Sodium Butyrate Improves Liver Glycogen Metabolism in Type 2 Diabetes Mellitus

Dietary inclusion of Clostridium butyricum cultures alleviated impacts of high-carbohydrate diets in largemouth bass (Micropterus salmoides)

A 60-d feeding trial was conducted to explore the potential regulatory effects of dietary Clostridium butyricum cultures (CBC) supplementation in high-carbohydrate diet (HCD) on carbohydrate utilisation, antioxidant capacity and intestinal microbiota of largemouth bass. Triplicate groups of largemouth bass (average weight 35·03 ± 0·04 g), with a destiny of twenty-eight individuals per tank, were fed low-carbohydrate diet and HCD supplemented with different concentration of CBC (0 %, 0·25 %, 0·50 % and 1·00 %). The results showed that dietary CBC inclusion alleviated the hepatic glycogen accumulation induced by HCD intake. Additionally, the expression of hepatic ampkα1 and insulin signaling pathway-related genes (ira, irb, irs, p13kr1 and akt1) increased linearly with dietary CBC inclusion, which might be associated with the activation of glycolysis-related genes (gk, pfkl and pk). Meanwhile, the expression of intestinal SCFA transport-related genes (ffar3 and mct1) was significantly increased with dietary CBC inclusion. In addition, the hepatic antioxidant capacity was improved with dietary CBC supplementation, as evidenced by linear decrease in malondialdehyde concentration and expression of keap1, and linear increase in antioxidant enzyme activities (total antioxidative capacity, total superoxide dismutase and catalase) and expression of antioxidant enzyme-related genes (nrf2, sod1, sod2 and cat). The analysis of bacterial 16S rRNA V3-4 region indicated that dietary CBC inclusion significantly reduced the enrichment of Firmicutes and potential pathogenic bacteria genus Mycoplasma but significantly elevated the relative abundance of Fusobacteria and Cetobacterium. In summary, dietary CBC inclusion improved carbohydrate utilization, antioxidant capacity and intestinal microbiota of largemouth bass fed HCD.

Rutin ameliorated lipid metabolism dysfunction of diabetic NAFLD via AMPK/SREBP1 pathway

BACKGROUND

In diabetic liver injury, nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease. Rutin is a bioflavonoid produced by the hydrolysis of glucosidases to quercetin. Its biological activities include lowering blood glucose, regulating insulin secretion, regulating dyslipidemia, and exerting anti-inflammatory effects have been demonstrated. However, its effect on diabetic NAFLD is rarely reported.

PURPOSE

Our study aimed to investigate the protective effects of Rutin on diabetic NAFLD and potential pharmacological mechanism.

METHODS

We used db/db mice as the animal model to investigate diabetic NAFLD. Oleic acid-treated (OA) HeLa cells were examined whether Rutin had the ability to ameliorate lipid accumulation. HepG2 cells treated with 30 mM/l d-glucose and palmitic acid (PA) were used as diabetic NAFLD in vitro models. Total cholesterol (TC) and Triglycerides (TG) levels were determined. Oil red O staining and BODIPY 493/503 were used to detect lipid deposition within cells. The indicators of inflammation and oxidative stress were detected. The mechanism of Rutin in diabetic liver injury with NAFLD was analyzed using RNA-sequence and 16S rRNA, and the expression of fat-synthesizing proteins in the 5' adenosine monophosphate-activated protein kinase (AMPK) pathway was investigated. Compound C inhibitors were used to further verify the relationship between AMPK and Rutin in diabetic NAFLD.

RESULTS

Rutin ameliorated lipid accumulation in OA-treated HeLa. In in vitro and in vivo models of diabetic NAFLD, Rutin alleviated lipid accumulation, inflammation, and oxidative stress. 16S analysis showed that Rutin could reduce gut microbiota dysregulation, such as the ratio of Firmicutes to Bacteroidetes. RNA-seq showed that the significantly differentially genes were mainly related to liver lipid metabolism. And the ameliorating effect of Rutin on diabetic NAFLD was through AMPK/SREBP1 pathway and the related lipid synthesis proteins was involved in this process.

CONCLUSION

Rutin ameliorated diabetic NAFLD by activating the AMPK pathway and Rutin might be a potential new drug ingredient for diabetic NAFLD.

Harnessing and delivering microbial metabolites as therapeutics via advanced pharmaceutical approaches

Microbial metabolites have emerged as key players in the interplay between diet, the gut microbiome, and host health. Two major classes, short-chain fatty acids (SCFAs) and tryptophan (Trp) metabolites, are recognized to regulate inflammatory, immune, and metabolic responses within the host. Given that many human diseases are associated with dysbiosis of the gut microbiome and consequent reductions in microbial metabolite production, the administration of these metabolites represents a direct, multi-targeted treatment. While a multitude of preclinical studies showcase the therapeutic potential of both SCFAs and Trp metabolites, they often rely on high doses and frequent dosing regimens to achieve systemic effects, thereby constraining their clinical applicability. To address these limitations, a variety of pharmaceutical formulations approaches that enable targeted, delayed, and/or sustained microbial metabolite delivery have been developed. These approaches, including enteric encapsulations, esterification to dietary fiber, prodrugs, and nanoformulations, pave the way for the next generation of microbial metabolite-based therapeutics. In this review, we first provide an overview of the roles of microbial metabolites in maintaining host homeostasis and outline how compromised metabolite production contributes to the pathogenesis of inflammatory, metabolic, autoimmune, allergic, infectious, and cancerous diseases. Additionally, we explore the therapeutic potential of metabolites in these disease contexts. Then, we provide a comprehensive and up-to-date review of the pharmaceutical strategies that have been employed to enhance the therapeutic efficacy of microbial metabolites, with a focus on SCFAs and Trp metabolites.

Supplementation with Lactiplantibacillus brevis GKEX Combined with Resistance Exercise Training Improves Muscle Mass, Strength Performance, and Body Fat Condition in Healthy Humans

In addition to maintaining good exercise and dietary habits, recent studies have shown that probiotics may have potential benefits for muscle mass and strength. It is worth noting that the effects may vary depending on the specific strains used. To date, no studies have analyzed the effects of Lactiplantibacillus brevis in this context. Here, we combine the L. brevis strain GKEX with resistance training to further understand its effects on muscle mass, thickness, performance, and fat loss. In a six-week intervention for a double-blind randomized trial, 52 healthy subjects were divided into two groups (10 male and 16 female participants in each group): a placebo group (two capsules/day, containing 0 CFU of GKEX per capsule) and a GKEX group (two capsules/day, containing 1 × 1010 CFU of GKEX per capsule). Before the intervention, no differences were observed between the two groups in any of the tests (body composition, muscle thickness, exercise performance, and blood parameters). However, supplementation with GKEX significantly improved muscle mass and thickness, as well as grip strength, muscle strength, and explosive performance, when compared to the associated parameters before the intervention. Additionally, GKEX supplementation promoted a reduction in the body fat percentage (p < 0.05). Through analysis of the change amount, we observed that GKEX supplementation yielded significantly improved benefits when compared to the placebo group (p < 0.05). In summary, our findings support the notion that a six-week resistance exercise training program combined with L. brevis GKEX supplementation has superior additive effects that enhance muscle mass and strength performance, while also reducing body fat percentage. This intervention can promote muscle gain and fat loss.

Sodium butyrate ameliorated diabetic nephropathy-associated tubulointerstitial inflammation by modulating the tight junctions of renal tubular epithelial cells

As one of the most significant pathological changes of diabetic nephropathy (DN), tubulointerstitial fibrosis (TIF) had a close relationship with tubulointerstitial inflammation (TI), and the occurrence of TI could have resulted from the disrupted tight junctions (TJs) of renal tubular epithelial cells (RTECs). Studies have demonstrated that sodium butyrate (NaB), a typical short chain fatty acid (SCFA), played an important regulatory role in intestinal TJs and inflammation. In this study, our in vivo and in vitro results showed that accompanied by TI, renal tubular TJs were gradually disrupted in the process of DN-related TIF. In HG and LPS co-cultured HK-2 cells and db/db mice, NaB treatment regained the TJs of RTECs via the sphingosine 1-phosphate receptor-1 (S1PR1)/AMPK signaling pathway, relieving inflammation. Small interfering RNA of S1PR1, S1PR1 antagonist W146 and agonist SEW2871, and AMPK agonist AICAR were all used to further confirm the essential role of the S1PR1/AMPK signaling pathway in NaB's TJ protection in RTECs in vitro. Finally, NaB administration not only improved the renal function and TIF, but also relieved the TI of db/db mice. These findings suggested that the use of NaB might be a potential adjuvant treatment strategy for DN-associated TIF, and this protective effect was linked to the TJ modulation of RTECs via the S1PR1/AMPK signaling pathway, leading to the improvement of TI.

Characteristics of elderly diabetes patients: focus on clinical manifestation, pathogenic mechanism, and the role of traditional Chinese medicine

Diabetes mellitus has become a major public health issue globally, putting an enormous burden on global health systems and people. Among all diseased groups, a considerable part of patients are elderly, while their clinical features, pathogenic processes, and medication regimens are different from patients of other ages. Despite the availability of multiple therapies and techniques, there are still numerous elderly diabetes patients suffering from poor blood glucose control, severe complications, and drug adverse effects, which negatively affect the quality of life in their golden years. Traditional Chinese Medicine (TCM) has been widely used in the treatment of diabetes for several decades, and its relevant clinical practice has confirmed that it has a satisfactory effect on alleviating clinical symptoms and mitigating the progression of complications. Chinese herbal medicine and its active components were used widely with obvious clinical advantages by multiple targets and signaling pathways. However, due to the particular features of elderly diabetes, few studies were conducted to explore Traditional Chinese Medicine intervention on elderly diabetic patients. This study reviews the research on clinical features, pathogenic processes, treatment principles, and TCM treatments, hoping to provide fresh perspectives on the prevention and management strategies for elderly diabetes.

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

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

A Metabolite Perspective on the Involvement of the Gut Microbiota in Type 2 Diabetes

Type 2 diabetes (T2D) is a commonly diagnosed condition that has been extensively studied. The composition and activity of gut microbes, as well as the metabolites they produce (such as short-chain fatty acids, lipopolysaccharides, trimethylamine N-oxide, and bile acids) can significantly impact diabetes development. Treatment options, including medication, can enhance the gut microbiome and its metabolites, and even reverse intestinal epithelial dysfunction. Both animal and human studies have demonstrated the role of microbiota metabolites in influencing diabetes, as well as their complex chemical interactions with signaling molecules. This article focuses on the importance of microbiota metabolites in type 2 diabetes and provides an overview of various pharmacological and dietary components that can serve as therapeutic tools for reducing the risk of developing diabetes. A deeper understanding of the link between gut microbial metabolites and T2D will enhance our knowledge of the disease and may offer new treatment approaches. Although many animal studies have investigated the palliative and attenuating effects of gut microbial metabolites on T2D, few have established a complete cure. Therefore, conducting more systematic studies in the future is necessary.

Butyrate restores the fat/lean mass ratio balance and energy metabolism and reinforces the tight junction-mediated intestinal epithelial barrier in prediabetic mice independently of its anti-inflammatory and epigenetic actions

Tissue/cellular actions of butyrate on energy metabolism and intestinal barrier in normal metabolic conditions or prediabetes are still unclear. In this work, we investigated the beneficial effect of dietary supplementation with sodium butyrate on energy metabolism, body mass composition, and intestinal epithelial barrier mediated by tight junction (TJ) in chow diet-fed normal and high-fat diet (HF)-fed prediabetic mice, considering the well-known butyrate action as an epigenetic and inflammatory regulator. Butyrate significantly reduced the fat/lean mass ratio, slightly ameliorated dyslipidemia, restored oral glucose tolerance, and increased basal energy expenditure in prediabetic HF-fed mice but had no effect on control animals. Such effects were observed in the absence of significant alterations in the hypothalamic expression of orexigenic and anorexigenic genes and motor activity. Also, butyrate suppressed the whitening effect of HF on brown adipose tissue but did not affect cell bioenergetics in immortalized UCP1-positive adipocytes in vitro. Butyrate reinforced the intestinal epithelial barrier in HF-fed mice and in Caco-2 monolayers, which involved higher trafficking of TJ proteins to the cell-cell contact region of the intestinal epithelia, without affecting TJ gene expression or the acetylation level of histones H3 and H4 in vivo. All metabolic and intestinal effects of butyrate in prediabetic mice occurred in the absence of detectable changes in systemic or local inflammation, or alterations in endotoxemia markers. Butyrate has no effect on chow diet-fed mice but, in the context of HF-induced prediabetes, it prevents metabolic and intestinal dysfunctions independently of its anti-inflammatory and epigenetic actions.

Intestinal Microbiotas and Alcoholic Hepatitis: Pathogenesis and Therapeutic Value

Alcoholic hepatitis (AH) is a rapidly progressing and severe stage of alcoholic liver disease, presenting a grim prognosis. Extensive research has elucidated several underlying mechanisms that contribute to the development of AH, including metabolic alterations, immune stimulation, and intestinal dysbiosis. These pathological changes intricately intertwine during the progression of AH. Notably, recent studies have increasingly highlighted the pivotal role of alterations in the intestinal microbiota in the pathogenesis of AH. Consequently, future investigations should place significant emphasis on exploring the dynamics of intestinal microbiota. In this comprehensive review, we consolidate the primary causes of AH while underscoring the influence of gut microbes. Furthermore, by examining AH treatment strategies, we delineate the potential therapeutic value of interventions targeting the gut microbiota. Given the existing limitations in AH treatment options, we anticipate that this review will contribute to forthcoming research endeavors aimed at advancing AH treatment modalities.

Enzymatically prepared alginate oligosaccharides improve broiler chicken growth performance by modulating the gut microbiota and growth hormone signals

BACKGROUND

Alginate oligosaccharide (AOS) holds great potential as a novel feed supplement in farm animals. However, the effects of AOS on chicken health and the underlying mechanisms are not fully understood. This study aimed to optimize the enzymatic preparation of AOS by using bacterial alginate lyases expressed in yeast, investigate the effects of the prepared AOS on the growth performance and gut health of broiler chickens, and reveal the underlying mechanisms.

RESULTS

Five alginate lyases from bacteria were cloned into Pichia pastoris GS115 and the alginate lyase PDE9 was expressed at relatively high yield, activity and stability in P. pastoris. Animal trials were carried out using 320 1-day-old male Arbor Acres broilers (four groups; 8 replicates/group × 10 chicks/replicate) receiving either a basal diet or the same diet supplemented with 100, 200 and 400 mg/kg PDE9-prepared AOS for 42 d. The results showed that dietary supplementation of 200 mg/kg AOS displayed the highest activity in promoting the birds' ADG and ADFI (P < 0.05). AOS ameliorated the intestinal morphology, absorption function and barrier function, as indicated by the enhanced (P < 0.05) intestinal villus height, maltase activity, and the expression of PEPT, SGLT1, ZNT1, and occludin. AOS also increased serum insulin-like growth factor-1, ghrelin (P < 0.05), and growth hormone (P < 0.1). Moreover, the concentrations of acetate, isobutyrate, isovalerate, valerate, and total SCFAs in cecum of birds fed AOS were significantly higher than the control birds (P < 0.05). Metagenomic analysis indicated that AOS modulated the chicken gut microbiota structure, function, and microbial interactions and promoted the growth of SCFAs-producing bacteria, for example, Dorea sp. 002160985; SCFAs, especially acetate, were found positively correlated with the chicken growth performance and growth-related hormone signals (P < 0.05). We further verified that AOS can be utilized by Dorea sp. to grow and to produce acetate in vitro.

CONCLUSIONS

We demonstrated that the enzymatically produced AOS effectively promoted broiler chicken growth performance by modulating the chicken gut microbiota structure and function. For the first time, we established the connections among AOS, chicken gut microbiota/SCFAs, growth hormone signals and chicken growth performance.

Cardiac angiogenesis enhances by activating Mir-126 and related target proteins in type 2 diabetic rats: Rescue combination effect of Sodium butyrate and voluntary exercise therapy

Objective

type 2 diabetes, metabolic disorder, is one of the main risk factors for cardiovascular disease, leading to angiogenesis injury. The present study wanted to discover the effect of sodium butyrate (NaB) and voluntary exercise, alone or together, on miR-126 and related proteins in rats with type 2 diabetes.

Methods

thirty-five male Wistar rats (200-250 g) were randomly divided into five groups: control, diabetes, diabetes-NaB, diabetes-exercise, and diabetes-NaB-exercise. Type 2 diabetes was induced by intraperitoneal injection of streptozotocin (35 mg/kg) and high-fat diet. The rats were then administrated NaB (200 mg/kg. ip) or were subjected to voluntary exercise, or combined NaB and voluntary exercise for 8 weeks. MiR-126 expression in the cardiac tissue was determined by real-time PCR, and the SPRED-1 and RAF proteins expression levels were measured by western blot.

Results

NaB and voluntary exercise up-regulated cardiac miR-126 and RAF expression levels and down-regulated SPRED-1 in cardiac tissue of type 2 diabetic rats. Moreover, the combination of NaB and voluntary exercise amplified their effects on those parameters. Both NaB and voluntary exercise or together markedly modulated serum glucose and HbA1c.

Conclusion

The present findings demonstrated that NaB combined with exercise could improve cardiac angiogenesis by increasing miR-126 and affecting related proteins. Thus, NaB together with voluntary exercise might be a promising intervention for the treatment and prevention of type 2 diabetes.

Association of gut microbiota and glucose metabolism in children with disparate degrees of adiposity

OBJECTIVE

To investigate the characteristics of gut microbiota in children with disparate degrees of adiposity, and analyze the association between gut microbiota, glucose metabolism indicators, and inflammatory factors.

METHODS

Clinical data were examined in 89 Chinese children. Children with a body fat percentage ≥ 30% were diagnosed as obese, and ≥ 35% in males and ≥ 40% in females were further defined as severe obesity. The composition of gut microbiota was determined by 16S rDNA-based metagenomics.

RESULTS

The study population (9.75 ± 1.92-year-old) was characterized as normal weight (n = 29), mild obesity (n = 27) and severe obesity (n = 33) groups. Linear discriminant analysis Effect Size (LEfSe) analysis found that compared to the severe obesity group, subjects with mild obesity had more prevalent members of the phylum Fusobacteria, the genus Alistipes, and fewer members of genus Granulicatella and Clostridium (p < 0.05). For subjects with mild obesity, Spearman's correlation analysis revealed that fasting plasma glucose positively correlated with species A. indistinctus, A. putredinis, and negatively correlated with species Ruminococcus gnavus; LBP negatively correlated with species Clostridium hathewayi, and Blautia producta. For subjects with severe obesity, oral glucose tolerance test 2 h plasma glucose (OGTT2HPG) negatively correlated with the phylum Synergistetes, genus Pyramidobacter, species Veillonella parvula, P. piscolens, and positively correlated with species B. producta, INS and HOMA-IR negatively correlated with the genus Haemophilus, species H. parainfluenzae, lipopolysaccharide-binding protein (LBP) negatively correlated with the phylum Actinobacteria, genus Bifidobacterium, Lactobacillus, and species B. longum (all p < 0.05). Phylogenetic investigation of communities by reconstruction of unobserved states 2 (PICRUSt2) analysis discerned that the glucose metabolism pathway, gluconeogenesis I was curtailed in the severe obesity group.

CONCLUSION

The gut microbiota could favourably compensate for glucose metabolism in children with obesity. Genus Haemophilus and Bifidobacterium longum may influence glucose tolerance and insulin resistance in children with severe obesity.

Changes in the Microbiota and their Roles in Patients with Type 2 Diabetes Mellitus

An association between type 2 diabetes mellitus (T2DM) and gut microbiota is well established, but the results of related studies are inconsistent. The purpose of this investigation is to elucidate the characteristics of the gut microbiota in T2DM and non-diabetic subjects. Forty-five subjects were recruited for this study, including 29 T2DM patients and 16 non-diabetic subjects. Biochemical parameters, including body mass index (BMI), fasting plasma glucose (FPG), serum total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL), and hemoglobin A1c (HbA1c), were analyzed and correlated with the gut microbiota. Bacterial community composition and diversity were detected in fecal samples using direct smear, sequencing, and real-time polymerase chain reaction (PCR). In this study, it was observed that indicators such as BMI, FPG, HbA1c, TC, and TG in T2DM patients were on the rise, concurrent with dysbiosis of the microbiota. We observed an increase in Enterococci and a decrease in Bacteroides, Bifidobacteria, and Lactobacilli in patients with T2DM. Meanwhile, total short-chain fatty acids (SCFAs) and D-lactate concentrations were decreased in the T2DM group. In addition, FPG was positively correlated with Enterococcus and negatively correlated with Bifidobacteria, Bacteroides, and Lactobacilli. This study reveals that microbiota dysbiosis is associated with disease severity in patients with T2DM. The limitation of this study is that only common bacteria were noted in this study, and more in-depth related studies are urgently needed.

Yishen Huashi granule modulated lipid metabolism in diabetic nephropathy via PI3K/AKT/mTOR signaling pathways

Aim

Diabetic nephropathy (DN) is the primary cause of end-stage renal disease worldwide. Although etiology for DN is complex and still needs to be fully understood, lipid metabolism disorder is found to play a role in it. Previously, we found Yishen Huashi (YSHS) granule could inhibit diabetic damage and reduce level of microalbuminuria (mALB) in DN animals. To explore its role and mechanism in lipid metabolism under DN settings, this study was designed.

Materials and methods

DN rats were induced by streptozotocin (STZ), HepG₂ and CaCO₂ cells were applied for in vitro study. Hematoxylin-Eosin (HE), periodic acid-Schiff (PAS) staining, and Transmission Electron Microscopy (TEM) were applied for histological observation; 16s Sequencing was used for intestinal microbiota composition analysis; western blotting (WB) and immunofluorescence were carried out for molecular biological study, and enzyme-linked immunosorbent assay (ELISA) was used for lipid determination.

Results

YSHS administration significantly reduced levels of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein (LDL-C), while increased level of high-density lipoprotein (HDL-C); meanwhile, histological changes and steatosis of the liver was ameliorated, integrity of the intestinal barrier was enhanced, and dysbacteriosis within intestinal lumen was ameliorated. Mechanism study found that YSHS modulated mitophagy within hepatocytes and inhibited mTOR/AMPK/PI3K/AKT signaling pathway.

Conclusion

In conclusion, we found in the present study that YSHS administration could ameliorate lipid metabolism disorder in DN animals, and its modulation on intestinal-liver axis played a significant role in it.

Targeted Delivery of Butyrate Improves Glucose Homeostasis, Reduces Hepatic Lipid Accumulation and Inflammation in db/db Mice

Butyrate produced by the gut microbiota has beneficial effects on metabolism and inflammation. Butyrate-producing bacteria are supported by diets with a high fiber content, such as high-amylose maize starch (HAMS). We investigated the effects of HAMS- and butyrylated HAMS (HAMSB)-supplemented diets on glucose metabolism and inflammation in diabetic db/db mice. Mice fed HAMSB had 8-fold higher fecal butyrate concentration compared to control diet-fed mice. Weekly analysis of fasting blood glucose showed a significant reduction in HAMSB-fed mice when the area under the curve for all five weeks was analyzed. Following treatment, fasting glucose and insulin analysis showed increased homeostatic model assessment (HOMA) insulin sensitivity in the HAMSB-fed mice. Glucose-stimulated insulin release from isolated islets did not differ between the groups, while insulin content was increased by 36% in islets of the HAMSB-fed mice. Expression of insulin 2 was also significantly increased in islets of the HAMSB-fed mice, while no difference in expression of insulin 1, pancreatic and duodenal homeobox 1, MAF bZIP transcription factor A and urocortin 3 between the groups was observed. Hepatic triglycerides in the livers of the HAMSB-fed mice were significantly reduced. Finally, mRNA markers of inflammation in liver and adipose tissue were reduced in mice fed HAMSB. These findings suggest that HAMSB-supplemented diet improves glucose metabolism in the db/db mice, and reduces inflammation in insulin-sensitive tissues.

Butyrate: More Than a Short Chain Fatty Acid

PURPOSE OF REVIEW

The mechanistic understanding of the importance and the potential benefits of the gut microbiome has exploded in potential roles in human health and disease. Short chain fatty acids (SCFAs), including butyrate, are one of the key metabolic end products that has been a major focus of microbiome understanding. This brief review aims to describe butyrate's relation to certain biological concepts and their clinical application.

RECENT FINDINGS

Butyrate has reportedly been described as a potent pro-resolution molecule that has a significant role in maintaining gut immunity, supporting gut barrier function, regulation of histone deacetylase (HDAC), and numerous systemic roles. Further research is needed to explore potential benefits of adding SCFAs for patients receiving total parenteral nutrition. Butyrate plays several biological roles in intestinal epithelium anti-inflammatory pathways with clear benefits in numerous acute and chronic disease states and overall human health helping to maintain homeostasis.

Gut Microbiome and Its Impact on Obesity and Obesity-Related Disorders

PURPOSE OF REVIEW

The prevalence of overweight and obesity has been increasing worldwide at an alarming rate. Gut microbiota intimately influence host energy metabolism, and immune response. Studies indicate a prominent role of gut dysbiosis in propagating inflammation that is associated with the development of obesity and obesity-related disorders such as type 2 diabetes mellitus, metabolic syndrome, and non-alcoholic fatty liver disease. This article will review the current literature on gut microbiome and its impact on obesity and obesity-related disorders.

RECENT FINDINGS

An altered gut microbial composition in obesity and obesity-related disorders is associated with enhanced energy extraction from the non-digestible dietary carbohydrates, increased gut permeability, increased production of proinflammatory metabolites, such as lipopolysaccharides, resulting in systemic inflammation and insulin resistance. Gut microbiota modulation can be achieved either by dietary manipulation or by administration of probiotics, prebiotics, synbiotics, and/or fecal microbiota transplantation aiming at the improvement of the gut dysbiosis in obesity and metabolic disorders. Further clinical trials are required to better elucidate the dose, and frequency of these interventions and also their long-term impact on host metabolism.

Lacticaseibacillus rhamnosus Hao9 exerts antidiabetic effects by regulating gut microbiome, glucagon metabolism, and insulin levels in type 2 diabetic mice

Introduction

Type 2 diabetes mellitus (T2DM) is a metabolic disease that has led to a significant global public health burden.

Methods

In this work, we investigated the effects of Lacticaseibacillus rhamnosus Hao9 on T2DM in mice with high-fat diet- and streptozotocin (STZ)-induced diabetes (diabetic mice) and explored the underlying mechanisms.

Results

We found that 10⁹ colony forming units (CFUs) of Hao9 per day significantly reduced fasting blood glucose and insulin levels (p < 0.001) in diabetic mice. Moreover, Hao9 enhanced liver antioxidant capacity and significantly decreased glucose-6-phosphatase and phosphoenolpyruvate carboxykinase expression in the livers of diabetic mice (p < 0.001). Hao9 also reduced the serum concentrations of pro-inflammatory cytokines such as tumor necrosis factor alpha (TNFα), interleukin-1β (IL1β), and IL6 (p < 0.05) and improved intestinal barrier function in diabetic mice. The composition of the gut microbiome was modulated by Hao9, with an increased abundance of Roseburia, Eubacterium, and Lacticaseibacillus, and decreased abundance of Escherichia/Shigella. Notably, Lacticaseibacillus was detected at both weeks 5 and 12 post-treatment, suggesting sustained colonization of the gut by Hao9.

Discussion

The supplementation of Hao9 improved gut microbiota, glucose metabolism, and insulin levels significantly in T2DM mice. That means Hao9 contributes to improving T2DM symptoms with its potential beneficial effects. Therefore, Hao9 is a promising dietary supplement for the treatment of T2DM.

Butyrate Attenuates Hepatic Steatosis Induced by a High-Fat and Fiber-Deficient Diet via the Hepatic GPR41/43-CaMKII/HDAC1-CREB Pathway

SCOPE

Hepatic steatosis is a major health issue that can be attenuated by a healthy diet. This study investigates the effects and molecular mechanisms of butyrate, a dietary fiber metabolite of gut microbiota, on lipid metabolism in hepatocytes.

METHODS AND RESULTS

This study examines the effects of butyrate (0-8 mM) on lipid metabolism in primary hepatocytes. The results show that butyrate (2 mM) consistently inhibits lipogenic genes and activates lipid oxidation-related gene expression in hepatocytes. Furthermore, butyrate modulates lipid metabolism genes, reduces fat droplet accumulation, and activates the calcium/calmodulin-dependent protein kinase II (CaMKII)/histone deacetylase 1 (HDAC1)-cyclic adenosine monophosphate response element binding protein (CREB) signaling pathway in the primary hepatocytes and liver of wild-type (WT) mice, but not in G-protein-coupled receptor 41 (GPR41) knockout and 43 (GPR43) knockout mice. This suggests that butyrate regulated hepatic lipid metabolism requires GPR41 and GPR43. Finally, the study finds that dietary butyrate supplementation (5%) ameliorates hepatic steatosis and abnormal lipid metabolism in the liver of mice fed a high-fat and fiber-deficient diet for 15 weeks.

CONCLUSION

This work reveals that butyrate improves hepatic lipid metabolism through the GPR41/43-CaMKII/HDAC1-CREB pathway, providing support for consideration of butyrate as a dietary supplement to prevent the progression of NAFLD induced by the Western-style diet.

Protein Targeting to Glycogen (PTG): A Promising Player in Glucose and Lipid Metabolism

Protein phosphorylation and dephosphorylation are widely considered to be the key regulatory factors of cell function, and are often referred to as "molecular switches" in the regulation of cell metabolic processes. A large number of studies have shown that the phosphorylation/dephosphorylation of related signal molecules plays a key role in the regulation of liver glucose and lipid metabolism. As a new therapeutic strategy for metabolic diseases, the potential of using inhibitor-based therapies to fight diabetes has gained scientific momentum. PTG, a protein phosphatase, also known as glycogen targeting protein, is a member of the protein phosphatase 1 (PP1) family. It can play a role by catalyzing the dephosphorylation of phosphorylated protein molecules, especially regulating many aspects of glucose and lipid metabolism. In this review, we briefly summarize the role of PTG in glucose and lipid metabolism, and update its role in metabolic regulation, with special attention to glucose homeostasis and lipid metabolism.

Butyrate to combat obesity and obesity-associated metabolic disorders: Current status and future implications for therapeutic use

Evidence is increasing that disturbances in the gut microbiome may play a significant role in the etiology of obesity and type 2 diabetes. The short chain fatty acid butyrate, a major end product of the bacterial fermentation of indigestible carbohydrates, is reputed to have anti-inflammatory properties and positive effects on body weight control and insulin sensitivity. However, whether butyrate has therapeutic potential for the treatment and prevention of obesity and obesity-related complications remains to be elucidated. Overall, animal studies strongly indicate that butyrate administered via various routes (e.g., orally) positively affects adipose tissue metabolism and functioning, energy and substrate metabolism, systemic and tissue-specific inflammation, and insulin sensitivity and body weight control. A limited number of human studies demonstrated interindividual differences in clinical effectiveness suggesting that outcomes may depend on the metabolic, microbial, and lifestyle-related characteristics of the target population. Hence, despite abundant evidence from animal data, support of human data is urgently required for the implementation of evidence-based oral and gut-derived butyrate interventions. To increase the efficacy of butyrate-focused interventions, future research should investigate which factors impact treatment outcomes including baseline gut microbial activity and functionality, thereby optimizing targeted-interventions and identifying individuals that merit most from such interventions.

Sodium Butyrate Attenuated Diabetes-Induced Intestinal Inflammation by Modulating Gut Microbiota

Background

Diabetes mellitus (DM) continues to be one of the world's most costly and complex metabolic disorders. Accumulating evidence has shown that intestinal dysbiosis and associated inflammation can facilitate the onset and progression of DM. In this work, our goal was to investigate how sodium butyrate (SB) controls the gut microbiota to reduce the intestinal inflammation brought on by diabetes.

Methods

Male KK-Ay mice were randomized into two groups: the DM model group (intragastric administration of 0.9% normal saline) and the SB treatment group (intragastric administration of 1,000 mg/kg/d SB). The C57BL/6J mice were used as the control group (intragastric administration of 0.9% normal saline). These mice were administered via gavage for 8 weeks.

Results

The results revealed that SB-treated mice significantly reduced fasting blood glucose (FBG), body weight, 24 h food and water intake, and improved islet histopathology in DM model mice. SB reduced TNF-α, IL-1β, and iNOS, whereas it enhanced the expression of the anti-inflammatory Arg-1 marker on intestinal macrophages and the secretion of anti-inflammatory IL-10. Specifically, SB was linked to a marked drop in the expression of the Th17 marker RORγt and a substantial increase in the expression of the Treg marker Foxp3. SB treatment was associated with significant reductions in the levels of Th17-derived cytokines such as IL-17 and IL-6, whereas anti-inflammatory Treg-derived cytokines such as TGF-β were increased. Additionally, the analysis results from 16S rDNA sequencing suggested that SB significantly reversed the variations in intestinal flora distribution and decreased the relative abundance of Weissella confusa and Anaerotruncus colihominis DSM 17241 at the species level as well as Leuconostocaceae, Streptococcaceae, and Christensenellaceae at the family, genus, and species levels. These distinct florae may serve as a diagnostic biomarker for DM-induced intestinal inflammation. In addition, the heat map of phylum and OTU level revealed a close relationship between DM-induced intestinal inflammation and intestinal microbiota.

Conclusions

The present study suggested that SB may reduce DM-induced intestinal inflammation by regulating the gut microbiota.

Probiotic Lactiplantibacillus plantarum Tana Isolated from an International Weightlifter Enhances Exercise Performance and Promotes Antifatigue Effects in Mice

Exercise causes changes in the gut microbiota, and in turn, the composition of the gut microbiota affects exercise performance. In addition, the supplementation of probiotics is one of the most direct ways to change the gut microbiota. In recent years, the development and application of human-origin probiotics has gradually attracted attention. Therefore, we obtained intestinal Lactiplantibacillus plantarum “Tana” from a gold-medal-winning weightlifter, who has taken part in various international competitions such as the World Championships and the Olympic Games, to investigate the benefits of Tana supplementation for improving exercise performance and promoting antifatigue effects in mice. A total of 40 male Institute of Cancer Research (ICR) mice were divided into four groups (10 mice/group): (1) vehicle (0 CFU/mice/day), (2) Tana-1× (6.15 × 107 CFU/mice/day), (3) Tana-2× (1.23 × 108 CFU /mice/day), and (4) Tana-5× (3.09 × 108 CFU/mice/day). After four weeks of Tana supplementation, we found that the grip strength, endurance exercise performance, and glycogen storage in the liver and muscle were significantly improved compared to those in the vehicle group (p < 0.05). In addition, supplementation with Tana had significant effects on fatigue-related biochemical markers; lactate, ammonia, and blood urea nitrogen (BUN) levels and creatine kinase (CK) activity were significantly lowered (p < 0.05). We also found that the improved exercise performance and antifatigue benefits were significantly dose-dependent on increasing doses of Tana supplementation (p < 0.05), which increased the abundance and ratio of beneficial bacteria in the gut. Taken together, Tana supplementation for four weeks was effective in improving the gut microbiota, thereby enhancing exercise performance, and had antifatigue effects. Furthermore, supplementation did not cause any physiological or histopathological damage.

Oligofructose restores postprandial short-chain fatty acid levels during high-fat feeding

OBJECTIVE

Obesity is associated with consumption of a Western diet low in dietary fiber, while prebiotics reduce body weight. Fiber induces short-chain fatty acid (SCFA) production, and SCFA administration is beneficial to host metabolic homeostasis. However, the role of endogenous SCFA signaling in the development of obesity is contentious. Therefore, the primary objective of this study is to evaluate the postprandial time course of SCFA production and uptake in healthy (chow-fed), Western diet-fed (high-fat diet [HFD]) obese, and oligofructose-treated HFD-fed (HFD + OFS) rats.

METHODS

Male Sprague-Dawley rats were maintained on chow or HFD for 5 weeks, with or without supplementation of 10% OFS for 3 weeks. SCFAs were measured in the ileum, cecum, colon, portal vein, and vena cava at 0, 2, 4, 6, and 8 hours postprandially.

RESULTS

Postprandial cecal and portal vein SCFAs were decreased in obese rats compared with lean chow controls, whereas no differences were observed in fasting SCFA concentrations. OFS supplementation increased SCFA levels in the cecum and portal vein during obesity. Butyrate levels were positively associated with portal glucagon-like peptide 1 and adiposity and with Roseburia relative abundance.

CONCLUSIONS

The current study demonstrates that obesity is associated with reduced SCFA production, and that OFS supplementation increases SCFA levels. Additionally, postprandial butyrate production appears to be beneficial to host energy homeostasis.

Lactobacillus plantarum PL-02 Supplementation Combined With Resistance Training Improved Muscle Mass, Force, and Exercise Performance in Mice

Increasing numbers of researchers are investigating the benefits of probiotics in enhancing exercise performance and verifying the role of the gut–muscle axis. In our previous study, Lactobacillus plantarum PL-02 improved exercise performance and muscle mass. Therefore, the purpose of this study was to investigate whether supplementation with PL-02 combined with resistance training has a synergistic effect on exercise performance and muscle mass. All the animals were assigned into four groups (n = 8/group): a sedentary control with normal distilled water group (vehicle, n = 8); PL-02 supplementation group (PL-02, 2.05 × 10⁹ CFU, n = 8); resistance training group (RT, n = 8); PL-02 supplementation combined with resistance training group (PL-02 + RT, 2.05 × 10⁹ CFU, n = 8). Supplementation with PL-02 for four consecutive weeks combined with resistance exercise training significantly improved the grip strength and the maximum number of crawls; increased the time of exhaustive exercise; significantly reduced the time required for a single climb; and reduced the lactate, blood ammonia, creatine kinase, and blood urea nitrogen produced after exercise (p < 0.05). In addition, it produced substantial benefits for increasing muscle mass without causing any physical damage. In summary, our findings confirmed that PL-02 or RT supplementation alone is effective in improving muscle mass and exercise performance and in reducing exercise fatigue, but the combination of the two can achieve increased benefits.

Targeting gut microbiota-derived butyrate improves hepatic gluconeogenesis through the cAMP-PKA-GCN5 pathway in late pregnant sows

Short chain fatty acids (SCFAs) produced by gut microbiota affected hepatic glucose metabolism via the gut-liver axis. The present study aimed to investigate the effects of butyrate produced by gut microbiota on hepatic gluconeogenesis in late-pregnancy sows. A total of 240 primiparous sows in late pregnancy were tested for blood glucose using a glucose meter before feeding and grouped according to their blood glucose level as follows: 0-3.0 mmol L^-1 (low blood glucose group, LG group) and 3.1-5.0 mmol L^-1 (normal blood glucose group, NG group). Colonic SCFAs and microbiota, SCFAs in the portal vein and liver, and acetylation and phosphorylation levels in the liver samples were analyzed. Hepatocytes from pregnant sows were examined for the effect of butyrate on hepatic glucose gluconeogenesis. In vivo experiments showed that the reproductive performance, serum glucose metabolism index, colonic butyrate and butyrate-producing bacteria decreased in the LG group compared with the NG group. Correlation analysis found a positive correlation among colonic butyrate, butyrate-producing bacteria and the serum glucose metabolism index. Moreover, the hepatic cAMP concentration, PKA activity, GCN5 phosphorylation, and the expression of G6P and PEPCK were decreased and PGC1-α acetylation was increased in the LG group compared with the NG group. In vitro, sodium butyrate significantly stimulated the cAMP concentration, PKA activity, GCN5 phosphorylation, and the expression of G6P and PEPCK and inhibited PGC-1α acetylation in the LG group of hepatocytes from late-pregnancy sows. Interestingly, another in vivo experiment showed that dietary 1-kestose, a natural regulator of gut bacteria, significantly increased butyrate and butyrate-producing bacteria, and improved the reproductive performance and serum glucose metabolism index in late-pregnancy sows. Taken together, we found that targeting gut microbiota-derived butyrate could improve hepatic gluconeogenesis through the cAMP-PKA-GCN5 pathway in late-pregnancy sows.

Changes in gut microbiota, metabolite SCFAs, and GPR43 expression in obese diabetic mice after sleeve gastrectomy

AIMS

To evaluate changes in short-chain fatty acid levels and G protein-coupled receptor 43 expression and distribution in gut microbiota and explore their relationships in obese diabetic mice after sleeve gastrectomy.

METHODS AND RESULTS

Diet-induced obese mice and obese diabetic ob/ob mice were established. Changes in glucose metabolism, lipid metabolism, gut microbiota, metabolite short-chain fatty acids, and G protein-coupled receptor 43 expression were assessed in both models 10 weeks postoperatively. Mice that underwent sleeve gastrectomy exhibited sustained weight loss and reduced glucose, insulin, leptin, and cholesterol levels. Metagenomic sequencing revealed significant characteristic alterations in gut microbiota after sleeve gastrectomy, which were correlated with changes in fecal short-chain fatty acid levels. Postoperatively, G protein-coupled receptor 43 expression in the colon tissue was upregulated in both models, whereas its expression in the adipose tissue was downregulated in the diet-induced obese mouse model.

CONCLUSIONS

Metabolic improvement in obese and diabetic mice after sleeve gastrectomy is associated with alterations in gut microbiota, short-chain fatty acid levels, and G protein-coupled receptor 43 expression.

SIGNIFICANCE AND IMPACT OF STUDY

Our findings reveal a possible mechanism through which sleeve gastrectomy improves obesity and diabetes via changes in bacteria producing short-chain fatty acids and G protein-coupled receptor 43.

Acid-treated high-amylose corn starch suppresses high-fat diet-induced steatosis

Resistant starch (RS) has been reported to improve steatosis as well as obesity. Type 4 resistant starch (RS4), a chemically modified starch, is particularly hard to digest and suggesting higher efficacy. However, because the effects of RS4 on steatosis are not yet fully understood, the effects of RS4 on steatosis were examined using a murine high-fat diet model. Seven-week-old male mice were divided into three groups and fed a normal diet, a high-fat diet (HFD), or a high-fat diet with added RS (HFD + RS). Amylofiber SH^® produced from acid-treated corn starch was used as the dietary RS. At 22 weeks old, hepatic steatosis and short chain fatty acid (SCFA) content and gut microbiota in cecum stool samples were analyzed. The ratio of body weight to 7 weeks was significantly suppressed in the HFD + RS group compared to the HFD group (132.2 ± 1.4% vs. 167.2 ± 3.9%, p = 0.0076). Macroscopic and microscopic steatosis was also suppressed in the HFD + RS group. Analysis of cecum stool samples revealed elevated SCFA levels in the HFD + RS group compared with the HFD group. Metagenome analysis revealed that Bifidobacterium (17.9 ± 1.9% vs. 3.6 ± 0.7%, p = 0.0019) and Lactobacillus (14.8 ± 3.4% vs. 0.72 ± 0.23%, p = 0.0045), which degrade RS to SCFA, were more prevalent in the HFD + RS group than the HFD group. In conclusion, RS4 suppressed steatosis, and increased Bifidobacterium and Lactobacillus, and SCFAs. RS4 may prevent steatosis by modulating the intestinal environment.

Probiotic Strains Isolated from an Olympic Woman’s Weightlifting Gold Medalist Increase Weight Loss and Exercise Performance in a Mouse Model

Obesity is a worldwide health problem. Calorie-restricted diets constitute a common intervention for treating obesity. However, an improper calorie-restricted diet can lead to malnutrition, fatigue, poor concretion, muscle loss, and reduced exercise performance. Probiotics have been introduced as an alternative treatment for obesity. In the present study, we tested the weight loss and exercise performance enhancement effectiveness of probiotic strains of different origins, including four isolated from an Olympic weightlifting gold medalist (Bifidobacterium longum subsp. longum OLP-01, Lactobacillus plantarum PL-02, Lactobacillus salivarius subsp. salicinius SA-03, and Lactococcus lactis subsp. lactis LY-66). A high-fat diet (HFD) was used to induce obesity in 16 groups of mice (n = 8/group). The mice were administered probiotic supplements at a dosage of 4.1 × 10⁹ CFU/kg/day for 10 weeks. All probiotic supplementation groups showed a significant reduction in body weight and fat mass compared with the HFD group. TYCA06, CS-773, BLI-02, PL-02, bv-77, and OLP-01 were the most effective in facilitating weight loss and fat reduction, which may be due to fatty-acid absorbing activity. PL-02, LY-66, TYCA06, CS-773, and OLP-01 elevated the animals’ grip strength and exhaustive running duration. PL-02, LY-66, and OLP-01 increased tissue glycogen (liver and muscle) levels and muscle capillary density and reduced blood lactate production levels after exercise. In conclusion, OLP-01, PL-02, LY-66, TYCA06, and CS-773 were highly effective in enhancing weight loss and exercise performance. This study should be repeated on humans in the future to further confirm the findings.

Gut Microbiota: An Important Player in Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is one of the common metabolic diseases in the world. Due to the rise in morbidity and mortality, it has become a global health problem. To date, T2DM still cannot be cured, and its intervention measures mainly focus on glucose control as well as the prevention and treatment of related complications. Interestingly, the gut microbiota plays an important role in the development of metabolic diseases, especially T2DM. In this review, we introduce the characteristics of the gut microbiota in T2DM population, T2DM animal models, and diabetic complications. In addition, we describe the molecular mechanisms linking host and the gut microbiota in T2DM, including the host molecules that induce gut microbiota dysbiosis, immune and inflammatory responses, and gut microbial metabolites involved in pathogenesis. These findings suggest that we can treat T2DM and its complications by remodeling the gut microbiota through interventions such as drugs, probiotics, prebiotics, fecal microbiota transplantation (FMT) and diets.

Gut microbiota in patients with obesity and metabolic disorders - a systematic review

BACKGROUND

Previous observational studies have demonstrated inconsistent and inconclusive results of changes in the intestinal microbiota in patients with obesity and metabolic disorders. We performed a systematic review to explore evidence for this association across different geography and populations.

METHODS

We performed a systematic search of MEDLINE (OvidSP) and Embase (OvidSP) of articles published from Sept 1, 2010, to July 10, 2021, for case-control studies comparing intestinal microbiome of individuals with obesity and metabolic disorders with the microbiome of non-obese, metabolically healthy individuals (controls). The primary outcome was bacterial taxonomic changes in patients with obesity and metabolic disorders as compared to controls. Taxa were defined as "lean-associated" if they were depleted in patients with obesity and metabolic disorders or negatively associated with abnormal metabolic parameters. Taxa were defined as "obesity-associated" if they were enriched in patients with obesity and metabolic disorders or positively associated with abnormal metabolic parameters.

RESULTS

Among 2390 reports screened, we identified 110 full-text articles and 60 studies were included. Proteobacteria was the most consistently reported obesity-associated phylum. Thirteen, nine, and ten studies, respectively, reported Faecalibacterium, Akkermansia, and Alistipes as lean-associated genera. Prevotella and Ruminococcus were obesity-associated genera in studies from the West but lean-associated in the East. Roseburia and Bifidobacterium were lean-associated genera only in the East, whereas Lactobacillus was an obesity-associated genus in the West.

CONCLUSIONS

We identified specific bacteria associated with obesity and metabolic disorders in western and eastern populations. Mechanistic studies are required to determine whether these microbes are a cause or product of obesity and metabolic disorders.

Epigenetic modifications in pancreas development, diabetes, and therapeutics

A recent International Diabetes Federation report suggests that more than 463 million people between 20 and 79 years have diabetes. Of the 20 million women affected by hyperglycemia during pregnancy, 84% have gestational diabetes. In addition, more than 1.1 million children or adolescents are affected by type 1 diabetes. Factors contributing to the increase in diabetes prevalence are complex and include contributions from genetic, environmental, and epigenetic factors. However, molecular regulatory mechanisms influencing the progression of an individual towards increased susceptibility to metabolic diseases such as diabetes are not fully understood. Recent studies suggest that the pathogenesis of diabetes involves epigenetic changes, resulting in a persistently dysregulated metabolic phenotype. This review summarizes the role of epigenetic mechanisms, mainly DNA methylation and histone modifications, in the development of the pancreas, their contribution to the development of diabetes, and the potential employment of epigenetic modulators in diabetes treatment.

Antidiabetic Effects of Bifidobacterium longum subsp. longum BL21 through Regulating Gut Microbiota Structure in Type 2 Diabetic Mice

Bifidobacterium longum subsp. longum BL21 (BL21) possess hypoglycemic activity, but its anti-diabetic mechanism has rarely been illustrated. In the present work, the effect of BL21 on type 2 diabetes mellitus...

Structure-Based design of Marine-derived Meridianin C derivatives as glycogen synthase kinase 3β inhibitors with improved oral bioavailability: From aminopyrimidyl-indoles to the sulfonyl analogues

Glycogen synthase kinase 3β (GSK-3β) has become an attractive target for the treatment of diabetes. Compound I is an indole-based GSK-3β inhibitor designed from the Meridianin C, a marine natural product (MNP) isolated from Aplidium meridianum. However, this compound has a moderate inhibitory activity toward GSK-3β (IC₅₀ = 24.4 μM), moderate glucose uptake (38%), and especially, a low oral bioavailability (F = 11.4%). In the present study, applying the structure-based design strategy, a series of derivatives modified on the indole moiety were synthesized based on the lead compound I, followed by evaluating their cytotoxic activity, antihyperglycemic activity, and kinase inhibitory activity. Among this series, compound 6x with a sulfonyl group displayed the highest glucose uptake (83.5%) in muscle L6 cells, showing much higher inhibitory activity against GSK-3β (IC₅₀ = 5.25 μM). Molecular docking indicated that compound 6x was properly inserted into the ATP-binding binding pocket of GSK-3β with a higher docking score (-8.145 kcal/mol) compared with that of compound I (-6.950 kcal/mol), interpreting the higher kinase inhibitory activity toward GSK-3β. Remarkably, compound 6x showed favorable drug-like properties, including significantly better oral bioavailability (F = 47.4%) and no two-week acute toxicity at a dose of 1 g/kg. Our findings suggest that these MNP-derived sulfonyl indole derivatives could be used as lead compounds for the development of anti-hyperglycemic drugs.

L-ergothioneine and metformin alleviates liver injury in experimental type-2 diabetic rats via reduction of oxidative stress, inflammation, and hypertriglyceridemia

Type-2 diabetes (T2D) is associated with liver toxicity. L-ergothioneine (L-egt) has been reported to reduce toxicity in tissues exposed to injury, while metformin is commonly prescribed to manage T2D. Hence, this study evaluates the hepatoprotective role of L-egt, with or without metformin, in T2D male rats. A total of 36 adult male Sprague-Dawley rats were randomly divided into non-diabetic (n = 12) and diabetic (n = 24) groups. After induction of diabetes, animals were divided into six groups (n = 6) and treated orally either with deionized water, L-egt (35 mg/kg bodyweight (bwt)), metformin (500 mg/kg bwt), or a combination of L-egt and metformin for 7 weeks. Body weight and blood glucose were monitored during the experiment. Thereafter, animals were euthanized and liver tissue was excised for biochemical, ELISA, real-time quantitative PCR, and histopathological analysis. L-egt with or without metformin reduced liver hypertrophy, liver injury, triglycerides, oxidative stress, and inflammation. Also, L-egt normalized mRNA expression of SREBP-1c, fatty acid synthase, nuclear factor kappa B, transforming growth factor β1, nuclear factor erythroid 2-related factor 2, and sirtuin-1 in diabetic rats. Furthermore, co-administration of L-egt with metformin to diabetic rats reduced blood glucose and insulin resistance. These results provide support to the therapeutic benefits of L-egt in the management of liver complications associated with T2D.

Curcumin ameliorates hypertension via gut-brain communication in spontaneously hypertensive rat

Gut dysbiosis and dysregulation of gut-brain communication have been identified in hypertensive patients and animal models. Previous studies have shown that probiotic or prebiotic treatments exert positive effects on the pathophysiology of hypertension. This study aimed to examine the hypothesis that the microbiota-gut-brain axis is involved in the antihypertensive effects of curcumin, a potential prebiotic obtained from Curcuma longa. Male 8- to 10-week-old spontaneously hypertensive rats (SHRs) and Wistar Kyoto (WKY) rats were divided into four groups: WKY rats and SHRs treated with vehicle and SHRs treated with curcumin in dosage of 100 or 300 mg/kg/day for 12 weeks. Our results show that the elevated blood pressure of SHRs was markedly decreased in both curcumin-treated groups. Curcumin treatment also altered the gut microbial composition and improved intestinal pathology and integrity. These factors were associated with reduced neuroinflammation and oxidative stress in the hypothalamus paraventricular nucleus (PVN). Moreover, curcumin treatment increased butyrate levels in the plasma, which may be the result of increased butyrate-producing gut microorganisms. In addition, curcumin treatment also activated G protein-coupled receptor 43 (GPR 43) in the PVN. These results indicate that curcumin reshapes the composition of the gut microbiota and ameliorates the dysregulation of the gut-brain communication to induce antihypertensive effects.

Butyrate ameliorates skeletal muscle atrophy in diabetic nephropathy by enhancing gut barrier function and FFA2-mediated PI3K/Akt/mTOR signals

BACKGROUND AND PURPOSE

Muscle protein catabolism in patients with diabetic nephropathy (DN) results in striking loss of muscle proteins, which increases morbidity and mortality risks. Evidence shows that short-chain fatty acids (SCFAs) play an important role in health maintenance and disease development. Recently, the connection between butyrate (a SCFA) and DN has been revealed, although the relationship between butyrate and muscle atrophy remains unclear.

EXPERIMENTAL APPROACH

We studied changes in serum butyrate levels in DN patients using metabolomic analyses. In db/db mice, protective effects of butyrate on DN-induced muscle atrophy. were explored. Inhibition of muscle atrophy by butyrate and the underlying mechanism(s) were studied in C2C12 cells exposed to high glucose/lipopolysaccharide (HG/LPS).

KEY RESULTS

Butyrate levels in DN patients were significantly decreased. In db/db mice, supplementing normal diet with butyrate improved intestinal barrier function. Concurrently, butyrate alleviated muscle atrophy, promoted PI3K/Akt/mTOR signalling, and suppressed oxidative stress and autophagy in skeletal muscle of db/db mice, and in HG/LPS-exposed C2C12 cells. Further, FFA2 receptors, key components of SCFA signalling, were decreased in skeletal muscle of db/db mice and in HG/LPS-exposed C2C12 cells. Overexpression of FFA2 receptors activated PI3K/Akt/mTOR signalling and inhibited oxidative stress and autophagy in HG/LPS-exposed C2C12 cells. Silencing of FFA2 blocked PI3K/Akt/mTOR signalling that was improved by butyrate, as well as the suppression of oxidative stress and reduction of autophagy.

CONCLUSION AND IMPLICATION

Butyrate exerts protective effects on muscle atrophy induced by DN by enhancing intestinal barrier function and activating the FFA2 receptor-mediated PI3K/Akt/mTOR pathway.

Antidiabetic effect of konjac glucomannan via insulin signaling pathway regulation in high-fat diet and streptozotocin-induced diabetic rats

Type 2 diabetes mellitus is a chronic metabolic disorder that tends to disarray various metabolic pathways. Dietary-mediated T2DM prevention garners much attention in recent decades. Hence, this study was intended to elucidate the antidiabetic properties of Konjac glucomannan (KGM) in diabetic rats. Our experimental design includes five groups, with six rats in each group. Group 1 feeding standard diet pallet alone served as control rats; group 2 was KGM control rats administered intragastrically with KGM (120 mg/kg b.w.). Group 3 was developed as diabetic rats with a high-fat diet and an intraperitoneal injection of Streptozotocin-40 mg/kg b.w. Group 4 were diabetic rats treated with KGM (80 mg/kg b.w.), and group 5 were diabetic rats received rosiglitazone treatment (4 mg/kg b.w.). The results showed that STZ-induced diabetic rats significantly elevate liver marker enzymes and gluconeogenesis enzymes. Diminished glycolytic enzymes, liver glycogen, insulin signaling genes, and proteins were also seen in diabetic rats. Treatment with KGM augmented glycolytic enzymes and liver glycogen. On the other hand, KGM diminished gluconeogenesis, liver marker enzymes, upregulated gene, and protein expression of the insulin pathway. The current results suggest dietary KGM can offer a better health benefit in the treatment of T2DM.

Effectiveness of human-origin Lactobacillus plantarum PL-02 in improving muscle mass, exercise performance and anti-fatigue

Gut microbiota is very important for energy metabolism and regulation, which in turn affect the health and physiological functions of the host, and provide energy required for exercise. Supplementation with probiotics may be one of the ways to change the gut microbiota. In recent years, many studies have shown that probiotic supplementation can effectively improve sports performance. In this study, we screened Lactobacillus plantarum (PL-02), a probiotic of human-origin, from the intestines of 2008 Olympic women's 48 kg weightlifting gold medalist and explored the role of PL-02 in improved exercise endurance performance, reduced fatigue biochemical parameters, and changes in body composition. Male Institute of Cancer Research (ICR) mice were assigned to 0, 2.05 × 109, 4.10 × 109 and 1.03 × 1010 CFU/kg/day groups and were fed by oral gavage once daily for 4 weeks. The results showed that 4 weeks of PL-02 supplementation could significantly increase muscle mass, muscle strength and endurance performance, and hepatic and muscular glycogen storage. Furthermore, PL-02 could significantly decrease lactate, blood urea nitrogen (BUN), ammonia, and creatine kinase (CK) levels after exercise (p < 0.05). We believe that PL-02 can be used as a supplement to improve exercise performance and for its anti-fatigue effect.

Melatonin ameliorates endocrine dysfunction and defective sperm integrity associated with high-fat diet-induced obesity in male Wistar rats

Obesity (OBS) has been established as a link to male hypogonadism with consequent infertility. Previous studies have shown that melatonin (MEL) modulates hypothalamic-pituitary-gonadal function. The present study therefore investigated the hypothesis that MEL supplementation would attenuate spermatogenic and steroidogenic dysfunctions associated with obesity induced by high-fat diet (HFD). Twenty-four adult male Wistar rats (n = 6/group) were used: control group received vehicle (normal saline), obese group received 40% high-fat diet and distilled water, MEL-treated group received MEL (4 mg/kg), and OBS + MEL group received MEL and 40% HFD and the treatment lasted for 12 weeks. HFD caused increased body weight, glucose intolerance, plasma triglyceride and low-density lipoprotein cholesterol/ very low-density lipoprotein cholesterol and malondialdehyde, as well as decreased antioxidant capacity, high-density lipoprotein cholesterol, gonadotrophin-releasing hormone, follicle-stimulating hormone and testosterone and altered sperm parameters. However, all these alterations were attenuated when supplemented with MEL. Taken together, these results indicate that HFD exposure causes endocrine dysfunction and disrupted sperm parameters in obese animals, which are accompanied by lipid peroxidation/defective antioxidant capacity. In addition, the present results suggest that melatonin supplementation restores endocrine function and sperm integrity in obese rat model by suppression of oxidative stress-dependent mechanism.

Inhibitory effects of Humulus japonicus extract against hepatic injury in a diabetic rat model

Chronic diabetes mellitus (DM) can cause liver dysfunction and other complications. As Humulus japonicus is known to have anti-inflammatory and antioxidative effects, we sought to evaluate the hepatoprotective effect of H. japonicus extract (HJE) on a DM model. HJE reduced aspartate aminotransferase, alanine aminotransferase, and direct bilirubin levels and restored albumin activities relative to those found in the DM model. The abnormal levels of triglyceride, total cholesterol, high-density lipoprotein, and low-density lipoprotein in DM returned to normal levels after HJE treatment. DM-induced inflammation of the liver was ameliorated by HJE through reduction of tumor necrosis factor-α, interleukin-1β, and cyclooxygenase-2 levels. HJE treatment downregulated malondialdehyde levels that were increased by DM. However, the downregulated superoxide dismutase and glutathione levels in DM were increased by HJE. Histological studies showed that HJE improves the liver tissue damage caused by DM. Collectively, our findings suggest that HJE may improve liver damage in DM and exhibit an inhibitory effect on hepatic injury through its anti-inflammatory and antioxidative actions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-021-00924-w.

Aqueous Blackcurrant Extract Improves Insulin Sensitivity and Secretion and Modulates the Gut Microbiome in Non-Obese Type 2 Diabetic Rats

This study was undertaken to determine whether aqueous blackcurrant extracts (BC) improve glucose metabolism and gut microbiomes in non-obese type 2 diabetic animals fed a high-fat diet and to identify the mechanism involved. Partially pancreatectomized male Sprague–Dawley rats were provided a high-fat diet containing 0% (control), 0.2% (L-BC; low dosage), 0.6% (M-BC; medium dosage), and 1.8% (H-BC; high dosage) blackcurrant extracts; 0.2% metformin (positive-C); plus 1.8%, 1.6%, 1.2%, 0%, and 1.6% dextrin, specifically indigestible dextrin, daily for 8 weeks. Daily blackcurrant extract intakes were equivalent to 100, 300, and 900 mg/kg body weight (bw). After a 2 g glucose or maltose/kg bw challenge, serum glucose and insulin concentrations during peak and final states were obviously lower in the M-BC and H-BC groups than in the control group (p < 0.05). Intraperitoneal insulin tolerance testing showed that M-BC and H-BC improved insulin resistance. Hepatic triglyceride deposition, TNF-α expression, and malondialdehyde contents were lower in the M-BC and H-BC groups than in the control group. Improvements in insulin resistance in the M-BC and H-BC groups were associated with reduced inflammation and oxidative stress (p < 0.05). Hyperglycemic clamp testing showed that insulin secretion capacity increased in the acute phase (2 to 10 min) in the M-BC and H-BC groups and that insulin sensitivity in the hyperglycemic state was greater in these groups than in the control group (p < 0.05). Pancreatic β-cell mass was greater in the M-BC, H-BC, and positive-C groups than in the control group. Furthermore, β-cell proliferation appeared to be elevated and apoptosis was suppressed in these three groups (p < 0.05). Serum propionate and butyrate concentrations were higher in the M-BC and H-BC groups than in the control group. BC dose-dependently increased α-diversity of the gut microbiota and predicted the enhancement of oxidative phosphorylation-related microbiome genes and downregulation of carbohydrate digestion and absorption-related genes, as determined by PICRUSt2 analysis. In conclusion, BC enhanced insulin sensitivity and glucose-stimulated insulin secretion, which improved glucose homeostasis, and these improvements were associated with an incremental increase of the α-diversity of gut microbiota and suppressed inflammation and oxidative stress.

Metabolic profiles of oligosaccharides derived from four microbial polysaccharides by faecal inocula from type 2 diabetes patients

In vitro digestion of curdlan oligosaccharides (COSs), pullulan oligosaccharides (POSs), xanthan gum oligosaccharides (XGOSs) and gellan gum oligosaccharides (GGOSs) was investigated. These four oligosaccharides showed resistance to simulated saliva and gastric and small intestinal fluid. In further fermentation with faecal microbiota from healthy subjects and type 2 diabetes (T2D) patients, COS fermentation significantly increased the abundance of Bifidobacterium spp. and Lactobacillus spp. and the production of short-chain fatty acids in healthy and T2D groups. Digestion of XGOS enhanced the growth of the Clostridium leptum subgroup and significantly increased butyric acid production in healthy and T2D groups. Sole fermentation with COS, POS, XGOS and GGOS exhibited different metabolic profiles between healthy and T2D groups, and more small molecule polyols were produced in the T2D group than in the healthy group. This study provides a novel perspective on the reconstruction of gut microbiota and metabolism by POS, COS, GGOS and XGOS intervention.

Total flavonoids of Astragalus Ameliorated Bile Acid Metabolism Dysfunction in Diabetes Mellitus

Astragalus Radix is one of the common traditional Chinese medicines used to treat diabetes. However, the underlying mechanism is not fully understood. Flavones are a class of active components that have been reported to exert various activities. Existing evidence suggests that flavones from Astragalus Radix may be pivotal in modulating progression of diabetes. In this study, total flavones from Astragalus Radix (TFA) were studied to observe its effects on metabolism of bile acids both in vivo and in vitro. C57BL/6J mice were treated with STZ and high-fat feeding to construct diabetic model, and HepG2 cell line was applied to investigate the influence of TFA on liver cells. We found a serious disturbance of bile acids and lipid metabolism in diabetic mice, and oral administration or cell incubation with TFA significantly reduced the production of total cholesterol (TCHO), total triglyceride, glutamic oxalacetic transaminase (AST), glutamic-pyruvic transaminase (ALT), and low-density lipoprotein (LDL-C), while it increased the level of high-density lipoprotein (HDL-C). The expression of glucose transporter 2 (GLUT2) and cholesterol 7α-hydroxylase (CYP7A1) was significantly upregulated on TFA treatment, and FXR and TGR5 play pivotal role in modulating bile acid and lipid metabolism. This study supplied a novel understanding towards the mechanism of Astragalus Radix on controlling diabetes.

Liver proteomics analysis reveals abnormal metabolism of bile acid and arachidonic acid in Chinese hamsters with type 2 diabetes mellitus

Non-obese, spontaneous, and genetically predisposed type 2 diabetic Chinese hamsters exhibit metabolic abnormalities similar to those observed in human T2DM. Here, tandem mass tag (TMT)-based quantitative proteomics technology was used to screen and identify differentially abundant proteins in the liver that are associated with diabetes in Chinese hamsters. GO and KEGG pathway enrichment analysis were conducted to validate the findings, as well as qRT-PCR and western blotting. In total, 103 proteins were identified in the livers of diabetic hamsters, of which 48 were up-regulated and 55 were down-regulated. KEGG pathway enrichment analysis further demonstrated that linoleic acid metabolism, arachidonic acid metabolism, bile secretion, and other pathways were affected. Moreover, AQP9 and EPHX1 were significantly down-regulated in the bile secretion pathway, whereas PTGES2, Cyp2c27, and Cyp2c70 were associated with the arachidonic acid metabolic pathway. Serum levels of bile acid (BA) and arachidonic acid (AA) in diabetic Chinese hamsters were significantly higher than those in control hamsters. Cumulatively, our findings indicate that the five candidate proteins may be associated with abnormal BA and AA metabolism, suggesting their involvement in pathological changes in the livers of Chinese hamsters with T2DM. SIGNIFICANCE: The liver proteomics of Chinese hamsters describes differentially abundant proteins associated with T2DM, while promoting this animal model as an appropriate and ideal platform for investigating underlying molecular mechanisms of T2DM. This study reveals abnormal bile acid and arachidonic acid metabolism in T2DM hamsters, which may provide insights for studying the relationship between candidate proteins and KEGG pathways to elucidate the underlying molecular mechanism associated with T2DM.