Lactobacillus rhamnosus NCDC17 ameliorates type-2 diabetes by improving gut function, oxidative stress and inflammation in high-fat-diet fed and streptozotocintreated rats

Restoration of gut dysbiosis through Clostridium butyricum and magnesium possibly balance blood glucose levels: an experimental study

Diabetes mellitus (DM) is a chronic metabolic disorder characterized by an elevated level of blood glucose due to the absence of insulin secretion, ineffectiveness, or lack of uptake of secreted insulin in the body. The improperly diagnosed and poorly managed DM can cause severe damage to organs in the body like the nerves, eyes, heart, and kidneys. This study was aimed at investigating the effect of Clostridium butyricum (probiotic) with magnesium supplementation to evaluate the effect on gut microbial dysbiosis and blood glucose levels. In the laboratory, 6-8 weeks old 24 male albino rats weighing 200-250 g were given free access to water and food. Diabetes was induced using streptozotocin (60 mg/kg) in overnight fasted rats. Diabetic rats were randomly divided into four groups (n = 6, 6 replicates in each group). Metformin (100 mg/kg/day) with a standard basal diet was provided to control group (G0), Clostridium butyricum (1.5 × 105 CFU/day) with standard basal diet was provided to treatment group (G1), magnesium (500 mg/kg/day) was provided to group (G2). Clostridium butyricum (1.5 × 105 CFU/day) and magnesium (300 mg/kg/day) in combination with a standard basal diet was provided to group (G3). Blood Glucose, Magnesium blood test and microbial assay were done. Random blood glucose levels were monitored twice a week for 21 days and were represented as mean of each week. The results conclude that Clostridium butyricum (1.5 × 105 CFU) is very effective in balancing random blood glucose levels from 206.6 ± 67.7 to 85.1 ± 3.8 (p = 0.006) compared to other groups (p > 0.005). The results of stool analysis showed that Clostridium butyricum as probiotic restores microbial dysbiosis as evident by the 105 CFU Clostridium butyricum load in G1, which was higher than G0, G2 and G3 which were 103 and 104 CFU respectively. The findings of this study conclude that Clostridium butyricum supplementation improved blood glucose levels and intestinal bacterial load in type II diabetes mellitus.

Gut microbiota and type 2 diabetes mellitus: a focus on the gut-brain axis

Type 2 diabetes mellitus (T2DM) has become one of the most serious public healthcare challenges, contributing to increased mortality and disability. In the past decades, significant progress has been made in understanding the pathogenesis of T2DM. Mounting evidence suggested that gut microbiota (GM) plays a significant role in the development of T2DM. Communication between the GM and the brain is a complex bidirectional connection, known as the "gut-brain axis," via the nervous, neuroendocrine, and immune systems. Gut-brain axis has an essential impact on various physiological processes, including glucose metabolism, food intake, gut motility, etc. In this review, we provide an outline of the gut-brain axis. We also highlight how the dysbiosis of the gut-brain axis affects glucose homeostasis and even results in T2DM.

Probiotic-fermented edible herbs as functional foods: A review of current status, challenges, and strategies

Recently, consumers have become increasingly interested in natural, health-promoting, and chronic disease-preventing medicine and food homology (MFH). There has been accumulating evidence that many herbal medicines, including MFH, are biologically active due to their biotransformation through the intestinal microbiota. The emphasis of scientific investigation has moved from the functionally active role of MFH to the more subtle role of biotransformation of the active ingredients in probiotic-fermented MFH and their health benefits. This review provides an overview of the current status of research on probiotic-fermented MFH. Probiotics degrade toxins and anti-nutritional factors in MFH, improve the flavor of MFH, and increase its bioactive components through their transformative effects. Moreover, MFH can provide a material base for the growth of probiotics and promote the production of their metabolites. In addition, the health benefits of probiotic-fermented MFH in recent years, including antimicrobial, antioxidant, anti-inflammatory, anti-neurodegenerative, skin-protective, and gut microbiome-modulating effects, are summarized, and the health risks associated with them are also described. Finally, the future development of probiotic-fermented MFH is prospected in combination with modern development technologies, such as high-throughput screening technology, synthetic biology technology, and database construction technology. Overall, probiotic-fermented MFH has the potential to be used in functional food for preventing and improving people's health. In the future, personalized functional foods can be expected based on synthetic biology technology and a database on the functional role of probiotic-fermented MFH.

Integrated Analysis of the Transcriptome and Microbial Diversity in the Intestine of Miniature Pig Obesity Model

Obesity, a key contributor to metabolic disorders, necessitates an in-depth understanding of its pathogenesis and prerequisites for prevention. Guangxi Bama miniature pig (GBM) offers an apt model for obesity-related studies. In this research, we used transcriptomics and 16S rRNA gene sequencing to discern the differentially expressed genes (DEGs) within intestinal (jejunum, ileum, and colon) tissues and variations in microbial communities in intestinal contents of GBM subjected to normal diets (ND) and high-fat, high-carbohydrate diets (HFHCD). After a feeding duration of 26 weeks, the HFHCD-fed experimental group demonstrated notable increases in backfat thickness, BMI, abnormal blood glucose metabolism, and blood lipid levels alongside the escalated serum expression of pro-inflammatory factors and a marked decline in intestinal health status when compared to the ND group. Transcriptomic analysis revealed a total of 1669 DEGs, of which 27 had similar differences in three intestinal segments across different groups, including five immune related genes: COL6A6, CYP1A1, EIF2AK2, NMI, and LGALS3B. Further, we found significant changes in the microbiota composition, with a significant decrease in beneficial bacterial populations within the HFHCD group. Finally, the results of integrated analysis of microbial diversity with transcriptomics show a positive link between certain microbial abundance (Solibacillus, norank_f__Saccharimonadaceae, Candidatus_Saccharimonas, and unclassified_f__Butyricicoccaceae) and changes in gene expression (COL6A6 and NMI). Overall, HFHCD appears to co-contribute to the initiation and progression of obesity in GBM by aggravating inflammatory responses, disrupting immune homeostasis, and creating imbalances in intestinal flora.

Deciphering the Role of the Gut Microbiota in Exposure to Emerging Contaminants and Diabetes: A Review

Emerging pollutants, a category of compounds currently not regulated or inadequately regulated by law, have recently become a focal point of research due to their potential toxic effects on human health. The gut microbiota plays a pivotal role in human health; it is particularly susceptible to disruption and alteration upon exposure to a range of toxic environmental chemicals, including emerging contaminants. The disturbance of the gut microbiome caused by environmental pollutants may represent a mechanism through which environmental chemicals exert their toxic effects, a mechanism that is garnering increasing attention. However, the discussion on the toxic link between emerging pollutants and glucose metabolism remains insufficiently explored. This review aims to establish a connection between emerging pollutants and glucose metabolism through the gut microbiota, delving into the toxic impacts of these pollutants on glucose metabolism and the potential role played by the gut microbiota.

Crosstalk between glucagon-like peptide 1 and gut microbiota in metabolic diseases

Gut microbiota exert influence on gastrointestinal mucosal permeability, bile acid metabolism, short-chain fatty acid synthesis, dietary fiber fermentation, and farnesoid X receptor/Takeda G protein-coupled receptor 5 (TGR5) signal transduction. The incretin glucagon-like peptide 1 (GLP-1) is mainly produced by L cells in the gut and regulates postprandial blood glucose. Changes in gut microbiota composition and function have been observed in obesity and type 2 diabetes (T2D). Meanwhile, the function and rhythm of GLP-1 have also been affected in subjects with obesity or T2D. Therefore, it is necessary to discuss the link between the gut microbiome and GLP-1. In this review, we describe the interaction between GLP-1 and the gut microbiota in metabolic diseases. On the one hand, gut microbiota metabolites stimulate GLP-1 secretion, and gut microbiota affect GLP-1 function and rhythm. On the other hand, the mechanism of action of GLP-1 on gut microbiota involves the inflammatory response. Additionally, we discuss the effects and mechanism of various interventions, such as prebiotics, probiotics, antidiabetic drugs, and bariatric surgery, on the crosstalk between gut microbiota and GLP-1. Finally, we stress that gut microbiota can be used as a target for metabolic diseases, and the clinical application of GLP-1 receptor agonists should be individualized.

Advancing lifelong precision medicine for cardiovascular diseases through gut microbiota modulation

The gut microbiome is known as the tenth system of the human body that plays a vital role in the intersection between health and disease. The considerable inter-individual variability in gut microbiota poses both challenges and great prospects in promoting precision medicine in cardiovascular diseases (CVDs). In this review, based on the development, evolution, and influencing factors of gut microbiota in a full life circle, we summarized the recent advances on the characteristic alteration in gut microbiota in CVDs throughout different life stages, and depicted their pathological links in mechanism, as well as the highlight achievements of targeting gut microbiota in CVDs prevention, diagnosis and treatment. Personalized strategies could be tailored according to gut microbiota characteristics in different life stages, including gut microbiota-blood metabolites combined prediction and diagnosis, dietary interventions, lifestyle improvements, probiotic or prebiotic supplements. However, to fulfill the promise of a lifelong cardiovascular health, more mechanism studies should progress from correlation to causality and decipher novel mechanisms linking specific microbes and CVDs. It is also promising to use the burgeoning artificial intelligence and machine learning to target gut microbiota for developing diagnosis system and screening for new therapeutic interventions.

The Intervention of Probiotics on Type 2 Diabetes Mellitus in Animal Models

Type 2 diabetes accounts for more than 90% of diabetes patients with the incidence and prevalence continuously rising globally. As a prospective therapy strategy for type 2 diabetes, probiotics have shown beneficial effects both in animal experiments and human clinical trials. This review summarizes the commonly used animal models in probiotic intervention research and presents the evidence and mechanism of diabetes intervention with probiotics in these animal models. Probiotics can help maintain glucose homeostasis, improve lipid metabolism, promote the production of short-chain fatty acids, and reduce inflammatory reactions in animal models. However, the clinical translation of benefits from probiotics is still challenged by intrinsic differences between experimental animal models and humans, and the application of humanized non-rodent diabetic animal models may contribute to the clinical translation of probiotics in the future.

Integrated 16S rRNA sequencing and nontargeted metabolomics analysis to reveal the mechanisms of Yu-Ye Tang on type 2 diabetes mellitus rats

Introduction

Yu-Ye Tang (YYT) is a classical formula widely used in treatment of type 2 diabetes mellitus (T2DM). However, the specific mechanism of YYT in treating T2DM is not clear.

Methods

The aim of this study was to investigate the therapeutic effect of YYT on T2DM by establishing a rat model of T2DM. The mechanism of action of YYT was also explored through investigating gut microbiota and serum metabolites.

Results

The results indicated YYT had significant therapeutic effects on T2DM. Moreover, YYT could increase the abundance of Lactobacillus, Candidatus_Saccharimonas, UCG-005, Bacteroides and Blautia while decrease the abundance of and Allobaculum and Desulfovibrio in gut microbiota of T2DM rats. Nontargeted metabolomics analysis showed YYT treatment could regulate arachidonic acid metabolism, alanine, aspartate and glutamate metabolism, arginine and proline metabolism, glycerophospholipid metabolism, pentose and glucuronate interconversions, phenylalanine metabolism, steroid hormone biosynthesis, terpenoid backbone biosynthesis, tryptophan metabolism, and tyrosine metabolism in T2DM rats.

Discussion

In conclusion, our research showed that YYT has a wide range of therapeutic effects on T2DM rats, including antioxidative and anti-inflammatory effects. Furthermore, YYT corrected the altered gut microbiota and serum metabolites in T2DM rats. This study suggests that YYT may have a therapeutic impact on T2DM by regulating gut microbiota and modulating tryptophan and glycerophospholipid metabolism, which are potential key pathways in treating T2DM.

The Influence of Gut Microbial Species on Diabetes Mellitus

Diabetes mellitus (DM) is a metabolic disorder with an alarming incidence rate and a considerable burden on the patient's life and health care providers. An increase in blood glucose level and insulin resistance characterizes it. Internal and external factors such as urbanization, obesity, and genetic mutations could increase the risk of DM. Microbes in the gut influence overall health through immunity and nutrition. Recently, more studies have been conducted to evaluate and estimate the role of the gut microbiome in diabetes development, progression, and management. This review summarizes the current knowledge addressing three main bacterial species: Bifidobacterium adolescentis, Bifidobacterium bifidum, and Lactobacillus rhamnosus and their influence on diabetes and its underlying molecular mechanisms. Most studies illustrate that using those bacterial species positively reduces blood glucose levels and activates inflammatory markers. Additionally, we reported the relationship between those bacterial species and metformin, one of the commonly used antidiabetic drugs. Overall, more research is needed to understand the influence of the gut microbiome on the development of diabetes. Furthermore, more efforts are required to standardize the model used, concentration ranges, and interpretation tools to advance the field further.

Psidium cattleianum fruit extract prevents systemic alterations in an animal model of type 2 diabetes mellitus: comparison with metformin effects

Objective: In this study, we aimed to determine the role of Psidium cattleianum extract (PCE) and compare its effects with those of metformin (Met) in an animal model with type 2 diabetes mellitus (T2DM).Methods: T2DM was induced in rats using a high-fat diet (HFD), followed by a single dose of streptozotocin (STZ). Met and PCE were administered intragastrically once a day throughout the experiment, and their effects on biochemical, inflammatory, oxidative, and histological parameters were evaluated.Results: Met and PCE prevented the increase in serum levels of glucose, total cholesterol (TC), triacylglycerol (TG), very low-density lipoprotein (VLDL) and interleukin-6 (IL-6) induced by T2DM, and restored redox homeostasis in the liver and brain. Met increased the serum levels of anti-inflammatory cytokine and interleukin-10 (IL-10). Furthermore, both treatments restored the liver and pancreas from marked cellular disorganisation, vacuolisation, and necrosis, with PCE being more effective than Met in recovering histological changes.Conclusion: PCE is a promising agent for the prevention of T2DM complications.

Gut microbiota and bile acids partially mediate the improvement of fibroblast growth factor 21 on methionine-choline-deficient diet-induced non-alcoholic fatty liver disease mice

Non-alcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis, inflammation, and fibrosis, as well as gut dysbiosis. Fibroblast growth factor 21 (FGF21), which regulates glucose and lipid metabolism, has been proven to have a good effect on NAFLD. However, the modulating process between FGF21 and gut microbiota remains unclear in treating NAFLD. Here, the fecal microbiota composition of 30 patients with NAFLD who had undergone liver biopsy and 29 matched healthy participants were studied, together with the fecal bile acid (BA) profile. Treatment with FGF21 was given in methionine-choline-deficient (MCD) diet-induced NAFLD model C57BL/6 mice. An antibiotic cocktail and fecal microbiota transplantation were used to further confirm the benefits of FGF21 that were partially attributable to the change in gut microbiota. Patients with NAFLD had higher serum FGF21 levels and dysregulated fecal microbiota compositions and fecal BA profiles. In NAFLD mice, FGF21 significantly reduced steatohepatitis and collagen deposition in vivo and restored intestinal structure. FGF21 treatment also changed gut microbiota composition and regulated dysbiosis in BA metabolism. After treatment with an antibiotic cocktail, FGF21 partially alleviated hepatic and intestinal damage in NAFLD mice. Furthermore, fecal microbiota transplantation from FGF21-treated mice showed benefits similar to FGF21 therapy. The improvement using FGF21 in MCD diet-induced NAFLD mice is partially mediated via gut microbiota and BA. Gut microbiota-regulated BA metabolism may be a potential target of FGF21 in improving NAFLD.

Phenolic, flavonoid, and β-carotene contents of provitamin A cassava hydrolysate with free and encapsulated Lactobacillus rhamnosus GG improves antioxidant biomarkers in kidney, heart and liver of Wistar rats

In vitro antioxidant activity and possible in vivo antioxidative effects of provitamin A cassava hydrolysate inoculated with free or encapsulated Lactobacillus rhamnosus GG (LGG), a ready-to-drink probiotic beverage containing natural β-carotene and other phytochemicals, were evaluated. Provitamin A cassava was orally administered to male Wistar rats (n = 40, 120-150 g) for 30 days. Regression analysis showed the phenolic and total flavonoid contents of provitamin A cassava hydrolysate contributed 68% and 95%, respectively, to the antioxidant activity (by 1,1-diphenyl-2-picrylhydrazyl assay) (83.3 ± 1.8-87 ± 1.8%). in vivo study showed that malondialdehyde and superoxide dismutase activities were lowered or unchanged with a significant increase in antioxidant biomarkers (reduced glutathione, glutathione-S-transferase, and glutathione peroxidase) in the kidney, heart, and liver of all rats administered provitamin A cassava hydrolysate with LGG, especially at doses 2 × 10¹⁰ CFU, compared to control. Provitamin A cassava hydrolysate with LGG showed significant antioxidant activity In vitro and in vivo, thus indicating its potential usefulness in the food industry as an antioxidant beverage. PRACTICAL APPLICATION: This study reports the antioxidant properties of provitamin A cassava hydrolysate, which can be consumed as a refreshing beverage while also delivering antioxidant benefits. In the food and beverage industry, provitamin A cassava hydrolysate could be applied as a nutraceutical beverage with therapeutic functions. This product innovation increases the value-addition of cassava and expands the nondairy food matrix options used as probiotic carriers.

Pharmacomicrobiomics and type 2 diabetes mellitus: A novel perspective towards possible treatment

Type 2 diabetes mellitus (T2DM), a major driver of mortality worldwide, is more likely to develop other cardiometabolic risk factors, ultimately leading to diabetes-related mortality. Although a set of measures including lifestyle intervention and antidiabetic drugs have been proposed to manage T2DM, problems associated with potential side-effects and drug resistance are still unresolved. Pharmacomicrobiomics is an emerging field that investigates the interactions between the gut microbiome and drug response variability or drug toxicity. In recent years, increasing evidence supports that the gut microbiome, as the second genome, can serve as an attractive target for improving drug efficacy and safety by manipulating its composition. In this review, we outline the different composition of gut microbiome in T2DM and highlight how these microbiomes actually play a vital role in its development. Furthermore, we also investigate current state-of-the-art knowledge on pharmacomicrobiomics and microbiome's role in modulating the response to antidiabetic drugs, as well as provide innovative potential personalized treatments, including approaches for predicting response to treatment and for modulating the microbiome to improve drug efficacy or reduce drug toxicity.

Impact of gut-peripheral nervous system axis on the development of diabetic neuropathy

Diabetes is a chronic metabolic disease caused by a reduction in the production and/or action of insulin, with consequent development of hyperglycemia. Diabetic patients, especially those who develop neuropathy, presented dysbiosis, with an increase in the proportion of pathogenic bacteria and a decrease in the butyrate-producing bacteria. Due to this dysbiosis, diabetic patients presented a weakness of the intestinal permeability barrier and high bacterial product translocation to the bloodstream, in parallel to a high circulating levels of pro-inflammatory cytokines such as TNF-α. In this context, we propose here that dysbiosis-induced increased systemic levels of bacterial products, like lipopolysaccharide (LPS), leads to an increase in the production of pro-inflammatory cytokines, including TNF-α, by Schwann cells and spinal cord of diabetics, being crucial for the development of neuropathy.

Milk Fermented with Pediococcus acidilactici Strain BE Improves High Blood Glucose Levels and Pancreatic Beta-Cell Function in Diabetic Rats

This study evaluated the effects of milk fermented with Pediococcus acidilactici strain BE and Pediococcus pentosaceus strain M103 on diabetes in rats (Rattus norvegicus). The bacteria were separately used as starter cultures for milk fermentation, and the products were then fed to diabetic rats for 15 days. Blood glucose levels, immunohistochemical and histological indicators, lipid profiles, and total lactic acid bacterium counts were evaluated before and after treatment. The administration of milk fermented with P. acidilactici strain BE reduced blood glucose levels from 410.27±51.60 to 304.07±9.88 mg/dL (p<0.05), similar to the effects of metformin (from 382.30±13.39 mg/dL to 253.33±40.66 mg/dL, p<0.05). Increased insulin production was observed in diabetic rats fed milk fermented with P. acidilactici strain BE concomitant with an increased number and percentage area of immunoreactive beta-cells. The structure of insulin-producing beta-cells was improved in diabetic rats fed milk fermented with P. acidilactici strain BE or metformin (insulin receptor substrate scores of 5.33±0.94 and 3.5±0.5, respectively). This suggests that the administration of milk fermented with P. acidilactici BE potentially reduces blood glucose levels and improves pancreatic beta-cell function in diabetic rats.

The probiotic Bacillus subtilis BS50 decreases gastrointestinal symptoms in healthy adults: a randomized, double-blind, placebo-controlled trial

ABSTRACT

Durable spore-forming probiotics are increasingly formulated into foods, beverages, and dietary supplements. To help meet this demand, the safety and efficacy of daily supplementation of Bacillus subtilis BS50 for 6 weeks was investigated in a randomized, double-blind, placebo-controlled, parallel clinical trial of 76 healthy adults. Before and during supplementation, gastrointestinal symptoms were recorded daily using a multi-symptom questionnaire. Clinical chemistry, hematology, plasma lipids, and intestinal permeability and inflammation markers were measured at baseline and end of study. Compared to placebo, 2 × 10⁹ colony-forming units (CFU) BS50 per day increased the proportion of participants showing improvement from baseline to week 6 in the composite score for bloating, burping, and flatulence (47.4% vs. 22.2%), whereby the odds of detecting an improvement were higher with BS50 (OR [95% CI]: 3.2 [1.1, 8.7], p = .024). Analyses of individual gastrointestinal symptoms indicate that BS50 increased the proportion of participants showing an improvement at week 6 compared to placebo for burping (44.7% vs. 22.2%, p = .041) and bloating (31.6% vs. 13.9%, p = .071), without affecting other symptoms. There were no clinically meaningful changes in clinical chemistry, hematology, plasma lipids and intestinal permeability and other inflammation markers. In conclusion, the results suggest that dietary supplementation of 2 × 10⁹ CFU Bacillus subtilis BS50 per day is a well-tolerated and safe strategy to alleviate gas-related gastrointestinal symptoms in healthy adults.

ABBREVIATIONS

AE adverse event; BHD bowel habits diary; BMI body mass index; BSS Bristol Stool Scale; CFU colony-forming unit; CRP C-reactive protein; FGID functional gastrointestinal disorder; GI gastrointestinal; GITQ Gastrointestinal Tolerance Questionnaire; GLP-1 glucagon-like peptide 1; GSRS Gastrointestinal Symptom Rating Scale; HDL-C high-density lipoprotein-cholesterol; IBS irritable bowel syndrome; IL-10 interleukin-10; ITT intent-to-treat; LBP lipopolysaccharide binding protein; LDL-C low-density lipoprotein-cholesterol; PP per protocol; PYY peptide YY; TG triglyceride; total-C total cholesterol.

Gut microbiome and human health: Exploring how the probiotic genus Lactobacillus modulate immune responses

The highest density of microbes resides in human gastrointestinal tract, known as “Gut microbiome”. Of note, the members of the genus Lactobacillus that belong to phyla Firmicutes are the most important probiotic bacteria of the gut microbiome. These gut-residing Lactobacillus species not only communicate with each other but also with the gut epithelial lining to balance the gut barrier integrity, mucosal barrier defence and ameliorate the host immune responses. The human body suffers from several inflammatory diseases affecting the gut, lungs, heart, bone or neural tissues. Mounting evidence supports the significant role of Lactobacillus spp. and their components (such as metabolites, peptidoglycans, and/or surface proteins) in modulatingimmune responses, primarily through exchange of immunological signals between gastrointestinal tract and distant organs. This bidirectional crosstalk which is mediated by Lactobacillus spp. promotes anti-inflammatory response, thereby supporting the improvement of symptoms pertaining to asthma, chronic obstructive pulmonary disease (COPD), neuroinflammatory diseases (such as multiple sclerosis, alzheimer’s disease, parkinson’s disease), cardiovascular diseases, inflammatory bowel disease (IBD) and chronic infections in patients. The metabolic disorders, obesity and diabetes are characterized by a low-grade inflammation. Genus Lactobacillus alleviates metabolic disorders by regulating the oxidative stress response and inflammatory pathways. Osteoporosis is also associated with bone inflammation and resorption. The Lactobacillus spp. and their metabolites act as powerful immune cell controllers and exhibit a regulatory role in bone resorption and formation, supporting bone health. Thus, this review demonstrated the mechanisms and summarized the evidence of the benefit of Lactobacillus spp. in alleviating inflammatory diseases pertaining to different organs from animal and clinical trials. The present narrative review explores in detail the complex interactions between the gut-dwelling Lactobacillus spp. and the immune components in distant organs to promote host’s health.

Dairy-Based Probiotic-Fermented Functional Foods: An Update on Their Health-Promoting Properties

Numerous studies have shown a link between the consumption of fermented dairy foods and improved health outcomes. Since the early 2000s, especially probiotic-based fermented functional foods, have had a revival in popularity, mostly as a consequence of claims made about their health benefits. Among them, fermented dairy foods have been associated with obesity prevention and in other conditions such as chronic diarrhea, hypersensitivity, irritable bowel syndrome, Helicobacter pylori infection, lactose intolerance, and gastroenteritis which all are intimately linked with an unhealthy way of life. A malfunctioning inflammatory response may affect the intestinal epithelial barrier’s ability to function by interfering with the normal metabolic processes. In this regard, several studies have shown that fermented dairy probiotics products improve human health by stimulating the growth of good bacteria in the gut at the same time increasing the production of metabolic byproducts. The fermented functional food matrix around probiotic bacteria plays an important role in the survival of these strains by buffering and protecting them from intestinal conditions such as low pH, bile acids, and other harsh conditions. On average, cultured dairy products included higher concentrations of lactic acid bacteria, with some products having as much as 109/mL or g. The focus of this review is on fermented dairy foods and associated probiotic products and their mechanisms of action, including their impact on microbiota and regulation of the immune system. First, we discussed whey and whey-based fermented products, as well as the organisms associated with them. Followed by the role of probiotics, fermented-product-mediated modulation of dendritic cells, natural killer cells, neutrophils, cytokines, immunoglobulins, and reinforcement of gut barrier functions through tight junction. In turn, providing the ample evidence that supports their benefits for gastrointestinal health and related disorders.

Bacillus subtilis M6 improves intestinal barrier, antioxidant capacity and gut microbial composition in AA broiler

Bacillus subtilis can secret a variety of substances to improve human and animal gut health via inhibiting the proliferation of pathogenic bacteria. In this study, a fast-growing and stress-resistant strain of Bacillus subtilis M6 (B. subtilis M6) were isolated, which showed a strong antibacterial activity to E. coli K88, S. typhimurium ATCC14028, and S. aureus ATCC25923 in vitro. In vivo studies showed that B. subtilis M6 can significantly improve the average daily gain (ADG) using an AA broiler model. Dietary B. subtilis M6 improved the intestinal morphology. The villus height of jejunum and ileum were significantly increased. The concentration of malondialdehyde (MDA) in the ileal mucosa was significantly reduced in B. subtilis M6 treatment group, which suggested the oxidative stress of the ileum was significantly relieved. Though the β diversity of treatments was not significantly, B. subtilis M6 improved the composition of intestinal microbes, especially at the level of caecum genus, the dominant genus was changed from Ruminococcus to Akkermansia, which indicated the change of intestinal carbohydrate nutrition. In conclusion, these data indicate that the B. subtilis M6 shows a probiotic potential to improve intestinal health via altering gut microbiota.

Bifidobacterium adolescentis Is Effective in Relieving Type 2 Diabetes and May Be Related to Its Dominant Core Genome and Gut Microbiota Modulation Capacity

The prevalence of diabetes mellitus is increasing globally. Probiotics have been shown to be an effective intervention for diabetes. This study focused on the relieving effects and possible mechanisms of 16 strains of two dominant Bifidobacterium species (B. bifidum and B. adolescentis, which exist in the human gut at different life stages) on type 2 diabetes (T2D). The results indicated that more B. adolescentis strains appeared to be superior in alleviating T2D symptoms than B. bifidum strains. This effect was closely related to the ability of B. adolescentis to restore the homeostasis of the gut microbiota, increase the abundance of short-chain fatty acid-producing flora, and alleviate inflammation in mice with T2D. In addition, compared with B. bifidum, B. adolescentis had a higher number of core genes, and these genes were more evolutionarily stable, including unique environmental tolerance, carbon and nitrogen utilization genes, and a blood sugar regulation gene, glgP. This may be one of the reasons why B. adolescentis is more likely to colonize in the adult gut and show a superior ability to relieve T2D. This study provides insights into future studies aimed at investigating probiotics for the treatment of metabolic diseases.

Probiotics-loaded nanoparticles attenuated colon inflammation, oxidative stress, and apoptosis in colitis

Promising therapy is needed for treating inflammatory bowel diseases (IBD) to overcome current treatment that inefficient and associated with unnecessary health risks. Recently, the concept of incorporating natural products into nanocarriers has been intended as a promising therapy for treating IBD via modulating their stability and bioavailability. Thus, we aimed to explore the potential alleviating effects of dietary nano-supplement combined with bacillus strains (Bacillus amyloliquefaciens; BANPs) in colitis model. Rats were orally gavaged by 5% DSS and the efficacy and mechanistic actions of BANPs were evaluated by assessing the severity of clinical signs and inflammatory and apoptosis response, histopathological and immunohistochemistry examination in colonic tissues. The severity of clinical signs was successfully alleviated and fecal Lcn-2 levels, an important colitic marker, were decreased in BANPs then free BA treated groups. In contrast, inflammatory markers overexpression IL-6, IL-1β, TNFα, COX-2, and iNOS in the colitic group were reduced more prominently in BANPs treated group, unlike free BA. The amelioration of BANPs to colon injury was also correlated with oxidative stress suppression along with restoring total antioxidant capacity. Interestingly, BANPs treatment modulated apoptotic markers as proved by downregulation of cytochrome c, and caspase-3 and upregulation of Bcl-2 and Bax than free BA. The severity of the histopathological alterations in the colon was greatly reduced in BANPs than free BA groups. Remarkably, over-expression of ki67 and IL-6 in colonic tissues were suppressed in BANPs group. These findings together highlighted the beneficial efficacy of BANPs in IBD treatment which are evidenced by colonic inflammation alleviation. Taken together, these results recommend that BANPs is a promising agent that encourages its possible therapeutic role in colitis treatment.

The Relationships between Gut Microbiota and Diabetes Mellitus, and Treatments for Diabetes Mellitus

Diabetes mellitus is considered to be a global epidemic. The combination of genetic susceptibility and an unhealthy lifestyle is considered to be the main trigger of this metabolic disorder. Recently, there has been increased interest in the roles of gut microbiota as a new potential contributor to this epidemic. Research, in recent years, has contributed to an in-depth characterization of the human microbiome and its associations with various diseases, including metabolic diseases and diabetes mellitus. It is known that diet can change the composition of gut microbiota, but it is unclear how this, in turn, may influence metabolism. The main objective of this review is to evaluate the pathogenetic association between microbiota and diabetes and to explore any new therapeutic agents, including nutraceuticals that may modulate the microbiota. We also look at several mechanisms involved in this process. There is a clear, bidirectional relationship between microbiota and diabetes. Current treatments for diabetes influence microbiota in various ways, some beneficial, but others with still unclear effects. Microbiota-aimed treatments have seen no real-world significant effects on the progression of diabetes and its complications, with more studies needed in order to find a really beneficial agent.

Dietary Beta-Hydroxy-Beta-Methyl Butyrate Supplementation Inhibits Hepatic Fat Deposition via Regulating Gut Microbiota in Broiler Chickens

The present study is aimed to explore the effects of different dietary beta-hydroxy-beta-methyl butyrate (HMB) levels (0, 0.05%, 0.10%, or 0.15%) on liver lipid metabolism on Wenshi broiler chickens. Results showed that HMB reduced the liver weight as well as liver concentrations of triacylglycerol (TG) and total cholesterol (TC) (quadratically, p < 0.05), and the lowest values were observed in the 0.10% HMB group. Meanwhile, HMB supplementation significantly altered the expression levels of key genes related to lipid metabolism in the liver of broiler chickens (p < 0.05). Furthermore, 16S rRNA gene sequencing revealed that HMB supplementation could greatly change the richness, diversity, and composition of the broiler gut microbiota, and the Bacteroidetes relative abundance at the phylum level and the Alistipes relative abundance at the genus level were affected (p < 0.05). Correlation analysis further suggested a strong association between Bacteroidetes relative abundance and lipid metabolism-related parameters (p < 0.05). Together, these data suggest that 0.10% HMB supplementation could inhibit hepatic fat deposition via regulating gut microbiota in broilers.

Modulation of the PI3K/Akt/mTOR signaling pathway by probiotics as a fruitful target for orchestrating the immune response

The mammalian target of rapamycin (mTOR) and the phosphatidylinositol-3-kinase (PI3K)/protein kinase B or Akt (PKB/Akt) signaling pathways are considered as two but somewhat interconnected significant immune pathways which play complex roles in a variety of physiological processes as well as pathological conditions. Aberrant activation of PI3K/Akt/mTOR signaling pathways has been reported to be associated in a wide variety of human diseases. Over the past few years, growing evidence in in vitro and in vivo models suggest that this sophisticated and subtle cascade mediates the orchestration of the immune response in health and disease through exposure to probiotics. An expanding body of literature has highlighted the contribution of probiotics and PI3K/Akt/mTOR signaling pathways in gastrointestinal disorders, metabolic syndrome, skin diseases, allergy, salmonella infection, and aging. However, longitudinal human studies are possibly required to verify more conclusively whether the investigational tools used to understand the regulation of these pathways might provide effective approaches in the prevention and treatment of various disorders. In this Review, we summarize the experimental evidence from recent peer-reviewed studies and provide a brief overview of the causal relationship between the effects of probiotics and their metabolites on the components of PI3K/Akt/mTOR signaling pathways and human disease.

Potential effects of mung bean protein and a mung bean protein-polyphenol complex on oxidative stress levels and intestinal microflora in aging mice

This study investigated the effects of mung bean protein (MPI) and a MPI-polyphenol complex on oxidative stress levels and intestinal microflora in a D-galactose-induced aging mouse model. MPI and MPI-polyphenol complex intervention significantly increased activity of superoxide dismutase (SOD) and catalase and other antioxidant enzymes, improved the abundance and diversity of intestinal flora, and decreased the Firmicutes to Bacteroidetes ratio. Among them, the complex was more conducive to the improvement of the activity of antioxidant enzymes. The addition of MPI and the MPI-polyphenol complex can help the proliferation of Bacteroidetes, Bifidobacterium and Roseburia in the intestinal tract of aging mice, and inhibit the growth of Firmicutes and Ruminococcus, and the proliferation effect of the complex on Bifidobacterium was better than that of MPI. MPI significantly upregulated five pathways related to lipid and energy metabolism. Roseburia and Muribaculaceae were negatively correlated with malondialdehyde levels and positively correlated with SOD and other antioxidant enzyme indices. Our findings showed that MPI and MPI-polyphenol complexes can delay aging in mice by reducing oxidative damage and regulating intestinal flora. We also found a strong relationship between the abundance of intestinal flora and the levels of oxidative stress-related enzymes. This study provides theoretical support for the health and anti-aging benefits of mung bean food products.

Fermented noni (Morinda citrifolia L.) fruit juice improved oxidative stress and insulin resistance under the synergistic effect of Nrf2/ARE pathway and gut flora in db/db mice and HepG2 cells

Oxidative stress interferes with blood glucose homeostasis, leading to insulin resistance (IR) and hyperglycemia, which eventually induces type 2 diabetes (T2DM). Fermented noni (Morinda citrifolia L.) fruit juice (FNJ) is...

Circadian secretion rhythm of GLP-1 and its influencing factors

Circadian rhythm is an inherent endogenous biological rhythm in living organisms. However, with the improvement of modern living standards, many factors such as prolonged artificial lighting, sedentarism, short sleep duration, intestinal flora and high-calorie food intake have disturbed circadian rhythm regulation on various metabolic processes, including GLP-1 secretion, which plays an essential role in the development of various metabolic diseases. Herein, we focused on GLP-1 and its circadian rhythm to explore the factors affecting GLP-1 circadian rhythm and its potential mechanisms and propose some feasible suggestions to improve GLP-1 secretion.

Gut-Microbial Metabolites, Probiotics and Their Roles in Type 2 Diabetes

Type 2 diabetes (T2D) is a worldwide prevalent metabolic disorder defined by high blood glucose levels due to insulin resistance (IR) and impaired insulin secretion. Understanding the mechanism of insulin action is of great importance to the continuing development of novel therapeutic strategies for the treatment of T2D. Disturbances of gut microbiota have been widely found in T2D patients and contribute to the development of IR. In the present article, we reviewed the pathological role of gut microbial metabolites including gaseous products, branched-chain amino acids (BCAAs) products, aromatic amino acids (AAAs) products, bile acids (BA) products, choline products and bacterial toxins in regulating insulin sensitivity in T2D. Following that, we summarized probiotics-based therapeutic strategy for the treatment of T2D with a focus on modulating gut microbiota in both animal and human studies. These results indicate that gut-microbial metabolites are involved in the pathogenesis of T2D and supplementation of probiotics could be beneficial to alleviate IR in T2D via modulation of gut microbiota.

Intervention of Gastrodin in Type 2 Diabetes Mellitus and Its Mechanism

As a severe metabolic disease, type 2 diabetes mellitus (T2DM) has become a serious threat to human health in recent years. Gastrodin, as a primary chemical constituent in Gastrodia elata Blume, has antidiabetic effects. However, the possible mechanisms are unclear. The aim of the present study was to investigate the effects and possible mechanisms of gastrodin on the treatment of T2DM. In vivo, after treatment with gastrodin for 6 weeks, fasting blood glucose levels, blood lipid metabolism, and insulin sensitivity index values were remarkably reduced compared with those of the diabetic control group. The values of aspartate aminotransferase and alanine aminotransferase also showed that gastrodin alleviates liver toxicity caused by diabetes. Moreover, gastrodin relieved pathological damage to the pancreas in T2DM rats. In vitro, gastrodin alleviated insulin resistance by increasing glucose consumption, glucose uptake, and glycogen content in dexamethasone-induced HepG2 cells. The Western blotting results showed that gastrodin upregulated the expression of insulin receptors and ubiquitin-specific protease 4 (USP4) and increased the phosphorylation of GATA binding protein 1 (GATA1) and protein kinase B (AKT) in vivo and in vitro. Furthermore, gastrodin decreased the ubiquitin level of the insulin receptor via UPS4 and increased the binding of GATA1 to the USP4 promoter. Additionally, administration of the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway inhibitors MK-2206 and LY294002 abolished the beneficial effects of gastrodin. Our results indicate that gastrodin promotes the phosphorylation of GATA1 via the PI3K/AKT pathway, enhances the transcriptional activity of GATA1, and then increases the expression level of USP4, thereby reducing the ubiquitination and degradation of insulin receptors and ultimately improving insulin resistance. Our study provides scientific evidence for the beneficial actions and underlying mechanism of gastrodin in the treatment of T2DM.

Gut Microbiota Dysbiosis Is a Crucial Player for the Poor Outcomes for COVID-19 in Elderly, Diabetic and Hypertensive Patients

A new infectious disease, named COVID-19, caused by the coronavirus associated to severe acute respiratory syndrome (SARS-CoV-2) has become pandemic in 2020. The three most common pre-existing comorbidities associated with COVID-19-related death are elderly, diabetic, and hypertensive people. A common factor among these risk groups for the outcome of death in patients infected with SARS-CoV-2 is dysbiosis, with an increase in the proportion of bacteria with a pro-inflammatory profile. Due to this dysbiosis, elderly, diabetic, and hypertensive people present a higher propensity to mount an inflammatory environment in the gut with poor immune editing, culminating in a weakness of the intestinal permeability barrier and high bacterial product translocation to the bloodstream. This scenario culminates in a low-grade, persistent, and systemic inflammation. In this context, we propose here that high circulating levels of bacterial products, like lipopolysaccharide (LPS), can potentiate the SARS-CoV-2-induced cytokines, including IL-6, being crucial for development of the cytokine storm in the severe form of the disease. A better understanding on the possible correlation between gut dysbiosis and poor outcomes observed in elderly, diabetic, and hypertensive people can be useful for the development of new therapeutic strategies based on modulation of the gut microbiota.

Oral Administration of Lactobacillus casei and Bifidobacterium bifidum Improves Glucagon like Peptide-1(GLP-1) and Glucose-Dependent Insulinotropic Polypeptide (GIP) Level in Streptozotocin Induced Diabetic Rats

The gut microbiome plays significant role in the function and integrity of the gastrointestinal tract. They also maintain immune homeostasis and host energy metabolism. The metabolic products of these intestinal microbes can alter carbohydrate metabolism, nutrient absorption and reduce appetite to promote healthy lifestyle. Intestinal disbiosis observed in metabolic disorders like obesity and diabetes. Restoration of dysbiosed gut microbiome through oral administration of probiotics that may have profound health effect in diabetes. In case of diabetes, reports postulated impaired level of incretin, therefore we explored the effect of oral administration of probiotic bacteria Lactobacillus casei NCDC 017 (LC017) and Bifidobacterium bifidum NCDC 231 (BB231) alone and in combination on secretion of incretin hormones such as glucagon like peptide-1 and glucose dependent insulinotropic polypeptide. Thirty six male Wistar rats were randomly divided into six groups and diabetes was induced by single dose of streptozotocin (50 mg/kg body weight) in experimental rats intraperitonially except a group of healthy rats. The diabetic rats were daily administered orally with single dose (~107cfu/ml) of LC017 and BB231 alone and in combination for 28 days. Also, one group of diabetic rats was treated with an anti-diabetic drug, acarbose (10mg/kg body weight) and used a standard control. The change in body weight, sucrose tolerance test, GLP-1, GIP level in serum and GLP-1 level in different part of intestine were observed. The results have shown reduction in body weight in diabetic rats as compared to non-diabetic rats but improved after treatment of probiotic bacteria. Administration of LC017 and BB231 significantly improved GLP-1 and GIP level which were initially impaired in diabetic rats and their combination significantly decreased glucose level in sucrose tolerance test. This study indicated that LC017 and BB231 have significant hypoglycaemic potential in diabetic rats by increasing GLP-1 and GIP level. These findings offered a base for the use of LC017 and BB231 for improvement and treatment of diabetes.

Hypoglycemic effects of space-induced Lactobacillus plantarum SS18-5 on type 2 diabetes in a rat model

Probiotics can improve dyslipidemia and promote metabolic control as a therapeutic approach for type 2 diabetes mellitus (T2DM). The hypoglycemic effects of space-induced Lactobacillus plantarum SS18-5 on T2DM were explored in 4-week-old male Sprague Dawley rats. The normal (N) group was fed a basal diet, while the other groups received a high glucose fat diet. T2DM was established by streptozotocin injection and the T2DM rats were randomly divided into three groups, a diabetic (D) group (T2DM rats treated with saline only), GS18 group (T2DM rats treated with 10⁹  CFU/ml of L. plantarum GS18), and SS18-5 group (T2DM rats treated with 10⁹  CFU/ml of L. plantarum SS18-5). After continuous gavage for 6 weeks, blood biochemical indices were measured and livers were collected for histopathological examination. The colon contents were collected for counting of Escherichia coli, Clostridium perfringens, and Lactobacillus sp. The results showed that L. plantarum SS18-5 effectively controlled the weight of rats, reduced levels of fasting blood glucose, glycosylated hemoglobin, and insulin, increased liver glycogen levels, improved abnormal metabolism of blood lipids, enhanced the effect of anti-lipid peroxidation, alleviated chronic inflammation and fatty liver disease, and regulated the intestinal microbiota by reducing the numbers of E. coli and C. perfringens, and increasing the numbers of Lactobacillus sp. From these results, we conclude that space-induced L. plantarum SS18-5 has the potential to improve T2DM by alleviating hypoglycemia and regulating the intestinal microbiota. PRACTICAL APPLICATIONS: With the exploration of the universe, a large number of studies have observed the changes of microorganisms in space flight, which provided a new method for high-quality microbial pharmaceuticals in the space environment. In this study, the space environment mutated. Lactobacillus plantarum SS18-5 can effectively improve the blood glucose of rats with type 2 diabetes, relieve oxidative stress, reduce blood lipid content, enhance immune capacity, and regulate intestinal microflora, which has potential use in the treatment of type 2 diabetes.

Lactobacillus plantarum HAC01 ameliorates type 2 diabetes in high-fat diet and streptozotocin-induced diabetic mice in association with modulating the gut microbiota

Type 2 diabetes mellitus (T2DM) is a serious metabolic disorder that occurs worldwide; however, this condition can be managed with probiotics. We assessed the potential therapeutic effects of Lactobacillus plantarum HAC01 on hyperglycemia and T2DM and determined their potential mechanisms using mice with high-fat diet (HFD) and streptozotocin (STZ)-induced diabetes. The diabetic model was established with an HFD and 50 mg kg^-1 STZ. L. plantarum HAC01 was then administered for 10 weeks. Body weight, food and water intake, biochemical parameters, and homeostasis model assessment for insulin resistance (HOMA-IR) were measured. Oral glucose tolerance test and histological analysis were performed, and the glucose metabolism-related gene expression and signaling pathways in the liver were determined. Fecal microbiota and serum short-chain fatty acids (SCFAs) were also analyzed. L. plantarum HAC01 significantly lowered blood glucose and HbA1c levels and improved glucose tolerance and HOMA-IR. Additionally, it increased the insulin-positive β-cell area in islets and decreased the mRNA expression levels of phosphoenolpyruvate carboxykinase and glucose 6-phosphatase, which are associated with gluconeogenesis. L. plantarum HAC01 also increased the phosphorylation of AMPK and Akt, which are involved in glucose metabolism in the liver. Notably, L. plantarum HAC01 increased the Akkermansiaceae family and increased SCFAs in serum. L. plantarum HAC01 could alleviate hyperglycemia and T2DM by regulating glucose metabolism in the liver, protecting the islet β-cell mass, and restoring the gut microbiota and SCFAs. L. plantarum HAC01 may thus be an effective therapeutic agent for T2DM.

Therapeutic and Improving Function of Lactobacilli in the Prevention and Treatment of Cardiovascular-Related Diseases: A Novel Perspective From Gut Microbiota

The occurrence and development of cardiovascular-related diseases are associated with structural and functional changes in gut microbiota (GM). The accumulation of beneficial gut commensals contributes to the improvement of cardiovascular-related diseases. The cardiovascular-related diseases that can be relieved by Lactobacillus supplementation, including hypercholesterolemia, atherosclerosis, myocardial infarction, heart failure, type 2 diabetes mellitus, and obesity, have expanded. As probiotics, lactobacilli occupy a substantial part of the GM and play important functional roles through various GM-derived metabolites. Lactobacilli ultimately have a beneficial impact on lipid metabolism, inflammatory factors, and oxidative stress to relieve the symptoms of cardiovascular-related diseases. However, the axis and cellular process of gut commensal Lactobacillus in improving cardiovascular-related diseases have not been fully elucidated. Additionally, Lactobacillus strains produce diverse antimicrobial peptides, which help maintain intestinal homeostasis and ameliorate cardiovascular-related diseases. These strains are a field that needs to be further investigated immediately. Thus, this review demonstrated the mechanisms and summarized the evidence of the benefit of Lactobacillus strain supplementation from animal studies and human clinical trials. We also highlighted a broad range of lactobacilli candidates with therapeutic capability by mining their metabolites. Our study provides instruction in the development of lactobacilli as a functional food to improve cardiovascular-related diseases.

The beneficial effects of the composite probiotics from camel milk on glucose and lipid metabolism, liver and renal function and gut microbiota in db/db mice

Background

Probiotics may have beneficial effects on patients with type 2 diabetes mellitus (T2DM). We separated 4 lactobacillus and 1 saccharomycetes from traditional fermented cheese whey (TFCW) and prepared composite probiotics from camel milk (CPCM) and investigated their effects on glucose and lipid metabolism, liver and renal function and gut microbiota in db/db mice.

Methods

CPCM was prepared in the laboratory and 40 db/db mice were randomly divided into 4 groups as metformin, low-dose and high-dose group and model group, and treated for 6 weeks. In addition, 10 C57BL/Ks mice as normal control group were used for comparison. Fasting blood glucose (FBG), body weight (BW), oral glucose tolerance test (OGTT), glycated hemoglobin (HbAlc), C-peptide (CP), triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), 24 h urinary microalbumin (24 h malb), urine ketone, urine sugar, pancreas and liver tissue and intestinal flora were tested.

Results

Compared to diabetic group, high dose CPCM significantly decreased FBG, OGTT, HbAlc and IRI, plasma TC, TG, LDL-C, 24 h malb, urine ketone and urine sugar, increased CP, HDL-C levels, improved the liver and kidney function, protected the function of islets, also increased intestinal tract lactic acid bacteria and Bifidobacterium, decreased Escherichia in db/db mice.

Conclusion

CPCM decreased FBG, OGTT and HbAlc, increased CP, modulated lipid metabolism and improved liver and kidney protected injury in db/db mice, which may be related to various probiotics acting through protecting the function of islets and regulating intestinal flora disturbance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03303-4.

Role of the gut microbiota in type 2 diabetes and related diseases

Type 2 diabetes is the fastest-growing metabolic disease in the world. Many clinical studies have found that type 2 diabetes patients have metabolic disorders and chronic inflammatory states accompanied by disturbances in the gut microbiota. The gut microbiota plays an important role in body metabolism and immune regulation, and disturbances in the gut microbiota in conjunction with destruction of the intestinal barrier in type 2 diabetes patients causes damage to multiple organs. Therefore, the gut microbiota may be a new therapeutic target for treating type 2 diabetes and related diseases. In this review, we introduce the characteristics of the gut microbiota in type 2 diabetes and related diseases, as well as highlight the potential molecular mechanisms of their effects on intestinal barrier disruption, metabolic disorders, and chronic inflammation. Finally, we summarize an intestinal microecological therapeutic strategy, with a focus on shaping the intestinal bacteria, to improve the malignant progress of type 2 diabetes and related diseases. AUTHOR SUMMARY: Type 2 diabetes (T2D) is the fastest-growing metabolic disease in the world. Many clinical studies have found that T2D patients have metabolic disorders and chronic inflammatory states, accompanied by disturbances of the gut microbiota and increased intestinal permeability. The number of human gut microbiota is more than 10 times of human cells, and they play an important role in the body's metabolism and immune regulation. The abnormal intestinal metabolites and intestinal barrier disruption caused by the gut microbiota dysbiosis in the T2D facilitate intestinal bacteria and their harmful metabolites entering the circulatory system. The abnormal entering will cause the damage to multiple organs through disturbing insulin sensitivity, glucose metabolism, and immune homeostasis. Therefore, the gut microbiota may be a new therapeutic target for improving T2D and its related diseases. In this review, we introduce the compositional characteristics of the gut microbiota in T2D, and highlight some new molecular mechanisms of their effects on intestinal barrier disruption, metabolic disorders and chronic inflammation in T2D and its related diseases. Finally, we summarize an intestinal microecological therapeutic strategy, with a focus on shaping the intestinal bacteria, to improve the malignant progress of T2D and related diseases.

Recognizing the Benefits of Pre-/Probiotics in Metabolic Syndrome and Type 2 Diabetes Mellitus Considering the Influence of Akkermansia muciniphila as a Key Gut Bacterium

Metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM) are diseases that can be influenced by the structure of gut microbiota, whose improvement is often neglected in metabolic pathology. This review highlights the following main aspects: the relationship between probiotics/gut microbes with the pathogenesis of MetS, the particular positive roles of Akkermansia muciniphila supplementation in the onset of MetS, and the interaction between dietary polyphenols (prebiotics) with gut microbiota. Therefore, an extensive and in-depth analysis of the often-neglected correlation between gut microbiota and chronic metabolic diseases was conducted, considering that this topic continues to fascinate and stimulate researchers through the discovery of novel strains and their beneficial properties.

Neuroprotection elicited by resveratrol in a rat model of hypothyroidism: Possible involvement of cholinergic signaling and redox status

Both the cholinergic pathway and oxidative stress are important mechanisms involved in the pathogenesis of hypothyroidism, a condition characterized by low levels of thyroid hormone that predispose the patient to brain dysfunction. Phenolic compounds have numerous health benefits, including antioxidant activity. This study evaluates the preventive effects of resveratrol in the cholinergic system and redox status in rats with methimazole-induced hypothyroidism. Hypothyroidism increases acetylcholinesterase (AChE) activity and density in the cerebral cortex and hippocampus and decreases the α7 and M1 receptor densities in the hippocampus. Hypothyroidism also increases cellular levels of reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS), but reduces total thiol content, and catalase and superoxide dismutase activities in the serum. In the cerebral cortex and hippocampus, hypothyroidism increases the levels of ROS and nitrites. In this study, resveratrol (50 mg/kg) treatment prevents the observed increase in AChE in the cerebral cortex, and increases the protein levels of NeuN, a marker of mature neurons. Resveratrol also prevents changes in serum ROS levels and brain structure, as well as the levels of TBARS, total thiol content, and serum catalase enzyme activity. These collective findings suggest that resveratrol has a high antioxidant capacity and can restore hypothyroidism-triggered alterations related to neurotransmission. Thus, it is a promising agent for the prevention of brain damage resulting from hypothyroidism.

A multiple-strain probiotic product provides a better enzymatic antioxidant response in individuals with constipation in a double-blind randomized controlled trial

OBJECTIVES

Probiotics may have beneficial effects on intestinal dysbiosis. However, the effects of probiotics on redox and inflammatory responses in intestinal constipation remain unknown. The aim of this study was to investigate the effect of a multiple-strain probiotic on the redox and inflammatory responses in individuals with intestinal constipation.

METHODS

A randomized, double-blind, placebo controlled clinical trial was conducted with individuals diagnosed with constipation (defined according to the Rome IV criteria). The participants were randomized into two groups to receive either a probiotic capsule (PC; n = 25) containing probiotic strains or to receive a control capsule (CC; n = 20) containing a matching placebo for 30 d. In the baseline and at the end of the study, biomarkers of the redox (malondialdehyde, carbonylated protein, antioxidant enzymes, and ferric-reducing antioxidant power) and inflammatory responses, and Rome IV criteria for constipation were analyzed.

RESULTS

The consumption of a multiple-strain probiotic attenuated the reduction of glutathione peroxidase (PC = -9.41 and CC = -19.60; P = 0.041) and glutathione-s-transferase activity (PC = -3.28 and CC = -12.08, P < 0.0001) in erythrocytes and marginally improved the symptom of feeling incomplete defecation in ≥25% of bowel movements, compared with the placebo group. No changes were observed in total antioxidant capacity, oxidative damage, and levels of inflammatory markers in the serum.

CONCLUSIONS

Our data suggested that a multiple-strain probiotic may provide a better enzymatic antioxidant response and partially alleviate the feeling of incomplete defecation in ≥25% of bowel movements in individuals with intestinal constipation.

Maintaining Digestive Health in Diabetes: The Role of the Gut Microbiome and the Challenge of Functional Foods

Over the last decades, the incidence of diabetes has increased in developed countries and beyond the genetic impact, environmental factors, which can trigger the activation of the gut immune system, seem to affect the induction of the disease process. Since the composition of the gut microbiome might disturb the normal interaction with the immune system and contribute to altered immune responses, the restoration of normal microbiota composition constitutes a new target for the prevention and treatment of diabetes. Thus, the interaction of gut microbiome and diabetes, focusing on mechanisms connecting gut microbiota with the occurrence of the disorder, is discussed in the present review. Finally, the challenge of functional food diet on maintaining intestinal health and microbial flora diversity and functionality, as a potential tool for the onset inhibition and management of the disease, is highlighted by reporting key animal studies and clinical trials. Early onset of the disease in the oral cavity is an important factor for the incorporation of a functional food diet in daily routine.

Lactobacillus fermentum MCC2759 and MCC2760 Alleviate Inflammation and Intestinal Function in High-Fat Diet-Fed and Streptozotocin-Induced Diabetic Rats

The growing incidence of type 2 diabetes and obesity has become a worldwide crisis with increased socio-economic burden. Changes in lifestyle and food habits resulting in dysbiosis of the gut microbiota and low-grade inflammation are linked to the rising incidence. The aim of this study was to investigate the effects of potential probiotic Lactobacillus fermentum MCC2759 and MCC2760 on intestinal markers of inflammation using a high-fat diet (HFD)-fed model and a streptozotocin (STZ)-induced diabetic model. Lact. fermentum administration showed improved oral glucose tolerance compared with the model controls of HFD (AUC 1518) and STZ (628.8). Plasma insulin levels improved in the Lact. fermentum treated groups of HFD + MCC2759 (129 ± 4.24 pmol/L) and HFD + MCC2760 (151.5 ± 9.19 pmol/L) in HFD study, while in STZ diabetic study, the insulin levels were normalized with Lact. fermentum administration, for D + MCC2759 (120.5 ± 7.77) and D + MCC2760 (138 ± 5.65 pmol/L) groups. The results showed reduction in inflammatory tone in liver, muscle, and adipose tissues of rats in both models with stimulation of anti-inflammatory IL-10 by real-time quantitative polymerase chain reaction. Additionally, the potential probiotic cultures also displayed normalization of markers related to intestinal barrier integrity (ZO-1), TLR-4 receptor, and insulin sensitivity (GLUT-4, GLP-1, adiponectin). Thus, the results suggest that Lact. fermentum could act as potential probiotic for lifestyle-related disorders such as obesity, diabetes, and metabolic syndrome as both prophylactic and adjunct therapies.

Molecular Response in Intestinal and Immune Tissues to in Ovo Administration of Inulin and the Combination of Inulin and Lactobacillus lactis Subsp. cremoris

Intestinal microbiota are a key factor in maintaining good health and production results in chickens. They play an important role in the stimulation of immune responses, as well as in metabolic processes and nutrient digestion. Bioactive substances such as prebiotics, probiotics, or a combination of the two (synbiotic) can effectively stimulate intestinal microbiota and therefore replace antibiotic growth promoters. Intestinal microbiota might be stimulated at the early stage of embryo development in ovo. The aim of the study was to analyze the expression of genes related to energy metabolism and immune response after the administration of inulin and a synbiotic, in which lactic acid bacteria were combined with inulin in the intestines and immune tissues of chicken broilers. The experiment was performed on male broiler chickens. Eggs were incubated for 21 days in a commercial hatchery. On day 12 of egg incubation, inulin as a prebiotic and inulin with Lactobacillus lactis subsp. cremoris as a synbiotic were delivered to the egg chamber. The control group was injected with physiological saline. On day 35 post-hatching, birds from each group were randomly selected and sacrificed. Tissues (spleen, cecal tonsils, and large intestine) were collected and intended for RNA isolation. The gene panel (ABCG8, HNF4A, ACOX2, APBB1IP, BRSK2, APOA1, and IRS2) was selected based on the microarray dataset and biological functions of genes related to the energy metabolism and immune responses. Isolated RNA was analyzed using the RT-qPCR method, and the relative gene expression was calculated. In our experiment, distinct effects of prebiotics and synbiotics following in ovo delivery were manifested in all analyzed tissues, with the lowest number of genes with altered expression shown in the large intestines of broilers. The results demonstrated that prebiotics or synbiotics provide a potent stimulation of gene expression in the spleen and cecal tonsils of broiler chickens. The overall number of gene expression levels and the magnitude of their changes in the spleen and cecal tonsils were higher in the group of synbiotic chickens compared to the prebiotic group.

Probiotics supplementation and insulin resistance: a systematic review

BACKGROUND

Research on intestinal microbiota has grown considerably, as well as the interest on probiotics' supplementation effects on metabolism. Considering high prevalence rates of metabolic diseases linked by insulin resistance, we performed a systematic review of existing literature which addressed the role of probiotics in modulating insulin sensitivity in animals and humans.

METHODS

This systematic review was based on PRISMA guidelines. Searches for original articles published in English from 1990 to January 2020 were made in the electronic database of PubMed from the National Library of Medicine, using Medical Subject Headings to identify longitudinal studies conducted in animals and humans which reported effects of probiotics in a variety of insulin resistance parameters.

RESULTS

Overall, results from 27 probiotic interventions (Lactobacillus, Bifidobacterium, Clostridium and Akkermansia) indicated significant beneficial changes in insulin resistance measures in animal studies. Additionally, they improved lipid profile, inflammatory and oxidative markers, short-chain fatty acids production and microbiota composition. In seven clinical trials, samples and designs were heterogeneous. Five showed benefits in insulin resistance parameters and in two others no effect was detected.

CONCLUSION

Available data regarding the effects of certain probiotics do not guarantee sustained amelioration of insulin resistance in humans. Consistent beneficial results for intestinal barrier function, immune system and metabolism were reported in animals may encourage long-term randomized clinical trials in people with obesity and cardiometabolic risk. Whether supplementation with probiotics in combination with medications and/or prebiotics, associated with a healthy lifestyle, will prove useful to attenuate insulin resistance requires further investigation.

Engineered probiotic and prebiotic nutraceutical supplementations in combating non-communicable disorders: A review

Nutritional supplementations are a form of nutrition sources that may help in improving health complexities throughout the life span of a person. Under the umbrella of food supplementations, nutraceuticals are products extracted from edible sources that provide medical benefits along with primary nutritional value, these can be considered as functional foods. These nutraceutical supplementations are also evidenced in altering the commensal gut microbiota and help to prevent or fight against chronic non-communicable degenerative diseases in adults including neurological disorders (Autism Spectrum Disorder [ASD], Parkinson's disease [PD] and Multiple sclerosis [MS]) and metabolic disorder (Type-II Diabetes, Obesity and non-alcoholic fatty liver disease). Even the complexities of preterm babies like extra-uterine growth restriction, necrotizing enterocolitis, infant eczema and allergy (during pregnancy) and bronchopulmonary dysplasia, etc. could also be lessened up by providing proper nutrition. Molecular perceptive of inflammatory and apoptotic modulators regulating the pathogenesis of these health risks, their control and management by probiotics and prebiotics could further emphasize the scientific overview of their utility. The pivotal role of nutraceutical supplementations in regulating or modulating molecular pathways coupled with the above mentioned non-communicable diseases are briefly described. Lastly, an overall introduction to the sophisticated genome-editing techniques and advanced delivery systems in therapeutic activities applicable under these health risks are also emphasized in this paper.

Propionate inhibits fat deposition via affecting feed intake and modulating gut microbiota in broilers

As one of the 3 main short-chain fatty acids, the role of propionate in chicken fat metabolism is largely unknown. In this study, we demonstrated that dietary supplementation of coated sodium propionate (SP) moderately inhibits fat deposition in broiler chickens, as evidenced by the decreased adipocyte mean area (P < 0.01), the lowered triglyceride content in abdominal fat tissue (P < 0.01), and the reduced transcription of several lipogenic genes in liver and abdominal fat tissues (P < 0.05). Surprisingly, the propionate content was not significantly elevated either in serum or in the cecal chyme by SP administration (P > 0.05). However, SP application significantly decreased the average daily feed intake of broilers (P < 0.05). In addition, the composition of the cecal microbial communities was altered, with the ratio of Firmicutes to Bacteroidetes decreasing in particular (P < 0.05). At the genus level, SP application increased the richness of Alistipes, Lactobacillus, and Bifidobacterium, while reduced the abundance of Lachnospiraceae and Helicobacter significantly (P < 0.05). Moreover, in vitro experiments indicated that, although physiological concentrations of propionate (0.01 to 0.1 mmol) upregulated or downregulated the transcription of some fat synthesis-associated genes (P < 0.05), they did not significantly affect the triglyceride accumulation in hepatocytes and adipocytes (P > 0.05). These results suggest that feed supplementation with SP inhibits fat deposition in broilers by reducing feed and caloric intake, but not via direct regulation on hepatic fat synthesis or adipocytic fat deposition. Alteration in the relative populations of the gut microflora suggests that SP may have gut health implications.

The Potential of Lactobacillus spp. for Modulating Oxidative Stress in the Gastrointestinal Tract

The gastrointestinal (GI) tract is crucial for food digestion and nutrient absorption in humans. However, the GI tract is usually challenged with oxidative stress that can be induced by various factors, such as exogenous pathogenic microorganisms and dietary alterations. As a part of gut microbiota, Lactobacillus spp. play an important role in modulating oxidative stress in cells and tissues, especially in the GI tract. Oxidative stress is linked with excessive reactive oxygen species (ROS) that can be formed by a few enzymes, such as nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs). The redox mechanisms of Lactobacillus spp. may contribute to the downregulation of these ROS-forming enzymes. In addition, nuclear factor erythroid 2 (NFE2)-related factor 2 (Nrf-2) and nuclear factor kappa B (NF-κB) are two common transcription factors, through which Lactobacillus spp. modulate oxidative stress as well. As oxidative stress is closely associated with inflammation and certain diseases, Lactobacillus spp. could potentially be applied for early treatment and amelioration of these diseases, either individually or together with prebiotics. However, further research is required for revealing their mechanisms of action as well as their extensive application in the future.

Preclinical relevance of probiotics in type 2 diabetes: A systematic review

Type 2 diabetes (T2DM) is among the most prevalent metabolic diseases in the world and may result in several long-term complications. The crosstalk between gut microbiota and host metabolism is closely related to T2DM. Currently, fragmented data hamper defining the relationship between probiotics and T2DM. This systematic review aimed at investigating the effects of probiotics on T2DM in animal models. We systematically reviewed preclinical evidences using PubMed/MEDLINE and Scopus databases, recovering 24 original articles published until September 27th, 2019. This systematic review was performed according to PRISMA guidelines. We included experimental studies with animal models reporting the effects of probiotics on T2DM. Studies were sorted by characteristics of publications, animal models, performed analyses, probiotic used and interventions. Bias analysis and methodological quality assessments were examined through the SYRCLE's Risk of Bias tool. Probiotics improved T2DM in 96% of the studies. Most studies (96%) used Lactobacillus strains, and all of them led to improved glycaemia. All studies used rodents as models, and male animals were preferred over females. Results suggest that probiotics have a beneficial effect in T2DM animals and could be used as a supporting alternative in the disease treatment. Considering a detailed evaluation of the reporting and methodological quality, the current preclinical evidence is at high risk of bias. We hope that our critical analysis will be useful in mitigating the sources of bias in further studies.