FI development speed. Weighted quantile regression was used to identify the primary contributing factors.

RESULTS

Four classes of changes in the TyG-BMI and two FI trajectories were identified. Individuals in the third (OR = 1.25, 95% CI: 1.10-1.42) and fourth (OR = 1.83, 95% CI: 1.61-2.09) quartiles of baseline TyG-BMI, those with consistently second to highest (OR = 1.49, 95% CI: 1.32-1.70) and the highest (OR = 2.17, 95% CI: 1.84-2.56) TyG-BMI changes, and those in the third (OR = 1.20, 95% CI: 1.05-1.36) and fourth (OR = 1.94, 95% CI: 1.70-2.22) quartiles of the cumulative TyG-BMI had greater odds of experiencing a rapid FI trajectory. Higher frail risk was noted in those in the fourth quartile of baseline TyG-BMI (HR = 1.42, 95% CI: 1.28-1.58), with consistently second to highest (HR = 1.23, 95% CI: 1.12-1.34) and the highest TyG-BMI changes (HR = 1.58, 95% CI: 1.42-1.77), and those in the third (HR = 1.10, 95% CI: 1.00-1.21) and fourth quartile of cumulative TyG-BMI (HR = 1.46, 95% CI: 1.33-1.60). Participants with persistently second-lowest to the highest TyG-BMI changes (β = 0.15, 0.38 and 0.76 respectively) and those experiencing the third to fourth cumulative TyG-BMI (β = 0.25 and 0.56, respectively) demonstrated accelerated FI progression. A U-shaped association was observed between TyG-BMI levels and both rapid FI trajectory and higher frail risk, with BMI being the primary factor.

CONCLUSION

A higher TyG-BMI is associated with the rapid development of FI trajectory and a greater frail risk. However, excessively low TyG-BMI levels also appear to contribute to frail development. Maintaining a healthy TyG-BMI, especially a healthy BMI, may help prevent or delay the frail onset.

Alterations in gut microbiota and inflammatory cytokines after administration of antibiotics in mice

Antibiotics are widely used to treat bacterial infection and reduce the mortality rate, while antibiotic overuse can cause gut microbiota dysbiosis. The impact of antibiotics on gut microbiota is not fully understood. In our study, four commonly used antibiotics (ceftazidime, cefoperazone-sulbactam, imipenem-cilastatin, and moxifloxacin) were given subcutaneously to mice, and their impacts on the gut microbiota composition and serum cytokine levels were evaluated through 16S rRNA analysis and a multiplex immunoassay. Antibiotic treatment markedly reduced gut microbiota diversity and changed gut microbiota composition. Antibiotic treatment significantly increased and decreased the abundance of Firmicutes and Bacteroidota, respectively. The antibiotic treatments increased the abundance of opportunistic pathogens such as Enterococcus and decreased that of Lachnospiraceae and Muribaculaceae. For moxifloxacin, the significantly high abundance of Enterococcus and Klebsiella was observed after 14 and 21 days of treatment. However, a relatively low abundance of opportunistic pathogens was found after 14 days of imipenem-cilastatin treatment. Additionally, the serum levels of various pro-inflammatory cytokines, such as IL-1β, IL-12 (p70), and IL-17, significantly increased after 21 days of antibiotic treatments. Overall, these results provide a guide for rational use of antibiotics in clinical settings: short-term use of moxifloxacin is recommended with regard to gut microbiota health, and the 14-day use of imipenem-cilastatin may have a less severe impact than other antibiotics.IMPORTANCEAntibiotic treatments are directly associated with changes in gut microbiota and are effective against both pathogens and beneficial bacteria. Gut microbiota dysbiosis induced by antibiotic treatment could increase the risk of some diseases. Therefore, an adequate understanding of gut microbiota changes after antibiotic use is crucial. In this study, we investigated the effects of continuous treatment with antibiotics on gut microbiota, serum cytokines, and intestinal inflammatory response. Our results suggest that short-term use of moxifloxacin is recommended, and the 14-day use of imipenem-cilastatin may have a less severe effect on gut microbiota health than cefoperazone-sulbactam. These results provide useful guidance on the rational use of antibiotics with regard to gut microbiota health.

The potential role of gut microbiota-derived metabolites as regulators of metabolic syndrome-associated mitochondrial and endolysosomal dysfunction in Alzheimer's disease

Although the role of gut microbiota (GMB)-derived metabolites in mitochondrial and endolysosomal dysfunction in Alzheimer's disease (AD) under metabolic syndrome remains unclear, deciphering these host-metabolite interactions represents a major public health challenge. Dysfunction of mitochondria and endolysosomal networks (ELNs) plays a crucial role in metabolic syndrome and can exacerbate AD progression, highlighting the need to study their reciprocal regulation for a better understanding of how AD is linked to metabolic syndrome. Concurrently, metabolic disorders are associated with alterations in the composition of the GMB. Recent evidence suggests that changes in the composition of the GMB and its metabolites may be involved in AD pathology. This review highlights the mechanisms of metabolic syndrome-mediated AD development, focusing on the interconnected roles of mitochondrial dysfunction, ELN abnormalities, and changes in the GMB and its metabolites. We also discuss the pathophysiological role of GMB-derived metabolites, including amino acids, fatty acids, other metabolites, and extracellular vesicles, in mediating their effects on mitochondrial and ELN dysfunction. Finally, this review proposes therapeutic strategies for AD by directly modulating mitochondrial and ELN functions through targeting GMB metabolites under metabolic syndrome.

Host-microbe interactions: communication in the microbiota-gut-brain axis

Animals harbor a diverse array of symbiotic micro-organisms that coexist in communities across different body sites. These microbes maintain host homeostasis and respond to environmental insults to impact host physiological processes. Trillions of indigenous microbes reside in the gastrointestinal tract and engage with the host central nervous system (microbiota-gut-brain axis) by modulating immune responses, interacting with gut intrinsic and extrinsic nervous system, and regulating neuromodulators and biochemicals. These gut microbiota to brain signaling pathways are constantly informed by each other and are hypothesized to mediate brain health across the lifespan. In this review, we will examine the crosstalk of gut microbiota to brain communications in neurological pathologies, with an emphasis on microbial metabolites and neuromodulators, and provide a discussion of recent advances that help elucidate the microbiota as a therapeutic target for treating brain and behavioral disorders.

Metformin use associated with lower rate of hospitalization for influenza in individuals with diabetes

AIM

To investigate if patients with diabetes taking metformin have better outcomes versus those not taking metformin following an emergency room visit for influenza.

METHODS

Using electronic medical records, we performed a retrospective chart review of all adult patients with a diagnosis of diabetes seen in any Duke University Medical Center-affiliated emergency department for influenza over a 6-year period. We documented patient characteristics and comorbidities, and compared outcomes for patients taking metformin versus patients not taking metformin using both univariable and multivariable analyses. Our primary outcome was hospital admission rate. Secondary outcomes were in-hospital length of stay and in-hospital death.

RESULTS

Our cohort included 1023 adult patients with diabetes, of whom 59.9% were female. The mean age was 62.9 years, 58.4% were African American, 36.1% were White, and 81.9% were obese or overweight. Of these patients, 347 (34%) were taking metformin. Patients with diabetes taking metformin were less likely to be hospitalized following an emergency department visit for influenza than patients with diabetes not taking metformin (56.8% vs. 70.1%; p < 0.001). Of those patients admitted, there was no statistically significant difference in length of stay or death.

CONCLUSIONS

In patients with diabetes, metformin use is associated with lower rate of hospitalization following an emergency department visit for influenza.

The mediating role of chronic low-grade inflammation participation in the relationship between obesity and type 2 diabetes: findings from the NHANES

BACKGROUND

Chronic low-grade inflammation may mediate the relationship between obesity and diabetes, yet clinical research in this area remains scarce. Thus, this study aimed to explore the mediating role of chronic low-grade inflammation in this relationship using the National Health and Nutrition Examination Survey (NHANES).

METHODS

This study involved 2,482 participants enrolled in the NHANES between 2005 and 2016. Based on the complex sampling survey weights of NHANES, logistic regression models were fitted, adjusting for various covariates to investigate the relationship between BMI, INFLA score, and diabetes. Moreover, weighted quantile sum (WQS) regression models were fitted to analyze the proportional contribution of individual components within the INFLA score. Finally, mediation analysis was conducted to quantitatively assess the magnitude of the mediating effect of the INFLA score on the relationship between BMI and diabetes.

RESULTS

After adjusting for all potential confounding factors, a significant positive correlation was noted between INFLA score and diabetes [OR (95% CI), 1.038(1.003-1.075), p = 0.035]. Additionally, a significant positive correlation was observed between the high INFLA group and diabetes compared to the low INFLA group [OR (95% CI), 1.599(1.031-2.481), p = 0.037]. WQS regression models revealed that the proportional contributions of C-reactive protein, white blood cell count, platelet count, and neutrophil-to-lymphocyte ratio (NLR) were 55.5%, 34.8%, 8.46%, and 1.19%, respectively. Finally, the results of the mediation analysis indicated that the indirect effect of the INFLA score accounted for 10.20%.

CONCLUSIONS

Chronic low-grade inflammation was associated with diabetes and partially mediates the relationship between obesity and diabetes.

Health Benefits of Vegetarian Diets: An Insight into the Main Topics

Vegetarian diets are plant-based diets including all the edible foods from the Plant Kingdom, such as grains, legumes, vegetables, fruits, nuts, and seeds. Dairy and eggs can be added in small amounts in the lacto-ovo-vegetarian subtype, or not at all in the vegan subtype. The abundance of non-processed plant foods-typical of all well-planned diets, including vegetarian ones-can provide the body with numerous protective factors (fiber, phytocompounds), while limiting the intake of harmful nutrients like saturated fats, heme-iron, and cholesterol. The beneficial effects on health of this balance have been reported for many main chronic diseases, in both observational and intervention studies. The scientific literature indicates that vegetarians have a lower risk of certain types of cancer, overall cancer, overweight-obesity, type 2 diabetes, dyslipidemia, hypertension, and vascular diseases. Since the trend of following a vegetarian diet is increasing among citizens of developed countries, the knowledge in the field will benefit from further studies confirming the consistency of these findings and clarifying the effects of vegetarian diets on other controversial topics.

Kynurenines as a Novel Target for the Treatment of Inflammatory Disorders

This review discusses the potential of targeting the kynurenine pathway (KP) in the treatment of inflammatory diseases. The KP, responsible for the catabolism of the amino acid tryptophan (TRP), produces metabolites that regulate various physiological processes, including inflammation, cell cycle, and neurotransmission. These metabolites, although necessary to maintain immune balance, may accumulate excessively during inflammation, leading to systemic disorders. Key KP enzymes such as indoleamine 2,3-dioxygenase 1 (IDO1), indoleamine 2,3-dioxygenase 2 (IDO2), tryptophan 2,3-dioxygenase (TDO), and kynurenine 3-monooxygenase (KMO) have been considered promising therapeutic targets. It was highlighted that both inhibition and activation of these enzymes may be beneficial, depending on the specific inflammatory disorder. Several inflammatory conditions, including autoimmune diseases, for which modulation of KP activity holds therapeutic promise, have been described in detail. Preclinical studies suggest that this modulation may be an effective treatment strategy for diseases for which treatment options are currently limited. Taken together, this review highlights the importance of further research on the clinical application of KP enzyme modulation in the development of new therapeutic strategies for inflammatory diseases.

The Microbiota in Cancer: A Secondary Player or a Protagonist?

The intestinal microbiota and the human body are in a permanent interaction. There is a symbiotic relationship in which the microbiota plays a vitally important role in the performance of numerous functions, including digestion, metabolism, the development of lymphoid tissue, defensive functions, and other processes. It is a true metabolic organ essential for life and has potential involvement in various pathological states, including cancer and pathologies other than those of a digestive nature. A growing topic of great interest for its implications is the relationship between the microbiota and cancer. Dysbiosis plays a role in oncogenesis, tumor progression, and even the response to cancer treatment. The effect of the microbiota on tumor development goes beyond a local effect having a systemic effect. Another aspect of great interest regarding the intestinal microbiota is its relationship with drugs, modifying their activity. There is increasing evidence that the microbiota influences the therapeutic activity and side effects of antineoplastic drugs and also modulates the response of several tumors to antineoplastic therapy through immunological circuits. These data suggest the manipulation of the microbiota as a possible adjuvant to improve oncological treatment. Is it possible to manipulate the microbiota for therapeutic purposes?

Intersecting Pathways: The Role of Metabolic Dysregulation, Gastrointestinal Microbiome, and Inflammation in Acute Ischemic Stroke Pathogenesis and Outcomes

Acute ischemic stroke (AIS) remains a major cause of mortality and long-term disability worldwide, driven by complex and multifaceted etiological factors. Metabolic dysregulation, gastrointestinal microbiome alterations, and systemic inflammation are emerging as significant contributors to AIS pathogenesis. This review addresses the critical need to understand how these factors interact to influence AIS risk and outcomes. We aim to elucidate the roles of dysregulated adipokines in obesity, the impact of gut microbiota disruptions, and the neuroinflammatory cascade initiated by lipopolysaccharides (LPS) in AIS. Dysregulated adipokines in obesity exacerbate inflammatory responses, increasing AIS risk and severity. Disruptions in the gut microbiota and subsequent LPS-induced neuroinflammation further link systemic inflammation to AIS. Advances in neuroimaging and biomarker development have improved diagnostic precision. Here, we highlight the need for a multifaceted approach to AIS management, integrating metabolic, microbiota, and inflammatory insights. Potential therapeutic strategies targeting these pathways could significantly improve AIS prevention and treatment. Future research should focus on further elucidating these pathways and developing targeted interventions to mitigate the impacts of metabolic dysregulation, microbiome imbalances, and inflammation on AIS.

Urolithin B protects mice from diet-induced obesity, insulin resistance, and intestinal inflammation by regulating gut microbiota composition

The increasing prevalence of obesity and type 2 diabetes (T2D) signifies the failure of conventional treatments for these diseases. The gut microbiota has been proposed as a key player in the pathophysiology of diet-induced T2D. Urolithin B (Uro B), a gut microbiota-derived polyphenol metabolite, exerts several beneficial health effects. In this study, we investigated the metabolic effects of Uro B on high-fat/high-sucrose (HFHS)-fed mice and determined whether its antidiabetic effects are related to the modulation of the gut microbiota. C57BL/6J mice were fed either a chow or HFHS diet. HFHS-fed mice were administered daily with either a vehicle (water) or different doses of Uro B (100 or 200 mg kg-1) for eight weeks. The composition of the gut microbiota was assessed by 16S rRNA sequencing. The results showed that Uro B treatment reduced HFHS-induced weight gain and visceral obesity and decreased liver weight and triglyceride accumulation associated with blunted hepatic oxidative stress and inflammation. Furthermore, Uro B administration improved insulin sensitivity as revealed by improved insulin tolerance, a lower homeostasis model assessment of insulin resistance, and decreased glucose-induced hyperinsulinemia during the oral glucose tolerance test. Uro B treatment was found to lower the intestinal triglyceride content and alleviate intestinal inflammation and oxidative stress. Remarkably, Uro B treatment markedly increased the proportion of the mucin-degrading bacterium Akkermansia in metagenomic samples. In conclusion, Uro B exerts beneficial metabolic effects by alleviating HFHS diet-induced features of metabolic syndrome, which is associated with a proportional increase in the population of Akkermansia spp.

Edible bird's nest regulates glucose and lipid metabolic disorders via the gut-liver axis in obese mice

Edible bird's nest (EBN) is a traditional food known for its nourishing and functional properties and is found to be involved in anti-oxidation, anti-aging, and anti-influenza mechanisms, immune regulation, and improving cardiovascular diseases, among others. However, the potential of EBN to improve glycolipid metabolism disorders in high-fat-diet induced obesity and the underlying mechanisms remain unexplored. We examined the effects of EBN on glycolipid metabolism in obese mice fed a high-fat diet. Male C57BL/6J mice were fed a high-fat diet for 8 weeks to establish an obesity model. The obese mice were selected and divided into six groups: two model control groups (normal and high-fat diets) and four intervention groups [Neu5Ac and low-, medium-, and high-dose EBN], with 12 mice in each group. After 10 weeks of continuous gavage intervention, only mice in the high-dose EBN intervention group had lower body weight and total fat content, especially visceral fat. Meanwhile, intervention with three doses of EBN reduced serum FBG, TC, LDL, Ox-LDL, IL-1β, IL-6, and TNF-α levels and increased serum HDL levels and energy expenditure. Using the high dosage as a paradigm, EBN intervention increased the sialic acid content in LDL, decreased TMAO in the liver, and increased GLP-1 levels in sera. EBN increased the colonic abundances of Akkermansia, Lactobacillus, and Desulfovibrio and reduced those of Lysinibacillus and Bacillus. The changes in the microbial community contribute to increasing colonic bile acids, reducing lipopolysaccharide synthesis to protect the intestinal barrier, and lowering inflammation levels. Changes were also observed in colonic transcripts and metabolites and liver gene transcripts and metabolites, which were mainly enriched in pathways of glycolipid metabolism, immune function amelioration, inflammatory signal mitigation, circadian rhythm, bile acid metabolism and insulin resistance. Therefore, EBN may enhance the gut microbiota and intestinal immunity, relieve chronic inflammation levels in serum, improve antioxidant capacity and circadian rhythm in the liver, promote bile acid metabolism, and decrease lipid absorption and lipid synthesis via the gut-liver axis. Consequently, this may reduce blood lipid and fat accumulation as well as improve islet function and reduce blood glucose levels.

The Role of Gut Microbiome in Sleep Quality and Health: Dietary Strategies for Microbiota Support

Dietary components, including dietary fiber, unsaturated fatty acids, and polyphenols, along with meal timing and spacing, significantly affect the microbiota's capacity to produce various metabolites essential for quality sleep and overall health. This review explores the role of gut microbiota in regulating sleep through various metabolites such as short-chain fatty acids, tryptophan, serotonin, melatonin, and gamma-aminobutyric acid. A balanced diet rich in plant-based foods enhances the production of these sleep-regulating metabolites, potentially benefiting overall health. This review aims to investigate how dietary habits affect gut microbiota composition, the metabolites it produces, and the subsequent impact on sleep quality and related health conditions.

Global research trends on gut microbiota and metabolic dysfunction-associated steatohepatitis: Insights from bibliometric and scientometric analysis

Background

Metabolic dysfunction-associated steatohepatitis (MASH) is an inflammatory subtype of metabolic dysfunction-associated steatotic liver disease (MASLD) has recently been proposed as a replacement term for NAFLD, a common, multifactorial and poorly understood liver disease whose incidence is increasing worldwide. In recent years, there has been increasing scientific interest in exploring the relationship between gut microbiota and MASH. To learn more about the gut microbiota in MASH, this study aims to provide a comprehensive analysis of the knowledge structure and research hotspots from a bibliometric perspective.

Methods

We searched the Web of Science Core Collection for articles and reviews that covered the connections between gut microbiota and MASH over the last decade. The Online Analysis Platforms, VOSviewer, CiteSpace, the R tool "bibliometrix" were used to analyzed existing publications trends and hotspots.

Results

A total of 4,069 documents related to the interaction between gut microbiota and MASH were retrieved from 2014 to 2023. The number of annual publications increased significantly over the last decade, particularly in the United States and China. The University of California-San Diego was the most productive institution, while researcher Rohit Loomba published the most papers in the field. Younossi ZM was ranked as the first co-cited author and largest contributor of highly cited articles in the field. Gastroenterology and hepatology were the most common specialty category. The most cited journal in the last decade was Hepatology. The Keyword Bursts analysis highlighted the importance of studying the association between gut microbiota and MASH, as well as related factors such as metabolic syndrome, insulin resistance, endotoxemia and overgrowth of gut bacteria. Keyword clusters with co-citation were used to illustrate important topics including intestinal permeability, insulin sensitivity and liver immunology. The most common keywords include insulin resistance, obesity, dysbiosis, inflammation and oxidative stress, which are current hotspots.

Conclusion

Our analysis highlights key aspects of this field and emphasizes multiorgan crosstalk in MASLD/MASH pathogenesis. In particular, the central role of the gut-liver axis and the significant influence of gut microbiota dysbiosis on disease progression are highlighted. Furthermore, our results highlight the transformative potential of microbiota-specific therapies and cover the way for innovative healthcare and pharmaceutical strategies.

Longitudinal gut microbial signals are associated with weight loss: insights from a digital therapeutics program

Introduction

The gut microbiome's influence on weight management has gained significant interest for its potential to support better obesity therapeutics. Patient stratification leading to personalized nutritional intervention has shown benefits over one-size-fit-all diets. However, the efficacy and impact on the gut's microbiome of personalizing weight loss diets based on individual factors remains under-investigated.

Methods

This study assessed the impact of Digbi Health's personalized dietary and lifestyle program on weight loss and the gut microbiome end-points in 103 individuals. Participants' weight loss patterns and gut microbiome profiles were analyzed from baseline to follow-up samples.

Results

Specific microbial genera, functional pathways, and communities associated with BMI changes and the program's effectiveness were identified. 80% of participants achieved weight loss. Analysis of the gut microbiome identified genera and functional pathways associated with a reduction in BMI, including Akkermansia, Christensenella, Oscillospiraceae, Alistipes, and Sutterella, short-chain fatty acid production, and degradation of simple sugars like arabinose, sucrose, and melibiose. Network analysis identified a microbiome community associated with BMI, which includes multiple taxa known for associations with BMI and obesity.

Discussion

The personalized dietary and lifestyle program positively impacted the gut microbiome and demonstrated significant associations between gut microbial changes and weight loss. These findings support the use of the gut microbiome as an endpoint in weight loss interventions, highlighting potential microbiome biomarkers for further research.

The role of pyroptosis in metabolism and metabolic disease

Pyroptosis is a lytic and pro-inflammatory form of regulated cell death characterized by the formation of membrane pores mediated by the gasdermin protein family. Two main activation pathways have been documented: the caspase-1-dependent canonical pathway and the caspase-4/5/11-dependent noncanonical pathway. Pyroptosis leads to cell swelling, lysis, and the subsequent release of inflammatory mediators, including interleukin-1β (IL-1β) and interleukin-18 (IL-18). Chronic inflammation is a well-established foundation and driver for the development of metabolic diseases. Conversely, metabolic pathway dysregulation can also induce cellular pyroptosis. Recent studies have highlighted the significant role of pyroptosis modulation in various metabolic diseases, including type 2 diabetes mellitus, obesity, and metabolic (dysfunction) associated fatty liver disease. These findings suggest that pyroptosis may serve as a promising novel therapeutic target for metabolic diseases. This paper reviews an in-depth study of the current advancements in understanding the role of pyroptosis in the progression of metabolic diseases.

New insights into the interplay between autophagy, gut microbiota and insulin resistance in metabolic syndrome

Metabolic syndrome (MetS) is a widespread and multifactorial disorder, and the study of its pathogenesis and treatment remains challenging. Autophagy, an intracellular degradation system that maintains cellular renewal and homeostasis, is essential for maintaining antimicrobial defense, preserving epithelial barrier integrity, promoting mucosal immune response, maintaining intestinal homeostasis, and regulating gut microbiota and microbial metabolites. Dysfunctional autophagy is implicated in the pathological mechanisms of MetS, involving insulin resistance (IR), chronic inflammation, oxidative stress, and endoplasmic reticulum (ER) stress, with IR being a predominant feature. The study of autophagy represents a valuable field of research with significant clinical implications for identifying autophagy-related signals, pathways, mechanisms, and treatment options for MetS. Given the multifactorial etiology and various potential risk factors, it is imperative to explore the interplay between autophagy and gut microbiota in MetS more thoroughly. This will facilitate the elucidation of new mechanisms underlying the crosstalk among autophagy, gut microbiota, and MetS, thereby providing new insights into the diagnosis and treatment of MetS.

Understanding how pre- and probiotics affect the gut microbiome and metabolic health

The gut microbiome, a complex assembly of microorganisms, significantly impacts human health by influencing nutrient absorption, the immune system, and disease response. These microorganisms form a dynamic ecosystem that is critical to maintaining overall well-being. Prebiotics and probiotics are pivotal in regulating gut microbiota composition. Prebiotics nourish beneficial bacteria and promote their growth, whereas probiotics help maintain balance within the microbiome. This intricate balance extends to several aspects of health, including maintaining the integrity of the gut barrier, regulating immune responses, and producing metabolites crucial for metabolic health. Dysbiosis, or an imbalance in the gut microbiota, has been linked to metabolic disorders such as type 2 diabetes, obesity, and cardiovascular disease. Impaired gut barrier function, endotoxemia, and low-grade inflammation are associated with toll-like receptors influencing proinflammatory pathways. Short-chain fatty acids derived from microbial fermentation modulate anti-inflammatory and immune system pathways. Prebiotics positively influence gut microbiota, whereas probiotics, especially Lactobacillus and Bifidobacterium strains, may improve metabolic outcomes, such as glycemic control in diabetes. It is important to consider strain-specific effects and study variability when interpreting these findings, highlighting the need for further research to optimize their therapeutic potential. The aim of this report is therefore to review the role of the gut microbiota in metabolic health and disease and the effects of prebiotics and probiotics on the gut microbiome and their therapeutic role, integrating a broad understanding of physiological mechanisms with a clinical perspective.

The role of probiotics on microvascular complications of type-2 diabetes: Nephropathy and retinopathy

Diabetes is a multifactorial disorder that involves several molecular mechanisms and is still one of the key global health challenges with increasing prevalence and incidence. Gut microbiome dysbiosis could activate and recognize receptors that trigger the inflammation response and modulation of insulin sensitivity. In addition, the intricate role of gut microbiota dysbiosis in the onset and development of T2D (Type 2 diabetes mellitus) and associated microvascular complications was identified. These complications include diabetic nephropathy (DN) and diabetic retinopathy (DR), diabetic neuropathy, cerebrovascular disorders, and coronary heart disease. A recent interesting strategy to improve these complications is probiotics administration. The safety and health effects of probiotics against various diseases have been validated by various in vitro, in vivo and clinical studies. In this review, the related mechanisms between the gut microbiome, initiation, and progression of T2D and its common microvascular complications (DN and DR) have been discussed.

Gut microbiome signatures associated with type 2 diabetes in obesity in Mongolia

Mongolian people possess a unique dietary habit characterized by high consumption of meat and dairy products and fewer vegetables, resulting in the highest obesity rate in East Asia. Although obesity is a known cause of type 2 diabetes (T2D), the T2D rate is moderate in this population; this is known as the "Mongolian paradox." Since the gut microbiota plays a key role in energy and metabolic homeostasis as an interface between food and body, we investigated gut microbial factors involved in the prevention of the co-occurrence of T2D with obesity in Mongolians. We compared the gut microbiome and metabolome of Mongolian adults with obesity with T2D (DO: n = 31) or without T2D (NDO: n = 35). Dysbiotic signatures were found in the gut microbiome of the DO group; lower levels of Faecalibacterium and Anaerostipes which are known as short-chain fatty acid (SCFA) producers and higher levels of Methanobrevibacter, Desulfovibrio, and Solobacterium which are known to be associated with certain diseases. On the other hand, the NDO group exhibited a higher level of fecal SCFA concentration, particularly acetate. This is consistent with the results of the whole shotgun metagenomic analysis, which revealed a higher relative abundance of SCFA biosynthesis-related genes encoded largely by Anaerostipes hadrus in the NDO group. Multiple logistic regression analysis including host demographic parameters indicated that acetate had the highest negative contribution to the onset of T2D. These findings suggest that SCFAs produced by the gut microbial community participate in preventing the development of T2D in obesity in Mongolians.

Gut-Liver-Pancreas Axis Crosstalk in Health and Disease: From the Role of Microbial Metabolites to Innovative Microbiota Manipulating Strategies

The functions of the gut are closely related to those of many other organs in the human body. Indeed, the gut microbiota (GM) metabolize several nutrients and compounds that, once released in the bloodstream, can reach distant organs, thus influencing the metabolic and inflammatory tone of the host. The main microbiota-derived metabolites responsible for the modulation of endocrine responses are short-chain fatty acids (SCFAs), bile acids and glucagon-like peptide 1 (GLP-1). These molecules can (i) regulate the pancreatic hormones (insulin and glucagon), (ii) increase glycogen synthesis in the liver, and (iii) boost energy expenditure, especially in skeletal muscles and brown adipose tissue. In other words, they are critical in maintaining glucose and lipid homeostasis. In GM dysbiosis, the imbalance of microbiota-related products can affect the proper endocrine and metabolic functions, including those related to the gut-liver-pancreas axis (GLPA). In addition, the dysbiosis can contribute to the onset of some diseases such as non-alcoholic steatohepatitis (NASH)/non-alcoholic fatty liver disease (NAFLD), hepatocellular carcinoma (HCC), and type 2 diabetes (T2D). In this review, we explored the roles of the gut microbiota-derived metabolites and their involvement in onset and progression of these diseases. In addition, we detailed the main microbiota-modulating strategies that could improve the diseases' development by restoring the healthy balance of the GLPA.

Peanut Shell Extract Improves Mitochondrial Function in db/db Mice via Suppression of Oxidative Stress and Inflammation

Accumulating evidence shows a strong correlation between type 2 diabetes mellitus, mitochondrial dysfunction, and oxidative stress. We evaluated the effects of dietary peanut shell extract (PSE) supplementation on mitochondrial function and antioxidative stress/inflammation markers in diabetic mice. Fourteen db/db mice were randomly assigned to a diabetic group (DM in AIN-93G diet) and a PSE group (1% wt/wt PSE in AIN-93G diet) for 5 weeks. Six C57BL/6J mice were fed with an AIN-93G diet for 5 weeks (control group). Gene and protein expression in the liver, brain, and white adipose tissue (WAT) were determined using qRT-PCR and Immunoblot, respectively. Compared to the control group, the DM group had (i) increased gene and protein expression levels of DRP1 (fission), PINK1 (mitophagy), and TNFα (inflammation) and (ii) decreased gene and protein expression levels of MFN1, MFN2, OPA1 (fusion), TFAM, PGC-1α (biogenesis), NRF2 (antioxidative stress) and IBA1 (microglial activation) in the liver, brain, and WAT of db/db mice. Supplementation of PSE into the diet restored the DM-induced changes in the gene and protein expression of DRP1, PINK1, TNFα, MFN1, MFN2, OPA1, TFAM, PGC-1α, NRF2, and IBA1 in the liver, brain, and WAT of db/db mice. This study demonstrates that PSE supplementation improved mitochondrial function in the brain, liver, and WAT of db/db mice, in part due to suppression of oxidative stress and inflammation.

Insights into Gut Microbiome Composition in Hidradenitis Suppurativa: A Comprehensive Examination of Dietary Habits and Environmental Influences

This study explores the relationship between dietary habits, environmental influences, and gut microbiome composition in individuals with hidradenitis suppurativa (HS), a chronic inflammatory skin condition. A cohort of 80 participants, equally divided into HS patients and healthy controls, was assessed through comprehensive questionnaires capturing demographics, dietary habits, and other health-related information. Fecal samples were collected and analyzed using next-generation sequencing to examine microbiome composition. Despite previous studies suggesting gut dysbiosis in HS, this research found no significant differences in alpha-diversity and Shannon diversity index between the groups. However, significant disparities in dietary habits were observed, with HS patients showing higher sugar and milk consumption. The study also identified a significant correlation between coffee consumption and the presence of certain bacterial genera. While the study did not reveal major differences in microbiome diversity, the findings on dietary habits and specific microbiome components suggest potential targets for therapeutic intervention. These results underscore the importance of further research into the gut-skin axis and its role in HS, aiming to enhance management strategies through dietary modifications and lifestyle interventions.

Transfer of modified gut viromes improves symptoms associated with metabolic syndrome in obese male mice

Metabolic syndrome encompasses amongst other conditions like obesity and type-2 diabetes and is associated with gut microbiome (GM) dysbiosis. Fecal microbiota transplantation (FMT) has been explored to treat metabolic syndrome by restoring the GM; however, concerns on accidentally transferring pathogenic microbes remain. As a safer alternative, fecal virome transplantation (FVT, sterile-filtrated feces) has the advantage over FMT in that mainly bacteriophages are transferred. FVT from lean male donors have shown promise in alleviating the metabolic effects of high-fat diet in a preclinical mouse study. However, FVT still carries the risk of eukaryotic viral infections. To address this, recently developed methods are applied for removing or inactivating eukaryotic viruses in the viral component of FVT. Modified FVTs are compared with unmodified FVT and saline in a diet-induced obesity model on male C57BL/6 N mice. Contrasted with obese control, mice administered a modified FVT (nearly depleted for eukaryotic viruses) exhibits enhanced blood glucose clearance but not weight loss. The unmodified FVT improves liver pathology and reduces the proportions of immune cells in the adipose tissue with a non-uniform response. GM analysis suggests that bacteriophage-mediated GM modulation influences outcomes. Optimizing these approaches could lead to the development of safe bacteriophage-based therapies targeting metabolic syndrome through GM restoration.

Lipid- and glucose-lowering effects of Rhamnan sulphate from Monostroma nitidum with altered gut microbiota in mice

Rhamnan sulphate (RS) is a sulphated polysaccharide found in green algae such as Monostroma nitidum that exhibits various biological functions, including anticoagulant, antitumour, antiviral, and anti-obesity properties. In our previous clinical trial, we demonstrated that RS intake improves constipation. However, no specific bacteria showed a significant (p < .05) change. Notably, these results were obtained after a short RS inoculation period of only 2 weeks. In the present study, to evaluate the long-term effects of RS on the gut microbiota, we orally administered RS to BALB/c mice for 11 weeks, analyzed their blood biochemical data, and performed 16s rRNA-sequencing. Oral administration of RS increased body weight with increased food intake, whereas plasma total cholesterol and fasting plasma glucose levels decreased. RS-fed mice showed lower fasting insulin levels (p < .1) and decreased homeostatic model assessment for insulin resistance (HOMA-IR, p < .0001), suggesting that RS improved insulin resistance. In the feces of mice, the amounts of acetic and propionic acids increased. In the gut microbiota, predictive metagenomic profiling using the phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt2) revealed functional alterations in Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathways in RS-fed mice. Corresponding to the blood glucose-lowering effect, the glycolysis and tricarboxylic acid (TCA) cycle pathways were activated. In addition, the Firmicutes/Bacteroides (F/B) ratio, which may be associated with various health outcomes, was also reduced. These results suggest that the blood glucose-lowering effect, improvement in insulin resistance, and lipid-lowering effect of RS may be due to changes in the intestinal microbiota.

Prebiotics, probiotics, synbiotics and postbiotics to adolescents in metabolic syndrome

The prevalence of childhood and adolescent obesity has globally reached alarming dimensions and many adolescents affected by obesity already present one or more obesity-related comorbidities. In recent years, emerging evidence supporting the role of gut microbiota in the pathophysiology of metabolic diseases has been reported and the use of prebiotics, probiotics, synbiotics and postbiotics as a strategy to manipulate gut microbiota has become popular. The aim of this review is to explore the relationship between gut microbiota and metabolic syndrome in adolescents and to discuss the potential use of prebiotics, probiotics, synbiotics and postbiotics for the prevention and treatment of this clinical picture in adolescence. According to the most recent literature, prebiotics, probiotics and synbiotics have no clear effect on MetS, but a possible modulation of anthropometric parameters has been observed after synbiotic supplementation. Only one study has examined the role of postbiotics in alleviating metabolic complications in children with obesity but not in adolescents. More extensive research is needed to support the conclusions drawn so far and to develop effective microbiome-based interventions that may help improving the quality of life of children and adolescents exposed to the increasing prevalence of MetS.

Role of the Intestine and Its Gut Microbiota in Metabolic Syndrome and Obesity

The metabolic syndrome (MetSyn) is currently one of the biggest global health challenges because of its impact on public health. MetSyn includes the cluster of metabolic disorders including obesity, high blood pressure, hyperglycemia, high triglyceride levels, and hepatic steatosis. Together, these abnormalities increase the cardiovascular risk of individuals and pose a threat to healthcare systems worldwide. To better understand and address this complex issue, recent research has been increasingly focusing on unraveling the delicate interplay between metabolic disorders and the intestines and more specifically our gut microbiome. The gut microbiome entails all microorganisms inhabiting the gastrointestinal tract and plays a pivotal role in metabolic processes and overall health of its host. Emerging evidence proves an association between the gut microbiome composition and aspects of MetSyn, such as obesity. Understanding these relationships is crucial because they offer valuable insights into the mechanisms underlying development and progression of metabolic disorders and possible treatment options. Yet, how should we interpret this relationship? This review focuses on the interplay between the gut and MetSyn. In addition, we have reviewed the existing evidence of the gut microbiome and its association with and impact on metabolic disorders, in an attempt to understand the complex interactions and nature of this association. We also explored potential therapeutic options targeting the gut to modify metabolic disorders and obesity.

Reoxygenation Mitigates Intermittent Hypoxia-Induced Systemic Inflammation and Gut Microbiota Dysbiosis in High-Fat Diet-Induced Obese Rats

Background

Obstructive sleep apnea (OSA) is a prevalent sleep breathing disorder characterized by intermittent hypoxia (IH), with continuous positive airway pressure (CPAP) as its standard treatment. However, the effects of intermittent hypoxia/reoxygenation (IH/R) on weight regulation in obesity and its underlying mechanism remain unclear. Gut microbiota has gained attention for its strong association with various diseases. This study aims to explore the combined influence of IH and obesity on gut microbiota and to investigate the impact of reoxygenation on IH-induced alterations.

Methods

Diet-induced obese (DIO) rats were created by 8-week high-fat diet (HFD) feeding and randomly assigned into three groups (n=15 per group): normoxia (NM), IH (6% O2, 30 cycles/h, 8 h/day, 4 weeks), or hypoxia/reoxygenation (HR, 2-week IH followed by 2-week reoxygenation) management. After modeling and exposure, body weight and biochemical indicators were measured, and fecal samples were collected for 16S rRNA sequencing.

Results

DIO rats in the IH group showed increased weight gain (p=0.0016) and elevated systemic inflammation, including IL-6 (p=0.0070) and leptin (p=0.0004). Moreover, IH rats exhibited greater microbial diversity (p<0.0167), and significant alterations in the microbial structure (p=0.014), notably the order Clostridiales, accompanied by an upregulation of bile acid metabolism predicted pathway (p=0.0043). Reoxygenation not only improved IH-exacerbated obesity, systemic inflammation, leptin resistance, and sympathetic activation, but also showed the potential to restore IH-induced microbial alterations. Elevated leptin levels were associated with Ruminococcaceae (p=0.0008) and Clostridiales (p=0.0019), while body weight was linked to Blautia producta (p=0.0377). Additionally, the abundance of Lactobacillus was negatively correlated with leptin levels (p=0.0006) and weight (p=0.0339).

Conclusion

IH leads to gut dysbiosis and metabolic disorders, while reoxygenation therapy demonstrates a potentially protective effect by restoring gut homeostasis and mitigating inflammation. It highlights the potential benefits of CPAP in reducing metabolic risk among obese patients with OSA.

The Probiotic Strain Lactobacillus acidophilus CL1285 Reduces Fat Deposition and Oxidative Stress and Increases Lifespan in Caenorhabditis elegans

Caenorhabditis elegans was recently shown to be a powerful model for studying and identifying probiotics with specific functions. Lactobacillus acidophilus CL1285, Lacticaseibacillus casei LBC80R, and Lacticaseibacillus rhamnosus CLR2, which are three bacteria that were marketed by Bio-K+, were evaluated using the nematode C. elegans to study fat accumulation, lifespan, and resistance to oxidative stress. Although the general effects of probiotics in terms of protection against oxidative stress were highlighted, the CL1285 strain had an interesting and specific feature, namely its ability to prevent fat accumulation in nematodes; this effect was verified by both the Oil Red and Nile Red methods. This observed phenotype requires daf-16 and is affected by glucose levels. In addition, in a daf-16- and glucose-dependent manner, CL1285 extended the lifespan of C. elegans; this effect was unique to CL1285 and not found in the other L. acidophilus subtypes in this study. Our findings indicate that L. acidophilus CL1285 impacts fat/glucose metabolism in C. elegans and provides a basis to further study this probiotic, which could have potential health benefits in humans and/or in mammals.

Effect of Akkermansia muciniphila on pancreatic islet β-cell function in rats with prediabetes mellitus induced by a high-fat diet

Prediabetes is an important stage in the development of diabetes. It is necessary to find a safe, effective and sustainable way to delay and reverse the progression of prediabetes. Akkermansia muciniphila (A. muciniphila) is one of the key bacteria associated with glucose metabolism. Recent studies mainly focus on the effect of A. muciniphila on obesity and insulin resistance, but there is no research on the effect of A. muciniphila on pancreatic β-cell function and its mechanism in prediabetes. In this study, we investigated the effects of A. muciniphila on β-cell function, apoptosis and differentiation, as well as its effects on the gut microbiome, intestinal barrier, metaflammation and the expression of Toll-like receptors (TLRs) in a high-fat diet (HFD)-induced prediabetic rat model. The effect of A. muciniphila was compared with dietary intervention. The results showed both A. muciniphila treatment and dietary intervention can reduce metaflammation by repairing the intestinal barrier in rats with prediabetes induced by an HFD and improve β-cell secretory function, apoptosis and differentiation through signaling pathways mediated by TLR2 and TLR4. Additionally, A. muciniphila can further elevate β-cell secretion, attenuate apoptosis and improve differentiation and the TLR signaling pathway on the basis of diet.

Mechanisms of microbiota modulation: Implications for health, disease, and therapeutic interventions

Microbiota modulation, the intentional change in the structure and function of the microbial community, is an emerging trajectory that holds the promise to mitigate an infinite number of health issues. The present review illustrates the underlying principles of microbiota modulation and the various applications of this fundamental process to human health, healthcare management, and pharmacologic interventions. Different strategies, directing on dietary interventions, fecal microbiota transplantation, treatment with antibiotics, bacteriophages, microbiome engineering, and modulation of the immune system, are described in detail. This therapeutic implication is reflected in clinical applications to gastrointestinal disorders and immune-mediated diseases for microbiota-modulating agents. In addition to this, the review outlines the challenges of translating researched outcomes into clinical practice to consider safety and provides insights into future research directions of this rapidly developing area.

The proteomic profile is altered but not repaired after bariatric surgery in type 2 diabetes pigs

To reveal the sources of obesity and type 2 diabetes (T2D) in humans, animal models, mainly rodents, have been used. Here, we propose a pig model of T2D. Weaned piglets were fed high fat/high sugar diet suppling 150% of metabolizable energy. Measurements of weight gain, blood morphology, glucose plasma levels, cholesterol, and triglycerides, as well as glucose tolerance (oral glucose tolerance test, OGTT) were employed to observe T2D development. The histology and mass spectrometry analyses were made post mortem. Within 6 months, the high fat-high sugar (HFHS) fed pigs showed gradual and significant increase in plasma triglycerides and glucose levels in comparison to the controls. Using OGTT test, we found stable glucose intolerance in 10 out of 14 HFHS pigs. Mass spectrometry analysis indicated significant changes in 330 proteins in the intestine, liver, and pancreas of the HFHS pigs. These pigs showed also an increase in DNA base modifications and elevated level of the ALKBH proteins in the tissues. Six diabetic HFHS pigs underwent Scopinaro bariatric surgery restoring glycaemia one month after surgery. In conclusion, a high energy diet applied to piglets resulted in the development of hyperlipidaemia, hyperglycaemia, and type 2 diabetes being reversed by a bariatric procedure, excluding the proteomic profile utill one month after the surgery.

Association of gut microbiota with cerebral cortical thickness: A Mendelian randomization study

BACKGROUND

The causal relationship between gut microbiota and cerebral cortex development remains unclear. We aimed to scrutinize the plausible causal impact of gut microbiota on cortical thickness via Mendelian randomization (MR) study.

METHODS

Genome-wide association study (GWAS) data for 196 gut microbiota phenotypes (N = 18,340) were obtained as exposures, and GWAS data for cortical thickness-related traits (N = 51,665) were selected as outcomes. Inverse variance weighted was used as the main estimate method. A series of sensitivity analyses was used to test the robustness of the estimates including Cochran's Q test, MR-Egger intercept analysis, Steiger filtering, scatter plot funnel plot and leave-one-out analysis.

RESULTS

Genetic prediction of high Bacillales (β = 0.005, P = 0.032) and Lactobacillales (β = 0.010, P = 0.012) abundance was associated with a potential increase in global cortical thickness. For specific functional brain subdivisions, genetically predicted order Lactobacillales would potentially increase the thickness of the fusiform (β = 0.014, P = 0.016) and supramarginal (β = 0.017, P = 0.003). Meanwhile, order Bacillales would increase the thickness of fusiform (β = 0.007, P = 0.039), insula (β = 0.011, P = 0.003), rostralanteriorcingulate (β = 0.014, P = 0.002) and supramarginal (β = 0.006, P = 0.043). No significant estimates of heterogeneity or pleiotropy were found.

CONCLUSIONS

Through MR studies, we discovered genetic prediction of the Lactobacillales and Bacillales orders potentially linked to cortical thickness, affirming gut microbiota may enhance brain structure. Genetically predicted supramarginal and fusiform may be potential targets.