The role of gut microbiota (GM) and GM-related metabolites in diabetes and obesity. A review of analytical methods used to measure GM-related metabolites in fecal samples with a focus on metabolites' derivatization step

Gut microbiota and atrial cardiomyopathy

Atrial cardiomyopathy is a multifaceted heart disease characterized by structural and functional abnormalities of the atria and is closely associated with atrial fibrillation and its complications. Its etiology involves a number of factors, including genetic, infectious, immunologic, and metabolic factors. Recent research has highlighted the critical role of the gut microbiota in the pathogenesis of atrial cardiomyopathy, and this is consistent with the gut-heart axis having major implications for cardiac health. The aim of this work is to bridge the knowledge gap regarding the interactions between the gut microbiota and atrial cardiomyopathy, with a particular focus on elucidating the mechanisms by which gut dysbiosis may induce atrial remodeling and dysfunction. This article provides an overview of the role of the gut microbiota in the pathogenesis of atrial cardiomyopathy, including changes in the composition of the gut microbiota and the effects of its metabolites. We also discuss how diet and exercise affect atrial cardiomyopathy by influencing the gut microbiota, as well as possible future therapeutic approaches targeting the gut-heart axis. A healthy gut microbiota can prevent disease, but ecological dysbiosis can lead to a variety of symptoms, including the induction of heart disease. We focus on the pathophysiological aspects of atrial cardiomyopathy, the impact of gut microbiota dysbiosis on atrial structure and function, and therapeutic strategies exploring modulation of the microbiota for the treatment of atrial cardiomyopathy. Finally, we discuss the role of gut microbiota in the treatment of atrial cardiomyopathy, including fecal microbiota transplantation and oral probiotics or prebiotics. Our study highlights the importance of gut microbiota homeostasis for cardiovascular health and suggests that targeted interventions on the gut microbiota may pave the way for innovative preventive and therapeutic strategies targeting atrial cardiomyopathy.

Influence of Drugs and Toxins on Decomposition Dynamics: Forensic Implications

Drug and toxin-related deaths are common worldwide, making it essential to detect the postmortem concentration of various toxic substances at different stages of decomposition in a corpse. Indeed, determining the postmortem interval (PMI) and cause of death in an advanced stage of decomposed corpses has been a significant challenge in forensic investigations. Notably, the presence of drugs or toxins can have a significant impact on the microbial profile, potentially altering the succession of microbial communities and subsequent production of volatile organic compounds (VOCs), which, in turn, affect insect colonization patterns. This review aims to highlight the importance of investigating the interactions between drugs or toxins, microbial succession, VOC profiles, and insect behavior, which can provide valuable insights into forensic investigations as well as the ecological consequences of toxins occurring in decomposition. Overall, the detection of drugs and other toxins at different stages of decomposition can yield more precise forensic evidence, thereby enhancing the accuracy of PMI estimation and determination of the cause of death in decomposed remains.

Effects of bacterial extracellular vesicles derived from oral and gastrointestinal pathogens on systemic diseases

Oral microbiota and gastrointestinal microbiota, the two largest microbiomes in the human body, are closely correlated and frequently interact through the oral-gut axis. Recent research has focused on the roles of these microbiomes in human health and diseases. Under normal conditions, probiotics and commensal bacteria can positively impact health. However, altered physiological states may induce dysbiosis, increasing the risk of pathogen colonization. Studies suggest that oral and gastrointestinal pathogens contribute not only to localized diseases at their respective colonized sites but also to the progression of systemic diseases. However, the mechanisms by which bacteria at these local sites are involved in systemic diseases remain elusive. In response to this gap, the focus has shifted to bacterial extracellular vesicles (BEVs), which act as mediators of communication between the microbiota and the host. Numerous studies have reported the targeted delivery of bacterial pathogenic substances from the oral cavity and the gastrointestinal tract to distant organs via BEVs. These pathogenic components subsequently elicit specific cellular responses in target organs, thereby mediating the progression of systemic diseases. This review aims to elucidate the extensive microbial communication via the oral-gut axis, summarize the types and biogenesis mechanisms of BEVs, and highlight the translocation pathways of oral and gastrointestinal BEVs in vivo, as well as the impacts of pathogens-derived BEVs on systemic diseases.

Comparative characterization of the infant gut microbiome and their maternal lineage by a multi-omics approach

The human gut microbiome establishes and matures during infancy, and dysregulation at this stage may lead to pathologies later in life. We conducted a multi-omics study comprising three generations of family members to investigate the early development of the gut microbiota. Fecal samples from 200 individuals, including infants (0-12 months old; 55% females, 45% males) and their respective mothers and grandmothers, were analyzed using two independent metabolomics platforms and metagenomics. For metabolomics, gas chromatography and capillary electrophoresis coupled to mass spectrometry were applied. For metagenomics, both 16S rRNA gene and shotgun sequencing were performed. Here we show that infants greatly vary from their elders in fecal microbiota populations, function, and metabolome. Infants have a less diverse microbiota than adults and present differences in several metabolite classes, such as short- and branched-chain fatty acids, which are associated with shifts in bacterial populations. These findings provide innovative biochemical insights into the shaping of the gut microbiome within the same generational line that could be beneficial in improving childhood health outcomes.

The interplay between oral microbiota, gut microbiota and systematic diseases

Over the past two decades, the importance of microbiota in health and disease has become evident. The human gut microbiota and oral microbiota are the largest and second-largest microbiome in the human body, respectively, and they are physically connected as the oral cavity is the beginning of the digestive system. Emerging and exciting evidence has shown complex and important connections between gut microbiota and oral microbiota. The interplay of the two microbiomes may contribute to the pathological processes of many diseases, including diabetes, rheumatoid arthritis, nonalcoholic fatty liver disease, inflammatory bowel disease, pancreatic cancer, colorectal cancer, and so on. In this review, we discuss possible routes and factors of oral microbiota to affect gut microbiota, and the contribution of this interplay between oral and gut microbiota to systemic diseases. Although most studies are association studies, recently, there have been increasing mechanistic investigations. This review aims to enhance the interest in the connection between oral and gut microbiota, and shows the tangible impact of this connection on human health.

In Vitro Fermentation of Pleurotus eryngii Mushrooms by Human Fecal Microbiota: Metataxonomic Analysis and Metabolomic Profiling of Fermentation Products

Edible mushrooms contain biologically active compounds with antioxidant, antimicrobial, immunomodulatory and anticancer properties. The link between their anticancer and immunomodulatory properties with their possible prebiotic activity on gut micro-organisms has been the subject of intense research over the last decade. Lyophilized Pleurotus eryngii (PE) mushrooms, selected due to their strong lactogenic effect and anti-genotoxic, immunomodulatory properties, underwent in vitro static batch fermentation for 24 h by fecal microbiota from eight elderly apparently healthy volunteers (>65 years old). The fermentation-induced changes in fecal microbiota communities were examined using Next Generation Sequencing of the hypervariable regions of the 16S rRNA gene. Primary processing and analysis were conducted using the Ion Reporter Suite. Changes in the global metabolic profile were assessed by 1H NMR spectroscopy, and metabolites were assigned by 2D NMR spectroscopy and the MetaboMiner platform. PLS-DA analysis of both metataxonomic and metabolomic data showed a significant cluster separation of PE fermented samples relative to controls. DEseq2 analysis showed that the abundance of families such as Lactobacillaceae and Bifidobacteriaceae were increased in PE samples. Accordingly, in metabolomics, more than twenty metabolites including SCFAs, essential amino acids, and neurotransmitters discriminate PE samples from the respective controls, further validating the metataxonomic findings.

Gut Microbiome Composition in Patients with Chronic Urticaria: A Review of Current Evidence and Data

Recent studies have linked gut microorganism composition and chronic urticaria (CU); however, the underlying mechanisms responsible for this connection are unknown. Since the human immune system is in homeostasis with microbiota, and the composition of the microbiome regulates the development and function of the immune system, it is likely that an alteration of microbiota components (a dysbiosis) could influence the course of chronic spontaneous urticaria (CSU), including disease severity, patient quality of life and treatment outcome. To date, several studies have identified changes in the gut microbiota composition of patients with CSU, though only a few have exhibited metabolic abnormalities associated with gut dysbiosis. The studies on CSU patients predominantly showed that the relative abundance of beneficial bacteria was decreased (Firmicutes and Bacteroides), while that of opportunistic bacteria was increased (Enterobacteria and Proteobacteria). In addition, serum metabolome analysis revealed that gut microbiota-associated alterations in unsaturated fatty acids and the butanoate metabolism pathway may play a role in CSU. These findings are potentially associated with inflammation mediated by the imbalance of Th1/Th2/Th17 cytokines, which might contribute to CSU pathogenesis. Further research in this field could improve clinical, diagnostic, and therapeutic approaches to patients with CSU. By applying new knowledge on gut microbial communities and metabolomics, future CSU therapies could modify the microbiota composition using agents such as probiotics or other similar agents, which, in combination with current standard therapies, could hopefully lead to a reduction in symptoms and an improved quality of life for CSU patients.

The effects of a set amount of regular maternal exercise during pregnancy on gut microbiota are diet-dependent in mice and do not cause significant diversity changes

Background

Diet and exercise can affect the gut microbiota (GM); however, the effects of the same amount of exercise on gut microbiota changes in people on a low-fat diet (LFD) and high-fat diet (HFD) during pregnancy are unknown. Do different nutritional conditions respond equally to exercise intervention? This study aimed to investigate the effects of regular maternal exercise during pregnancy on the GM in mice fed different diets during pregnancy.

Methods

Six-week-old nulliparous female KunMing mice were fed either a HFD or LFD before and during pregnancy. Each group of mice were then randomly divided into two groups upon confirmation of pregnancy: sedentary (HFD or LFD; n = 4 and 5, respectively) and exercised (HFDex or LFDex, n = 5 and 6, respectively). Mice were sacrificed on day 19 of gestation and their colon contents were collected. We then performed 16S rDNA gene sequencing of the V3 and V4 regions of the GM.

Results

The pregnancy success rate was 60% for LFDex and 100% for HFDex. Both Chao1 and Simpson indices were not significantly different for either LFD vs. LFDex or HFD vs. HFDex. Desulfobacterota, Desulfovibrionia Desulfovibrionales, Desulfovibrionaceae, Desulfovibrio, Coriobacteriia, Coriobacteriales, and Eggerthellaceae were markedly decreased after exercise intervention in LFDex vs. LFD, whereas Actinobacteria, Bifidobacteriales, Bifidobacteriaceae, Bifidobacterium, and Bifidobacterium pseudolongum were significantly increased in LFDex vs. LFD. Furthermore, decreased Peptostreptococcales-Tissierellales and Peptostreptococcaceae and increased Bacteroides dorei were identified in the HFDex vs. HFD group. p_Desulfobacterota, c_Desulfovibrionia, o_Desulfovibrionales, f_Desulfovibrionaceae and g_Desulfovibrio were markedly decreased in the LFDex group vs. HFDex group.

Conclusions

Our data suggested that quantitative maternal exercise during pregnancy resulted in alterations in GM composition, but did not significantly change the diversity of the GM. These findings may have important implications when considering an individual's overall diet when recommending exercise during pregnancy.

Possible metabolic interplay between quality of life and fecal microbiota in a presenior population-Preliminary results

OBJECTIVES

The number of people aged ≥60 y is increasing worldwide, so establishing a relationship between lifestyle and health-associated factors, such as gut microbiota in an older population, is important. This study aimed to characterize the gut microbiota of a presenior population, and analyze the association between some bacteria and quality of life with the Short Form (SF) 36 questionnaire.

METHODS

Participants were adult men and women ages 50 to 80 y (n = 74). In addition to the SF-36 questionnaire, fecal samples were collected in cryotubes, and 16S RNA gene sequencing was performed to characterize microbial features. Participants were classified into two groups according to SF-36 punctuation. Linear and logistic regression models were performed to assess the possible association between any bacterial bowl and SF-36 score. Receiver operating characteristics curves were fitted to define the relative diagnostic strength of different bacterial taxa for the correct determination of quality of life.

RESULTS

A positive relationship was established between SF-36 score and Actinobacteria (P = 0.0310; R = 0.2510) compared with Peptostreptococcaceae (P = 0.0259; R = -0.2589), which increased with decreasing quality of life. Logistic regressions models and receiver operating characteristics curves showed that the relative abundance of Actinobacteria and Peptostreptococcaceae may be useful to predict quality of life in a presenior population (area under the curve: 0.71).

CONCLUSIONS

Quality of life may be associated with the relative abundance of certain bacteria, especially Actinobacteria and Peptostreptococcaceae, which may have a specific effect on certain markers and health care, which is important to improve quality of life in older populations.

Evaluation of fresh, frozen, and lyophilized fecal samples by SPME and derivatization methods using GC×GC-TOFMS

INTRODUCTION

Feces is a highly complex matrix containing thousands of metabolites. It also contains live bacteria and enzymes, and does not have a static chemistry. Consequently, proper control of pre-analytical parameters is critical to minimize unwanted variations in the samples. However, no consensus currently exists on how fecal samples should be stored/processed prior to analysis.

OBJECTIVE

The effects of sample handling conditions on fecal metabolite profiles and abundances were examined using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS).

METHODS

Solid-phase microextraction (SPME) and derivatization via trimethylsilylation (TMS) were employed as complementary techniques to evaluate fresh, frozen, and lyophilized fecal samples with expanded coverage of the fecal metabolome. The total number of detected peaks and the signal intensities were compared among the different handling conditions.

RESULTS

Our analysis revealed that the metabolic profiles of fecal samples depend greatly on sample handling and processing conditions, which had a more pronounced effect on results obtained by SPME than by TMS derivatization. Overall, lyophilization resulted in a greater amount of total and class-specific metabolites, which may be attributed to cell lysis and/or membrane disintegration.

CONCLUSIONS

A comprehensive comparison of the sample handling conditions provides a deeper understanding of the physicochemical changes that occur within the samples during freezing and lyophilization. Based on our results, snap-freezing at -80 °C would be preferred over lyophilization for handling samples in the field of fecal metabolomics as this imparts the least change from the fresh condition.

Resveratrol Butyrate Esters Inhibit Obesity Caused by Perinatal Exposure to Bisphenol A in Female Offspring Rats

Resveratrol butyrate esters (RBE) are derivatives of resveratrol (RSV) and butyric acid and exhibit biological activity similar to that of RSV but with higher bioavailability. The aim of this study was designed as an animal experiment to explore the effects of RBE on the serum biochemistry, and fat deposits in the offspring rats exposed to bisphenol A (BPA), along with the growth and decline of gut microbiota. We constructed an animal model of perinatal Bisphenol A (BPA) exposure to observe the effects of RBE supplementation on obesity, blood lipids, and intestinal microbiota in female offspring rats. Perinatal exposure to BPA led to weight gain, lipid accumulation, high levels of blood lipids, and deterioration of intestinal microbiota in female offspring rats. RBE supplementation reduced the weight gain and lipid accumulation caused by BPA, optimised the levels of blood lipids, significantly reduced the Firmicutes/Bacteroidetes (F/B) ratio, and increased and decreased the abundance of S24-7 and Lactobacillus, respectively. The analysis of faecal short-chain fatty acid (SCFA) levels revealed that BPA exposure increased the faecal concentration of acetate, which could be reduced via RBE supplementation. However, the faecal concentrations of propionate and butyrate were not only significantly lower than that of acetate, but also did not significantly change in response to BPA exposure or RBE supplementation. Hence, RBE can suppress BPA-induced obesity in female offspring rats, and it demonstrates excellent modulatory activity on intestinal microbiota, with potential applications in perinatological research.

Applications of Metabolomics in Forensic Toxicology and Forensic Medicine

Forensic toxicology and forensic medicine are unique among all other medical fields because of their essential legal impact, especially in civil and criminal cases. New high-throughput technologies, borrowed from chemistry and physics, have proven that metabolomics, the youngest of the “omics sciences”, could be one of the most powerful tools for monitoring changes in forensic disciplines. Metabolomics is a particular method that allows for the measurement of metabolic changes in a multicellular system using two different approaches: targeted and untargeted. Targeted studies are focused on a known number of defined metabolites. Untargeted metabolomics aims to capture all metabolites present in a sample. Different statistical approaches (e.g., uni- or multivariate statistics, machine learning) can be applied to extract useful and important information in both cases. This review aims to describe the role of metabolomics in forensic toxicology and in forensic medicine.

Nutritional Effects of the Enteral Nutritional Formula on Regulation of Gut Microbiota and Metabolic Level in Type 2 Diabetes Mellitus Mice

PURPOSE

Due to the adverse effects of antidiabetic drugs, nowadays, nutraceuticals have been of much interest to investigators. Therefore, the present study aimed to explore the potential effects of enteral nutritional (EN) formulas on the gut microbiota and metabolic regulation of type 2 diabetes mellitus (T2DM) mice and compare the differences between whey protein and soy protein.

METHODS

EN formulas made of whey protein or soy protein were administered for five weeks and then mice tissue samples were obtained to examine the metabolic parameters and histopathology of the pancreas, liver, jejunum and colon. 16S rRNA V3-V4 region gene sequencing was used to analyze the changes in the gut microbiota.

RESULTS

After the five-week intervention, the alpha diversity had recovered slightly, and the soy protein group (SPG) achieved a better effect than the whey protein group (LPG). The overall composition of gut microbiota was regulated. The abundance of Bacteroidetes and TM7 had raised significantly and the abundance of Firmicutes and Deferribacteres had declined after treatment, with no significant difference between the LPG and SPG. The types of beneficial bacteria were increased at the genus and species level. The level of hexokinase (HK) and pyruvate kinase (PK) had significantly recovered and inhibited the level of α-glucosidase. In addition, the EN formulas treatment reduced the levels of inflammatory factor (TNF-α) in liver and muscle. The level of glucose transporter type 2 (GLUT-2) levels in the liver and intestine also significantly increased. Moreover, the metabolism regulation of the SPG was better than that of the LPG. The EN formulas treatment improved the pancreas, liver, jejunum and colon histology.

CONCLUSION

The EN formulas regulated the overall structure of the gut microbiota and improved the metabolic level in streptozotocin/high-fat diet (STZ/HFD) diabetic mice. Therefore, EN formula may potentially become an effective nutritional adjunctive therapy for T2DM.