Gut microbiota and type 2 diabetes mellitus

Associations of composite dietary antioxidant index with suicidal ideation incidence and mortality among the U.S. population

Background

The relationship between CDAI and suicidal ideation is unclear. This study investigates the relationship between CDAI and suicidal ideation and examines the association between CDAI and all-cause mortality (ACM) or cardiovascular disease mortality (CVM) among participants with and without suicidal ideation.

Methods

Data from seven NHANES cycles (2005-2018) were analyzed using cross-sectional and prospective cohort studies. Weighted multivariable logistic regression models, restricted cubic spline (RCS) plots, and subgroup analyses explored the association between CDAI and suicidal ideation. Kaplan-Meier (KM) curves, weighted multivariable Cox proportional hazards models, and RCS assessed the relationship between CDAI and CVM or ACM.

Results

Among 30,976 participants aged over 20, 1,154 (3.72%) had suicidal ideation. Higher CDAI levels (Quartile 4) were associated with a 28% reduction in suicidal ideation compared to lower levels (Quartile 1). Over an average follow-up of 89 months, 3,267 participants (7.6%) died, including 808 (1.8%) from cardiovascular causes. Higher CDAI levels were linked to a 30, 68, and 28% reduction in ACM in the total population, those with suicidal ideation, and those without, respectively. CVM was reduced by 40% in the total population and by 41% in those without suicidal ideation.

Conclusion

CDAI is negatively associated with suicidal ideation and correlated with reduced ACM and CVM among participants with and without suicidal ideation.

The underlying causes, treatment options of gut microbiota and food habits in type 2 diabetes mellitus: a narrative review

Type 2 diabetes mellitus is a long-lasting endocrine disorder characterized by persistent hyperglycaemia, which is often triggered by an entire or relative inadequacy of insulin production or insulin resistance. As a result of resistance to insulin (IR) and an overall lack of insulin in the body, type 2 diabetes mellitus (T2DM) is a metabolic illness that is characterized by hyperglycaemia. Notably, the occurrence of vascular complications of diabetes and the advancement of IR in T2DM are accompanied by dysbiosis of the gut microbiota. Due to the difficulties in managing the disease and the dangers of multiple accompanying complications, diabetes is a chronic, progressive immune-mediated condition that plays a significant clinical and health burden on patients. The frequency and incidence of diabetes among young people have been rising worldwide. The relationship between the gut microbiota composition and the physio-pathological characteristics of T2DM proposes a novel way to monitor the condition and enhance the effectiveness of therapies. Our knowledge of the microbiota of the gut and how it affects health and illness has changed over the last 20 years. Species of the genus Eubacterium, which make up a significant portion of the core animal gut microbiome, are some of the recently discovered 'generation' of possibly helpful bacteria. In this article, we have focused on pathogenesis and therapeutic approaches towards T2DM, with a special reference to gut bacteria from ancient times to the present day.

Gut microbiota in relationship to diabetes mellitus and its late complications with a focus on diabetic foot syndrome: A review

Diabetes mellitus is a chronic disease affecting glucose metabolism. The pathophysiological reactions underpinning the disease can lead to the development of late diabetes complications. The gut microbiota plays important roles in weight regulation and the maintenance of a healthy digestive system. Obesity, diabetes mellitus, diabetic retinopathy, diabetic nephropathy and diabetic neuropathy are all associated with a microbial imbalance in the gut. Modern technical equipment and advanced diagnostic procedures, including xmolecular methods, are commonly used to detect both quantitative and qualitative changes in the gut microbiota. This review summarises collective knowledge on the role of the gut microbiota in both types of diabetes mellitus and their late complications, with a particular focus on diabetic foot syndrome.

Gut-targeted therapies for type 2 diabetes mellitus: A review

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by hyperglycemia and insulin resistance. The global prevalence of T2DM has reached epidemic proportions, affecting approximately 463 million adults worldwide in 2019. Current treatments for T2DM include lifestyle modifications, oral antidiabetic agents, and insulin therapy. However, these therapies may carry side effects and fail to achieve optimal glycemic control in some patients. Therefore, there is a growing interest in the role of gut microbiota and more gut-targeted therapies in the management of T2DM. The gut microbiota, which refers to the community of microorganisms that inhabit the human gut, has been shown to play a crucial role in the regulation of glucose metabolism and insulin sensitivity. Alterations in gut microbiota composition and diversity have been observed in T2DM patients, with a reduction in beneficial bacteria and an increase in pathogenic bacteria. This dysbiosis may contribute to the pathogenesis of the disease by promoting inflammation and impairing gut barrier function. Several gut-targeted therapies have been developed to modulate the gut microbiota and improve glycemic control in T2DM. One potential approach is the use of probiotics, which are live microorganisms that confer health benefits to the host when administered in adequate amounts. Several randomized controlled trials have demonstrated that certain probiotics, such as Lactobacillus and Bifidobacterium species, can improve glycemic control and insulin sensitivity in T2DM patients. Mechanisms may include the production of short-chain fatty acids, the improvement of gut barrier function, and the reduction of inflammation. Another gut-targeted therapy is fecal microbiota transplantation (FMT), which involves the transfer of fecal material from a healthy donor to a recipient. FMT has been used successfully in the treatment of Clostridioides difficile infection and is now being investigated as a potential therapy for T2DM. A recent randomized controlled trial showed that FMT from lean donors improved glucose metabolism and insulin sensitivity in T2DM patients with obesity. However, FMT carries potential risks, including transmission of infectious agents and alterations in the recipient's gut microbiota that may be undesirable. In addition to probiotics and FMT, other gut-targeted therapies are being investigated for the management of T2DM, such as prebiotics, synbiotics, and postbiotics. Prebiotics are dietary fibers that promote the growth of beneficial gut bacteria, while synbiotics combine probiotics and prebiotics. Postbiotics refer to the metabolic products of probiotics that may have beneficial effects on the host. The NIH SPARC program, or the Stimulating Peripheral Activity to Relieve Conditions, is a research initiative aimed at developing new therapies for a variety of health conditions, including T2DM. The SPARC program focuses on using electrical stimulation to activate peripheral nerves and organs, in order to regulate glucose levels in the body. The goal of this approach is to develop targeted, non-invasive therapies that can help patients better manage their diabetes. One promising area of research within the SPARC program is the use of electrical stimulation to activate the vagus nerve, which plays an important role in regulating glucose metabolism. Studies have shown that vagus nerve stimulation can improve insulin sensitivity and lower blood glucose levels in patients with T2DM. Gut-targeted therapies, such as probiotics and FMT, have shown potential for improving glycemic control and insulin sensitivity in T2DM patients. However, further research is needed to determine the optimal dose, duration, and safety of these therapies.

Exploring a Possible Link between the Fecal Microbiota and the Production Performance of Pigs

The backfat thickness of pigs not only affects the physical properties and taste of meat, but it also closely relates to the reproduction performance of sows. Accumulating evidence indicates that, apart from genetic factors, gut microbiota can also modulate the fat deposition and muscle growth. However, the differential microbiota in pigs with different backfat thickness, and whether microbiota affects backfat thickness, remains elusive. Firstly, 16S ribosomal RNA (16S rRNA) gene sequencing was performed on 62 fecal samples from pigs with different backfat thicknesses, and the compositions of microbiota among different groups with different backfat thicknesses were different. The abundance of Lactobacillus. reuteri (L. reuteri) and Prevotella sp RS2 was significantly higher in pigs with low-backfat thickness than that in pigs with middle and high-backfat thickness; meanwhile, the abundance of Desulfovibrio piger was significantly lower (p < 0.05) in pigs with low-backfat thickness. Furthermore, the functional profiling of microbial communities suggested that the abundance of isoquinoline alkaloid biosynthesis and styrene degradation were significantly lower (p < 0.05) in the low-backfat thickness group than that in middle and high-backfat thickness groups. Finally, L. reuteri fed to Meishan piglets was capable of improving the production performance and had the potential to reduce backfat thickness. This study provides new evidence that microbiota can regulate the phenotype of the host, and dietary supplementation with L. reuteri can improve the production performance of piglets.

Heat-Killed Lactiplantibacillus plantarum LRCC5314 Mitigates the Effects of Stress-Related Type 2 Diabetes in Mice via Gut Microbiome Modulation

The incidence of stress-related type 2 diabetes (stress-T2D), which is aggravated by physiological stress, is increasing annually. The effects of Lactobacillus, a key component of probiotics, have been widely studied in diabetes; however, studies on the effects of postbiotics are still limited. Here, we aimed to examine the mechanism through which heat-killed Lactiplantibacillus plantarum LRCC5314 (HK-LRCC5314) alleviates stress-T2D in a cold-induced stress-T2D C57BL/6 mouse model. HK-LRCC5314 markedly decreased body weight gain, adipose tissue (neck, subcutaneous, and epididymal) weight, and fasting glucose levels. In the adipose tissue, mRNA expression levels of stress-T2D associated factors (NPY, Y2R, GLUT4, adiponectin, and leptin) and pro-inflammatory factors (TNF-α, IL-6, and CCL-2) were also altered. Furthermore, HK-LRCC5314 increased the abundance of Barnesiella, Alistipes, and butyrate-producing bacteria, including Akkermansia, in feces and decreased the abundance of Ruminococcus, Dorea, and Clostridium. Thus, these findings suggest that HK-LRCC5314 exerts protective effects against stress-T2D via gut microbiome modulation, suggesting its potential as a supplement for managing stress-T2D.

Patients with ankylosing spondylitis have high risk of irritable bowel syndrome. A long-term nationwide population-based cohort study

OBJECTIVE

Ankylosing spondylitis (AS) is a chronic inflammatory disease, might carry a high risk of irritable bowel syndrome (IBS) due to abnormal gut microbiota or inflammatory reaction.

METHODS

We conducted a 14-year retrospective cohort study based on Taiwan's National Health Insurance Research Database (NHIRD). A total of 4007 patients with newly diagnosed AS (outpatient visits≧3 times, or hospitalization≧1 time) and 988,084 non-AS comparisons were enrolled during 2000-2012. To ensure baseline comparability, the propensity score was matched by age, gender, comorbidities, and other possible confounders. The outcome was the incidence of IBS, followed up to the end of 2013. Cox proportional hazard model calculated adjusted hazard ratio (aHR) and the cumulative incidence of both groups was analyzed by the Kaplan-Meier method.

RESULT

After propensity score matching, baseline demographic characteristics were comparable between AS patients and the comparison group. The crude HR for IBS in the AS group was significantly higher 2.41 (95%C.I. =1.84-3.16) than comparison group. After adjusting for possible confounders, adjusted HR was 2.50 (95%C.I.=1.91-3.29). The cumulative incidence of IBS in AS was significantly higher than non-AS comparisons during the 14-year follow-up (P<0.001).

CONCLUSION

This nationwide population-based cohort study showed that patients with AS have higher risks of IBS than those of the non-AS comparison group.

The Role of the Gut Microbiome in Diabetes and Obesity-Related Kidney Disease

Diabetic kidney disease (DKD) is a progressive disorder, which is increasing globally in prevalence due to the increased incidence of obesity and diabetes mellitus. Despite optimal clinical management, a significant number of patients with diabetes develop DKD. Hence, hitherto unrecognized factors are likely to be involved in the initiation and progression of DKD. An extensive number of studies have demonstrated the role of microbiota in health and disease. Dysregulation in the microbiota resulting in a deficiency of short chain fatty acids (SCFAs) such as propionate, acetate, and butyrate, by-products of healthy gut microbiota metabolism, have been demonstrated in obesity, type 1 and type 2 diabetes. However, it is not clear to date whether such changes in the microbiota are causative or merely associated with the diseases. It is also not clear which microbiota have protective effects on humans. Few studies have investigated the centrality of reduced SCFA in DKD development and progression or the potential therapeutic effects of supplemental SCFAs on insulin resistance, inflammation, and metabolic changes. SCFA receptors are expressed in the kidneys, and emerging data have demonstrated that intestinal dysbiosis activates the renal renin-angiotensin system, which contributes to the development of DKD. In this review, we will summarize the complex relationship between the gut microbiota and the kidney, examine the evidence for the role of gut dysbiosis in diabetes and obesity-related kidney disease, and explore the mechanisms involved. In addition, we will describe the role of potential therapies that modulate the gut microbiota to prevent or reduce kidney disease progression.

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.

Gut microbiota as a target for prevention and treatment of type 2 diabetes: Mechanisms and dietary natural products

Type 2 diabetes mellitus (T2DM) is among the most remarkable public health concerns globally. Accumulating research evidence documents that alteration of gut microbiota has an indispensable role in the onset and progression of obesity and T2DM. A reduced microbial diversity is linked to insulin resistance and energy metabolism, especially for the rise of the Firmicutes/Bacteroidetes ratio. Changes in metabolites followed by the gut dysbacteriosis are linked to the presence of T2DM. Moreover, endotoxin leakage and gut permeability caused by gut dysbacteriosis is more of a trigger for the onset and progression of T2DM. Research documents that natural products are remarkable arsenals of bioactive agents for the discovery of anti-T2DM drugs. Many studies have elucidated that the possible mechanisms of the anti-T2DM effects of natural products are remarkably linked to its regulation on the composition of gut microflora and the successive changes in metabolites directly or indirectly. This review presents a brief overview of the gut microbiota in T2DM and several relevant mechanisms, including short-chain fatty acids, biosynthesis and metabolism of branched-chain fatty acids, trimethylamine N-oxide, bile acid signaling, endotoxin leakage, and gut permeability, and describes how dietary natural products can improve T2DM via the gut microbiota.

Probiotics, prebiotics, and synbiotics added to dairy products: Uses and applications to manage type 2 diabetes

Diabetes mellitus type 2 (T2DM) is associated with hyperglycemia, insulin resistance, and gut dysbiosis. Probiotics and prebiotics can ameliorate T2DM through different mechanisms of action, such as reducing oxidative stress, or the inhibition of pro-inflammatory markers, among others. Multiple studies in vitro and in vivo have demonstrated the reduction of hyperglycemia, depressive behaviors, obesity, oxidative stress, and insulin resistance in diabetic patients through the consumption of dairy products, such as yogurt, fermented milk, and cheese, enriched with potential probiotic strains, prebiotic ingredients, and synbiotics (understood as a combination of both). Therefore, this review aims to provide an updated overview about the impact of dairy foods with probiotics, prebiotics, or synbiotics to prevent and manage T2DM, the mechanism of action related to the host health, and the future tendencies for developing new dairy foods. Despite the addition of probiotics, prebiotics, and synbiotics to dairy products could be highly beneficial, more evidence, especially from clinical trials, is needed to develop evidence-based T2DM prevention guidelines.

Therapeutic potential of melatonin as a chronobiotic and cytoprotective agent in diabetes mellitus

PURPOSE

Diabetes mellitus is a complex metabolic disorder characterized by hyperglycemia occurring as a result of dysregulation and balance of various metabolic pathways. In recent years, circadian misalignment (due to altered sleep/wake, feeding/fasting cycles), has been intimately linked with the development of diabetes mellitus. Herein, we review our knowledge of oxidative stress, circadian rhythms control of metabolism, and the effects of its disruption on homeostasis while emphasizing the importance of melatonin, a nocturnally peaking, pineal hormone, as a potential therapeutic drug for the prevention and treatment of diabetes.

METHODS

PubMed database was systematically searched for related articles and data from all types of studies, including clinical trials, review articles, and case reports were considered without limiting the study to one specific category.

RESULTS

Experimental and epidemiological evidence indicate melatonin's multifaceted effects in intermediary metabolism via resynchronization of the circadian rhythms and its deficiency is associated with metabolic derangements. As a chronobiotic, it cures insomnia and sleep disorders caused by shift work or jet lag. The antagonistic relationship between melatonin and insulin highlights its influence in regulating insulin secretion, its action, and melatonin treatment successfully improved glucose homeostasis, energy balance, and overall health in diabetes mellitus. Melatonin's cytoprotective role as an antioxidant and free radical scavenger, proved useful in combating oxidative stress, preserving beta-cell function, and influencing the development of diabetic complications.

CONCLUSION

The therapeutic application of melatonin as a chronobiotic and cytoprotective agent is of promising significance in diabetes mellitus. Future investigations are encouraged to fully explore the efficacy of this ubiquitous molecule in various metabolic disorders.

Nutrition and immune system: from the Mediterranean diet to dietary supplementary through the microbiota

The interaction between nutrition and the immune system is very complex. In particular, at every stage of the immune response, specific micronutrients, including vitamins and minerals play a key role and often synergistic, and the deficiency of only one essential nutrient may impair immunity. An individual's overall nutrition status and pattern of dietary intake (comprised of nutrients and non-nutritive bioactive compounds and food) and any supplementation with nutraceuticals including vitamins and minerals, can influence positively or negatively the function of the immune system. This influence can occur at various levels from the innate immune system and adaptive immune system to the microbiome. Although there are conflicting evidence, the current results point out that dietary supplementation with some nutrients such as vitamin D and zinc may modulate immune function. An update on the complex relationship between nutrition, diet, and the immune system through gut microbiota is the aim of this current review. Indeed, we will provide the overview of the link among immune function, nutrition and gut microbiota, paying particular attention at the effect of the Mediterranean diet on the immune system, and finally we will speculate the possible role of the main one functional supplements on immune function.

H. pylori Eradication Treatment Alters Gut Microbiota and GLP-1 Secretion in Humans

Changes in the intestinal microbial community and some metabolic disturbances, including obesity and type2 diabetes, are related. Glucagon-like peptide-1 (GLP-1) regulates glucose homeostasis. Microbiota have been linked to incretin secretion. Antibiotic use causes changes in microbial diversity and composition. Our aim was to evaluate the relationship between microbiota changes and GLP-1 secretion. A prospective case-control study with a Helicobacter pylori-positive patient model involving subjects under eradication therapy (omeprazole, clarithromycin, and amoxicillin). Forty patients with H. pylori infection and 20 matched participants, but negative for H. pylori antigen. Patients were evaluated before and two months after treatment. We analyzed anthropometric measurements, carbohydrate metabolism, lipid profile, and C-reactive protein. Gut microbiota composition was analyzed through 16S rRNA amplicon sequencing (IlluminaMiSeq). Eradication treatment for H. pylori decreased bacterial richness (Chao1, p = 0.041). Changes in gut microbiota profiles were observed at phylum, family, genus and species levels. GLP-1 secretion and variables of carbohydrate metabolism were improved. Correlations were seen between GLP-1 changes and variations within microbial community abundances, specifically Bifidobacterium adolescentis, the Lachnobacterium genus, and Coriobacteriaceae family. A conventional treatment to eradicate H. pylori could improve carbohydrate metabolism possibly in relation with an increase in GLP-1 secretion. GLP-1 secretion may be related to alterations in intestinal microbiota, specifically Lachnobacterium, B. adolescentis and Coriobacteriaceae.