Impact of the gut microbiota on the development of obesity and type 2 diabetes mellitus

Gut microbiota composition and type 2 diabetes: Are these subjects linked Together?

Purpose

Evidence suggests that changes in the composition of gut microbiota may be linked to metabolic disorders including type 2 diabetes (T2D). The present study aims to evaluate the compositional changes of the intestinal microbiota in patients with T2D as compared to healthy individuals.

Methods

In this case-control study, there were 18 T2D patients and 18 healthy individuals who served as controls. To profile the gut microbiota in both groups, bacterial DNA was extracted from fecal samples and analyzed using quantitative real-time polymerase chain reaction (qPCR).

Results

The study discovered that diabetics had significantly greater frequencies of the genus Bacteroides and the phylum Bacteroidetes than did controls (P = 0.03 and P < 0.001, respectively). Conversely, the Actinobacteria and Firmicutes phyla were significantly more abundant in the controls (P=0.01 for both). No significant differences were observed in the fecal populations of the genus Enterococcus, Clostridium clusters IV and XIVa, phylum Proteobacteria, and all bacteria between the studied groups (P=0.88, P=0.56, P=0.8, P=0.99, and P=0.7, respectively).

Conclusions

Our findings confirm that T2D may be associated with the gut microbiota fluctuations. These findings may be valuable for developing strategies to control or treatment T2D by restoring the intestinal microbiota through the strategic administration of specific probiotics/prebiotics and lifestyle and dietary modifications.

Association of Firmicutes/Bacteroidetes Ratio with Body Mass Index in Korean Type 2 Diabetes Mellitus Patients

BACKGROUND

The gut microbiome, which is the collection of microorganisms living in the gastrointestinal tract, has been shown to play a significant role in the development of metabolic disorders such as obesity and type 2 diabetes mellitus (T2DM). Studies have found that the ratio of Firmicutes to Bacteroidetes (F/B) is higher in obese individuals compared to lean individuals and tends to decrease with weight loss. However, the relationship between the F/B ratio and T2DM in Korean individuals, with or without obesity, is not fully understood.

OBJECTIVE

The objective of this study is to compare the F/B ratios and metabolic profiles of lean and obese Korean individuals with T2DM.

METHODS

In this study, 36 individuals with type 2 diabetes mellitus (T2DM) were recruited and classified into four groups (I, II, III, and IV) based on their body mass index (BMI). Group I had a BMI of less than 23.0, group II had a BMI between 23.0 and 24.9, group III had a BMI between 25.0 and 29.9, and group IV had a BMI of 30 kg/m2 or greater. Fecal samples were collected from all participants and sent to Chunlab Inc. (located in Seoul, Republic of Korea) for analysis. The changes in the major microbial phyla within the samples were investigated using quantitative real-time PCR. The collected data were then statistically analyzed using the SPSS program.

RESULTS

The levels of triglycerides and alanine transaminase in group I were significantly lower than in the other three groups. The amount of Actinobacteria in group IV was the highest among all four groups. The ratio of Firmicutes to Bacteroidetes increased as BMI increased, and this ratio was positively correlated with AST activity.

CONCLUSIONS

Our study showed that there is a correlation between the degree of obesity in individuals with diabetes and their gut microbiome. Additionally, the ratio of Firmicutes to Bacteroidetes (F/B ratio) may play a role in the metabolic effects of fatty liver disease, as it may contribute to obesity.

From gut to bone: deciphering the impact of gut microbiota on osteoporosis pathogenesis and management

Osteoporosis (OP) is characterized by decreased bone mineral density (BMD) and increased fracture risk, poses a significant global health burden. Recent research has shed light on the bidirectional relationship between gut microbiota (GM) and bone health, presenting a novel avenue for understanding OP pathogenesis and developing targeted therapeutic interventions. This review provides a comprehensive overview of the GM-bone axis, exploring the impact of GM on OP development and management. We elucidate established risk factors and pathogenesis of OP, delve into the diversity and functional changes of GM in OP. Furthermore, we examine experimental evidence and clinical observations linking alterations in GM composition or function with variations in BMD and fracture risk. Mechanistic insights into microbial mediators of bone health, such as microbial metabolites and products, are discussed. Therapeutic implications, including GM-targeted interventions and dietary strategies, are also explored. Finally, we identify future research directions and challenges in translating these findings into clinical practice.

Effects of Purified Vitexin and Iso-Vitexin from Mung Bean Seed Coat on Antihyperglycemic Activity and Gut Microbiota in Overweight Individuals' Modulation

Exceeding a healthy weight significantly elevates the likelihood of developing type 2 diabetes (T2DM). A commercially available singular constituent, available as either purified vitexin or iso-vitexin, has been associated with a decreased risk of T2DM, but its synergistic effect has not been reported yet. Vitexin and iso-vitexin were extracted using an ethanol-based solvent from mung bean seed coat (MBCE) and subsequently purified using preparative liquid chromatography (Prep-LC). Eleven mixture ratios of vitexin and/or iso-vitexin were determined for their antioxidant and antihyperglycemic activities. The 1:1.5 ratio of vitexin to iso-vitexin from MBCE demonstrated the most synergistic effects for enzyme inhibition and glucose uptake in HepG2 cells within an insulin-resistant system, while these ratios exhibited a significantly lower antioxidant capacity than that of each individual component. In a gut model system, the ratio of 1:1.5 (vitexin and iso-vitexin) regulated the gut microbiota composition in overweight individuals by decreasing the growth of Enterobacteriaceae and Enterococcaceae, while increasing in Ruminococcaceae and Lachnospiraceae. The application of vitexin/iso-vitexin for 24 h fermentation enhanced a high variety of abundances of 21 genera resulting in five genera of Parabacteroides, Ruminococcus, Roseburia, Enterocloster, and Peptacetobacter, which belonged to the phylum Firmicutes, exhibiting high abundant changes of more than 5%. Only two genera of Proteus and Butyricicoccus belonging to Proteobacteria and Firmicutes decreased. The findings suggest that these phytochemicals interactions could have synergistic effects in regulating glycemia, through changes in antihyperglycemic activity and in the gut microbiota in overweight individuals. This optimal ratio can be utilized by industries to formulate more potent functional ingredients for functional foods and to create nutraceutical supplements aimed at reducing the risk of T2DM in overweight individuals.

Discrete interplay of gut microbiota L-tryptophan metabolites in host biology and disease

The gut microbiota and the host maintain a conjoint relationship and together achieve optimal physiology via a multitude of interactive signalling cues. Dietary-derived L-tryptophan (L-trp) is enzymatically metabolized by the resident symbiotic gut microbiota to indole and various indole derivatives. Indole and indole metabolites secreted by the gut bacteria act locally in the intestinal cells as well as distally and modulate tissue-specific functions which are beneficial to the host. Functions attributed to these microbial indole metabolites in the host include regulation of intestinal permeability, immunity and mucosal roles, inflammation, and insulin sensitivity. On the other hand, dysregulation of gut microbiota L-trp metabolism compromises the optimal availability of indole and indole metabolites and can induce the onset of metabolic disorders, inflammation, liver steatosis, and decrease gut barrier integrity. Gut dysbiosis is regarded as one of the prime reasons for this deregulated microbial-derived indole metabolites. A number of indole metabolites from the gut bacteria have been identified recently displaying variable affinity towards xenobiotic nuclear receptors. Microbial metabolite mimicry concept can be used to design and develop novel indole-moiety-containing compounds with higher affinity towards the receptors and efficacy in preclinical studies. Such compounds may serve as therapeutic drugs in clinical trials in the future. In this article, I review L-trp metabolism in the host and gut microbiota and the various physiological functions, patho-physiologies associated with the microbial-released indole metabolites in the host, including the metabolite mimicry-based concept to develop tailored indole-containing novel experimental drugs.

Mechanism of Takifugu bimaculatus Skin Peptides in Alleviating Hyperglycemia in Rats with Type 2 Diabetic Mellitus Based on Microbiome and Metabolome Analyses

In this study, we aimed to explore the hypoglycemic effects of a hydrolysate on Takifugu bimaculatus skin (TBSH). The effect of the dipeptidyl peptidase-IV (DPP-IV) inhibitory activities from different TBSH fractions was investigated on basic indexes, gut hormones, blood lipid indexes, viscera, and the gut microbiota and its metabolites in rats with type 2 diabetes mellitus (T2DM). The results showed that the <1 kDa peptide fraction from TBSH (TBP) exhibited a more potent DPP-IV inhibitory effect (IC50 = 0.45 ± 0.01 mg/mL). T2DM rats were induced with streptozocin, followed by the administration of TBP. The 200 mg/kg TBP mitigated weight loss, lowered fasting blood glucose levels, and increased insulin secretion by 20.47%, 25.23%, and 34.55%, respectively, rectified irregular hormonal fluctuations, lipid metabolism, and tissue injuries, and effectively remedied gut microbiota imbalance. In conclusion, TBP exerts a hypoglycemic effect in rats with T2DM. This study offers the potential to develop nutritional supplements to treat T2DM and further promote the high-value utilization of processing byproducts from T. bimaculatus. It will provide information for developing nutritional supplements to treat T2DM and further promote the high-value utilization of processing byproducts from T. bimaculatus.

Medicinal plants of Southeast Asia with anti-α-glucosidase activity as potential source for type-2 diabetes mellitus treatment

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetes mellitus, a widespread chronic illness, affects millions worldwide, and its incidence is increasing alarmingly, especially in developing nations. Current pharmacological treatments can be costly and have undesirable side effects. To address this, medicinal plants with antidiabetic effects, particularly targeting α-glucosidase for controlling hyperglycaemia in type-2 diabetes mellitus (T2DM), hold promise for drug development with reduced toxicity and adverse reactions.

AIM OF THIS REVIEW

This review aims to succinctly collect information about medicinal plant extracts that exhibit antidiabetic potential through α-glucosidase inhibition using acarbose as a standard reference in Southeast Asia. The characteristics of this inhibition are based on in vitro studies.

MATERIALS AND METHODS

Relevant information on medicinal plants in Southeast Asia, along with α-glucosidase inhibition studies using acarbose as a positive control, was gathered from various scientific databases, including Scopus, PubMed, Web of Science, and Google Scholar.

RESULTS

About 49 papers were found from specific counties in Southeast Asia demonstrated notable α-glucosidase inhibitory potential of their medicinal plants, with several plant extracts showcasing activity comparable to or surpassing that of acarbose. Notably, 19 active constituents were identified for their α-glucosidase inhibitory effects.

CONCLUSIONS

The findings underscore the antidiabetic potential of the tested medicinal plant extracts, indicating their promise as alternative treatments for T2DM. This review can aid in the development of potent therapeutic medicines with increased effectiveness and safety for the treatment of T2DM.

Reinforcement of the intestinal mucosal barrier via mucus-penetrating PEGylated bacteria

The breakdown of the gut's mucosal barrier that prevents the infiltration of microorganisms, inflammatory cytokines and toxins into bodily tissues can lead to inflammatory bowel disease and to metabolic and autoimmune diseases. Here we show that the intestinal mucosal barrier can be reinforced via the oral administration of commensal bacteria coated with poly(ethylene glycol) (PEG) to facilitate their penetration into mucus. In mice with intestinal homoeostatic imbalance, mucus-penetrating PEGylated bacteria preferentially localized in mucus at the lower gastrointestinal tract, inhibited the invasion of pathogenic bacteria, maintained homoeostasis of the gut microbiota, stimulated the secretion of mucus and the expression of tight junctions, and prevented the mice from developing colitis and diabetes. Orally delivered PEGylated bacteria may help prevent and treat gastrointestinal disorders.

Inhibiting the CB1 receptor in CIH-induced animal model alleviates colon injury

Obstructive sleep apnea (OSA) can lead to intestinal injury, endotoxemia, and disturbance of intestinal flora. Additionally, as a crucial component of the endocannabinoid system, some studies have demonstrated that cannabinoid 1 (CB1) receptors are closely linked to the multiple organ dysfunction triggered by OSA. However, the role of the CB1 receptor in alleviating OSA-induced colon injury remains unclear. Here, through the construction of the OSA classic model, we found that the colon tissue of chronic intermittent hypoxia (CIH)-induced mice exhibited an overexpression of the CB1 receptor. The results of hematoxylin-eosin staining and transmission electron microscopy revealed that inhibition of the CB1 receptor could decrease the gap between the mucosa and muscularis mucosae, alleviate mitochondrial swelling, reduce microvilli shedding, and promote the recovery of tight junctions of CIH-induced mice. Furthermore, CB1 receptor inhibition reduced the levels of metabolic endotoxemia and inflammatory responses, exhibiting significant protective effects on the colon injury caused by CIH. At the molecular level, through western blotting and real-time polymerase chain reaction techniques, we found that inhibiting the CB1 receptor can significantly increase the expression of ZO-1 and Occludin proteins, which are closely related to the maintenance of intestinal mucosal barrier function. Through 16S rRNA high-throughput sequencing and short-chain fatty acid (SCFA) determination, we found that inhibition of the CB1 receptor increased the diversity of the microbial flora and controlled the makeup of intestinal flora. Moreover, butyric acid concentration and the amount of SCFA-producing bacteria, such as Ruminococcaceae and Lachnospiraceae, were both markedly elevated by CB1 receptor inhibition. The results of the spearman correlation study indicated that Lachnospiraceae showed a positive association with both ZO-1 and Occludin but was negatively correlated with the colon CB1 receptor, IL-1β, and TNF-α. According to this study, we found that inhibiting CB1 receptor can improve CIH-induced colon injury by regulating gut microbiota, reducing mucosal damage and promoting tight junction recovery. KEY POINTS: •CIH leads to overexpression of CB1 receptor in colon tissue. •CIH causes intestinal flora disorder, intestinal mucosal damage, and disruption of tight junctions. •Inhibition of CB1 receptor can alleviate the colon injury caused by CIH through regulating the gut microbiota, reducing mucosal injury, and promoting tight junction recovery.

Novel Insight into the Effect of Probiotics in the Regulation of the Most Important Pathways Involved in the Pathogenesis of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is considered one of the most common disorders worldwide. Although several treatment modalities have been developed, the existing interventions have not yielded the desired results. Therefore, researchers have focused on finding treatment choices with low toxicity and few adverse effects that could control T2DM efficiently. Various types of research on the role of gut microbiota in developing T2DM and its related complications have led to the growing interest in probiotic supplementation. Several properties make these organisms unique in terms of human health, including their low cost, high reliability, and good safety profile. Emerging evidence has demonstrated that three of the most important signaling pathways, including nuclear factor kappa B (NF-κB), phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt), and nuclear factor erythroid 2-related factor 2 (Nrf2), which involved in the pathogenesis of T2DM, play key functions in the effects of probiotics on this disease. Hence, we will focus on the clinical applications of probiotics in the management of T2DM. Then, we will also discuss the roles of the involvement of various probiotics in the regulation of the most important signaling pathways (NF-κB, PI3K/Akt, and Nrf2) involved in the pathogenesis of T2DM.

Obesity, Dietary Patterns, and Hormonal Balance Modulation: Gender-Specific Impacts

Understanding the intricate relationship between nutrition, hormonal balance, and gender-specific factors is crucial for developing targeted interventions to mitigate obesity-related endocrine disruptions and improve metabolic health. This narrative review examines the impact of various dietary patterns on hormonal regulation in both men and women, focusing on their effects on hormonal balance and metabolic health in the context of obesity. Calorie restriction, the Western diet, high-fat diets, low-CHO diets, plant-based diets, and the Mediterranean diet are analyzed in relation to their influence on obesity-related endocrine disruptions and metabolic health. Future research directions include investigating the specific mechanisms underlying dietary influences on hormonal regulation, addressing the gender-specific metabolic differences and body fat distribution, and exploring the dietary needs of individuals undergoing gender transition. Personalized dietary interventions tailored to individual metabolic and hormonal profiles are essential for optimizing health outcomes across the gender spectrum. By integrating gender-specific considerations into dietary recommendations, healthcare professionals can better support individuals in achieving optimal metabolic health and hormonal balance.

Microbiome and pregnancy: focus on microbial dysbiosis coupled with maternal obesity

Obesity is becoming a worldwide pandemic with over one billion people affected. Of women in the United States, who are of childbearing age, two-thirds of them are considered overweight/obese. Offspring of women with obesity have a greater likelihood of developing cardiometabolic disease later in life, therefore making obesity a transgenerational issue. Emerging topics such as maternal microbial dysbiosis with altered levels of bacterial phyla and maternal obesity programming offspring cardiometabolic disease are a novel area of research discussed in this review. In the authors' opinion, beneficial therapeutics will be developed from knowledge of bacterial-host interactions at the most specific level possible. Although there is an abundance of obesity-related microbiome research, it is not concise, readily available, nor easy to interpret at this time. This review details the current knowledge regarding the relationship between obesity and the gut microbiome, with an emphasis on maternal obesity.

Postbiotic potential of Bacillus velezensis KMU01 cell-free supernatant for the alleviation of obesity in mice

Attention toward the preventive effects of postbiotics on metabolic diseases has increased because of greater stability and safety over probiotics. However, studies regarding the bioactive effects of postbiotics, especially from probiotic Bacillus strains, are relatively limited. The anti-obesity effects of the cell-free culture supernatant of Bacillus velezensis KMU01 (CFS-B.vele) were evaluated using high-fat-diet (HFD)-induced mice. HFD-induced mice (n = 8 per group) received equal volumes of (1) CFS-B.vele (114 mg/kg) in PBS, (2) Xenical in PBS, or (3) PBS alone by oral gavage daily for 13 weeks. The results demonstrated that CFS-B.vele changed the gut microbiota and showed anti-obesity effects in HFD-induced obese mice. The elevated Firmicutes/Bacteroidota ratio induced by HFD was decreased in the CFS-B.vele group compared to the other groups (p < 0.05). The CFS-B.vele intervention led to the enrichment of SCFA-producers, such as Roseburia and Eubacterium, in the cecum, suggesting their potential involvement in the amelioration of obesity. Due to these changes, the various obesity-related biomarkers (body weight, fat in tissue, white adipose tissue weight and size, serum LDL-cholesterol level, hepatic lipid accumulation, and adipogenesis/lipogenesis-related gene/protein expression) were improved. Our findings suggest that CFS-B.vele has potential as a novel anti-obesity agent through modulation of the gut microbiota.

Maternal Phlorizin Intake Protects Offspring from Maternal Obesity-Induced Metabolic Disorders in Mice via Targeting Gut Microbiota to Activate the SCFA-GPR43 Pathway

Maternal obesity increases the risk of obesity and metabolic disorders (MDs) in offspring, which can be mediated by the gut microbiota. Phlorizin (PHZ) can improve gut dysbiosis and positively affect host health; however, its transgenerational metabolic benefits remain largely unclear. This study aimed to investigate the potential of maternal PHZ intake in attenuating the adverse impacts of a maternal high-fat diet on obesity-related MDs in dams and offspring. The results showed that maternal PHZ reduced HFD-induced body weight gain and fat accumulation and improved glucose intolerance and abnormal lipid profiles in both dams and offspring. PHZ improved gut dysbiosis by promoting expansion of SCFA-producing bacteria, Akkermansia and Blautia, while inhibiting LPS-producing and pro-inflammatory bacteria, resulting in significantly increased fecal SCFAs, especially butyric acid, and reduced serum lipopolysaccharide levels and intestinal inflammation. PHZ also promoted intestinal GLP-1/2 secretion and intestinal development and enhanced gut barrier function by activating G protein-coupled receptor 43 (GPR43) in the offspring. Antibiotic-treated mice receiving FMT from PHZ-regulated offspring could attenuate MDs induced by receiving FMT from HFD offspring through the gut microbiota to activate the GPR43 pathway. It can be regarded as a promising functional food ingredient for preventing intergenerational transmission of MDs and breaking the obesity cycle.

Role of gut-microbiota in disease severity and clinical outcomes

A delicate balance of nutrients, antigens, metabolites and xenobiotics in body fluids, primarily managed by diet and host metabolism, governs human health. Human gut microbiota is a gatekeeper to nutrient bioavailability, pathogens exposure and xenobiotic metabolism. Human gut microbiota starts establishing during birth and evolves into a resilient structure by adolescence. It supplements the host's metabolic machinery and assists in many physiological processes to ensure health. Biotic and abiotic stressors could induce dysbiosis in gut microbiota composition leading to disease manifestations. Despite tremendous scientific advancements, a clear understanding of the involvement of gut microbiota dysbiosis during disease onset and clinical outcomes is still awaited. This would be important for developing an effective and sustainable therapeutic intervention. This review synthesizes the present scientific knowledge to present a comprehensive picture of the role of gut microbiota in the onset and severity of a disease.

Metabolic Syndrome: A Narrative Review from the Oxidative Stress to the Management of Related Diseases

Metabolic syndrome (MS) is a growing disorder affecting thousands of people worldwide, especially in industrialised countries, increasing mortality. Oxidative stress, hyperglycaemia, insulin resistance, inflammation, dysbiosis, abdominal obesity, atherogenic dyslipidaemia and hypertension are important factors linked to MS clusters of different pathologies, such as diabesity, cardiovascular diseases and neurological disorders. All biochemical changes observed in MS, such as dysregulation in the glucose and lipid metabolism, immune response, endothelial cell function and intestinal microbiota, promote pathological bridges between metabolic syndrome, diabesity and cardiovascular and neurodegenerative disorders. This review aims to summarise metabolic syndrome's involvement in diabesity and highlight the link between MS and cardiovascular and neurological diseases. A better understanding of MS could promote a novel strategic approach to reduce MS comorbidities.

Short-Term Effects of Weight-Loss Meal Replacement Programs with Various Macronutrient Distributions on Gut Microbiome and Metabolic Parameters: A Pilot Study

It has emerged the gut microbiome is crucially linked to metabolic health and obesity. Macronutrient distribution has been discussed as a key parameter in weight-loss programs, but little is known about its impact on the gut microbiome. We investigated the effects of weight-loss meal replacement programs with different macronutrient ratios on the gut microbiota and metabolic parameters in subjects with overweight and obesity. Three low-calorie meal replacement programs with different ratios of carbohydrates, proteins, and lipids were designed: a balanced diet (Group B, 60:15:30), a high-lipid-low-carbohydrate diet (Group F, 35:20:55), and a protein-enriched diet (Group P, 40:25:35). Sixty overweight or obese participants were provided with the meals twice daily for 3 weeks. In all groups, diet intervention resulted in reduced body weight and BMI. The relative abundance of Bacteroidetes and Firmicutes phyla decreased and increased, respectively, which increased the Firmicutes/Bacteroidetes (F/B) ratio in all subjects, particularly in Groups B and P. Alpha- and beta-diversity were augmented at the phylum level in Group P. In conclusion, short-term interventions with weight-loss meal replacement programs increased butyrate-producing bacteria and the F/B ratio. Moreover, the protein-enriched diet significantly increased alpha- and beta-diversity compared to the balanced diet and the high-lipid-low-carbohydrate diet.

Bergapten exerts a chondroprotective effect in temporomandibular joint osteoarthritis by combining intestinal flora alteration and reactive oxygen species reduction

Bergapten, a furanocoumarin naturally occurring in bergamot essential oil, has been demonstrated to have the potential to alleviate osteoarthritis-related symptoms via its anti-inflammatory activity. Although its systemic bioavailability is limited, its precise mechanisms of action and effects on temporomandibular joint osteoarthritis (TMJOA) and its relationship with the intestinal flora remain unclear. Here, we explored the anti-TMJOA effect of BGT combined with the interleukin-1β-induced inflammatory response of chondrocytes in a monosodium iodoacetate (MIA)-induced TMJOA rat model. It was confirmed that BGT effectively reduced proinflammatory mediators and increased type II collagen, bone volume, and trabecular number of condyles in TMJOA rats. Importantly, the oral administration of BGT altered the intestinal flora of rats by increasing the relative abundances of nine prebiotic species and decreasing the relative abundance of one potential species. In addition, BGT considerably reduced reactive oxygen species (ROS) levels by suppressing glutathione, oxidized glutathione, and superoxide dismutase in the serum and malondialdehyde in urine. These results suggest that BGT exerts a chondroprotective effect, most likely by improving the intestinal flora and reducing ROS production associated with TMJOA in rats. This finding indicates a novel beneficial effect of BGT on the prevention and treatment of TMJOA.

The Gut Microbiota Differ in Exclusively Breastfed and Formula-Fed United States Infants and are Associated with Growth Status

BACKGROUND

Evidence regarding the effects of infant feeding type (exclusive breastfeeding compared with exclusive formula feeding) on the gut microbiota and how it impacts infant growth status is limited.

OBJECTIVES

The primary objective was to compare gut microbiota by feeding type and characterize the associations between gut microbiota and infant growth status.

METHODS

Stool samples from healthy, full-term infants (4-5 mo-old) who were either exclusively breastfed (BF) or exclusively formula-fed (FF) in Denver, CO, United States were collected, and fecal 16S ribosomal ribonucleic acid gene-based profiling was conducted. Length and weight were measured at the time of stool collection. Length-for-age z-score, weight-for-age z-scores (WAZ), and weight-for-length z-scores were calculated based on the World Health Organization standards. Associations between gut microbial taxa and anthropometric z-scores were assessed by Spearman's rank correlation test.

RESULTS

A total of 115 infants (BF n = 54; FF n = 61) were included in this study. Feeding type (BF compared with FF) was the most significant tested variable on gut microbiota composition (P < 1 × 10-⁶), followed by mode of delivery and race. Significant differences were observed in α-diversity, β-diversity, and relative abundances of individual taxa between BF and FF. BF infants had lower α-diversity than FF infants. Abundances of Bifidobacterium and Lactobacillus were greater in the breastfeeding group. FF infants had a higher relative abundance of unclassified Ruminococcaceae (P < 0.001), which was associated with a higher WAZ (P < 0.001) and length-for-age z-score (P < 0.01). Lactobacillus was inversely associated with WAZ (P < 0.05).

CONCLUSIONS

Feeding type is the main driver of gut microbiota differences in young infants. The gut microbiota differences based on feeding type (exclusive breast- or formula feeding) were associated with observed differences in growth status. This trial was registered at clinicaltrials.gov as NCT02142647, NCT01693406, and NCT04137445.

The effects of Ascophyllum nodosum, Camellia sinensis-leaf extract, and their joint interventions on glycolipid and energy metabolism in obese mice

Objectives

Obesity is often associated with glucolipid and/or energy metabolism disorders. Ascophyllum nodosum extract (seaweed extract, SE) and Camellia sinensis-leaf extract (tea extract, TE) have been reported to promote positive metabolic effects through different mechanisms. We investigated the effects of SE and TE on metabolic homeostasis in diet-induced obese mice and discussed their functional characteristics.

Methods

Male C57BL/6J mice fed with high-fat diets for 8 weeks were established as obese models and subsequently divided into different intervention groups, followed by SE, TE, and their joint interventions for 10 weeks. Body weight and food intake were monitored. Fasting glucose and oral glucose tolerance tests were interspersed during the experiment. After the intervention, the effects on obesity control were assessed based on body composition, liver pathology section, blood lipids and glucose, respiratory exchange ratio (RER), energy expenditure (EE1, EE2, and EE3), inflammatory factors, lipid anabolism enzymes, and gut flora of the obese mice.

Results

After continuous gavage intervention, the mice in the intervention groups exhibited lower body weight (lower ~4.93 g, vs. HFD 38.02 g), peri-testicular fat masses (lower ~0.61 g, vs. HFD 1.92 g), and perirenal fat masses (lower ~0.21 g, vs. HFD mice 0.70 g). All interventions prevented diet-induced increases in plasma levels of glucose, adiponectin, leptin, and the inflammatory factors IL-1β and TNF-α. The RER was modified by the interventions, while the rhythm of the RER was not. Blood lipids (total cholesterol, triglycerides, and LDL) decreased and were associated with lower lipid anabolism enzymes. In addition, the SE and TE interventions altered the structure and abundance of specific flora. Different interventions inhibited the growth of different genera positively associated with obesity (Escherichia-Shigella, Helicobacter, etc.) and promoted the growth of Akkermansia and Bacteroides, thus affecting the chronic inflammatory state.

Conclusion

SE and TE both have synergistic effects on weight control and glucolipid metabolism regulation by improving insulin sensitivity and reducing lipid synthesis-related enzyme expression, whereas the combination of SE and TE (3:1) has a better effect on regulating energy metabolism and inhibiting chronic inflammation.

Cordyceps cicadae polysaccharides alleviate hyperglycemia by regulating gut microbiota and its mmetabolites in high-fat diet/streptozocin-induced diabetic mice

Introduction

The polysaccharides found in Cordyceps cicadae (C. cicadae) have received increasing academic attention owing to their wide variety of therapeutic activities.

Methods

This study evaluated the hypoglycemic, antioxidant, and anti-inflammatory effects of polysaccharides from C. cicadae (CH-P). In addition, 16s rDNA sequencing and untargeted metabolomics analysis by liquid chromatography-mass spectrometry (LC-MS) were used to estimate the changes and regulatory relationships between gut microbiota and its metabolites. The fecal microbiota transplantation (FMT) was used to verify the therapeutic effects of microbial remodeling.

Results

The results showed that CH-P treatment displayed hypoglycemic, antioxidant, and anti-inflammatory effects and alleviated tissue damage induced by diabetes. The CH-P treatment significantly reduced the Firmicutes/Bacteroidetes ratio and increased the abundance of Bacteroides, Odoribacter, Alloprevotella, Parabacteroides, Mucispirillum, and significantly decreased the abundance of Helicobacter and Lactobacillus compared to the diabetic group. The alterations in the metabolic pathways were mostly related to amino acid biosynthesis and metabolic pathways (particularly those involving tryptophan) according to the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Correlation analysis showed that Bacteroides, Odoribacter, Alloprevotella, Parabacteroides, and Mucispirillum were positively correlated with indole and its derivatives, such as 5-hydroxyindole-3-acetic acid. Indole intervention significantly improved hyperglycemic symptoms and insulin sensitivity, and increased the secretion of glucagon-like peptide-1 (GLP-1) in diabetic mice. FMT reduced blood glucose levels, improved glucose tolerance, and increased insulin sensitivity in diabetic mice. However, FMT did not significantly improve GLP-1 levels.

Discussion

This indicates that C. cicadae polysaccharides alleviate hyperglycemia by regulating the production of metabolites other than indole and its derivatives by gut microbiota. This study provides an important reference for the development of novel natural products.

Microbiota revolution: How gut microbes regulate our lives

The human intestine is a natural environment ecosystem of a complex of diversified and dynamic microorganisms, determined through a process of competition and natural selection during life. Those intestinal microorganisms called microbiota and are involved in a variety of mechanisms of the organism, they interact with the host and therefore are in contact with the organs of the various systems. However, they play a crucial role in maintaining host homeostasis, also influencing its behaviour. Thus, microorganisms perform a series of biological functions important for human well-being. The host provides the microorganisms with the environment and nutrients, simultaneously drawing many benefits such as their contribution to metabolic, trophic, immunological, and other functions. For these reasons it has been reported that its quantitative and qualitative composition can play a protective or harmful role on the host health. Therefore, a dysbiosis can lead to an association of unfavourable factors which lead to a dysregulation of the physiological processes of homeostasis. Thus, it has pre-viously noted that the gut microbiota can participate in the pathogenesis of autoimmune diseases, chronic intestinal inflammation, diabetes mellitus, obesity and atherosclerosis, neurological disorders (e.g., neurological diseases, autism, etc.) colorectal cancer, and more.

Neuroprotective Effect of Ponicidin Alleviating the Diabetic Cognitive Impairment: Regulation of Gut Microbiota

Cognitive impairment is a major complication of diabetes mellitus, which is caused by constitutive hyperglycaemia. Ponicidin is a diterpenoid isolated from a Chinese traditional herb (Rabdosia rubescens) and demonstrates the various pharmacological effects. The goal of this study was to scrutinise the neuroprotective effect of ponicidin against diabetic nephropathy (DN) induced by streptozotocin (STZ). Intraperitoneal administration of STZ (55 mg/kg) was used for the induction of diabetes and rats were received oral administration of ponicidin (5, 10 and 15 mg/kg) until 28 days. The body weight, food intake, water intake and blood glucose level were assessed at regular time interval. Plasma insulin level, antioxidant, inflammatory cytokines, apoptosis marker and faecal gut microbiota compositions were estimated. DN-induced group rats revealed the augmented glucose level, water intake, food intake and reduced body weight. Ponicidin significantly (P < 0.001) repressed the glucose level and water food intake and improved the body weight and plasma insulin. Ponicidin significantly (P < 0.001) repressed the malonaldehyde (MDA) level and boosted the level of glutathione (GSH), glutathione reductase (GR) and superoxide dismutase (SOD) in the brain and serum level. Ponicidin significantly (P < 0.001) repressed the level of interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) and enhanced the level of interleukin-4 (IL-4), interleukin-10 (IL-10) in the brain and serum level. DN group rats exhibited the enhanced relative abundance of Firmicutes, along with enhancing the Firmicutes/Bacteroidetes ratio and repressing the Bacteroidetes relative abundance. Ponicidin effectually restored the relative abundance of Allobaculum, Lactobacillus and Ruminococcus genera. Our findings clearly demonstrated that ponicidin has a neuroprotective effect against diabetic cognitive impairment through modulating the gut microbiome.

Gut Microbiota and Their Associated Metabolites in Diabetes: A Cross Talk Between Host and Microbes-A Review

Dysbiosis of the gut microbiota's composition and function is important in developing insulin resistance and diabetes. Diabetes has also been linked to changes in the circulating and fecal metabolites. Evidence suggests the associations between the gut microbiota and the aberrant diabetes-related metabolome. Metabolites play a crucial role in the host-microbiota interactions. Researchers have used a combination of metagenomic and metabolomic approaches to investigate the relationships between gut microbial dysbiosis and metabolic abnormalities in diabetes. We summarized current discoveries on the associations between the gut microbiota and metabolites in type 1 diabetes, type 2 diabetes, and gestational diabetes mellitus in the scoping review. According to research, the gut microbiota changes might involve in the development of diabetes through modulating the host's metabolic pathways such as immunity, energy metabolism, lipid metabolism, and amino acid metabolism. These results add to our understanding of the interplay between the host and gut microbiota metabolism.

Indian sewage microbiome has unique community characteristics and potential for population-level disease predictions

Sewage wastewater pollutes water and poses a public health issue but it could also prove useful in certain research domains. Sewage is a complex niche relevant for research concerning 'one-health', human health, pollution and antibiotic resistance. Indian gut microbiome is also understudied due to sampling constraints and sewage could be used to explore it. Ostensibly, Indian sewage needs to be studied and here, we performed a cross-sectional pan-India sewage sampling to generate the first comprehensive Indian sewage microbiome. Indian sewage showed predominance of Burkholderiaceae, Rhodocyclaceae, Veillonellaceae, Prevotellaceae, etc. and has high representation of gut microbes. The identified gut microbes have overrepresentation of Veillonellaceae, Rikenellaceae, Streptococcaceae, and Bacillaceae. Imputed metagenomics of sewage microbiome indicated dominance of transport, motility, peptidases, amino acid metabolism, and antibiotic resistance genes. Microbiome-disease associations drawn using simple decision tree and random forest analysis identified specific microbes as potential predictors of diabetes and obesity in a city. Altogether, we generated the first Indian sewage microbiome and our non-invasive, high-throughput workflow could be emulated for future research, wastewater-based epidemiology and designing policies concerning public health.

Phylogenetic analysis of Prevotella copri from fecal and mucosal microbiota of IBS and IBD patients

BACKGROUND

Prevotella copri is the most abundant member of the genus Prevotella that inhabits the human large intestines. Evidences correlated the increase in Prevotella abundance to inflammatory disorders, suggesting a pathobiont role.

OBJECTIVES

The aim of this study was to investigate the phylogenetic dynamics of P. copri in patients with irritable bowel syndrome (IBS), inflammatory bowel diseases (IBDs) and in healthy volunteers (CTRL).

DESIGN

A phylogenetic approach was used to characterize 64 P. copri 16S rRNA sequences, selected from a metagenomic database of fecal and mucosal samples from 52 patients affected by IBD, 44 by IBS and 59 healthy.

METHODS

Phylogenetic reconstructions were carried out using the maximum likelihood (ML) and Bayesian methods.

RESULTS

Maximum likelihood phylogenetic tree applied onto reference and data sets, assigned all the reads to P. copri clade, in agreement with the taxonomic classification previously obtained. The longer mean genetic distances were observed for both the couples IBD and CTRL and IBD and IBS, respect to the distance between IBS and CTRL, for fecal samples. The intra-group mean genetic distance increased going from IBS to CTRLs to IBD, indicating elevated genetic variability within IBD of P. copri sequences. None clustering based on the tissue inflammation or on the disease status was evidenced, leading to infer that the variability seemed to not be influenced by concomitant diseases, disease phenotypes or tissue inflammation. Moreover, patients with IBS appeared colonized by different strains of P. copri. In IBS, a correlation between isolates and disease grading was observed.

CONCLUSION

The characterization of P. copri phylogeny is relevant to better understand the interactions between microbiota and pathophysiology of IBD and IBS, especially for future development of therapies based on microbes (e.g. probiotics and synbiotics), to restore the microbiota in these bowel diseases.

Effect of antimicrobial therapy on progression-free survival of immunotherapy and chemo-/immunotherapy in patients with non-small cell lung cancer

BACKGROUND

The choice between immunotherapy with a checkpoint inhibitor (CPI) and chemo-/immunotherapy (CIT) in patients with NSCLC stage IV is often discussed. There are some data that the effect of CPI therapy is impaired by antimicrobial therapy (AMT). Little is known about the influence of AMT on CIT.

PATIENTS AND METHODS

We retrospectively analysed 114 patients (age 68 ± 8.5 years) with NSCLC stage IV. Patients were treated according to the guidelines with either CPI alone (pembrolizumab, nivolumab, atezolizumab, cemiplimab) or CIT (Carboplatin/Pemetrexed/Pembrolizumab, Carboplatin/Paclitaxel/Pembrolizumab). We registered patients' characteristics including presence and timing of AMT. Group 1 consisted of 42 patients with AMT in the month before CPI or CIT, group 2 were 49 patients with AMT during CPI or CIT, and group 3 were 64 patients without AMT and CPI or CIT.

RESULTS

Group 1-3 showed comparable patients characteristics. Using cox-regression analysis, we found that AMT in the month before CPI resulted in a decreased progression-free survival (PFS) compared to patients with CPI and no AMT (14 ± 1.02 vs. 4 ± 1.02 months, p = 0.002, 95% CI 1.88-9). In patients, who were treated with CIT, there was no difference in PFS in those with or without AMT in the month before therapy (10 ± 2.5 vs. 6 ± 1.2 months, p = 0.7). Interestingly, AMT during CIT or CPI therapy showed no effect on PFS.

CONCLUSIONS

In a real-life setting, we found that AMT reduces PFS when given in the month before CIT therapy. AMT before or during CIT does not seem to influence PFS. As a consequence, AMT before start of therapy might be a factor that could lead to a preference of CIT instead of CPI in NSCLC stage IV patients.

Clinical benefits of β-glucan supplementation in children: a review

Malnutrition is a global concern since it affects 130 million children under the age of 5 worldwide. The child’s immunity is brutally compromised, making them susceptible to various diseases and infections, leading to a high mortality rate. Multiple strategies have been implemented to strengthen immunity in children with compromised immunity, such as rendering a balanced diet, fortifying food, dietary supplements, and introducing potential natural dietary fibers to maintain good nutrition status, such as β-glucan. A class of biologically active polysaccharides, sourced from yeast, mushroom, bacteria, and cereals with versatile immunomodulatory benefits that potentially primes the host immune system, drives several metabolic health effects, increases infection resistance, shields against the damaging effects of stress, and maintains healthy energy levels. This review focuses on the capabilities, underlying mechanisms, immune-stimulating potency, and clinically meaningful shreds of evidence to substantiate the multiple health benefits of β-glucan in children. Although, more clinical studies are required, current findings confirms the various biological response modifying abilities of β-glucan that may notably aid in the development of a strong immune system in children for their overall health and wellbeing.

The gut microbiome and obstructive sleep apnea syndrome in children

Obstructive sleep apnea syndrome (OSAS) in children has become a major public health problem that affects the physical and mental growth of children. OSAS can result in adverse outcomes during growth and development, inhibiting the normal development of the metabolic, cardiovascular, and immune systems. OSAS is characterized by partial or complete obstruction of the upper airway, and prolonged obstruction that causes intermittent hypoxia and sleep fragmentation in children. The human microbiota is a complex community that is in dynamic equilibrium in the human body. Intermittent hypoxia and sleep fragmentation induced by childhood OSAS alter the composition of the gut microbiome. At the same time, changes in the gut microbiome affect sleep patterns in children through immunomodulatory and metabolic mechanisms, and induce further comorbidities, such as obesity, hypertension, and cardiovascular disease. This article discusses recent progress in research into the mechanisms of OSAS-induced changes in the gut microbiota and its pathophysiology in children.

Analysis of the gut microbiome in obese native Tibetan children living at different altitudes: A case-control study

Objective

To explore the relationship between intestinal flora and obesity in Tibetan children at different altitudes.

Methods

Using16S rRNA gene sequencing results and blood lipid metabolism indexes to study the characteristics of the intestinal flora present in faeces and changes in blood lipid metabolism in obese children in Tibet who reside at different altitudes and to study correlations between blood lipid metabolism indicators and the intestinal flora composition.

Results

The results showed the following. (a) The triglyceride (TG) and low-density lipoprotein cholesterol (LDL-C) levels in the obesity groups were higher than those in the normal-weight groups, and those in the high-altitude obesity groups were lower than those in the low-altitude obesity groups. (b) The 16S rRNA gene sequencing results showed that altitude affected the composition and relative abundance of the gut microbiota. These parameters were basically the same among the low-altitude groups, while they were significantly lower in the high-altitude groups than in the low-altitude groups. (c) Groups that lived at different altitudes and had different body weights had different dominant bacterial genera. Megamonas was closely related to obesity, and its relative abundance in the low-altitude groups was higher than that in the high-altitude groups. Prevotella was associated with altitude, and its relative abundance in the high-altitude groups was higher than that in the low-altitude groups. In addition, Prevotella elicited changes in the abundance of Escherichia-Shigella. The lower prevalence of obesity and incidence of intestinal inflammation in those living at high altitudes were related to the abundance of Prevotella. (d) There were correlations between the gut microbiota composition and lipid metabolism indicators. The abundance of Romboutsia was positively correlated with TG and LDL-C levels but negatively correlated with high-density lipoprotein cholesterol (HDL-C) levels. The abundance of Akkermansia was negatively correlated with LDL-C levels, and the abundance of Blautia was negatively correlated with body mass index (BMI) and LDL-C levels.

Conclusions

The intestinal flora diversity varied by body weight and altitude, with lower diversity in those at higher altitudes and with lower body weights. Prevotella likely plays a role in suppressing obesity at high altitudes.

An Energy-Restricted Diet Including Yogurt, Fruit, and Vegetables Alleviates High-Fat Diet-Induced Metabolic Syndrome in Mice by Modulating the Gut Microbiota

BACKGROUND

The importance of the composition of an energy-restricted diet in the treatment of metabolic syndrome (MetS) is unknown.

OBJECTIVES

In this study we aimed to investigate the benefits of a novel dietary treatment (50% calorie restriction diet composed of yogurt, fruit, and vegetables [CR-YD]) in mice with MetS.

METHODS

Forty 7-wk-old male C57BL/6 J mice were randomly assigned to 4 groups (n = 10/group) that were fed for 14 wk ad libitum with a normal diet (ND; 10%:70%:20% energy from fat: carbohydrate: protein) or for 12 wk with a high-fat diet (HFD; 60:20:20) or the HFD followed by 2 wk of feeding with a 50% calorie-restricted HFD (CR-HFD) or YD (CR-YD, 21.2%:65.4%:13.4% energy). Body weight, fat deposition, hepatic steatosis, serum concentrations of inflammatory biomarkers, and glucose homeostasis were assessed. Fecal microbiota transplantation (FMT) was used to validate the roles of gut microbiota in MetS.

RESULTS

The HFD group had 50% greater body weight and 475% greater fat deposition than the ND group (P < 0.05). Compared with the HFD group, the CR-HFD and CR-YD groups had 22% and 31% lower body weight and 49% and 75% less fat deposition, respectively (P < 0.05). Compared with the CR-HFD group, the CR-YD group had 11% lower body weight, 96% less fat deposition, 500% less hepatic steatosis, 75% lower glucose, and 450% more hepatic Akkermansia bacteria (P < 0.05). The CR-YD group also had 50% lower histopathology scores and 1.35-fold higher levels of Claudin4 than the CR-HFD group (P < 0.05). The HFD + CR-YD fecal group had 10.6% lower body weight, 119% lower steatosis, and 17.9% lower glucose (P < 0.05) than the HFD + CR-HFD fecal group.

CONCLUSIONS

Compared with CR alone, the CR-YD diet has a better therapeutic effect in mice with HFD-induced MetS.

Sleep apnea is associated with the increase of certain genera of Ruminococcaceae and Lachnospiraceae in the gut microbiome of hypertensive patients

BACKGROUND

Obstructive sleep apnea (OSA) and hypertension are interrelated diseases linked to gut dysbiosis. This study aimed to investigate the effect of OSA on the gut microbiome in the context of hypertension and vice versa.

RESEARCH DESIGN AND METHODS

Of 211 consecutively screened patients, 52 completed polysomnography study, medical history questionnaires, and fecal sample collection. 16S rRNA gene sequencing was performed on fecal samples, and diversity, richness, and microbial taxa were analyzed using bioinformatics.

RESULTS

Alpha diversity showed slightly decreased diversity in OSA and hypertension groups without significant difference, and the hypoxia burden index (HBI) showed a weak positive correlation with Chao1 index (r = 0.342, p < 0.05) in OSA patients. Firmicutes-to-Bacteroidetes ratio was higher in patients with than without OSA. In hypertensive patients, those with OSA had higher Ruminococcus_1, Lachnoclostridium, Lachnospira, [Ruminococcus]_torques_group, and unidentified Lachnospiraceae levels than those without OSA. Conversely, in OSA patients, hypertensive patients had lower Faecalibacterium and Lachnospiraceae_NK4A136_group levels.

CONCLUSION

The present study suggests a possible compensatory mechanism for gut microbiome changes in sleep apnea pathophysiology. The positive correlation between HBI and alpha diversity, and increase in certain genera of Ruminococcaceae and Lachnospiraceae in OSA patients may represent an adaptive response to hypoxia.

Gut Microbiota and Therapy in Metastatic Melanoma: Focus on MAPK Pathway Inhibition

Gut microbiome (GM) and its either pro-tumorigenic or anti-tumorigenic role is intriguing and constitutes an evolving landscape in translational oncology. It has been suggested that these microorganisms may be involved in carcinogenesis, cancer treatment response and resistance, as well as predisposition to adverse effects. In melanoma patients, one of the most immunogenic cancers, immune checkpoint inhibitors (ICI) and MAPK-targeted therapy—BRAF/MEK inhibitors—have revolutionized prognosis, and the study of the microbiome as a modulating factor is thus appealing. Although BRAF/MEK inhibitors constitute one of the main backbones of treatment in melanoma, little is known about their impact on GM and how this might correlate with immune re-induction. On the contrary, ICI and their relationship to GM has become an interesting field of research due to the already-known impact of immunotherapy in modulating the immune system. Immune reprogramming in the tumor microenvironment has been established as one of the main targets of microbiome, since it can induce immunosuppressive phenotypes, promote inflammatory responses or conduct anti-tumor responses. As a result, ongoing clinical trials are evaluating the role of fecal microbiota transplant (FMT), as well as the impact of using dietary supplements, antibiotics and probiotics in the prediction of response to therapy. In this review, we provide an overview of GM’s link to cancer, its relationship with the immune system and how this may impact response to treatments in melanoma patients. We also discuss insights about novel therapeutic approaches including FMT, changes in diet and use of probiotics, prebiotics and symbiotics. Finally, we hypothesize on the possible pathways through which GM may impact anti-tumor efficacy in melanoma patients treated with targeted therapy, an appealing subject of which little is known.

Evaluation of fecal microbiota and its correlation with inflammatory, hormonal, and nutritional profiles in women

The present study evaluated the gut microbiota profiles of 40 women and correlated them with their nutritional, inflammatory, and hormonal profiles. Stool and blood samples were collected, and anthropometric measurements were obtained from 20 women diagnosed with obesity ("case" group) and 20 women with weight in the normal range ("control" group). Bacteria belonging to two phyla, Firmicutes and Bacteroidetes, one class, Mollicutes, and four genera were evaluated by real-time polymerase chain reaction. Levels of 18 inflammatory cytokines were measured using the Luminex assay, and ghrelin and leptin levels were measured using enzymatic immunoadsorption assay. Mollicutes proportion differed significantly between the case and control groups, and a significant positive association was detected between the presence of Mollicutes and obesity. Statistically significant differences were observed between the proportions of Firmicutes and Bacteroidetes in the two groups, with a higher proportion of Firmicutes/Bacteroidetes ratio among the gut microbiota of women in the case group compared to those of the control group. Higher counts of Escherichia coli and Clostridium spp. were observed in the control group than in the case group, whereas higher counts of Lactobacillus spp. and Bacteroides spp. were detected in the case group than in the control group. There was a positive correlation between interleukin-6 (IL-6) and interferon-γ (IFN-γ) levels and the anthropometric variables and a negative correlation between IL-10 and these variables. Leptin and ghrelin concentrations differed significantly between the two groups and showed positive and negative correlation with obesity predictors, respectively. Therefore, gut microbiota was associated with obesity in women from this study group. Moreover, this microbiota was associated with inflammatory profiles and alterations in ghrelin and leptin levels.

Dietary Blueberry Ameliorates Vascular Complications in Diabetic Mice Possibly through NOX4 and Modulates Composition and Functional Diversity of Gut Microbes

SCOPE

In diabetes, endothelial inflammation and dysfunction play a pivotal role in the development of vascular disease. This study investigates the effect of dietary blueberries on vascular complications and gut microbiome in diabetic mice.

METHODS AND RESULTS

Seven-week-old diabetic db/db mice consume a standard diet (db/db) or a diet supplemented with 3.8% freeze-dried blueberry (db/db+BB) for 10 weeks. Control db/+ mice are fed a standard diet (db/+). Vascular inflammation is assessed by measuring monocyte binding to vasculature and inflammatory markers. Isometric tension procedures are used to assess mesenteric artery function. db/db mice exhibit enhanced vascular inflammation and reduced endothelial-dependent vasorelaxation as compared to db/+ mice, but these are improved in db/db+BB mice. Blueberry supplementation reduces the expression of NOX4 and IκKβ in the aortic vessel and vascular endothelial cells (ECs) isolated from db/db+BB compared to db/db mice. The blueberry metabolites serum reduces glucose and palmitate induced endothelial inflammation in mouse aortic ECs. Further, blueberry supplementation increases commensal microbes and modulates the functional potential of gut microbes in diabetic mice.

CONCLUSION

Dietary blueberry suppresses vascular inflammation, attenuates arterial endothelial dysfunction, and supports the growth of commensal microbes in diabetic mice. The endothelial-specific vascular benefits of blueberries are mediated through NOX4 signaling.

A systematic review on the effects of nanomaterials on gut microbiota

Some nanomaterials (NMs) have been shown to possess antimicrobial activity and cause GM dysbiosis. Since NMs are being used widely, a systematic assessment of the effects of NMs on GM is warranted. In this systematic review, a total of 46 in vivo and 22 in vitro studies were retrieved from databases and search engines including Science-Direct, Pubmed and Google scholar. Criteria for assessment of studies included use of in vitro or in vivo studies, characterization of NMs, use of single or multiple doses as well as consistency of results. GM dysbiosis has been studied most widely on TiO2, Ag, Zn-based NMs. There was moderate evidence for GM dysbiosis caused by Zn- and Cu-based NMs, Cu-loaded chitosan NPs and Ag NMs, and anatase TiO2 NPs, as well as low evidence for SWCNTs, nanocellulose, SiO2, Se, nanoplastics, CeO2, MoO3 and graphene-based NMs. Most studies indicate adverse effects of NMs towards GM. However, more work is required to elucidate the differences on the reported effects of NM by type and sex of organisms, size, shape and surface properties of NMs as well as effects of exposure to mixtures of NMs. For consistency and better agreement among studies on GM dysbiosis, there is need for internationally agreed protocols on, inter alia, characterization of NMs, dosing (amounts, frequency and duration), use of sonication, test systems (both in vitro and in vivo), including oxygen levels for in vitro models.

Exercise for the Diabetic Gut-Potential Health Effects and Underlying Mechanisms

It can be assumed that changes in the gut microbiota play a crucial role in the development of type 2 diabetes mellitus (T2DM). It is generally accepted that regular physical activity is beneficial for the prevention and therapy of T2DM. Therefore, this review analyzes the effects of exercise training on the gut microbiota composition and the intestinal barrier function in T2DM. The current literature shows that regular exercise can influence the gut microbiota composition and the intestinal barrier function with ameliorative effects on T2DM. In particular, increases in the number of short-chain fatty acid (SCFA)-producing bacteria and improvements in the gut barrier integrity with reduced endotoxemia seem to be key points for positive interactions between gut health and T2DM, resulting in improvements in low-grade systemic inflammation status and glycemic control. However, not all aspects are known in detail and further studies are needed to further examine the efficacy of different training programs, the role of myokines, SCFA-producing bacteria, and SCFAs in the relevant metabolic pathways. As microbial signatures differ in individuals who respond differently to exercise training programs, one scientific focus could be the development of computer-based methods for the personalized analysis of the gut microbiota in the context of a microbiota/microbiome-based training program.

Changes in Metabolic Regulation and the Microbiota Composition after Supplementation with Different Fatty Acids in db/db Mice

Introduction

The effects of fatty acids on health vary and depend on the type, amount, and route of consumption. EPA and DHA have a defined role in health, unlike coconut oil.

Objective

The aim was to investigate the changes in metabolic regulation and the composition of the culture-dependent microbiota after supplementation with different fatty acids in db/db mice. Material and Methods. We were using 32 8-week-old db/db mice, supplemented for eight weeks with EPA/DHA derived from microalgae as well as coconut oil. The lipid, hormonal profiles, and composition of the culture-dependent microbiota and the phylogenetic analysis based on the 16S rRNA gene sequencing were determined for identification of the intestinal microbiota.

Results

Enriched diet with EPA/DHA reduced TNF-α, C-peptide, insulin resistance, resistin, and the plasma atherogenic index, but increased TC, LDL-c, VLDL-c, and TG without changes in HDL-c. Coconut oil raised the HDL-c, GIP, and TNF-α, with TG, insulin resistance, adiponectin, and C-peptide reduced.

Conclusion

The most abundant microbial populations were Firmicutes and the least Proteobacteria. EPA/DHA derived from microalgae contributes to improving the systemic inflammatory status, but depressed the diversity of the small intestine microbiota. Coconut oil only decreased the C-peptide, raising TNF-α, with an unfavorable hormonal and lipid profile.

Multi-Organ Crosstalk with Endocrine Pancreas: A Focus on How Gut Microbiota Shapes Pancreatic Beta-Cells

Type 2 diabetes (T2D) results from impaired beta-cell function and insufficient beta-cell mass compensation in the setting of insulin resistance. Current therapeutic strategies focus their efforts on promoting the maintenance of functional beta-cell mass to ensure appropriate glycemic control. Thus, understanding how beta-cells communicate with metabolic and non-metabolic tissues provides a novel area for investigation and implicates the importance of inter-organ communication in the pathology of metabolic diseases such as T2D. In this review, we provide an overview of secreted factors from diverse organs and tissues that have been shown to impact beta-cell biology. Specifically, we discuss experimental and clinical evidence in support for a role of gut to beta-cell crosstalk, paying particular attention to bacteria-derived factors including short-chain fatty acids, lipopolysaccharide, and factors contained within extracellular vesicles that influence the function and/or the survival of beta cells under normal or diabetogenic conditions.

Cerebrospinal Fluid from Healthy Pregnant Women Does Not Harbor a Detectable Microbial Community

Cerebrospinal fluid (CSF) circulating in the human central nervous system has long been considered aseptic in healthy individuals, because normally, the blood-brain barrier can protect against microbial invasions. However, this dogma has been called into question by several reports that microbes were identified in human brains, raising the question of whether there is a microbial community in the CSF of healthy individuals without neurological diseases. Here, we collected CSF samples and other samples, including one-to-one matched oral and skin swab samples (positive controls), from 23 pregnant women aged between 23 and 40 years. Normal saline samples (negative controls), sterile swabs, and extraction buffer samples (contamination controls) were also collected. Twelve of the CSF specimens were also used to evaluate the physiological activities of detected microbes. Metagenomic and metatranscriptomic sequencing was performed in these 116 specimens. A total of 620 nonredundant microbes were detected, which were dominated by bacteria (74.6%) and viruses (24.2%), while in CSF samples, metagenomic sequencing found only 26 nonredundant microbes, including one eukaryote, four bacteria, and 21 viruses (mostly bacteriophages). The beta diversity of microbes compared between CSF metagenomic samples and other types of samples (except negative controls) was significantly different from that of the CSF self-comparison. In addition, there was no active or viable microbe in the matched metagenomic and metatranscriptomic sequencing of CSF specimens after subtracting those also found in normal saline, DNA extraction buffer, and skin swab specimens. In conclusion, our results showed no strong evidence of a colonized microbial community present in the CSF of healthy individuals. IMPORTANCE The microbiome is prevalent throughout human bodies, with profound health implications. However, it remains unclear whether it is present and active in human CSF, which has been long considered aseptic due to the blood-brain barrier. Here, we applied unbiased metagenomic and metatranscriptomic sequencing to detect the presence of a microbiome in CSF collected from 23 pregnant women with matched controls. Analysis of 116 specimens found no strong evidence to support the presence of a colonized microbiome in CSF. Our findings will strengthen our understanding of the internal environment of the CSF in healthy people, which has strong implications for human health, especially for neurological infections and disorders, and will help further disease diagnostics, prevention, and therapeutics in clinical settings.

Human Gut Microbiota in Health and Selected Cancers

The majority of the epithelial surfaces of our body, and the digestive tract, respiratory and urogenital systems, are colonized by a vast number of bacteria, archaea, fungi, protozoans, and viruses. These microbiota, particularly those of the intestines, play an important, beneficial role in digestion, metabolism, and the synthesis of vitamins. Their metabolites stimulate cytokine production by the human host, which are used against potential pathogens. The composition of the microbiota is influenced by several internal and external factors, including diet, age, disease, and lifestyle. Such changes, called dysbiosis, may be involved in the development of various conditions, such as metabolic diseases, including metabolic syndrome, type 2 diabetes mellitus, Hashimoto's thyroidis and Graves' disease; they can also play a role in nervous system disturbances, such as multiple sclerosis, Alzheimer's disease, Parkinson's disease, and depression. An association has also been found between gut microbiota dysbiosis and cancer. Our health is closely associated with the state of our microbiota, and their homeostasis. The aim of this review is to describe the associations between human gut microbiota and cancer, and examine the potential role of gut microbiota in anticancer therapy.

Long term impact of vonoprazan-based Helicobacter pylori treatment on gut microbiota and its relation to post-treatment body weight changes

BACKGROUND

Vonoprazan-based Helicobacter pylori (H. pylori) treatment is highly effective in eradicating the target bacteria; however, its post-1-year impact on gut microbiota is unknown. This study evaluated the impact of vonoprazan-based H. pylori therapy on gut microbiota 1-year post-therapy and investigated the relationship between body weight changes and post-therapy gut microbiota perturbations.

MATERIALS AND METHODS

Between March and May 2019, 43 patients with H. pylori infections received either vonoprazan/amoxicillin (VA) or vonoprazan/amoxicillin/clarithromycin (VAC) therapy. Fecal samples were collected prior to treatment and 1 year after treatment. The alpha and beta diversities and the bacterial taxa composition ratios were determined using polymerase chain reaction amplification of the V3-V4 region of the 16S ribosomal RNA gene. The correlation between body weight changes and relative abundances of genera post-therapy was also analyzed.

RESULTS

Among the 43 patients, 18 received VA therapy and 21 received VAC therapy. One year after treatment, the alpha diversity was significantly higher in both the treatment groups (p < .001, using observed operational taxonomic units and Chao1 index), and beta diversity was significantly different in both the groups (p = .001, using unweighted UniFrac distance) compared with baseline findings. Significant positive correlations were found between body weight changes and the relative abundances of Coprococcus spp. (p = .037) and Odoribacter spp. (p = .022) post-therapy.

CONCLUSION

Vonoprazan-based H. pylori therapies are associated with long-term impacts on gut microbiota, including effects on bacterial species richness, and potentially affect metabolism by altering the microbiota.

TRIAL REGISTRATION NUMBER

UMIN000040025.

Gut microbiota-a positive contributor in the process of intermittent fasting-mediated obesity control

Historically, intermittent fasting (IF) has been considered as an effective strategy for controlling the weight of athletes before competition. Along with excellent insight into its application in various spaces by numerous studies, increasing IF-mediated positive effects have been reported, including anti-aging, neuroprotection, especially obesity control. Recently, the gut microbiota has been considered as an essential manipulator for host energy metabolism and its structure has been reported to be sensitive to dietary structure and habits, indicating that there is a potential and strong association between IF and gut microbiota. In this paper, we focus on the crosstalk between these symbionts and energy metabolism during IF which hold the promise to optimize host energy metabolism at various physical positions, including adipose tissue, liver and intestines, and further improve milieu internal homeostasis. Moreover, this paper also discusses the positive function of a potential recommendatory strain (Akkermansia muciniphila) based on the observational data for IF-mediated alternated pattern of gut microbiota and a hopefully regulatory pathway (circadian rhythm) for gut microbiota in IF-involved improvement on host energy metabolism. Finally, this review addresses the limitation and perspective originating from these studies, such as the association with tissue-specific bio-clock and single strain research, which may continuously reveal novel viewpoints and mechanisms to understand the energy metabolism and develop new strategies for treating obesity, diabetes, and metabolic disorders.

Effect of antimicrobial therapy on progression-free survival of patients with non-small cell lung cancer receiving checkpoint inhibitor- and chemotherapy

BACKGROUND

Checkpoint inhibitor therapy (CPI) has significantly changed therapy in non-small cell lung cancer (NSCLC) in recent years. There are some data that the effect of CPI therapy is influenced by the microbiome. Little is known about the influence and timing of antimicrobial therapy (AMT) on the microbiome-mediated effect on CPI therapy.

PATIENTS AND METHODS

We retrospectively analysed 70 patients (age 68 ± 9.2 years) with NSCLC stage IV. Patients were treated according to the guidelines with either CPI alone (pembrolizumab, nivolumab, atezolizumab) or chemotherapy (platin doublet or docetaxel/nintedanib or pemetrexed). We registered patient's characteristics including presence and timing of AMT. Group 1 consisted of 27 patients with AMT in the month before CPI- or chemotherapy, group 2 was 30 patients with AMT during CPI- or chemotherapy, and group 3 was 43 patients without AMT.

RESULTS

Groups 1-3 showed comparable patient characteristics. Using cox-regression analysis, we found that AMT in the month before CPI resulted in a decreased progression-free survival (PFS) compared to patients with CPI and no AMT (14 ± 1.56 vs. 5 ± 0.99, p = 0.005, 95% CI: 0.13-0.67). In patients, who were treated with chemotherapy alone, there was no difference in PFS in those with or without AMT in the month before therapy (5 ± 0.99 vs. 6 ± 0.81 months, p = 0.3). Interestingly, AMT during chemotherapy or CPI therapy showed no effect on PFS.

CONCLUSIONS

In a real-life setting, we found that AMT reduces PFS when given in the month before CPI therapy. AMT before chemotherapy and during CPI and chemotherapy seems not to influence PFS. The best PFS was seen in patients without AMT before CPI therapy. This implies the need for an even more restrictive use of AMT in the context of patients with NSCLC stage IV disease.

A metagenomic study of the gut microbiome in PTB'S disease

BACKGROUND

There is an abundant link between the gut microbiota and human health and it plays a critical role in the clinic. It is recognized that microbial dysregulation contributes to the pathogenesis of tuberculosis (TB), but the underlying mechanisms remain unclear. In this study, we investigated the association of gut microbiome composition with TB as well as its possible roles in the development of this disease.

METHODS

Fecal samples were collected from 10 TB patients and 20 healthy control samples. DNA extracted from fecal samples was subjected to 16S rDNA gene sequencing analysis on the Illumina MiSeq platform.

RESULTS

Compared with healthy control samples, the gut microbiome of patients with TB was characterized by the decreased Alpha diversity. Perhaps, the decrease of microbial diversity which results in microbial dysregulation is the reason for clinical patients with more symptoms. The PTB group showed the most unique microbiota by higher abundance of Bifidobacteriaceae, Bifidobacteriales, Coriobacteriaceae, Coriobacteriales, Actinobacteria, Caulobacteraceae, Phyllobacteriaceae, Rhizobiales, Burkholderiaceae, Burkholderiaceae. Inflammatory status in PTB patients may be associated with the increased abundance of Clostridia and decreased abundance of Prevotella. We found that the abundance of Solobacterium and Actinobacteria was higher in the patients. There were 4 significant differences (p<0.05) in the two groups which belonged to four metabolic categories, including endocytosis, phosphotransferase system (PTS), toluene degradation, and amoebiasis.

CONCLUSION

We applied the approach of metagenomic sequencing to characterize the features of gut microbiota in PTB patients. The present study provided a detailed analysis of the characterization of the gut microbiota in patients based on the clinic. According to the metagenome analysis, our results indicated that the gut microbiota in PTB patients was significantly different from healthy control samples as characterized by the bacteria and metabolic pathway. The richness of the gut microbiota in patients was revealed. It was hypothesized that the above-mentioned changes of the gut microbiota could exert an impact on the development of PTB through the downstream regulation of the immune status of the host by way of the gut-lung axis.

The impact of the Th17:Treg axis on the IgA-Biome across the glycemic spectrum

Secretory IgA (SIgA) is released into mucosal surfaces where its function extends beyond that of host defense to include the shaping of resident microbial communities by mediating exclusion/inclusion of respective microbes and regulating bacterial gene expression. In this capacity, SIgA acts as the fulcrum on which host immunity and the health of the microbiota are balanced. We recently completed an analysis of the gut and salivary IgA-Biomes (16S rDNA sequencing of SIgA-coated/uncoated bacteria) in Mexican-American adults that identified IgA-Biome differences across the glycemic spectrum. As Th17:Treg ratio imbalances are associated with gut microbiome dysbiosis and chronic inflammatory conditions such as type 2 diabetes, the present study extends our prior work by examining the impact of Th17:Treg ratios (pro-inflammatory:anti-inflammatory T-cell ratios) and the SIgA response (Th17:Treg-SIgA axis) in shaping microbial communities. Examining the impact of Th17:Treg ratios (determined by epigenetic qPCR lymphocyte subset quantification) on the IgA-Biome across diabetes phenotypes identified a proportional relationship between Th17:Treg ratios and alpha diversity in the stool IgA-Biome of those with dysglycemia, significant changes in community composition of the stool and salivary microbiomes across glycemic profiles, and genera preferentially abundant by T-cell inflammatory phenotype. This is the first study to associate epigenetically quantified Th17:Treg ratios with both the larger and SIgA-fractionated microbiome, assess these associations in the context of a chronic inflammatory disease, and offers a novel frame through which to evaluate mucosal microbiomes in the context of host responses and inflammation.

Short-chain fatty acids as modulators of redox signaling in health and disease

Short-chain fatty acids (SCFAs), produced by colonic bacteria and obtained from the diet, have been linked to beneficial effects on human health associated with their metabolic and signaling properties. Their physiological functions are related to their aliphatic tail length and dependent on the activation of specific membrane receptors. In this review, we focus on the mechanisms underlying SCFAs mediated protection against oxidative and mitochondrial stress and their role in regulating metabolic pathways in specific tissues. We critically evaluate the evidence for their cytoprotective roles in suppressing inflammation and carcinogenesis and the consequences of aging. The ability of these natural compounds to induce signaling pathways, involving nuclear erythroid 2-related factor 2 (Nrf2), contributes to the maintenance of redox homeostasis under physiological conditions. SCFAs may thus serve as nutritional and therapeutic agents in healthy aging and in vascular and other diseases such as diabetes, neuropathologies and cancer.

•

SCFAs are a link between the microbiota, redox signaling and host metabolism.

•

SCFAs modulate Nrf2 redox signaling through specific free fatty acid receptors.

•

Butyrate induces epigenetic regulation and/or Nrf2 nuclear translocation.

•

Butyrate and propionate protect the blood-brain barrier by facilitating docosahexaenoic acid transport.

•

Regulation of redox homeostasis by SCFAs supports their potential as therapeutic nutrients in health and disease.