Prebiotics as a Tool for the Prevention and Treatment of Obesity and Diabetes: Classification and Ability to Modulate the Gut Microbiota

Resistant starch-enriched brown rice exhibits prebiotic properties and enhances gut health in obese mice

Resistant starch serves as a prebiotic in the large intestine, aiding in the maintenance of a healthy intestinal environment and mitigating associated chronic illnesses. This study aimed to investigate the impact of resistant starch-enriched brown rice (RBR) on intestinal health and functionality. We assessed changes in resistant starch concentration, structural alterations, and branch chain length distribution throughout the digestion process using an in vitro model. The efficacy of RBR in the intestinal environment was evaluated through analyses of its prebiotic potential, effects on intestinal microbiota, and intestinal function-related proteins in obese animals fed a high-fat diet. RBR exhibited a higher yield of insoluble fraction in both the small and large intestines compared to white and brown rice. The total digestible starch content decreased, while the resistant starch content significantly increased during in vitro digestion. Furthermore, RBR notably enhanced the growth of four probiotic strains compared to white and brown rice, displaying higher proliferation activity than the positive control, FOS. Notably, consumption of RBR by high-fat diet-induced obese mice suppressed colon shortening, increased Bifidobacteria growth, and improved intestinal permeability. These findings underscore the potential prebiotic and gut health-promoting attributes of RBR, offering insights for the development of functional foods aimed at preventing gastrointestinal diseases.

Metabolic syndrome's new therapy: Supplement the gut microbiome

This letter to the editor discusses the publication on gut microbiome supplementation as therapy for metabolic syndrome. Gut microbiome dysbiosis disrupts intestinal bacterial homeostasis and is related to chronic inflammation, insulin resistance, cardiovascular diseases, type 2 diabetes mellitus, and obesity. Previous research has found that increasing the abundance of beneficial microbiota in the gut modulates metabolic syndrome by reducing chronic inflammation and insulin resistance. Prebiotics, probiotics, synbiotics, and postbiotics are often used as supplements to increase the number of beneficial microbes and thus the production of short-chain fatty acids, which have positive effects on the gut microbiome and metabolic syndrome. In this review article, the author summarizes the available supplements to increase the abundance of beneficial gut microbiota and reduce the abundance of harmful microbiota in patients with metabolic disorders. Our group is also researching the role of the gut microbiota in chronic liver disease. This article will be of great help to our research. At the end of the letter, the mechanism of the gut microbiota in chronic liver disease is discussed.

Prebiotic Systems Containing Anthocyanin-Rich Pomegranate Flower Extracts with Antioxidant and Antidiabetic Effects

Pomegranate flower extract, rich in anthocyanins, demonstrates beneficial health-promoting properties such as an anti-diabetic and antioxidant effect, among others. However, the potential health-promoting properties may be hindered by the low stability of anthocyanins. Therefore, the aim of our study was to assess whether stabilizing carriers, namely HP-γ-cyclodextrin (HP-γ-CD), α-cyclodextrin (α-CD), Methyl-β-cyclodextrin (Me-β-CD), Inulin (Inu) and Arabic gum (AGu) affect the antioxidant and antidiabetic activity of lyophilized pomegranate flower extract, how they influence stability, release profile, and whether the systems exhibit prebiotic activity. Interactions between pomegranate flower extract and these factors were analyzed using FT-IR. The structures were examined through microscopic imaging while for the prepared prebiotic systems, antidiabetic activity was determined and confirmed by the inhibition of α-amylase and α-glucosidase; antioxidant activity was expressed by DPPH and CUPRAC assays. The content of pelargonidin-3,5-glucoside in these systems was assessed using the HPLC method. The release profiles of pelargonidin-3,5-glucoside were examined in a medium at pH = 6.8 and pH = 1.2, and the stability was assessed after subjecting the systems to high temperatures (T = 90 °C). The prebiotic potential was evaluated for 10 prebiotic bacterial strains (Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus brevis Lactobacillus rhamnosus gg, Lactobacillus reuteri, Pediococcus pentosaceus, Lactococcus lactis, Lactobacillus fermentum lf, Streptococcus thermophilus). As a result of the conducted research, better functionalities of the obtained systems containing Pomegranate flower extract were proven in terms of prebiotic and antidiabetic effects. The obtained delivery systems for pelargonidin-3,5-glucoside allow for better use of its health-promoting effects.

Past, present, and future of microbiome-based therapies

Technological advances in studying the human microbiome in depth have enabled the identification of microbial signatures associated with health and disease. This confirms the crucial role of microbiota in maintaining homeostasis and the host health status. Nowadays, there are several ways to modulate the microbiota composition to effectively improve host health; therefore, the development of therapeutic treatments based on the gut microbiota is experiencing rapid growth. In this review, we summarize the influence of the gut microbiota on the development of infectious disease and cancer, which are two of the main targets of microbiome-based therapies currently being developed. We analyze the two-way interaction between the gut microbiota and traditional drugs in order to emphasize the influence of gut microbial composition on drug effectivity and treatment response. We explore the different strategies currently available for modulating this ecosystem to our benefit, ranging from 1st generation intervention strategies to more complex 2nd generation microbiome-based therapies and their regulatory framework. Lastly, we finish with a quick overview of what we believe is the future of these strategies, that is 3rd generation microbiome-based therapies developed with the use of artificial intelligence (AI) algorithms.

Dichotomous effect of dietary fiber in pediatrics: a narrative review of the health benefits and tolerance of fiber

Dietary fibers are associated with favorable gastrointestinal, immune, and metabolic health outcomes when consumed at sufficient levels. Despite the well-described benefits of dietary fibers, children and adolescents continue to fall short of daily recommended levels. This gap in fiber intake (i.e., "fiber gap") might increase the risk of developing early-onset pediatric obesity and obesity-related comorbidities such as type 2 diabetes mellitus into adulthood. The structure-dependent physicochemical properties of dietary fiber are diverse. Differences in solubility, viscosity, water-holding capacity, binding capability, bulking effect, and fermentability influence the physiological effects of dietary fibers that aid in regulating appetite, glycemic and lipidemic responses, and inflammation. Of growing interest is the fermentation of fibers by the gut microbiota, which yields both beneficial and less favorable end-products such as short-chain fatty acids (e.g., acetate, propionate, and butyrate) that impart metabolic and immunomodulatory properties, and gases (e.g., hydrogen, carbon dioxide, and methane) that cause gastrointestinal symptoms, respectively. This narrative review summarizes (1) the implications of fibers on the gut microbiota and the pathophysiology of pediatric obesity, (2) some factors that potentially contribute to the fiber gap with an emphasis on undesirable gastrointestinal symptoms, (3) some methods to alleviate fiber-induced symptoms, and (4) the therapeutic potential of whole foods and commonly marketed fiber supplements for improved health in pediatric obesity.

Microbial-Based Bioactive Compounds to Alleviate Inflammation in Obesity

The increased prevalence of obesity with several other metabolic disorders, including diabetes and non-alcoholic fatty liver disease, has reached global pandemic proportions. Lifestyle changes may result in a persistent positive energy balance, hastening the onset of these age-related disorders and consequently leading to a diminished lifespan. Although suggestions have been raised on the possible link between obesity and the gut microbiota, progress has been hampered due to the extensive diversity and complexities of the gut microbiota. Being recognized as a potential biomarker owing to its pivotal role in metabolic activities, the dysregulation of the gut microbiota can give rise to a persistent low-grade inflammatory state associated with chronic diseases during aging. This chronic inflammatory state, also known as inflammaging, induced by the chronic activation of the innate immune system via the macrophage, is controlled by the gut microbiota, which links nutrition, metabolism, and the innate immune response. Here, we present the functional roles of prebiotics, probiotics, synbiotics, and postbiotics as bioactive compounds by underscoring their putative contributions to (1) the reduction in gut hyperpermeability due to lipopolysaccharide (LPS) inactivation, (2) increased intestinal barrier function as a consequence of the upregulation of tight junction proteins, and (3) inhibition of proinflammatory pathways, overall leading to the alleviation of chronic inflammation in the management of obesity.

Microbiome-modulating nutraceuticals ameliorate dyslipidemia in type 2 diabetes: A systematic review, meta-analysis, and meta-regression of clinical trials

AIMS

Type 2 Diabetes is intrinsically linked to cardiovascular disease (CVD) via diabetic dyslipidemia, both of which remain global health concerns with annually increasing prevalence. Given the established links between gut microbiome dysbiosis and metabolic diseases, its modulation is an attractive target to ameliorate metabolic imbalances in such patients. There is a need to quantitively summarise, analyse, and describe future directions in this field.

METHODS

We conducted a systematic review, meta-analysis, and meta-regression following searches in major scientific databases for clinical trials investigating the effect of pro/pre/synbiotics on lipid profile published until April 2022. Data were pooled using random-effects meta-analysis and reported as mean differences with 95% confidence intervals (CIs). PROSPERO No. CRD42022348525.

RESULTS

Data from 47 trial comparisons across 42 studies (n = 2692) revealed that, compared to placebo/control groups, the administration of pro/pre/synbiotics was associated with statistically significant changes in total cholesterol (-9.97 mg/dL [95% CI: -15.08; -4.87], p < 0.0001), low-density lipoprotein (-6.29 mg/dL [95% CI: -9.25; -3.33], p < 0.0001), high-density lipoprotein (+3.21 mg/dL [95% CI: 2.20; 4.22], p < 0.0001), very-low-density lipoprotein (-4.52 mg/dL [95% CI: -6.36; -2.67], p < 0.0001) and triglyceride (-22.93 mg/dL [95% CI: -33.99; -11.87], p < 0.001). These results are influenced by patient characteristics such as age or baseline BMI, and intervention characteristics such as dosage and duration.

CONCLUSIONS

Our study shows that adjunct supplementation with a subset of pro/pre/synbiotics ameliorates dyslipidemia in diabetic individuals and has the potential to reduce CVD risk. However, widespread inter-study heterogeneity and the presence of several unknown confounders limit their adoption in clinical practice; future trials should be designed with these in mind.

Gut microbiome supplementation as therapy for metabolic syndrome

The gut microbiome is defined as an ecological community of commensal symbiotic and pathogenic microorganisms that exist in our body. Gut microbiome dysbiosis is a condition of dysregulated and disrupted intestinal bacterial homeostasis, and recent evidence has shown that dysbiosis is related to chronic inflammation, insulin resistance, cardiovascular diseases (CVD), type 2 diabetes mellitus (T2DM), and obesity. It is well known that obesity, T2DM and CVD are caused or worsened by multiple factors like genetic predisposition, environmental factors, unhealthy high calorie diets, and sedentary lifestyle. However, recent evidence from human and mouse models suggest that the gut microbiome is also an active player in the modulation of metabolic syndrome, a set of risk factors including obesity, hyperglycemia, and dyslipidemia that increase the risk for CVD, T2DM, and other diseases. Current research aims to identify treatments to increase the number of beneficial microbiota in the gut microbiome in order to modulate metabolic syndrome by reducing chronic inflammation and insulin resistance. There is increasing interest in supplements, classified as prebiotics, probiotics, synbiotics, or postbiotics, and their effect on the gut microbiome and metabolic syndrome. In this review article, we have summarized current research on these supplements that are available to improve the abundance of beneficial gut microbiota and to reduce the harmful ones in patients with metabolic syndrome.

Nutrient synergy: definition, evidence, and future directions

Nutrient synergy refers to the concept that the combined effects of two or more nutrients working together have a greater physiological impact on the body than when each nutrient is consumed individually. While nutrition science traditionally focuses on isolating single nutrients to study their effects, it is recognized that nutrients interact in complex ways, and their combined consumption can lead to additive effects. Additionally, the Dietary Reference Intakes (DRIs) provide guidelines to prevent nutrient deficiencies and excessive intake but are not designed to assess the potential synergistic effects of consuming nutrients together. Even the term synergy is often applied in different manners depending on the scientific discipline. Considering these issues, the aim of this narrative review is to investigate the potential health benefits of consuming different nutrients and nutrient supplements in combination, a concept we define as nutrient synergy, which has gained considerable attention for its impact on overall well-being. We will examine how nutrient synergy affects major bodily systems, influencing systemic health. Additionally, we will address the challenges associated with promoting and conducting research on this topic, while proposing potential solutions to enhance the quality and quantity of scientific literature on nutrient synergy.

The Role of Gut Microbiome Supplementation in COVID-19 Management

COVID-19, which is caused by the RNA virus, SARS-CoV-2, mainly affects the respiratory system and has a varied clinical presentation. However, several studies have shown that COVID-19 can also affect the gastrointestinal (GI) system. Patients can experience various GI symptoms, such as vomiting and diarrhea, and the virus has been detected in the stool samples of patients hospitalized with COVID-19. There have also been rare reports of COVID-19 presenting with isolated GI symptoms and lack of respiratory symptoms, and the virus has also been detected for prolonged periods in the fecal samples of COVID-19 patients. Major alterations in the gut microbiome in the form of depletion of beneficial organisms and an abundance of pathogenic organisms have been reported in the fecal samples of hospitalized COVID-19 patients. Although the US FDA has approved several drugs to manage COVID-19, their efficacy remains modest. So, there is a constant ongoing effort to investigate novel treatment options for COVID-19. Health supplements like probiotics, prebiotics, postbiotics, and synbiotics have been popularly known for their various health benefits. In this review, we have summarized the current literature, which shows the potential benefit of these health supplements to mitigate and/or prevent the clinical presentation of COVID-19.

Recent insights of obesity-induced gut and adipose tissue dysbiosis in type 2 diabetes

An imbalance in microbial homeostasis, referred to as dysbiosis, is critically associated with the progression of obesity-induced metabolic disorders including type 2 diabetes (T2D). Alteration in gut microbial diversity and the abundance of pathogenic bacteria disrupt metabolic homeostasis and potentiate chronic inflammation, due to intestinal leakage or release of a diverse range of microbial metabolites. The obesity-associated shifts in gut microbial diversity worsen the triglyceride and cholesterol level that regulates adipogenesis, lipolysis, and fatty acid oxidation. Moreover, an intricate interaction of the gut-brain axis coupled with the altered microbiome profile and microbiome-derived metabolites disrupt bidirectional communication for instigating insulin resistance. Furthermore, a distinct microbial community within visceral adipose tissue is associated with its dysfunction in obese T2D individuals. The specific bacterial signature was found in the mesenteric adipose tissue of T2D patients. Recently, it has been shown that in Crohn's disease, the gut-derived bacterium Clostridium innocuum translocated to the mesenteric adipose tissue and modulates its function by inducing M2 macrophage polarization, increasing adipogenesis, and promoting microbial surveillance. Considering these facts, modulation of microbiota in the gut and adipose tissue could serve as one of the contemporary approaches to manage T2D by using prebiotics, probiotics, or faecal microbial transplantation. Altogether, this review consolidates the current knowledge on gut and adipose tissue dysbiosis and its role in the development and progression of obesity-induced T2D. It emphasizes the significance of the gut microbiota and its metabolites as well as the alteration of adipose tissue microbiome profile for promoting adipose tissue dysfunction, and identifying novel therapeutic strategies, providing valuable insights and directions for future research and potential clinical interventions.

Polysaccharide from Ziyang Selenium-Enriched Green Tea Prevents Obesity and Promotes Adipose Thermogenesis via Modulating the Gut Microbiota

The objective of the current study was to explore the potential mechanism of Ziyang selenium-enriched green tea polysaccharide (Se-GTP) against obesity. The results showed that Se-GTP significantly alleviated obesity and related metabolic disorders caused by high-fat diet (HFD) in mice. 16S rRNA gene sequencing results revealed that Se-GTP improved gut microbiota disturbance of obese mice and facilitated proliferation of probiotics such as Bacteroides, Bifidobacterium, Lactobacillus, and Akkermansia. In addition, the colonic content of succinate, a product of microbial metabolite in connection with adipocyte thermogenesis, was significantly enhanced by Se-GTP treatment. Therefore, Se-GTP facilitated brown adipose tissue (BAT) thermogenesis and inguinal white adipose tissue (iWAT) browning in obese mice, which could be revealed by increased expressions of thermogenic marker proteins UCP1, PGC-1α, and CIDEA in BAT and iWAT. Interestingly, Se-GTP intervention also observably increased the content of M2-like macrophages in iWAT of obese mice. To summarize, the results of this study are the first to show that Se-GTP can stimulate the browning of iWAT and BAT thermogenesis to counteract obesity, which may be pertinent with the alteration of gut microbiota in obese mice.

In vitro screening and characterization of lactic acid bacteria from Lithuanian fermented food with potential probiotic properties

The present work aimed to identify probiotic candidates from Lithuanian homemade fermented food samples. A total of 23 lactic acid bacteria were isolated from different fermented food samples. Among these, only 12 showed resistance to low pH, tolerance to pepsin, bile salts, and pancreatin. The 12 strains also exhibited antimicrobial activity against Staphylococcus aureus ATCC 29213, Salmonella Typhimurium ATCC 14028, Streptococcus pyogenes ATCC 12384, Streptococcus pyogenes ATCC 19615, and Klebsiella pneumoniae ATCC 13883. Cell-free supernatants of isolate 3A and 55w showed the strongest antioxidant activity of 26.37 μg/mL and 26.06 μg/mL, respectively. Isolate 11w exhibited the strongest auto-aggregation ability of 79.96% as well as the strongest adhesion to HCT116 colon cells (25.671 ± 0.43%). The selected strains were tested for their synbiotic relation in the presence of a prebiotic. The selected candidates showed high proliferation in the presence of 4% as compared to 2% galactooligosaccharides. Among the strains tested for tryptophan production ability, isolate 11w produced the highest L-tryptophan levels of 16.63 ± 2.25 μm, exhibiting psychobiotic ability in the presence of a prebiotic. The safety of these strains was studied by ascertaining their antibiotic susceptibility, mucin degradation, gelatin hydrolysis, and hemolytic activity. In all, isolates 40C and 11w demonstrated the most desirable probiotic potentials and were identified by 16S RNA and later confirmed by whole genome sequencing as Lacticaseibacillus paracasei 11w, and Lactiplantibacillus plantarum 40C: following with the harboring plasmid investigation. Out of all the 23 selected strains, only Lacticaseibacillus paracasei 11w showed the potential and desirable probiotic properties.

Prebiotic effect of poly-D-3-hydroxybutyrate prevents dyslipidemia in obese mice

Obesity is a global health problem caused by genetic, environmental, and psychological factors and is associated with various health disorders. As such, there is a growing focus on the prevention of obesity and related diseases. The gut microbiota plays a crucial role in these diseases and has become a therapeutic target. Prebiotics, such as poly-d-3-hydroxybutyric acid (PHB), have gained attention for their potential to alter the gut microbiota, promote beneficial bacterial growth, and alleviate obesity. In this study, we examined the prebiotic effects of PHB in obese mice. We found that, in C57BL/6N mice, PHB reduced blood lipid levels. Analysis of the intestinal microflora also revealed an increase in short-chain fatty acid-producing bacteria. When PHB was administered to obese mice, subcutaneous fat and dyslipidemia were reduced, and the number of beneficial bacteria in the intestinal microflora increased. Furthermore, fatty degradation and oxidative stress were suppressed in the liver. PHB regulates gut bacterial changes related to obesity and effectively inhibits dyslipidemia, suggesting that it could be a prebiotic agent for curing various obesity-related diseases. In summary, PHB increases the beneficial gut microbiota, leading to an alleviation of obesity-associated dyslipidemia.

Non-dairy prebiotics: Conceptual relevance with nutrigenomics and mechanistic understanding of the effects on human health

The increasing health awareness of consumers has made a shift towards vegan and non-dairy prebiotics counterparts. Non-dairy prebiotics when fortified with vegan products have interesting properties and widely found its applications in food industry. The chief vegan products that have prebiotics added include water-soluble plant-based extracts (fermented beverages, frozen desserts), cereals (bread, cookies), and fruits (juices & jelly, ready to eat fruits). The main prebiotic components utilized are inulin, oligofructose, polydextrose, fructooligosaccharides, and xylooligosaccharides. Prebiotics' formulations, type and food matrix affect food products, host health, and technological attributes. Prebiotics from non-dairy sources have a variety of physiological effects that help to prevent and treat chronic metabolic diseases. This review focuses on mechanistic insight on non-dairy prebiotics affecting human health, how nutrigenomics is related to prebiotics development, and role of gene-microbes' interactions. The review will provide industries and researchers with important information about prebiotics, mechanism of non-dairy prebiotics and microbe interaction as well as prebiotic based vegan products.

Potential role of tirzepatide towards Covid-19 infection in diabetic patients: a perspective approach

In Covid-19, variations in fasting blood glucose are considered a distinct risk element for a bad prognosis and outcome in Covid-19 patients. Tirazepatide (TZT), a dual glucagon-like peptide-1 (GLP-1)and glucose-dependent insulinotropic polypeptide (GIP) receptor agonist may be effective in managing Covid-19-induced hyperglycemia in diabetic and non-diabetic patients. The beneficial effect of TZT in T2DM and obesity is related to direct activation of GIP and GLP-1 receptors with subsequent improvement of insulin sensitivity and reduction of body weight. TZT improves endothelial dysfunction (ED) and associated inflammatory changes through modulation of glucose homeostasis, insulin sensitivity, and pro-inflammatory biomarkers release. TZT, through activation of the GLP-1 receptor, may produce beneficial effects against Covid-19 severity since GLP-1 receptor agonists (GLP-1RAs) have anti-inflammatory and pulmoprotective implications in Covid-19. Therefore, GLP-1RAs could effectively treat severely affected Covid-19 diabetic and non-diabetic patients. Notably, using GLP-1RAs in T2DM patients prevents glucose variability, a common finding in Covid-19 patients. Therefore, GLP-1RAs like TZT could be a therapeutic strategy in T2DM patients with Covid-19 to prevent glucose variability-induced complications. In Covid-19, the inflammatory signaling pathways are highly activated, resulting in hyperinflammation. GLP-1RAs reduce inflammatory biomarkers like IL-6, CRP, and ferritin in Covid-19 patients. Therefore, GLP-1RAs like TZ may be effective in Covid-19 patients by reducing the inflammatory burden. The anti-obesogenic effect of TZT may reduce Covid-19 severity by ameliorating body weight and adiposity. Furthermore, Covid-19 may induce substantial alterations in gut microbiota. GLP-1RA preserves gut microbiota and prevents intestinal dysbiosis. Herein, TZT, like other GLP-1RA, may attenuate Covid-19-induced gut microbiota alterations and, by this mechanism, may mitigate intestinal inflammation and systemic complications in Covid-19 patients with either T2DM or obesity. As opposed to that, glucose-dependent insulinotropic polypeptide (GIP) was reduced in obese and T2DM patients. However, activation of GIP-1R by TZT in T2DM patients improves glucose homeostasis. Thus, TZT, through activation of both GIP and GLP-1, may reduce obesity-mediated inflammation. In Covid-19, GIP response to the meal is impaired, leading to postprandial hyperglycemia and abnormal glucose homeostasis. Therefore, using TZT in severely affected Covid-19 patients may prevent the development of glucose variability and hyperglycemia-induced oxidative stress. Moreover, exaggerated inflammatory disorders in Covid-19 due to the release of pro-inflammatory cytokines like IL-1β, IL-6, and TNF-α may lead to systemic inflammation and cytokine storm development. Besides, GIP-1 inhibits expression of IL-1β, IL-6, MCP-1, chemokines and TNF-α. Therefore, using GIP-1RA like TZT may inhibit the onset of inflammatory disorders in severely affected Covid-19 patients. In conclusion, TZT, through activation of GLP-1 and GIP receptors, may prevent SARS-CoV-2-induced hyperinflammation and glucose variability in diabetic and non-diabetic patients.

Weight Loss Supplements

Being overweight or obese can predispose people to chronic diseases and metabolic disorders such as cardiovascular illnesses, diabetes, Alzheimer's disease, and cancer, which are costly public health problems and leading causes of mortality worldwide. Many people hope to solve this problem by using food supplements, as they can be self-prescribed, contain molecules of natural origin considered to be incapable of causing damage to health, and the only sacrifice they require is economic. The market offers supplements containing food plant-derived molecules (e.g., primary and secondary metabolites, vitamins, and fibers), microbes (probiotics), and microbial-derived fractions (postbiotics). They can control lipid and carbohydrate metabolism, reduce appetite (interacting with the central nervous system) and adipogenesis, influence intestinal microbiota activity, and increase energy expenditure. Unfortunately, the copious choice of products and different legislation on food supplements worldwide can confuse consumers. This review summarizes the activity and toxicity of dietary supplements for weight control to clarify their potentiality and adverse reactions. A lack of research regarding commercially available supplements has been noted. Supplements containing postbiotic moieties are of particular interest. They are easier to store and transport and are safe even for people with a deficient immune system.

Key elements determining the intestinal region-specific environment of enteric neurons in type 1 diabetes

Diabetes, as a metabolic disorder, is accompanied with several gastrointestinal (GI) symptoms, like abdominal pain, gastroparesis, diarrhoea or constipation. Serious and complex enteric nervous system damage is confirmed in the background of these diabetic motility complaints. The anatomical length of the GI tract, as well as genetic, developmental, structural and functional differences between its segments contribute to the distinct, intestinal region-specific effects of hyperglycemia. These observations support and highlight the importance of a regional approach in diabetes-related enteric neuropathy. Intestinal large and microvessels are essential for the blood supply of enteric ganglia. Bidirectional morpho-functional linkage exists between enteric neurons and enteroglia, however, there is also a reciprocal communication between enteric neurons and immune cells on which intestinal microbial composition has crucial influence. From this point of view, it is more appropriate to say that enteric neurons partake in multidirectional communication and interact with these key players of the intestinal wall. These interplays may differ from segment to segment, thus, the microenvironment of enteric neurons could be considered strictly regional. The goal of this review is to summarize the main tissue components and molecular factors, such as enteric glia cells, interstitial cells of Cajal, gut vasculature, intestinal epithelium, gut microbiota, immune cells, enteroendocrine cells, pro-oxidants, antioxidant molecules and extracellular matrix, which create and determine a gut region-dependent neuronal environment in diabetes.

Gut Microbiome in the Progression of NAFLD, NASH and Cirrhosis, and Its Connection with Biotics: A Bibliometric Study Using Dimensions Scientific Research Database

There is growing evidence that gut microbiota dysbiosis is linked to the etiopathogenesis of nonalcoholic fatty liver disease (NAFLD), from the initial stage of disease until the progressive stage of nonalcoholic steatohepatitis (NASH) and the final stage of cirrhosis. Conversely, probiotics, prebiotics, and synbiotics have shown promise in restoring dysbiosis and lowering clinical indicators of disease in a number of both preclinical and clinical studies. Additionally, postbiotics and parabiotics have recently garnered some attention. The purpose of this bibliometric analysis is to assess recent publishing trends concerning the role of the gut microbiome in the progression of NAFLD, NASH and cirrhosis and its connection with biotics. The free access version of the Dimensions scientific research database was used to find publications in this field from 2002 to 2022. VOSviewer and Dimensions' integrated tools were used to analyze current research trends. Research into the following topics is expected to emerge in this field: (1) evaluation of risk factors which are correlated with the progression of NAFLD, such as obesity and metabolic syndrome; (2) pathogenic mechanisms, such as liver inflammation through toll-like receptors activation, or alteration of short-chain fatty acids metabolisms, which contribute to NAFLD development and its progression in more severe forms, such as cirrhosis; (3) therapy for cirrhosis through dysbiosis reduction, and research on hepatic encephalopathy a common consequence of cirrhosis; (4) evaluation of diversity, and composition of gut microbiome under NAFLD, and as it varies under NASH and cirrhosis by rRNA gene sequencing, a tool which can also be used for the development of new probiotics and explore into the impact of biotics on the gut microbiome; (5) treatments to reduce dysbiosis with new probiotics, such as Akkermansia, or with fecal microbiome transplantation.

In Vitro Production of Galactooligosaccharides by a Novel β-Galactosidase of Lactobacillus bulgaricus

β-galactosidase is an enzyme with dual activity and important industrial application. As a hydrolase, the enzyme eliminates lactose in milk, while as a trans-galactosidase it produces prebiotic galactooligosaccharides (GOS) with various degrees of polymerization (DP). The aim of the present study is the molecular characterization of β-galactosidase from a Bulgarian isolate, Lactobacillus delbrueckii subsp. bulgaricus 43. The sequencing of the β-gal gene showed that it encodes a new enzyme with 21 amino acid replacements compared to all other β-galactosidases of this species. The molecular model revealed that the new β-galactosidase acts as a tetramer. The amino acids D207, H386, N464, E465, Y510, E532, H535, W562, N593, and W980 form the catalytic center and interact with Mg²⁺ ions and substrate. The β-gal gene was cloned into a vector allowing heterologous expression of E. coli BL21(DE3) with high efficiency, as the crude enzyme reached 3015 U/mL of the culture or 2011 U/mg of protein. The enzyme's temperature optimum at 55 °C, a pH optimum of 6.5, and a positive influence of Mg²⁺, Mn²⁺, and Ca²⁺ on its activity were observed. From lactose, β-Gal produced a large amount of GOS with DP3 containing β-(1→3) and β-(1→4) linkages, as the latter bond is particularly atypical for the L. bulgaricus enzymes. DP3-GOS formation was positively affected by high lactose concentrations. The process of lactose conversion was rapid, with a 34% yield of DP3-GOS in 6 h, and complete degradation of 200 g/L of lactose for 12 h. On the other hand, the enzyme was quite stable at 55 °C and retained about 20% of its activity after 24 h of incubation at this temperature. These properties expand our horizons as regards the use of β-galactosidases in industrial processes for the production of lactose-free milk and GOS-enriched foods.

Novel insights into the pathogenic impact of diabetes on the gastrointestinal tract

Type 2 and type 1 diabetes are common endocrine disorders with a progressively increasing incidence worldwide. These chronic, systemic diseases have multiorgan implications, and the whole gastrointestinal (GI) tract represents a frequent target in terms of symptom appearance and interdependent pathophysiological mechanisms. Metabolic alterations linked with diabetic complications, neuropathy and disrupted hormone homeostasis can lead to upper and/or lower GI symptoms in up to 75% of diabetic patients, with multifactorial involvement of the oesophagus, stomach, upper and lower intestine, and of the gallbladder. On the other hand, altered gastrointestinal motility and/or secretions are able to affect glucose and lipid homeostasis in the short and long term. Finally, diabetes has been linked with increased cancer risk at different levels of the GI tract. The presence of GI symptoms and a comprehensive assessment of GI function should be carefully considered in the management of diabetic patients to avoid further complications and to ameliorate the quality of life. Additionally, the presence of gastrointestinal dysfunction should be adequately managed to improve metabolic homeostasis, the efficacy of antidiabetic treatments and secondary prevention strategies.

The Effect of Probiotic Strains on Myocardial Infarction Size, Biochemical and Immunological Parameters in Rats with Systemic Inflammatory Response Syndrome and Polymorbidity

Numerous experimental and clinical studies have shown the effectiveness of various probiotic strains in metabolic disorders, gastrointestinal and liver diseases, immune system pathology. The effects of probiotics on cardiovascular dysfunction are less well known. The development and validation of a new experimental model in rats, including obesity, acute colon inflammation and antibiotic-induced dysbiosis, with common characteristics of systemic inflammatory response syndrome (SIRS), became the basis for investigating the effects of probiotic drugs on myocardial resistance to ischemic-reperfusion injury (IRI) using an in vivo model of infarction after coronary occlusion. A 24% increase in myocardial infarction compared to intact animals (p < 0.05) and significant changes in leukogram, biochemical and immunological parameters were found in Wistar rats with SIRS modelling. Introduction of a mixture of strains of Lactobacillus acidophilus (LA-5) and Bifidobacterium animalis subsp. lactis (BB-12) to animals with SIRS reduced infarct size to a value close to the control. Rats treated with LA-5 and BB-12 also showed normalization of the leukocyte count, bile acids, transforming growth factor-β, interleukins: IL-1α, IL-2, IL-6, IL-8, tumor necrosis factor-α, lipopolysaccharide and monocyte chemoattractant protein-1 in blood in comparison with the SIRS group and with the groups treated with other probiotic strains. The obtained data convincingly show the prospects for further study of the cardiotropic potential of probiotic microorganisms in translational studies.

Salidroside Affects Gut Microbiota Structure in db/db Mice by Affecting Insulin, Blood Glucose and Body Weight

PURPOSE

The purpose of this study was to investigate the regulatory effect of salidroside on the intestinal flora of mice with type 2 diabetes (T2DM) and its protective effect in the body.

PATIENTS AND METHODS

We acclimated 8-week-old mice for 7 days, divided them into 4 groups, and continued dosing for 8 weeks. We recorded weekly blood glucose levels and body weight for each mouse. After the completion of the feeding cycle, the 16S rRNA of the intestinal flora in the mice was sequenced, and the insulin and C-peptide levels in each group of mice were measured. Four samples were taken from each group for liver and kidney section staining.

RESULTS

Our results showed that gut microbiota diversity and function were significantly different between the diabetic mice and healthy mice and that insulin levels, body weight, and blood glucose levels could significantly influence gut microbiota changes at the genus level. The gut microbiota diversity and function of db/db mice were also altered after salidroside administration. Salidroside could attenuate inflammatory damage, lipid accumulation and inflammatory changes in the diabetic liver, as well as diabetic kidney damage. Candidatus arthromitus and Odoribacter are important species of the microbiota during diabetes and may serve as potential therapeutic targets.

CONCLUSION

Our investigation of the associated pathological conditions and fecal microbiota in db/db mice provides new insights into the pathogenesis of T2DM and provides implications for the diagnosis and treatment of T2DM.