The effects of butyrate supplementation on glycemic control, lipid profile, blood pressure, nitric oxide level and glutathione peroxidase activity in type 2 diabetic patients: A randomized triple -blind, placebo-controlled trial

The Effect of Picein on Inhibitory Avoidance Memory and Activity of Antioxidant Enzymes in Hippocampus of Male Rats with Scopolamine-Induced Injury

Alzheimer disease (AD) is a common neurologic disorder, impairing memory and spatial perception. Consistent with the extensive search for its treatment, we investigated the effect of Picein on inhibitory avoidance memory, lipid peroxidation, and the activity of hippocampal antioxidant enzymes in rats. Forty adult male Wistar rats were randomized into control group (no intervention), model group (intraperitoneal injection of 3-mg/kg scopolamine), and three interventional groups (1.5-, 2.5-, and 5-mg/kg intraventricular Picein, once a day for 7 days, 24 h after scopolamine injection). After behavioral test, the rats' hippocampus was isolated for measuring oxidative stress markers, including enzymes superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GPX), catalase (CAT), and total antioxidant capacity (TAC). One-way ANOVA was used for comparing numeric variables among the groups using SPSS v.21. The results showed scopolamine decreased SOD, GPX, and CAT enzymes, and TAC level, and increased MDA level, compared with the control group (P < 0.001) that confirmed the scopolamine-induced AD model. The two doses of 2.5- and 5-mg/kg Picein increased latency for entering the dark room, compared to the scopolamine group (P < 0.05), making them similar to the control group. The number of entries into the dark room in the 2.5-mg/kg Picein reduced and approached the control group (P < 0.05). The 2.5-mg/kg Picein decreased MDA and increased SOD, GPX, and TAC, more than 5 mg/kg Picein, both different than scopolamine; only 2.5-mg/kg Picein had different CAT, compared to scopolamine group (P < 0.05). In conclusion, by lowering oxidative stress in the hippocampus, Picein was able to prevent the scopolamine-induced impaired learning and avoidance memory in rats.

Effect of Sodium Butyrate Supplementation on Type 2 Diabetes-Literature Review

Background: Type 2 diabetes mellitus (T2DM) represents a major global health burden, with prevalence rates escalating due to rapid urbanization, economic growth, and the obesity epidemic. Despite intensive research, the underlying molecular mechanisms remain incompletely understood, with emerging evidence suggesting multifactorial origins involving genetic, epigenetic, lifestyle, and environmental factors. Methods: This review synthesizes current epidemiological data on T2DM prevalence, risk factors, and demographic patterns from 1990 to 2017, and discusses projected trends through 2030. We examine the role of intestinal barrier dysfunction and gut microbiota dysbiosis in T2DM pathogenesis, highlighting key mechanistic insights. Furthermore, we analyze recent findings on the role of butyrate, a major short-chain fatty acid, in preserving gut integrity and its potential therapeutic effects on metabolic health. Results: Global T2DM prevalence has risen markedly across all age groups, with particularly high rates in Western Europe and Pacific Island nations. Disruption of the intestinal barrier ("leaky gut") and gut microbiota alterations contribute significantly to systemic inflammation and insulin resistance, which are pivotal features in T2DM development. Butyrate plays a central role in maintaining epithelial barrier function, modulating immune responses, and regulating glucose metabolism. Preclinical studies have demonstrated that sodium butyrate supplementation improves gut integrity, reduces systemic endotoxemia, and ameliorates metabolic parameters. Emerging clinical evidence suggests benefits of sodium butyrate, particularly when combined with prebiotic fibers, in improving glycemic control and reducing inflammatory markers in T2DM patients. Conclusions: Gut barrier integrity and microbiota composition are critical factors in T2DM pathogenesis. Sodium butyrate shows promise as a complementary therapeutic agent in T2DM management, although further large-scale, long-term clinical trials are required to confirm its efficacy and safety. Targeting gut health may represent a novel strategy for the prevention and treatment of T2DM.

Gut microbiota-derived short-chain fatty acids and their role in human health and disease

Short-chain fatty acids (SCFAs) are a group of organic compounds produced by the fermentation of dietary fibre by the human gut microbiota. They play diverse roles in different physiological processes of the host with implications for human health and disease. This Review provides an overview of the complex microbial metabolism underlying SCFA formation, considering microbial interactions and modulating factors of the gut environment. We explore the multifaceted mechanistic interactions between SCFAs and the host, with a particular focus on the local actions of SCFAs in the gut and their complex interactions with the immune system. We also discuss how these actions influence intestinal and extraintestinal diseases and emerging therapeutic strategies using SCFAs.

Endogenous Metabolites in Metabolic Diseases: Pathophysiologic Roles and Therapeutic Implications

Breakthroughs in metabolomics technology have revealed the direct regulatory role of metabolites in physiology and disease. Recent data have highlighted the bioactive metabolites involved in the etiology and prevention and treatment of metabolic diseases such as obesity, nonalcoholic fatty liver disease, type 2 diabetes mellitus, and atherosclerosis. Numerous studies reveal that endogenous metabolites biosynthesized by host organisms or gut microflora regulate metabolic responses and disorders. Lipids, amino acids, and bile acids, as endogenous metabolic modulators, regulate energy metabolism, insulin sensitivity, and immune response through multiple pathways, such as insulin signaling cascade, chemical modifications, and metabolite-macromolecule interactions. Furthermore, the gut microbial metabolites short-chain fatty acids, as signaling regulators have a variety of beneficial impacts in regulating energy metabolic homeostasis. In this review, we will summarize information about the roles of bioactive metabolites in the pathogenesis of many metabolic diseases. Furthermore, we discuss the potential value of metabolites in the promising preventive and therapeutic perspectives of human metabolic diseases.

Plant-based antioxidant peptides: impact on oxidative stress and gut microbiota

Plant-based peptides can be obtained from natural and climate-friendly sources. These peptides show various bioactivities including antioxidant activity. Oxidative stress has an impact on the gut microbiota causing inflammation, insulin resistance, osteoporosis, cancer, and several chronic diseases like type 2 diabetes, arthritis, hypertension, and atherosclerosis. Therefore, antioxidant peptides may significantly affect oxidative stress as a potential alternative to conventional medication. The production of antioxidant peptides from plant-based protein sources through conventional and innovative approaches may provide promising strategies to improve gut microbiota. Recent studies in plant-based antioxidant peptides (PBAP) focus on their advanced identification and characterization techniques, structure-activity relationship, improvement of extraction and purification, cellular and molecular mechanisms, specific health applications in preventing and managing conditions with gut microbiota, and commercial applications in nutraceuticals. Short-chain fatty acids and reactive sulfur species are specific gut-derived metabolites that can improve metabolic function by modulating oxidative stress and the immune system. This review highlights the influence of food oxidants on the gut microbiota and PBAP-induced modulation of gut microbiota. Moreover, the production of PBAP and the challenges in their application will be discussed.

The Role of Short-Chain Fatty Acids in Metabolic Dysfunction-Associated Steatotic Liver Disease and Other Metabolic Diseases

With its increasing prevalence, metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as a major global public health concern over the past few decades. Growing evidence has proposed the microbiota-derived metabolites short-chain fatty acids (SCFAs) as a potential factor in the pathophysiology of MASLD and related metabolic conditions, such as obesity and type 2 diabetes mellitus (T2DM). By influencing key pathways involved in energy homeostasis, insulin sensitivity, and inflammation, SCFAs play an important role in gut microbiota composition, intestinal barrier function, immune modulation, and direct metabolic signaling. Furthermore, recent animal and human studies on therapeutic strategies targeting SCFAs demonstrate their potential for treating these metabolic disorders.

Novel insights into the role of gut microbiota and its metabolites in diabetic chronic wounds

Wounds in patients with diabetes present significant physical and economic challenges due to impaired healing and prolonged inflammation, exacerbated by complex interactions between microbes. Especially, the development and healing of diabetic foot ulcers (DFUs) remain an urgent clinical problem. The human gut harbors a vast microbial ecosystem comprising intestinal flora and their metabolic products. Recent advancements in research have illuminated the concept of the "gut-skin axis," revealing intricate relationships between gut microbiota, microbiota-derived metabolites, and various skin diseases, including DFUs. This review aims to unravel the formation and healing process of DFUs in the context of the gut-skin axis. We reviewed the current research progress worldwide regarding to the gut-skin axis, compared and discussed significant changes in the microbiota colonizing the skin and gut in patients with DFUs. The roles of microbiota-derived metabolites such as lipopolysaccharides, short-chain fatty acids, and trimethylamine-N-oxide in the development of DFUs are highlighted. We also reviewed treatment strategies currently employed in clinical practice and identified potential therapeutic targets such as probiotics for treating DFUs. The need for more comprehensive experimental designs to elucidate the intricate relationship between gut microbiota and its metabolites in the context of DFUs are therefore highlighted.

Butyrate: A potential mediator of obesity and microbiome via different mechanisms of actions

Butyrate, a short-chain fatty acid, is a crucial product of gut microbial fermentation with significant implications for various metabolic and physiological processes. Dietary sources of butyrate are limited, primarily derived from the fermentation of dietary fibers by butyrate-producing gut bacteria. Butyrate exerts its effects primarily as a histone deacetylase (HDAC) inhibitor and through signaling pathways involving G protein-coupled receptors (GPCRs). Its diverse benefits include promoting gut health, enhancing energy metabolism, and potentially alleviating complications associated with obesity. However, the exact role of butyrate in obesity is still under investigation, with a limited number of human trials necessitating further research to determine its efficacy and safety profile. Moreover, butyrate impact on the gut-brain axis and its modulation of microbiome effect on behavior highlight its broader importance in regulating host physiology. A thorough understanding of the metabolic pathways and mechanisms of butyrate is essential for developing targeted interventions for metabolic disorders. Continued research is crucial to fully realize its therapeutic potential and optimize its clinical applications in human health. In summary, this review illuminates the multifaceted role of butyrate as a potential mediator of obesity and related metabolic changes.

Research Progress in the Relationship between Intestinal Flora and Diabetes Mellitus

Diabetes mellitus is a common chronic metabolic disease characterized by a high incidence and disability rate. Intestinal flora refers to the microbial community that lives in the intestines and plays a crucial role in maintaining intestinal health and the human immune system. In recent years, an increasing body of research has revealed a close relationship between intestinal flora and diabetes. The pathophysiological mechanisms between them have also been constantly uncovered, and the regulation of intestinal flora has shown promising efficacy in the adjuvant treatment of diabetes. This study mainly summarized the characteristics and mechanisms of intestinal flora in patients with diabetes in recent years, as well as the methods of regulating intestinal flora to prevent and treat diabetes, and prospected the future research direction. This will offer a theoretical basis for the clinical adjuvant treatment of diabetes with intestinal flora and the development of new drugs.

Low-Molecular-Weight Compounds Produced by the Intestinal Microbiota and Cardiovascular Disease

Cardiovascular disease is the main cause of mortality in industrialized countries, with over 500 million people affected worldwide. In this work, the roles of low-molecular-weight metabolites originating from the gut microbiome, such as short-chain fatty acids, hydrogen sulfide, trimethylamine, phenylacetic acid, secondary bile acids, indoles, different gases, neurotransmitters, vitamins, and complex lipids, are discussed in relation to their CVD-promoting or preventing activities. Molecules of mixed microbial and human hepatic origin, such as trimethylamine N-oxide and phenylacetylglutamine, are also presented. Finally, dietary agents with cardioprotective effects, such as probiotics, prebiotics, mono- and poly-unsaturated fatty acids, carotenoids, and polyphenols, are also discussed. A special emphasis is given to their gut microbiota-modulating properties.

The gut microbiota and diabetes: research, translation, and clinical applications - 2023 Diabetes, Diabetes Care, and Diabetologia Expert Forum

This article summarises the state of the science on the role of the gut microbiota (GM) in diabetes from a recent international expert forum organised by Diabetes, Diabetes Care, and Diabetologia, which was held at the European Association for the Study of Diabetes 2023 Annual Meeting in Hamburg, Germany. Forum participants included clinicians and basic scientists who are leading investigators in the field of the intestinal microbiome and metabolism. Their conclusions were as follows: (1) the GM may be involved in the pathophysiology of type 2 diabetes, as microbially produced metabolites associate both positively and negatively with the disease, and mechanistic links of GM functions (e.g. genes for butyrate production) with glucose metabolism have recently emerged through the use of Mendelian randomisation in humans; (2) the highly individualised nature of the GM poses a major research obstacle, and large cohorts and a deep-sequencing metagenomic approach are required for robust assessments of associations and causation; (3) because single time point sampling misses intraindividual GM dynamics, future studies with repeated measures within individuals are needed; and (4) much future research will be required to determine the applicability of this expanding knowledge to diabetes diagnosis and treatment, and novel technologies and improved computational tools will be important to achieve this goal.

Sodium butyrate prevents cytokine-induced β-cell dysfunction through restoration of stromal interaction molecule 1 expression and activation of store-operated calcium entry

Sodium butyrate (NaB) improves β-cell function in preclinical models of diabetes; however, the mechanisms underlying these beneficial effects have not been fully elucidated. In this study, we investigated the impact of NaB on β-cell function and calcium (Ca2+) signaling using ex vivo and in vitro models of diabetes. Our results show that NaB significantly improved glucose-stimulated insulin secretion in islets from human organ donors with type 2 diabetes and in cytokine-treated INS-1 β cells. Consistently, NaB improved glucose-stimulated Ca2+ oscillations in mouse islets treated with proinflammatory cytokines. Because the oscillatory phenotype of Ca2+ in the β cell is governed by changes in endoplasmic reticulum (ER) Ca2+ levels, we explored the relationship between NaB and store-operated calcium entry (SOCE), a rescue mechanism that acts to refill ER Ca2+ levels through STIM1-mediated gating of plasmalemmal Orai channels. We found that NaB treatment preserved basal ER Ca2+ levels and restored SOCE in IL-1β-treated INS-1 cells. Furthermore, we linked these changes with the restoration of STIM1 levels in cytokine-treated INS-1 cells and mouse islets, and we found that NaB treatment was sufficient to prevent β-cell death in response to IL-1β treatment. Mechanistic experiments revealed that NaB mediated these beneficial effects in the β-cell through histone deacetylase (HDAC) inhibition, iNOS suppression, and modulation of AKT-GSK-3 signaling. Taken together, these data support a model whereby NaB treatment promotes β-cell function and Ca2+ homeostasis under proinflammatory conditions through pleiotropic effects that are linked with maintenance of SOCE. These results also suggest a relationship between β-cell SOCE and gut microbiome-derived butyrate that may be relevant in the treatment and prevention of diabetes.

Genomic and functional diversity of the human-derived isolates of Faecalibacterium

Introduction

Faecalibacterium is one of the most abundant bacteria in the gut microbiota of healthy adults, highly regarded as a next-generation probiotic. However, the functions of Faecalibacterium genomes from cultured strains and the distribution of different species in populations may differ among different sources.

Methods

We here performed an extensive analysis of pan-genomes, functions, and safety evaluation of 136 Faecalibacterium genomes collected from 10 countries.

Results

The genomes are clustered into 11 clusters, with only five of them were characterized and validly nomenclated. Over 80% of the accessory genes and unique genes of Faecalibacterium are found with unknown function, which reflects the importance of expanding the collection of Faecalibacterium strains. All the genomes have the potential to produce acetic acid and butyric acid. Nine clusters of Faecalibacterium are found significantly enriched in the healthy individuals compared with patients with type II diabetes..

Discussion

This study provides a comprehensive view of genomic characteristic and functions and of culturable Faecalibacterium bacterium from human gut, and enables clinical advances in the future.

Short-Chain Fatty Acids and Human Health: From Metabolic Pathways to Current Therapeutic Implications

The gastrointestinal tract is home to trillions of diverse microorganisms collectively known as the gut microbiota, which play a pivotal role in breaking down undigested foods, such as dietary fibers. Through the fermentation of these food components, short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate are produced, offering numerous health benefits to the host. The production and absorption of these SCFAs occur through various mechanisms within the human intestine, contingent upon the types of dietary fibers reaching the gut and the specific microorganisms engaged in fermentation. Medical literature extensively documents the supplementation of SCFAs, particularly butyrate, in the treatment of gastrointestinal, metabolic, cardiovascular, and gut-brain-related disorders. This review seeks to provide an overview of the dynamics involved in the production and absorption of acetate, propionate, and butyrate within the human gut. Additionally, it will focus on the pivotal roles these SCFAs play in promoting gastrointestinal and metabolic health, as well as their current therapeutic implications.

Harnessing and delivering microbial metabolites as therapeutics via advanced pharmaceutical approaches

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

Short-Chain Fatty Acids-A Product of the Microbiome and Its Participation in Two-Way Communication on the Microbiome-Host Mammal Line

PURPOSE OF REVIEW

The review aims to describe short-chain fatty acids (SCFAs) as metabolites of bacteria, their complex influence on whole-body metabolism, and alterations in the SCFA profile in obesity and after bariatric surgery (BS).

RECENT FINDINGS

The fecal profile of SCFAs in obese patients differs from that of lean patients, as well as their gut microbiota composition. In obese patients, a lower diversity of bacteria is observed, as well as higher concentrations of SCFAs in stool samples. Obesity is now considered a global epidemic and bariatric surgery (BS) is an effective treatment for severe obesity. BS affects the structure and functioning of the digestive system, and also alters gut microbiota and the concentration of fecal SCFAs. Generally, after BS, SCFA levels are lower but levels of branched short-chain fatty acids (BSCFAs) are elevated, the effect of which is not fully understood. Moreover, changes in the profile of circulating SCFAs are little known and this is an area for further research. Obesity seems to be inherently associated with changes in the SCFA profile. It is necessary to better understand the impact of BS on microbiota and the metabolome in both feces and blood as only a small percentage of SCFAs are excreted. Further research may allow the development of a personalized therapeutic approach to the BS patient in terms of diet and prebiotic intervention.

A microbiome-targeting fibre-enriched nutritional formula is well tolerated and improves quality of life and haemoglobin A1c in type 2 diabetes: A double-blind, randomized, placebo-controlled trial

AIMS

To investigate a prebiotic fibre-enriched nutritional formula on health-related quality of life and metabolic control in type 2 diabetes.

MATERIALS AND METHODS

This was a 12-week, double-blind, placebo-controlled study with an unblinded dietary advice only comparator arm. Participants were randomized 2:1:1 to a prebiotic fibre-enriched nutritional formula (Active), a placebo fibre-absent nutritional formula (Placebo), or non-blinded dietary advice alone (Diet). Primary endpoint was change in core Type 2 Diabetes Distress Assessment System (cT2-DDAS) at week 12. Glycated haemoglobin (HbA1c) change was a key secondary endpoint.

RESULTS

In total, 192 participants were randomized. Mean age was 54.3 years, HbA1c 7.8%, and body mass index 35.9 kg/m2 . At week 12, cT2-DDAS reduced significantly in Active versus Placebo (-0.4, p = .03), and HbA1c was reduced significantly in Active vs Placebo (-0.64%, p = .01). Gut microbiome sequencing revealed that the relative abundance of two species of butyrate-producing bacteria (Roseburia faecis and Anaerostipes hadrus) increased significantly in Active vs. Placebo.

CONCLUSIONS

A microbiome-targeting nutritional formula significantly improved cT2-DDAS and HbA1c, suggesting the potential for prebiotic fibre as a complement to lifestyle and/or pharmaceutical interventions for managing type 2 diabetes.

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

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

Protective role of butyrate in obesity and diabetes: New insights

Studies in human microbiota dysbiosis have shown that short-chain fatty acids (SCFAs) like propionate, acetate, and particularly butyrate, positively affect energy homeostasis, behavior, and inflammation. This positive effect can be demonstrated in the reduction of butyrate-producing bacteria observed in the gut microbiota of individuals with type 2 diabetes (T2DM) and other energy-associated metabolic alterations. Butyrate is the major end product of dietary fiber bacterial fermentation in the large intestine and serves as the primary energy source for colonocytes. In addition, it plays a key role in reducing glycemia and improving body weight control and insulin sensitivity. The major mechanisms involved in butyrate regulation include key signaling pathways such as AMPK, p38, HDAC inhibition, and cAMP production/signaling. Treatment strategies using butyrate aim to increase its intestine levels, bioavailability, and improvement in delivery either through direct supplementation or by increasing dietary fiber in the diet, which ultimately generates a higher production of butyrate in the gut. In the final part of this review, we present a summary of the most relevant studies currently being carried out in humans.

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

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