Crosstalk between intestinal microbiota, adipose tissue and skeletal muscle as an early event in systemic low-grade inflammation and the development of obesity and diabetes

Sargassum horneri extract fermented by Lactiplantibacillus pentosus SH803 mediates adipocyte metabolism in 3T3-L1 preadipocytes by regulating oxidative damage and inflammation

Sargassum horneri (S. horneri), a brown seaweed excessively proliferating along Asian coastlines, are damaging marine ecosystems. Thus, this study aimed to enhance nutritional value of S. horneri through lactic acid bacteria fermentation to increase S. horneri utilization as a functional food supplement, and consequently resolve coastal S. horneri accumulation. S. horneri supplemented fermentation was most effective with Lactiplantibacillus pentosus SH803, thus this product (F-SHWE) was used for further in vitro studies. F-SHWE normalized expressions of oxidative stress related genes NF-κB, p53, BAX, cytochrome C, caspase 9, and caspase 3, while non-fermented S. horneri (SHWE) did not, in a H2O2-induced HT-29 cell model. Moreover, in an LPS-induced HT-29 cell model, F-SHWE repaired expressions of inflammation marker genes ZO1, IL1β, IFNγ more effectively than SHWE. For further functional assessment, F-SHWE was also treated in 3T3-L1 adipocytes. As a result, F-SHWE decreased lipid accumulation, along with gene expression of adipogenesis markers PPARγ, C/EBPα, C/EBPβ, aP2, and Lpl; lipogenesis markers Lep, Akt, SREBP1, Acc, Fas; inflammation markers IFN-γ and NF-κB. Notably, gene expression of C/EBPβ, IFN-γ and NF-κB were suppressed only by F-SHWE, suggesting the enhancing effect of fermentation on obesity-related properties. Compositional analysis attributed the protective effects of F-SHWE to acetate, an organic acid significantly higher in F-SHWE than SHWE. Therefore, F-SHWE is a novel potential anti-obesity agent, providing a strategy to reduce excess S. horneri populations along marine ecosystems.

Tissue-resident bacteria in metabolic diseases: emerging evidence and challenges

Although the impact of the gut microbiome on health and disease is well established, there is controversy regarding the presence of microorganisms such as bacteria and their products in organs and tissues. However, recent contamination-aware findings of tissue-resident microbial signatures provide accumulating evidence in support of bacterial translocation in cardiometabolic disease. The latter provides a distinct paradigm for the link between microbial colonizers of mucosal surfaces and host metabolism. In this Perspective, we re-evaluate the concept of tissue-resident bacteria including their role in metabolic low-grade tissue and systemic inflammation. We examine the limitations and challenges associated with studying low bacterial biomass samples and propose experimental and analytical strategies to overcome these issues. Our Perspective aims to encourage further investigation of the mechanisms linking tissue-resident bacteria to host metabolism and their potentially actionable health implications for prevention and treatment.

Metabolic Dysfunction-Associated Steatotic Liver Disease in People Living with HIV-Limitations on Antiretroviral Therapy Selection

Chronic liver disease is one of the main causes of morbidity and mortality in people living with HIV (PLWH). The increasing life expectancy of PLWH, effective treatment for viral hepatitis, and Western dietary patterns as well as the adverse effects of antiretroviral therapy (ART) have rendered metabolic dysfunction-associated steatotic liver disease (MASLD) the most common chronic liver disease in PLWH. The risk factors for MASLD in PLWH include traditional MASLD risk factors and additional virus-specific factors, including the adverse effects of ART. The management of patients suffering from HIV and MASLD is often challenging. Apart from the conventional management of MASLD, there are also certain limitations concerning the use of ART in this patient population. In general, the appropriate combination of antiretroviral drugs should be chosen to achieve the triad of effective viral suppression, avoidance of mitochondrial dysfunction, and deterrence of worsening the patient's metabolic profile. In the current review, we discuss the epidemiology of MASLD in PLWH, the risk factors, and the disease pathogenesis, as well as the limitations in the use of ART in this patient population, while practical recommendations on how to overcome these limitations are also given.

The Probiotic Kluyveromyces lactis JSA 18 Alleviates Obesity and Hyperlipidemia in High-Fat Diet C57BL/6J Mice

Obesity poses a significant threat to various health conditions such as heart diseases, diabetes, high blood pressure, and heart attack, with the gut microbiota playing a crucial role in maintaining the body's energy balance. We identified a novel probiotic fungal strain, Kluyveromyces lactis JSA 18 (K. lactis), which was isolated from yak milk and was found to possess anti-obesity properties. Additionally, Lactobacillus plantarum CGMCC 8198 (LP8198) from our previous study was also included to evaluate its anti-obesity properties. The findings indicated that K. lactis caused a notable reduction in weight gain, liver and fat indexes, and hyperlipidemia in mice fed a high-fat diet (HFD). Administering K. lactis and LP8198 to mice on a high-fat diet resulted in a reduction of serum triglyceride levels. Furthermore, the supplements reduced ALT and AST activity, and inhibited the production of inflammatory cytokines such as TNF-α and IL-1β. In addition, lipid metabolism was enhanced by the downregulation of ACC1, PPAR-γ, SREBP-1, and Fasn. Moreover, this study found that K. lactis and LP8198 have little effect on gut bacteria. Additionally, K. lactis partially influenced intestinal fungi, while LP8198 had a minor influence on gut mycobiota. The main goal of this research was to show how effective K. lactis can be as a probiotic in combating obesity.

Probiotics ameliorate endocrine disorders via modulating inflammatory pathways: a systematic review

Probiotics has offered a new prospect to treat and manage a variety of endocrine disorders such as obesity, diabetes, non- alcoholic fatty liver disease and metabolic syndrome. The precise mechanisms by which probiotics exert their beneficial effects on endocrine disorders and its associated problems are still indecisive. It seems that regulating the immune system and suppressing pro-inflammatory pathways like tumor necrosis factor-α and interleukin-6 or triggering anti-inflammatory pathways like interleukin-4 and 10 may be one of the potential mechanisms in the managing of endocrine disorders. In this systematic review, we hypothesized that various probiotic strains (Lactobacillus, Biofidiobacteria, Streptococcus, Entrococcus, Clostridium, and Bacillus) alone or in combination with each other could manage endocrine disorders via modulating inflammatory pathways such as suppressing pro-inflammatory cytokines (IL-6, IL-12, TNF-α, TNF-β, NFκB, and MCP-1), stimulating anti-inflammatory cytokines (IL-4,IL-6, IL-22, IL-23, IL-33, and TGF-β) and maintaining other factors like C-reactive protein, Toll like receptors, LPS, and NK cells. Data source this search was performed in PubMed and Scopus. Both human and animal studies were included. Among more than 15,000 papers, 25 studies were identified as eligible for more assessments. Quality assessment of the studies was cheeked by two researchers independently by title and abstract screening, then article which have inclusion criteria were included, and data retrieved from the included full text studies as the authors had originally reported. Results specified that Lactobacillus has been the most widely used probiotic as well as which one exhibiting the extend of the therapeutic effects on endocrine disorders, especially obesity by modulating immune responses. Also, most studies have revealed that probiotics through suppressing pro-inflammatory pathways specially via reducing levels TNF-α cytokine exhibited protective or beneficial effects on endocrine diseases particularly obesity as well as through decreasing level of IL-6 induced therapeutic effects in diabetes. This systematic review suggests that probiotics could ameliorate endocrine disorders via their immunomodulatory effects.

Buyang Huanwu Decoction Alleviates Atherosclerosis by Regulating gut Microbiome and Metabolites in Apolipoprotein E-deficient Mice fed with High-fat Diet

ABSTRACT

The traditional Chinese herbal prescription Buyang Huanwu decoction (BHD), effectively treats atherosclerosis. However, the mechanism of BHD in atherosclerosis remains unclear. We aimed to determine whether BHD could alleviate atherosclerosis by altering the microbiome-associated metabolic changes in atherosclerotic mice. An atherosclerotic model was established in apolipoprotein E-deficient mice fed high-fat diet, and BHD was administered through gavage for 12 weeks at 8.4 g/kg/d and 16.8 g/kg/d. The atherosclerotic plaque size, composition, serum lipid profile, and inflammatory cytokines, were assessed. Mechanistically, metabolomic and microbiota profiles were analyzed by liquid chromatography-mass spectrometry and 16S rRNA gene sequencing, respectively. Furthermore, intestinal microbiota and atherosclerosis-related metabolic parameters were correlated using Spearman analysis. Atherosclerotic mice treated with BHD exhibited reduced plaque area, aortic lumen occlusion, and lipid accumulation in the aortic root. Nine perturbed serum metabolites were significantly restored along with the relative abundance of microbiota at the family and genus levels but not at the phylum level. Gut microbiome improvement was strongly negatively correlated with improved metabolite levels. BHD treatment effectively slows the progression of atherosclerosis by regulating altered intestinal microbiota and perturbed metabolites.

Gut microbiota, intestinal permeability, and systemic inflammation: a narrative review

The intestine is the largest interface between the internal body and the external environment. The intestinal barrier is a dynamic system influenced by the composition of the intestinal microbiome and the activity of intercellular connections, regulated by hormones, dietary components, inflammatory mediators, and the enteric nervous system (ENS). Over the years, it has become increasingly evident that maintaining a stable intestinal barrier is crucial to prevent various potentially harmful substances and pathogens from entering the internal environment. Disruption of the barrier is referred to as 'leaky gut' or leaky gut wall syndrome and seems to be characterized by the release of bacterial metabolites and endotoxins, such as lipopolysaccharide (LPS), into the circulation. This condition, mainly caused by bacterial infections, oxidative stress, high-fat diet, exposure to alcohol or chronic allergens, and dysbiosis, appear to be highly connected with the development and/or progression of several metabolic and autoimmune systemic diseases, including obesity, non-alcoholic fatty liver disease (NAFLD), neurodegeneration, cardiovascular disease, inflammatory bowel disease, and type 1 diabetes mellitus (T1D). In this review, starting from a description of the mechanisms that enable barrier homeostasis and analyzing the relationship between this complex ecosystem and various pathological conditions, we explore the role of the gut barrier in driving systemic inflammation, also shedding light on current and future therapeutic interventions.

Comparison of the low-calorie DASH diet and a low-calorie diet on serum TMAO concentrations and gut microbiota composition of adults with overweight/obesity: a randomized control trial

This study compares two diets, Dietary Approaches to Stop Hypertension (DASH) and a Low-Calorie Diet on Trimethylamine N-oxide (TMAO) levels and gut microbiota. 120 obese adults were randomly allocated to these three groups: a low-calorie DASH diet, a Low-Calorie diet, or a control group for 12 weeks. Outcomes included plasma TMAO, lipopolysaccharides (LPS), and gut microbiota profiles. After the intervention, the low-calorie DASH diet group demonstrated a greater decrease in TMAO levels (-20 ± 8.1 vs. -10.63 ± 4.6 μM) and a significant decrease in LPS concentration (-19.76 ± 4.2 vs. -5.68 ± 2.3) compared to the low-calorie diet group. Furthermore, the low-calorie DASH diet showed a higher decrease in the Firmicutes and Bactericides (F/B) ratio, which influenced TMAO levels, compared to the Low-Calorie diet (p = 0.028). The current study found the low-calorie DASH diet improves TMAO and LPS in comparison to a Low-Calorie diet.

Exercise-inducible circulating extracellular vesicle irisin promotes browning and the thermogenic program in white adipose tissue

AIM

Exercise can reduce body weight and promote white fat browning, but the underlying mechanisms remain largely unknown. This study investigated the role of fibronectin type III domain-containing protein 5 (FNDC5)/Irisin, a hormone released from exercising muscle, in the browning of white fat in circulating extracellular vesicles (EVs).

METHODS

Mice were subjected to a 4 weeks of running table exercise, and fat browning was analyzed via histology, protein blotting and qPCR. Circulating EVs were extracted by ultrahigh-speed centrifugation, and ELISA was used to measure the irisin concentration in the circulating EVs. Circulating EVs that differentially expressed irisin were applied to adipocytes, and the effect of EV-irisin on adipocyte energy metabolism was analyzed by immunofluorescence, protein blotting, and cellular oxygen consumption rate analysis.

RESULTS

During sustained exercise, the mice lost weight and developed fat browning. FNDC5 was induced, cleaved, and secreted into irisin, and irisin levels subsequently increased in the plasma during exercise. Interestingly, irisin was highly expressed in circulating EVs that effectively promoted adipose browning. Mechanistically, the circulating EV-irisin complex is transported intracellularly by the adipocyte membrane receptor integrin αV, which in turn activates the AMPK signaling pathway, which is dependent on mitochondrial uncoupling protein 1 to cause mitochondrial plasmonic leakage and promote heat production. After inhibition of the AMPK signaling pathway, the effects of the EV-irisin on promoting fat browning were minimal.

CONCLUSION

Exercise leads to the accumulation of circulating EV-irisin, which enhances adipose energy metabolism and thermogenesis and promotes white fat browning in mice, leading to weight loss.

Effect of Short-Chain Fatty Acids on Inflammatory and Metabolic Function in an Obese Skeletal Muscle Cell Culture Model

The fermentation of non-digestible carbohydrates produces short-chain fatty acids (SCFAs), which have been shown to impact both skeletal muscle metabolic and inflammatory function; however, their effects within the obese skeletal muscle microenvironment are unknown. In this study, we developed a skeletal muscle in vitro model to mimic the critical features of the obese skeletal muscle microenvironment using L6 myotubes co-treated with 10 ng/mL lipopolysaccharide (LPS) and 500 µM palmitic acid (PA) for 24 h ± individual SCFAs, namely acetate, propionate and butyrate at 0.5 mM and 2.5 mM. At the lower SCFA concentration (0.5 mM), all three SCFA reduced the secreted protein level of RANTES, and only butyrate reduced IL-6 protein secretion and the intracellular protein levels of activated (i.e., ratio of phosphorylated-total) NFκB p65 and STAT3 (p < 0.05). Conversely, at the higher SCFA concentration (2.5 mM), individual SCFAs exerted different effects on inflammatory mediator secretion. Specifically, butyrate reduced IL-6, MCP-1 and RANTES secretion, propionate reduced IL-6 and RANTES, and acetate only reduced RANTES secretion (p < 0.05). All three SCFAs reduced intracellular protein levels of activated NFκB p65 and STAT3 (p < 0.05). Importantly, only the 2.5 mM SCFA concentration resulted in all three SCFAs increasing insulin-stimulated glucose uptake compared to control L6 myotube cultures (p < 0.05). Therefore, SCFAs exert differential effects on inflammatory mediator secretion in a cell culture model, recapitulating the obese skeletal muscle microenvironment; however, all three SCFAs exerted a beneficial metabolic effect only at a higher concentration via increasing insulin-stimulated glucose uptake, collectively exerting differing degrees of a beneficial effect on obesity-associated skeletal muscle dysfunction.

Gut Microbiota of Apis mellifera at Selected Ontogenetic Stages and Their Immunogenic Potential during Summer

Honeybees (Apis mellifera) are pollinating agents of economic importance. The role of the gut microbiome in honeybee health has become increasingly evident due to its relationship with immune function, growth, and development. Although their dynamics at various developmental stages have been documented, their dynamics during the era of colony collapse disorder and immunogenic potential, which are connected to the antagonistic immune response against pathogens, need to be elucidated. Using 16S rRNA gene Illumina sequencing, the results indicated changes in the gut microbiota with the developmental stage. The bacterial diversity of fifth stage larva was significantly different among the other age groups, in which Fructobacillus, Escherichia-Shigella, Bombella, and Tyzzerella were unique bacteria. In addition, the diversity of the worker bee microbiome was distinct from that of the younger microbiome. Lactobacillus and Gilliamella remained conserved throughout the developmental stages, while Bifidobacterium colonized only worker bees. Using an in silico approach, the production potential of lipopolysaccharide-endotoxin was predicted. Forager bees tend to have a higher abundance rate of Gram-negative bacteria. Our results revealed the evolutionary importance of some microbiome from the larval stage to the adult stage, providing insight into the potential dynamics of disease response and susceptibility. This finding provides a theoretical foundation for furthering the understanding of the function of the gut microbiota at various developmental stages related to probiotic development and immunogenic potential.

Bioactives and their roles in bone metabolism of osteoarthritis: evidence and mechanisms on gut-bone axis

Bioactives significantly modify and maintain human health. Available data suggest that Bioactives might play a beneficial role in chronic inflammatory diseases. Although promised, defining their mechanisms and opting to weigh their benefits and limitations is imperative. Detailed mechanisms by which critical Bioactives, including probiotics and prebiotics such as dietary lipids (DHA, EPA, alpha LA), vitamin D, polysaccharides (fructooligosaccharide), polyphenols (curcumin, resveratrol, and capsaicin) potentially modulate inflammation and bone metabolism is limited. Certain dietary bioactive significantly impact the gut microbiota, immune system, and pain response via the gut-immune-bone axis. This narrative review highlights a recent update on mechanistic evidence that bioactive is demonstrated demonstrated to reduce osteoarthritis pathophysiology.

The association between dietary intake of macro- and micronutrients and multimorbidity: a cross-sectional study in Cyprus

Research on the link between diet and multimorbidity is scarce, despite significant studies investigating the relationship between diet and individual chronic conditions. This study examines the association of dietary intake of macro- and micronutrients with multimorbidity in Cyprus's adult population. It was conducted as a cross-sectional study, with data collected using a standardised questionnaire between May 2018 and June 2019. The questionnaire included sociodemographic information, anthropometrics, medical history, dietary habits, sleep quality, smoking habits, and physical activity. The participants were selected using a stratified sampling method from adults residing in the five government-controlled municipalities of the Republic of Cyprus. The study included 1137 adults with a mean age of 40⋅8 years, of whom 26 % had multimorbidity. Individuals with multimorbidity consumed higher levels of sodium (P = 0⋅009) and vitamin A (P = 0⋅010) compared to those without multimorbidity. Additionally, higher fibre and sodium intake were also observed in individuals with at least one chronic disease of the circulatory system or endocrine system, compared to those with no chronic diseases in these systems (P < 0⋅05). Logistic regression models revealed that individuals with ≥2 chronic diseases compared to 0 or 1 chronic disease had higher fat intake (OR = 1⋅06, 95 % CI: 1⋅02, 1⋅10), higher iron intake (OR = 1⋅05, 95 % CI: 1⋅01, 1⋅09), lower mono-unsaturated fat intake (OR = 0⋅91, 95 % CI: 0⋅86, 0⋅96), and lower zinc intake (OR = 0⋅98, 95 % CI: 0⋅96, 0⋅99). Future research should replicate these results to further explore the intricate relationships between nutrient intake and multimorbidity. Our study's findings suggest that specific dietary components may contribute to preventing and managing multimorbidity.

Targeting gut-liver axis by dietary lignans ameliorate obesity: evidences and mechanisms

An imbalance between energy consumption and energy expenditure causes obesity. It is characterized by increased adipose accumulation and accompanied by chronic low-grade inflammation. Many studies have suggested that the gut microbiota of the host mediates the relationship between high-fat diet consumption and the development of obesity. Diet and nutrition of the body are heavily influenced by gut microbiota. The alterations in the microbiota in the gut may have effects on the homeostasis of the host's energy levels, systemic inflammation, lipid metabolism, and insulin sensitivity. The liver is an important organ for fat metabolism and gut-liver axis play important role in the fat metabolism. Gut-liver axis is a bidirectional relationship between the gut and its microbiota and the liver. As essential plant components, lignans have been shown to have different biological functions. Accumulating evidences have suggested that lignans may have lipid-lowering properties. Lignans can regulate the level of the gut microbiota and their metabolites in the host, thereby affecting signaling pathways related to fat synthesis and metabolism. These signaling pathways can make a difference in inhibiting fat accumulation, accelerating energy metabolism, affecting appetite, and inhibiting chronic inflammation. It will provide the groundwork for future studies on the lipid-lowering impact of lignans and the creation of functional meals based on those findings.

The Role of Lipids in the Regulation of Immune Responses

Lipid metabolism plays a major role in the regulation of the immune system. Exogenous (dietary and microbial-derived) and endogenous (non-microbial-derived) lipids play a direct role in regulating immune cell activation, differentiation and expansion, and inflammatory phenotypes. Understanding the complexities of lipid-immune interactions may have important implications for human health, as certain lipids or immune pathways may be beneficial in circumstances of acute infection yet detrimental in chronic inflammatory diseases. Further, there are key differences in the lipid effects between specific immune cell types and location (e.g., gut mucosal vs. systemic immune cells), suggesting that the immunomodulatory properties of lipids may be tissue-compartment-specific, although the direct effect of dietary lipids on the mucosal immune system warrants further investigation. Importantly, there is recent evidence to suggest that lipid-immune interactions are dependent on sex, metabolic status, and the gut microbiome in preclinical models. While the lipid-immune relationship has not been adequately established in/translated to humans, research is warranted to evaluate the differences in lipid-immune interactions across individuals and whether the optimization of lipid-immune interactions requires precision nutrition approaches to mitigate or manage disease. In this review, we discuss the mechanisms by which lipids regulate immune responses and the influence of dietary lipids on these processes, highlighting compelling areas for future research.

Gut Microbiota and Adipose Tissue Microenvironment Interactions in Obesity

Obesity is an increasingly serious global health problem. Some studies have revealed that the gut microbiota and its metabolites make important contributions to the onset of obesity. The gut microbiota is a dynamic ecosystem composed of diverse microbial communities with key regulatory functions in host metabolism and energy balance. Disruption of the gut microbiota can result in obesity, a chronic metabolic condition characterized by the excessive accumulation of adipose tissue. Host tissues (e.g., adipose, intestinal epithelial, and muscle tissues) can modulate the gut microbiota via microenvironmental interactions that involve hormone and cytokine secretion, changes in nutrient availability, and modifications of the gut environment. The interactions between host tissues and the gut microbiota are complex and bidirectional, with important effects on host health and obesity. This review provides a comprehensive summary of gut microbiota changes associated with obesity, the functional roles of gut microbiota-derived metabolites, and the importance of the complex interactions between the gut microbiota and target tissues in the pathogenesis of obesity. It places particular emphasis on the roles of adipose tissue microenvironment interactions in the onset of obesity.

Lactobacillus plantarum HF02 alleviates lipid accumulation and intestinal microbiota dysbiosis in high-fat diet-induced obese mice

BACKGROUND

Obesity is closely associated with lipid accumulation and intestinal microbiota dysbiosis. It has been proved that probiotics supplement contributes to alleviate obesity. The objective of this study was to investigate the mechanism by which Lactobacillus plantarum HF02 (LP-HF02) alleviated lipid accumulation and intestinal microbiota dysbiosis in high-fat diet-induced obese mice.

RESULTS

Our results showed that LP-HF02 ameliorated body weight, dyslipidemia, liver lipid accumulation, and liver injury in obese mice. As expected, LP-HF02 inhibited pancreatic lipase activity in small intestinal contents and increased fecal triglyceride levels, thereby reducing dietary fat hydrolysis and absorption. Moreover, LP-HF02 ameliorated the intestinal microbiota composition, as evidenced by the enhanced ratio of Bacteroides to Firmicutes, the decreased abundance of pathogenic bacteria (including Bacteroides, Alistipes, Blautia, and Colidextribacter) and the increased abundance of beneficial bacteria (including Muribaculaceae, Akkermansia, Faecalibaculum, and Rikenellaceae_RC9_gut_group). LP-HF02 also increased fecal short-chain fatty acids (SCFAs) levels and colonic mucosal thickness, and subsequently decreased serum lipopolysaccharide (LPS), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) levels in obese mice. Additionally, reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot results demonstrated that LP-HF02 ameliorated hepatic lipid accumulation via activating the adenosine monophosphate (AMP)-activated protein kinase (AMPK) pathway.

CONCLUSION

Therefore, our results indicated that LP-HF02 could be considered as a probiotic preparation for preventing obesity. © 2023 Society of Chemical Industry.

Indoleacrylic acid produced by Parabacteroides distasonis alleviates type 2 diabetes via activation of AhR to repair intestinal barrier

BACKGROUND

Anti-inflammatory therapy is an effective strategy in the treatment of type 2 diabetes (T2D). Studies found that inflammatory responses in vivo were strongly associated with defects in the mucosal barrier function of the gut epithelium. While some microbial strains could help repair the intestinal mucosa and maintain the integrity of the intestinal barrier, the specific mechanisms remain to be fully elucidated. The present study investigated the effects of Parabacteroides distasonis (P. distasonis) on the intestinal barrier and the inflammation level in T2D rats and explored the specific mechanisms.

RESULTS

By analyzing the intestinal barrier function, the inflammatory conditions, and the gut microbiome, we found that P. distasonis could attenuate insulin resistance by repairing the intestinal barrier and reducing inflammation caused by the disturbed gut microbiota. We quantitatively profiled the level of tryptophan and indole derivatives (IDs) in rats and fermentation broth of the strain, demonstrating that indoleacrylic acid (IA) was the most significant factor correlated with the microbial alterations among all types of endogenous metabolites. Finally, we used molecular and cell biological techniques to determine that the metabolic benefits of P. distasonis were mainly attributed to its ability to promote IA generation, active the aryl hydrocarbon receptor (AhR) signaling pathway, and increase the expression level of interleukin-22 (IL-22), thus enhancing the expression of intestinal barrier-related proteins.

CONCLUSIONS

Our study revealed the effects of P. distasonis in the treatment of T2D via intestinal barrier repairment and inflammation reduction and highlighted a host-microbial co-metabolite indoleacrylic acid that could active AhR to perform its physiological effects. Our study provided new therapeutic strategies for metabolic diseases by targeting the gut microbiota and tryptophan metabolism.

Mechanisms linking bariatric surgery to adipose tissue, glucose metabolism, fatty liver disease and gut microbiota

PURPOSE

In the last 20 years, bariatric surgery has achieved an important role in translational and clinical research because of obesity comorbidities. Initially, a tool to lose weight, bariatric surgery now has been shown to be involved in several metabolic pathways.

METHODS

We conducted a narrative review discussing the underlying mechanisms that could explain the impact of bariatric surgery and the relationship between obesity and adipose tissue, T2D, gut microbiota, and NAFLD.

RESULTS

Bariatric surgery has an impact in the relation between obesity and type 2 diabetes, but in addition  it induces the white-to-brown adipocyte trans-differentiation, by enhancing thermogenesis. Another issue is the connection of bariatric surgery with the gut microbiota and its role in the complex mechanism underlying weight gain.

CONCLUSION

Bariatric surgery modifies gut microbiota, and these modifications influence lipid metabolism, leading to improvement of non-alcoholic fatty liver disease.

Prebiotic properties of the polysaccharide from Rosa roxburghii Tratt fruit and its protective effects in high-fat diet-induced intestinal barrier dysfunction: A fecal microbiota transplantation study

Polysaccharide from Rosa roxburghii Tratt fruit (RTFP) ameliorates high-fat diet (HFD)-induced colitis in mice. However, it is still unknown whether the gut microbiota can mediate the anti-colitis effects of RTFP in mice. This research aims to investigate the role of gut microbes in modulating RTFP in colitis mice through fecal microbiota transplantation (FMT). The findings demonstrated that RTFP exhibited prebiotic effects on HFD-induced colitis mice. After FMT treatment (transplatation of the microbiota from the fecal sample to each recipient daily), the fecal microbiota of RTFP-treated donor mice remarkably alleviated colitis-related symptoms (e.g., colonic inflammation, loss of body weight, gut microbiota dysbiosis, and loss of barrier integrity) and upregulated the expression of tight junction proteins compared to the HFD-treated donor mice. Overall, RTFP can reduce the severity of HFD-induced colitis by regulating gut microbiota.

Exercise Restores Hypothalamic Health in Obesity by Reshaping the Inflammatory Network

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

Deficiency of exchange protein directly activated by cAMP (EPAC)-1 in mice augments glucose intolerance, inflammation, and gut dysbiosis associated with Western diet

BACKGROUND

Gut microbiota (GM) dysregulation, known as dysbiosis, has been proposed as a crucial driver of obesity associated with "Western" diet (WD) consumption. Gut dysbiosis is associated with increased gut permeability, inflammation, and insulin resistance. However, host metabolic pathways implicated in the pathophysiology of gut dysbiosis are still elusive. Exchange protein directly activated by cAMP (Epac) plays a critical role in cell-cell junction formation and insulin secretion. Here, we used homozygous Epac1-knockout (Epac1^-/-), Epac2-knockout (Epac2^-/-), and wild-type (WT) mice to investigate the role of Epac proteins in mediating gut dysbiosis, gut permeability, and inflammation after WD feeding.

RESULTS

The 16S rRNA gene sequencing of fecal DNA showed that the baseline GM of Epac2^-/-, but not Epac1^-/-, mice was represented by a significantly higher Firmicutes to Bacteroidetes ratio and significant alterations in several taxa compared to WT mice, suggesting that Epac2^-/- mice had gut dysbiosis under physiological conditions. However, an 8-week WD led to a similar gut microbiome imbalance in mice regardless of genotype. While Epac1 deficiency modestly exacerbated the WD-induced GM dysbiosis, the WD-fed Epac2^-/- mice had a more significant increase in gut permeability than corresponding WT mice. After WD feeding, Epac1^-/-, but not Epac2^-/-, mice had significantly higher mRNA levels of tumor necrosis factor-alpha (TNF-α) and F4/80 in the epididymal white adipose tissue (EWAT), increased circulating lipocalin-2 protein and more severe glucose intolerance, suggesting greater inflammation and insulin resistance in WD-fed Epac1^-/- mice than corresponding WT mice. Consistently, Epac1 protein expression was significantly reduced in the EWAT of WD-fed WT and Epac2^-/- mice.

CONCLUSION

Despite significantly dysregulated baseline GM and a more pronounced increase in gut permeability upon WD feeding, WD-fed Epac2^-/- mice did not exhibit more severe inflammation and glucose intolerance than corresponding WT mice. These findings suggest that the role of gut dysbiosis in mediating WD-associated obesity may be context-dependent. On the contrary, we demonstrate that deficiency of host signaling protein, Epac1, drives inflammation and glucose intolerance which are the hallmarks of WD-induced obesity. Video abstract.

Comparing the long non-coding RNA expression profiles of skeletal muscle and kidney tissues from patients with diabetes

Background

Diabetes causes the dysregulation of several organs, and these effects are often closely associated with changes in the expression of long non-coding RNAs (lncRNAs), a group of non-coding RNAs, within these tissues. Previous studies have described a variety of changes in the expression profile of several lncRNAs from different organs in response to the pathogenesis of diabetes. However, none of these studies compared the expression profiles of these lncRNAs between these organs. This study was designed to identify common and specific lncRNAs involved in the progression of diabetes in the skeletal muscles and kidneys.

Methods

Publicly available RNA sequencing data of diabetic patients was obtained from the Gene Expression Omnibus database. By analyzing the expression of lncRNAs in these datasets, differentially expressed lncRNAs in each tissue between non-diabetic and diabetic patients were identified. To identify any lncRNAs changed in common in both kidney and muscle tissues, those lncRNAs that are significantly dysregulated in both datasets were selected.

Results

These evaluations identified a series of novel lncRNAs unique to each organ and several transcripts that were common to both skeletal muscle and kidney tissues in these patients. Interestingly, the genomic location of these lncRNAs suggests that they reside in close proximity to several protein-coding genes known to be related to diabetes suggesting that these lncRNAs may have a regulatory relationship with their neighboring genes.

Conclusion

These results offer valuable insights into the role of lncRNAs during the pathogenesis of diabetes.

Probiotic Mechanisms Affecting Glucose Homeostasis: A Scoping Review

The maintenance of a healthy status depends on the coexistence between the host organism and the microbiota. Early studies have already focused on the nutritional properties of probiotics, which may also contribute to the structural changes in the gut microbiota, thereby affecting host metabolism and homeostasis. Maintaining homeostasis in the body is therefore crucial and is reflected at all levels, including that of glucose, a simple sugar molecule that is an essential fuel for normal cellular function. Despite numerous clinical studies that have shown the effect of various probiotics on glucose and its homeostasis, knowledge about the exact function of their mechanism is still scarce. The aim of our review was to select in vivo and in vitro studies in English published in the last eleven years dealing with the effects of probiotics on glucose metabolism and its homeostasis. In this context, diverse probiotic effects at different organ levels were highlighted, summarizing their potential mechanisms to influence glucose metabolism and its homeostasis. Variations in results due to different methodological approaches were discussed, as well as limitations, especially in in vivo studies. Further studies on the interactions between probiotics, host microorganisms and their immunity are needed.

The crude guava polysaccharides ameliorate high-fat diet-induced obesity in mice via reshaping gut microbiota

Guava is a popular fruit consumed worldwide with beneficial effects in regulation of glucose and lipid metabolism. Although polysaccharides are a major phytochemical component of guava, to date, the alleviative effects of polysaccharides from the guava fruit against diet-induced obesity remain unclear. The relationship between the anti-obesity effects of guava polysaccharide (GP) and gut microbiota is unknown. In current study, seven-week-old C57BL/6 mice were fed high-fat diet (HFD) supplemented with GP (100 mg/kg) by oral gavage for 11 weeks. GP supplementation alleviated HFD-induced body weight gain and visceral obesity, and reduced serum cholesterol, triglyceride, and LDL-C levels. In addition, GP ameliorated insulin resistance and prevented hepatic lipid accumulation and meta-inflammation in both liver and adipose tissues in obese mice. Remarkably, GP treatment restored the Firmicutes/Bacteroidetes ratio, induced growth of beneficial bacteria including Clostridium XlVa, Parvibacter, and Enterorhabdus, and decreased in inflammation-related bacteria Mucispirillum in mice fecal samples, accompanied with enhanced production of colonic short chain fatty acids especially butyric acid. However, the metabolic benefits of GP diminished in antibiotics-treated HFD-fed mice. Overall, GP improved metabolic profiles in HFD-induced obese mice via the mediation of gut microbiota-dependent pathways. GP might be developed and utilized as prebiotics in nutraceutical and food industry.

Integrating 16S rRNA gene sequencing and metabolomics to evaluate the association between gut microbiota and serum metabolites in patients with myositis

AIMS

Gut microbiota and metabolites have a profound impact on the maintenance of body health. In this study, we assessed the association between gut microbiota and serum metabolite changes in myositis using 16S rRNA gene sequencing and metabolomics to provide new ideas for screening and treating myositis.

METHODS AND RESULTS

Blood and fecal samples were collected from twenty myositis patients and twenty healthy control subjects. Then, 16S rRNA gene sequencing, enzyme-linked immunosorbent assays, and untargeted metabolomics study were performed to evaluate the relationship between gut microbiota and serum metabolites in patients with myositis. Compared to healthy control subjects, the blood samples from the patients with myositis had elevated levels of interleukin-4 (IL-4), tumor necrosis factor-α (TNF-α), and malondialdehyde (MDA), and decreased superoxide dismutase (SOD) levels. The increase in Bacteroidota (including Bacteroides and Parabacteroides, but not Prevotella) and the decrease in Firmicutes in the patients were accompanied by functional changes in amino acid and lipid metabolism. The gut microbiota (Bacteroides and Parabacteroides) were negatively correlated with the differential serum metabolites (glutamate and taurine). The differential serum metabolites (glutamate, pyrrolidonecarboxylic acid, and taurine) were also correlated with inflammatory factors (IL-4 and TNF-α) and oxidative stress indexes (MDA and SOD).

CONCLUSION

Dysbiosis of gut microbiota in patients with myositis was accompanied by changes in inflammatory factors, oxidative stress indexes, and small molecule metabolites in serum.

SIGNIFICANCE AND IMPACT OF STUDY

Blood and fecal biomarkers could be used for screening myositis.

Short-Term High-Fat Diet Fuels Colitis Progression in Mice Associated With Changes in Blood Metabolome and Intestinal Gene Expression

Clinical cases and animal experiments show that high-fat (HF) diet is involved in inflammatory bowel disease (IBD), but the specific mechanism is not fully clear. A close association between long-term HF-induced obesity and IBD has been well-documented. However, there has been limited evaluation of the impact of short-term HF feeding on the risk of intestinal inflammation, particularly on the risk of disrupted metabolic homeostasis. In this study, we analyzed the metabolic profile and tested the vulnerability of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis after short-term HF feeding in mice. The results showed that compared with the control diet (CD), the fatty acid (FA), amino acid (AA), and bile acid (BA) metabolisms of mice in the HF group were significantly changed. HF-fed mice showed an increase in the content of saturated and unsaturated FAs and a decrease in the content of tryptophan (Trp). Furthermore, the disturbed spatial distribution of taurocholic acid (TCA) in the ileum and colon was identified in the HF group using matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI). After HF priming, mice on TNBS induction were subjected to more severe colonic ulceration and histological damage compared with their CD counterparts. In addition, TNBS enema induced higher gene expressions of mucosal pro-inflammatory cytokines under HF priming conditions. Overall, our results show that HF may promote colitis by disturbing lipid, AA, and BA metabolic homeostasis and inflammatory gene expressions.

Individuals with Metabolic Syndrome Show Altered Fecal Lipidomic Profiles with No Signs of Intestinal Inflammation or Increased Intestinal Permeability

BACKGROUND

Metabolic Syndrome (MetS) is a clinical diagnosis where patients exhibit three out of the five risk factors: hypertriglyceridemia, low high-density lipoprotein (HDL) cholesterol, hyperglycemia, elevated blood pressure, or increased abdominal obesity. MetS arises due to dysregulated metabolic pathways that culminate with insulin resistance and put individuals at risk to develop various comorbidities with far-reaching medical consequences such as non-alcoholic fatty liver disease (NAFLD) and cardiovascular disease. As it stands, the exact pathogenesis of MetS as well as the involvement of the gastrointestinal tract in MetS is not fully understood. Our study aimed to evaluate intestinal health in human subjects with MetS.

METHODS

We examined MetS risk factors in individuals through body measurements and clinical and biochemical blood analysis. To evaluate intestinal health, gut inflammation was measured by fecal calprotectin, intestinal permeability through the lactulose-mannitol test, and utilized fecal metabolomics to examine alterations in the host-microbiota gut metabolism.

RESULTS

No signs of intestinal inflammation or increased intestinal permeability were observed in the MetS group compared to our control group. However, we found a significant increase in 417 lipid features of the gut lipidome in our MetS cohort. An identified fecal lipid, diacyl-glycerophosphocholine, showed a strong correlation with several MetS risk factors. Although our MetS cohort showed no signs of intestinal inflammation, they presented with increased levels of serum TNFα that also correlated with increasing triglyceride and fecal diacyl-glycerophosphocholine levels and decreasing HDL cholesterol levels.

CONCLUSION

Taken together, our main results show that MetS subjects showed major alterations in fecal lipid profiles suggesting alterations in the intestinal host-microbiota metabolism that may arise before concrete signs of gut inflammation or intestinal permeability become apparent. Lastly, we posit that fecal metabolomics could serve as a non-invasive, accurate screening method for both MetS and NAFLD.

MiR-122-5p regulates the pathogenesis of childhood obesity by targeting CPEB1

BACKGROUND

Childhood obesity is strongly associated with inflammation which contributes to the development of several obesity-related disorders. Accumulating evidence has suggested that microRNAs (miRNAs) are involved in the pathogenesis of multiple human diseases, including childhood obesity. MiR-122-5p was reported to be related to obesity in childhood, however, the detailed function and mechanism of miR-122-5p are still obscure.

METHODS

Simpson-Golabi-Behmel syndrome (SGBS) adipocytes were cocultured with macrophage cell line THP-1 or macrophage-conditioned medium (MacCM) to promote cytokine expression. Oil Red O staining was used to detect the accumulation of lipid droplets in SGBS cells. The expression of interleukin 6 (IL-6), IL-8, and monocyte chemoattractant protein 1 (MCP-1) at mRNA and protein levels was assessed by RT-qPCR and ELISA, respectively. Western blotting was used for measuring protein levels of target genes of miR-122-5p. The luciferase reporter assay was applied for detecting the binding relation between miR-122-5p and cytoplasmic polyadenylation element binding protein 1 (CPEB1).

RESULTS

Coculture of SGBS adipocytes and THP-1 macrophages/MacCM promoted IL-6, IL-8, and MCP-1 expression at mRNA and protein levels. Overexpression of miR-122-5p inhibited IL-6, IL-8, and MCP-1 expression in SGBS adipocytes, and this inhibitory effect was rescued by CPEB1 upregulation. CPEB1 3'-untranslated region was directly targeted by miR-122-5p.

CONCLUSION

MiR-122-5p suppresses cytokine expression in SGBS adipocytes by targeting CPEB1.

Chronic Inflammation in Obesity and Cancer Cachexia

Chronic inflammation has long been linked to obesity and related conditions such as type 2 diabetes and metabolic syndrome. According to current research, the increased risk of cancer in people with certain metabolic diseases may be due to chronic inflammation. Adipocytokines, which are pro-inflammatory cytokines secreted in excess, are elevated in many chronic metabolic diseases. Cytokines and inflammatory mediators, which are not directly linked to DNA, are important in tumorigenesis. Cachexia, a type of metabolic syndrome linked to the disease, is associated with a dysregulation of metabolic pathways. Obesity and cachexia have distinct metabolic characteristics, such as insulin resistance, increased lipolysis, elevated free fatty acids (FFA), and ceramide levels, which are discussed in this section. The goal of this research project is to create a framework for bringing together our knowledge of inflammation-mediated insulin resistance.

Role of the Microbiome in the Pathogenesis of COVID-19

The ongoing pandemic coronavirus disease COVID-19 is caused by the highly contagious single-stranded RNA virus, SARS-coronavirus 2 (SARS-CoV-2), which has a high rate of evolution like other RNA viruses. The first genome sequences of SARS-CoV-2 were available in early 2020. Subsequent whole-genome sequencing revealed that the virus had accumulated several mutations in genes associated with viral replication and pathogenesis. These variants showed enhanced transmissibility and infectivity. Soon after the first outbreak due to the wild-type strain in December 2019, a genetic variant D614G emerged in late January to early February 2020 and became the dominant genotype worldwide. Thereafter, several variants emerged, which were found to harbor mutations in essential viral genes encoding proteins that could act as drug and vaccine targets. Numerous vaccines have been successfully developed to assuage the burden of COVID-19. These have different rates of efficacy, including, although rarely, a number of vaccinated individuals exhibiting side effects like thrombosis. However, the recent emergence of the Britain strain with 70% more transmissibility and South African variants with higher resistance to vaccines at a time when several countries have approved these for mass immunization has raised tremendous concern regarding the long-lasting impact of currently available prophylaxis. Apart from studies addressing the pathophysiology, pathogenesis, and therapeutic targets of SARS-CoV-2, analysis of the gut, oral, nasopharyngeal, and lung microbiome dysbiosis has also been undertaken to find a link between the microbiome and the pathogenesis of COVID-19. Therefore, in the current scenario of skepticism regarding vaccine efficacy and challenges over the direct effects of currently available drugs looming large, investigation of alternative therapeutic avenues based on the microbiome can be a rewarding finding. This review presents the currently available understanding of microbiome dysbiosis and its association with cause and consequence of COVID-19. Taking cues from other inflammatory diseases, we propose a hypothesis of how the microbiome may be influencing homeostasis, pro-inflammatory condition, and the onset of inflammation. This accentuates the importance of a healthy microbiome as a protective element to prevent the onset of COVID-19. Finally, the review attempts to identify areas where the application of microbiome research can help in reducing the burden of the disease.

Association Between Gut Microbiota and Osteoarthritis: A Review of Evidence for Potential Mechanisms and Therapeutics

Osteoarthritis (OA) is a multifactorial joint disease characterized by degeneration of articular cartilage, which leads to joints pain, disability and reduced quality of life in patients with OA. Interpreting the potential mechanisms underlying OA pathogenesis is crucial to the development of new disease modifying treatments. Although multiple factors contribute to the initiation and progression of OA, gut microbiota has gradually been regarded as an important pathogenic factor in the development of OA. Gut microbiota can be regarded as a multifunctional “organ”, closely related to a series of immune, metabolic and neurological functions. This review summarized research evidences supporting the correlation between gut microbiota and OA, and interpreted the potential mechanisms underlying the correlation from four aspects: immune system, metabolism, gut-brain axis and gut microbiota modulation. Future research should focus on whether there are specific gut microbiota composition or even specific pathogens and the corresponding signaling pathways that contribute to the initiation and progression of OA, and validate the potential of targeting gut microbiota for the treatment of patients with OA.

Molecular Mechanisms of Hawthorn Extracts in Multiple Organs Disorders in Underlying of Diabetes: A Review

Diabetes mellitus (DM) is one of the most important metabolic disorders associated with chronic hyperglycemia and occurs when the body cannot manage insulin secretion, insulin action, or both. Autoimmune destruction of pancreatic beta cells and insulin resistance are the major pathophysiological factors of types 1 and 2 of DM, respectively. Prolonged hyperglycemia leads to multiple organs dysfunctions, including nephropathy, neuropathy, cardiomyopathy, gastropathy, and micro- and macrovascular disorders. The basis of the metabolic abnormalities in carbohydrate, fat, and protein in diabetes is insufficient action of insulin on various target tissues. Medicinal plants are rich sources of bioactive chemical compounds with therapeutic effects. The beneficial effects of leaves, fruits, and flowers extracts of Crataegus oxyacantha, commonly called hawthorn, belonging to the Rosaceae family, are widely used as hawthorn-derived medicines. Data in this review have been collected from the scientific articles published in databases such as Science Direct, Scopus, PubMed, Web of Science, and Scientific Information Database from 2000 to 2021. Based on this review, hawthorn extracts appear both therapeutic and protective effects against diabetic-related complications in various organs through molecular mechanisms, such as decreasing triglyceride, cholesterol, very low density lipoprotein and increasing the antioxidant activity of superoxide dismutase, catalase, glutathione peroxidase, total antioxidant capacity, decreasing malondialdehyde level, and attenuating tumor necrosis factor alpha, interleukin 6 and sirtuin 1/AMP-activated protein kinase (AMPK)/nuclear factor kappa B (NF-κB) pathway and increasing the phosphorylation of glucose transporter 4, insulin receptor substrate 1, AKT and phosphoinositide 3-kinases, and attenuating blood sugar and regulation of insulin secretion, insulin resistance, and improvement of histopathological changes in pancreatic beta cells. Collectively, hawthorn can be considered as one new target for the research and development of innovative drugs for the prevention or treatment of DM and related problems.

Citrus reticulatae pericarpium Extract Decreases the Susceptibility to HFD-Induced Glycolipid Metabolism Disorder in Mice Exposed to Azithromycin in Early Life

Background

Studies have shown that gut microbe disorder in mice due to early-life antibiotic exposure promotes glycolipid metabolism disorder in adulthood. However, the underlying mechanism remains unclear and there is not yet an effective intervention or treatment for this process.

Purpose

The study investigated whether early-life azithromycin (AZT) exposure in mice could promote high-fat diet (HFD)-induced glycolipid metabolism disorder in adulthood. Moreover, the effect of citrus reticulata pericarpium (CRP) extract on glycolipid metabolism disorder via regulation of gut microbiome in mice exposed to antibodies early in life were investigated.

Methods and Results

Three-week-old mice were treated with AZT (50 mg/kg/day) via drinking water for two weeks and then were fed a CRP diet (1% CRP extract) for four weeks and an HFD for five weeks. The results showed that early-life AZT exposure promoted HFD-induced glycolipid metabolism disorder, increased the levels of inflammatory factors, promoted the flora metabolism product trimethylamine N-oxide (TMAO), and induced microbial disorder in adult mice. Importantly, CRP extract mitigated these effects.

Conclusion

Taken together, these findings suggest that early-life AZT exposure increases the susceptibility to HFD-induced glycolipid metabolism disorder in adult mice, and CRP extract can decrease this susceptibility by regulating gut microbiome.

A calorie-restricted diet enriched with tree nuts and peanuts reduces the expression of CX3CR1 in peripheral blood mononuclear cells in patients with coronary artery disease

Background: The modification of the gut microbiome has been proposed to alter immune response which is a key driver in low-grade inflammation as well as metabolic markers. This study was conducted to determine the effects of a low-calorie diet with and without nuts on some gut bacterial abundance, metabolic markers, and gene expression in peripheral blood mononuclear cells (PBMCs) in stable coronary artery disease patients with overweight or obesity. Methods: Overweight or obese patients with stable coronary artery disease of both genders were randomly allocated to a nut-free calorie-restricted diet as 25% of energy deficit (CRD) or a CRD enriched with 39-60 gr/d of mixed nuts (CRDEN) for 8 weeks (32 patients in CRD and 35 patients in CRDEN). Mixed nuts consisted of equal amounts of unsalted pistachios, almonds, and peanuts. Microbiota analysis was performed by quantitative real-time polymerase chain reaction method on feces collected before and after the intervention, using primers targeting 16S ribosomal DNA of 4 different bacterial genera, including Bacteroides, Prevotella, Bifidobacterium, and Lactobacillus. We examined the plasma concentrations of glucose, insulin, adiponectin as well as expression of toll-like receptor-4 (TLR4) and fractalkine receptor (CX3CR1) in PBMCs. Results: A significant reduction in expression of CX3CR1 (p=0.04) and a tendency to lower expression of TLR4 in PBMCs (p=0.06) was observed in the CRDEN group at the end of the study compared to the CRD group. The abundance of fecal Prevotella also tended to increase in CRDEN compared to the CRD group (p=0.06). Plasma insulin and adiponectin had no significant changes. There was a positive correlation between fecal Prevotella abundance and plasma adiponectin at baseline (r=0.315, p=0.015) and the end of the study (r=0.380, p=0.003). Conclusion: Our results suggest that the inclusion of mixed tree nuts and peanuts in a low-calorie diet for 8 weeks led to a lower CX3CR expression in PBMCs in a cohort of overweight or obese patients with stable CAD. This finding provides another beneficial effect of diet supplemented with nuts on factors associated with inflammation. Trial registration: this clinical study has been registered at the clinical trial registration center (clinicaltrial.gov): NCT04078919 on September 6, 2019.

High-Fat, Western-Style Diet, Systemic Inflammation, and Gut Microbiota: A Narrative Review

The gut microbiota is responsible for recovering energy from food, providing hosts with vitamins, and providing a barrier function against exogenous pathogens. In addition, it is involved in maintaining the integrity of the intestinal epithelial barrier, crucial for the functional maturation of the gut immune system. The Western diet (WD)—an unhealthy diet with high consumption of fats—can be broadly characterized by overeating, frequent snacking, and a prolonged postprandial state. The term WD is commonly known and intuitively understood. However, the strict digital expression of nutrient ratios is not precisely defined. Based on the US data for 1908–1989, the calory intake available from fats increased from 32% to 45%. Besides the metabolic aspects (hyperinsulinemia, insulin resistance, dyslipidemia, sympathetic nervous system and renin-angiotensin system overstimulation, and oxidative stress), the consequences of excessive fat consumption (high-fat diet—HFD) comprise dysbiosis, gut barrier dysfunction, increased intestinal permeability, and leakage of toxic bacterial metabolites into the circulation. These can strongly contribute to the development of low-grade systemic inflammation. This narrative review highlights the most important recent advances linking HFD-driven dysbiosis and HFD-related inflammation, presents the pathomechanisms for these phenomena, and examines the possible causative relationship between pro-inflammatory status and gut microbiota changes.

The impact of the Th17:Treg axis on the IgA-Biome across the glycemic spectrum

Secretory IgA (SIgA) is released into mucosal surfaces where its function extends beyond that of host defense to include the shaping of resident microbial communities by mediating exclusion/inclusion of respective microbes and regulating bacterial gene expression. In this capacity, SIgA acts as the fulcrum on which host immunity and the health of the microbiota are balanced. We recently completed an analysis of the gut and salivary IgA-Biomes (16S rDNA sequencing of SIgA-coated/uncoated bacteria) in Mexican-American adults that identified IgA-Biome differences across the glycemic spectrum. As Th17:Treg ratio imbalances are associated with gut microbiome dysbiosis and chronic inflammatory conditions such as type 2 diabetes, the present study extends our prior work by examining the impact of Th17:Treg ratios (pro-inflammatory:anti-inflammatory T-cell ratios) and the SIgA response (Th17:Treg-SIgA axis) in shaping microbial communities. Examining the impact of Th17:Treg ratios (determined by epigenetic qPCR lymphocyte subset quantification) on the IgA-Biome across diabetes phenotypes identified a proportional relationship between Th17:Treg ratios and alpha diversity in the stool IgA-Biome of those with dysglycemia, significant changes in community composition of the stool and salivary microbiomes across glycemic profiles, and genera preferentially abundant by T-cell inflammatory phenotype. This is the first study to associate epigenetically quantified Th17:Treg ratios with both the larger and SIgA-fractionated microbiome, assess these associations in the context of a chronic inflammatory disease, and offers a novel frame through which to evaluate mucosal microbiomes in the context of host responses and inflammation.

Dysbiosis of the gut microbiome impairs mouse skeletal muscle adaptation to exercise

There is emerging evidence of a gut microbiome-skeletal muscle axis. The purpose of this study was to determine if an intact gut microbiome was necessary for skeletal muscle adaptation to exercise. Forty-two 4-month-old female C57BL/6J mice were randomly assigned to untreated (U) or antibiotic-treated (T) non-running controls (CU or CT, respectively) or progressive weighted wheel running (PoWeR, P) untreated (PU) or antibiotic-treated (PT) groups. Antibiotic treatment resulted in disruption of the gut microbiome as indicated by a significant depletion of gut microbiome bacterial species in both CT and PT groups. The training stimulus was the same between PU and PT groups as assessed by weekly (12.35 ± 2.06 vs. 11.09 ± 1.76 km/week, respectively) and total (778.9 ± 130.5 vs. 703.8 ± 112.9 km, respectively) running activity. In response to PoWeR, PT showed less hypertrophy of soleus type 1 and 2a fibres and plantaris type 2b/x fibres compared to PU. The higher satellite cell and myonuclei abundance of PU plantaris muscle after PoWeR was not observed in PT. The fibre-type shift of PU plantaris muscle to a more oxidative type 2a fibre composition following PoWeR was blunted in PT. There was no difference in serum cytokine levels among all groups suggesting disruption of the gut microbiome did not induce systemic inflammation. The results of this study provide the first evidence that an intact gut microbiome is necessary for skeletal muscle adaptation to exercise. KEY POINTS: Dysbiosis of the gut microbiome caused by continuous antibiotic treatment did not affect running activity. Continuous treatment with antibiotics did not result in systemic inflammation as indicated by serum cytokine levels. Gut microbiome dysbiosis was associated with blunted fibre type-specific hypertrophy in the soleus and plantaris muscles in response to progressive weighted wheel running (PoWeR). Gut microbiome dysbiosis was associated with impaired PoWeR-induced fibre-type shift in the plantaris muscle. Gut microbiome dysbiosis was associated with a loss of PoWeR-induced myonuclei accretion in the plantaris muscle.

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

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

Comparative effects of alive and pasteurized Akkermansia muciniphila on normal diet-fed mice

Recently, Akkermansia muciniphila an anaerobic member of the gut microbiota, has been proposed as a next-generation probiotic. The aim of this study was evaluation of the effect of alive and pasteurized A. muciniphila on health status, intestinal integrity, immune response, lipid metabolism, and gut microbial composition in normal-diet fed mice as well as direct effects of the bacterium on Caco-2 cell line. A total of 30 mice were distributed into three different groups, control, alive, and pasteurized A. muciniphila-treated group. After acclimation, control and treatment groups were administrated with PBS and 10⁹ CFU/200µL of bacterial suspension for 5 weeks, respectively. Besides, Caco-2 separately exposed to alive, pasteurized A. muciniphila and PBS for 24 h. The results showed that administration of A. muciniphila leads to reduction in body, liver, and white adipose weight. Histology data revealed both treatments had no adverse effects in colon, liver, and adipose tissues as well as induced better gut structure. Moreover, biochemical parameters and inflammatory biomarkers in plasma demonstrated that pasteurized A. muciniphila had more pronounce effect. Furthermore, alive A. muciniphia had better effects on the modulation of gene expression related to fatty acid synthesis, energy homeostasis, and immune response in the liver; meanwhile, these effects in the adipose was more in the pasteurized A. muciniphila administration. More importantly, the improvement of gut health by enhancing strengthen intestinal integrity and maintaining immune homeostasis was seen in both treatments; notably, pasteurized A. muciniphila had more effective. Similarly, treatment with the pasteurized form more effectively upregulated tight junction and regulated immune response-related genes in Caco-2 cell line. Both treatments triggered the improvement of microbiota communities, particularly the alive form. Therefore, both forms of A. muciniphila could modulate lipid and immune homeostasis, improved some gut microbiota, and promoted the overall health, while all these effects were dominantly observed in pasteurized form. In conclusion, pasteurized A. muciniphila can be considered as new medical supplement to maintain health state and prevent diseases in normal mice through different mechanisms.

Gut Microbiota in Adipose Tissue Dysfunction Induced Cardiovascular Disease: Role as a Metabolic Organ

The gut microbiome has emerged as a key regulator of host metabolism. Accumulating evidence has indicated that the gut microbiota is involved in the development of various human diseases. This association relies on the structure and metabolites of the gut microbiota. The gut microbiota metabolizes the diet ingested by the host into a series of metabolites, including short chain fatty acids, secondary bile acids, trimethylamine N-oxide, and branched-chain amino acids, which affects the physiological processes of the host by activating numerous signaling pathways. In this review, we first summarize the various mechanisms through which the gut microbiota influences adipose tissue dysfunction and metabolic processes that subsequently cause cardiovascular diseases, highlighting the complex interactions between gut microbes, their metabolites, and the metabolic activity of the host. Furthermore, we investigated the current status of clinical therapies for adipose tissue dysfunction directed at the gut microbiota. Finally, we discuss the challenges that remain to be addressed before this field of research can be translated to everyday clinical practice.

The Na/K-ATPase α1/Src interaction regulates metabolic reserve and Western diet intolerance

AIM

Highly prevalent diseases such as insulin resistance and heart failure are characterized by reduced metabolic flexibility and reserve. We tested whether Na/K-ATPase (NKA)-mediated regulation of Src kinase, which requires two NKA sequences specific to the α1 isoform, is a regulator of metabolic capacity that can be targeted pharmacologically.

METHODS

Metabolic capacity was challenged functionally by Seahorse metabolic flux analyses and glucose deprivation in LLC-PK1-derived cells expressing Src binding rat NKA α1, non-Src-binding rat NKA α2 (the most abundant NKA isoform in the skeletal muscle), and Src binding gain-of-function mutant rat NKA α2. Mice with skeletal muscle-specific ablation of NKA α1 (skα1-/-) were generated using a MyoD:Cre-Lox approach and were subjected to treadmill testing and Western diet. C57/Bl6 mice were subjected to Western diet with or without pharmacological inhibition of NKA α1/Src modulation by treatment with pNaKtide, a cell-permeable peptide designed by mapping one of the sites of NKA α1/Src interaction.

RESULTS

Metabolic studies in mutant cell lines revealed that the Src binding regions of NKA α1 are required to maintain metabolic reserve and flexibility. Skα1-/- mice had decreased exercise endurance and mitochondrial Complex I dysfunction. However, skα1-/- mice were resistant to Western diet-induced insulin resistance and glucose intolerance, a protection phenocopied by pharmacological inhibition of NKA α1-mediated Src regulation with pNaKtide.

CONCLUSIONS

These results suggest that NKA α1/Src regulatory function may be targeted in metabolic diseases. Because Src regulatory capability by NKA α1 is exclusive to endotherms, it may link the aerobic scope hypothesis of endothermy evolution to metabolic dysfunction.

Effect of probiotic supplementation along with calorie restriction on metabolic endotoxemia, and inflammation markers in coronary artery disease patients: a double blind placebo controlled randomized clinical trial

Purpose

Alterations in the gut microbiome (dysbiosis) has been associated with increased microbial translocation, leading to chronic inflammation in coronary artery disease (CAD). It has been proposed that modulation of gut microbiota by probiotic might modify metabolic endotoxemia. Therefore, the purpose of this study was to examine the effects of Lactobacillus rhamnosus GG (LGG) on endotoxin level, and biomarkers of inflammation in CAD participants.

Methods

This study was a 12-weeks randomized, double-blind, and intervention on 44 patients with CAD. Patients were randomly allocated to receive either one LGG capsule 1.6 × 10⁹ colony-forming unit (CFU) or the placebo capsules for 12 weeks. In addition, all the participants were also prescribed a calorie-restricted diet. Serum levels of interleukin-1β (IL-1β), Toll-like receptor 4 (TLR4), interleukin-10 (IL-10), and lipopolysaccharide (LPS), were assessed before and after the intervention.

Results

A significant decrease in IL1-Beta concentration (− 1.88 ± 2.25, vs. 0.50 ± 1.58 mmol/L, P = 0.027), and LPS levels (− 5.88 ± 2.70 vs. 2.96+ 5.27 mg/L, P = 0.016), was observed after the probiotic supplementation compared with the placebo. Participants who had ≥2.5 kg weight loss showed significantly improved cardiovascular-related factors, compared to patients with < 2.5 kg weight reduction, regardless of the supplement they took.

Conclusion

These data provide preliminary evidence that probiotic supplementation has beneficial effects on metabolic endotoxemia, and mega inflammation in participants with CAD.

Oxyntomodulin May Distinguish New-Onset Diabetes After Acute Pancreatitis From Type 2 Diabetes

OBJECTIVE

New-onset diabetes is an important sequela of acute pancreatitis, but there are no biomarkers to differentiate it from the much more common type 2 diabetes. The objective was to investigate whether postprandial circulating levels of gut hormones can serve this purpose.

METHODS

This was a case-control study nested into a prospective longitudinal cohort study that included 42 insulin-naive cases with new-onset prediabetes/diabetes after acute pancreatitis (NODAP) and prediabetes/diabetes followed by acute pancreatitis (T2D-AP), sex matched with 21 healthy controls. All individuals underwent a standardized mixed-meal test, and blood samples were assayed for gut hormones (glucose-dependent insulinotropic peptide, glucagon-like peptide-1, oxyntomodulin, and peptide YY). Analysis of variance and linear regression analysis were conducted in unadjusted and adjusted models (accounting for age, homeostatic model assessment of β-cell function, and magnetic resonance imaging-derived body fat composition).

RESULTS

Oxyntomodulin levels were significantly lower in NODAP compared with T2D-AP and healthy controls (P = 0.027 and P = 0.001, respectively, in the most adjusted model). Glucagon-like peptide-1 and peptide YY were significantly lower in NODAP compared with T2D-AP (P = 0.001 and P = 0.014, respectively, in the most adjusted model) but not compared with healthy controls (P = 1.000 and P = 0.265, respectively, in the most adjusted model). Glucose-dependent insulinotropic peptide levels were not significantly different between NODAP and T2D-AP.

DISCUSSION

Oxyntomodulin is a promising biomarker to guide the differential diagnosis of new-onset diabetes after acute pancreatitis. However, external validation studies are warranted before it can be recommended for routine use in clinical practice.

Putting ATM to BED: How Adipose Tissue Macrophages Are Affected by Bariatric Surgery, Exercise, and Dietary Fatty Acids

With increasing adiposity in obesity, adipose tissue macrophages contribute to adipose tissue malfunction and increased circulating proinflammatory cytokines. The chronic low-grade inflammation that occurs in obesity ultimately gives rise to a state of metainflammation that increases the risk of metabolic disease. To date, only lifestyle and surgical interventions have been shown to be somewhat effective at reversing the negative consequences of obesity and restoring adipose tissue homeostasis. Exercise, dietary interventions, and bariatric surgery result in immunomodulation, and for some individuals their effects are significant with or without weight loss. Robust evidence suggests that these interventions reduce chronic inflammation, in part, by affecting macrophage infiltration and promoting a phenotypic switch from the M1- to M2-like macrophages. The purpose of this review is to discuss the impact of dietary fatty acids, exercise, and bariatric surgery on cellular characteristics affecting adipose tissue macrophage presence and phenotypes in obesity.

A New Strain of Christensenella minuta as a Potential Biotherapy for Obesity and Associated Metabolic Diseases

Obesity is associated with gut microbiota dysbiosis, characterized by a high Firmicutes/Bacteroidetes ratio. Gut-dwelling bacteria of the Christensenellaceae family have been proposed to act as keystones of the human gut ecosystem and to prevent adipogenesis. The objectives of the present study were to demonstrate the antiobesity potential of a new strain of Christensenella minuta in preclinical models and explore related mechanisms of action. The antiobesity potential of C. minuta DSM33407 was assessed in a diet-induced obesity mouse model. Changes in hepatic lipid metabolism were explored using targeted transcriptomics. Effects on gut microbiota were further assessed in a humanized Simulator of the Human Intestinal Microbial Ecosystem (SHIME®) model inoculated with obese fecal samples. Shotgun metagenomics was applied to study microbial community structures in both models. C. minuta DSM33407 protected from diet-induced obesity and regulated associated metabolic markers such as glycemia and leptin. It also regulated hepatic lipid metabolism through a strong inhibition of de novo lipogenesis and maintained gut epithelial integrity. In the humanized SHIME® model, these effects were associated with modulations of the intestinal microbiota characterized by a decreased Firmicutes/Bacteroidetes ratio. These data indicate that C. minuta DSM33407 is a convincing therapeutic candidate for the management of obesity and associated metabolic disorders.

Nutritional Modulation of the Microbiome and Immune Response

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

Dietary Fibre Intake in Type 2 and New-Onset Prediabetes/Diabetes after Acute Pancreatitis: A Nested Cross-Sectional Study

The association between intake of dietary fibre and glucose metabolism has been extensively investigated in numerous metabolic disorders. However, little is known about this association in individuals after an attack of acute pancreatitis (AP). The aim was to investigate the associations between intake of dietary fibre and markers of glucose metabolism in individuals with new-onset prediabetes or diabetes after acute pancreatitis (NODAP), pre-exiting type 2 prediabetes or diabetes, and normoglycaemia after acute pancreatitis. This cross-sectional study was nested within the parent prospective longitudinal cohort study. The studied markers of glucose metabolism were fasting plasma glucose and glycated haemoglobin. Habitual intake of dietary fibre was determined using the EPIC-Norfolk food frequency questionnaire. Multivariable linear regression analyses were conducted. The study included a total of 108 individuals after AP. In the NODAP group, increased intakes of total fibre (β = −0.154, p = 0.006), insoluble fibre (β = −0.133, p = 0.01), and soluble fibre (β = −0.13, p = 0.02) were significantly associated with a reduction in fasting plasma glucose. Increased intakes of vegetables (β = −0.069, p = 0.004) and nuts (β = −0.039, p = 0.038) were significantly associated with a reduction in fasting plasma glucose. Increased intake of nuts (β = −0.054, p = 0.001) was also significantly associated with a reduction in glycated haemoglobin. None of the above associations were significant in the other study groups. Habitual intake of dietary fibre was inversely associated with fasting plasma glucose in individuals with NODAP. Individuals after an attack of AP may benefit from increasing their intake of dietary fibre (specifically, vegetables and nuts) with a view to preventing NODAP.

Regulatory effects of hawthorn polyphenols on hyperglycemic, inflammatory, insulin resistance responses, and alleviation of aortic injury in type 2 diabetic rats

Hawthorn polyphenol extract (HPE) is beneficial for patients with type 2 diabetes (T2D). However, the mechanism underlying its beneficial effects remains unclear. We investigated the inhibitory effects and mechanisms of HPE on insulin resistance, inflammation, and aortic injury in T2D rats, using metformin (MF) as a positive control. High-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) was used to determine the primary polyphenols in HPE. Hematoxylin & Eosin (H&E) staining was used to evaluate pathological conditions of the skeletal muscle, liver, and aorta vessels in each group. The levels of serum and intestinal tissue oxidative stress, tumor necrosis factor α (TNF-α), and inflammatory interleukin-6 (IL-6) were also assessed. Western blotting was used to evaluate protein expression levels in the associated molecular pathway. Volatile organic compounds (VOCs) from colon contents were determined using headspace-gas chromatography-ion mobility chromatography. Our results showed that supplementation with 300 mg HPE/kg body weight over four weeks significantly improved total cholesterol (TC), total triglyceride (TG), insulin, and lipopolysaccharide (LPS) levels in diabetic rats (p < 0.01). The lesions of skeletal muscle, liver, and aorta in diabetic rats were significantly improved. HPE supplementation also significantly downregulated the inflammatory factors (IL-6, TNF-α, and MCP-1) in the liver of diabetic rats via the SIRT1/AMPK/NF-κB signaling pathway. Furthermore, HPE significantly reduced insulin resistance in T2D rats by upregulating the phosphorylation of glucose absorption protein (GLUT4) and insulin resistance-associated proteins, p-IRS1, p-AKT, and p-PI3K, in the rat liver (p < 0.01). The findings show that HPE could also alleviate aortic injury by activating SIRT1 and regulating the NF-κB and Wnt2/β-catenin signaling pathways. Overall, the results of this study suggest that both HPE and MF have similar inhibitory effects on T2D in rats and that HPE could be used as a functional food component in the adjuvant treatment of T2D.