Probiotics, prebiotics, synbiotics and insulin sensitivity

The relationship between dietary intake of live microbes and insulin resistance among healthy adults in the US: a cross-sectional study from NHANES 2003-2020

Dietary intake of live microbes may benefit human health, but less is known about the role in insulin resistance. This study was developed with the goal of evaluating potential relationships between IR and dietary live microbes. The National Health and Nutrition Examination Survey (NHANES) dataset was leveraged to collect data from 6,333 subjects 18 + years of age. The Sanders system for the classification of dietary live microbe intake (containing Low (< 104 CFU/g), Medium (104-107 CFU/g), or High (> 107 CFU/g) levels of live microbes) was then used to separate these patients into three groups (low, medium, or high). Fasting blood glucose and insulin levels were used to approximate IR based on the homeostasis model of insulin resistance (HOMA-IR). Weighted linear regressions were used to assess the relationship between IR and live microbe intake. After fully adjusting for confounding factors, subjects in the groups exhibiting medium and high levels of live microbe intake exhibited HOMA-IR scores that were below those of subjects in the low group. The relationship between live microbe intake and HOMA-IR scores was also potentially impacted by ethnicity. In summary, a negative correlation was detected between dietary live microbe intake and HOMA-IR values.

Effect of probiotics at different intervention time on glycemic control in patients with type 2 diabetes mellitus: a systematic review and meta-analysis

Background

Type 2 diabetes mellitus(T2DM) is characterized by hyperglycemia. Gut microbiome adjustment plays a positive part in glucose regulation, which has become a hotspot. Probiotics have been studied for their potential to control the gut flora and to treat T2DM. However, the conclusion of its glucose-lowering effect is inconsistent based on different probiotic intervention times.

Objectives

To comprehensively evaluate how various probiotic intervention times affect glycemic control in people with T2DM.

Methods

We retrieved PubMed, Embase, Web of Science, and Cochrane Library on randomized controlled trials(RCTs)regarding the impact of probiotics on glycemic control in patients with T2DM from the inception to November 16, 2023. Separately, two researchers conducted a literature analysis, data extraction, and bias risk assessment of the involved studies. We followed the PRISMA guidelines, used RevMan 5.4 software for meta-analysis, and assessed the risk of bias by applying the Cochrane Handbook for Systematic Reviews 5.1.0.

Results

We included eight RCTs with 507 patients. Meta-analysis revealed that the use of probiotics might considerably reduce levels of glycosylated hemoglobin (HbA1c) {mean deviation (MD) = -0.33, 95% confidence interval (CI) (-0.59, -0.07), p = 0.01}, Insulin {standard mean deviation (SMD) = -0.48, 95% CI (-0.74, -0.22), p = 0.0003} and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR){SMD = -1.36, 95% CI (-2.30, -0.41), p = 0.005} than placebo group. No statistically significant differences were found regarding fasting blood glucose (FBG) and body mass index (BMI) {SMD = -0.39, 95% CI (-0.83, 0.05), p = 0.08}, {SMD = -0.40, 95% CI (-1.07, 0.27), p = 0.25}, respectively. Subgroup analyses, grouped by intervention times, showed that six to eight weeks of intervention improved HbA1c compared to the control group (p < 0.05), both six to eight weeks and 12-24 weeks had a better intervention effect on Insulin, and HOMA-IR (p < 0.05).In contrast, there was no statistically significant variation in the length between FBG and BMI regarding duration.

Conclusion

This meta-analysis found probiotics at different intervention times play a positive role in modulating glucose in T2DM, specifically for HbA1c in six to eight weeks, Insulin and HOMA-IR in six to eight weeks, and 12-24 weeks. To confirm our findings, further excellent large-sample research is still required.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier CRD42023483325.

Improved Gut Health May Be a Potential Therapeutic Approach for Managing Prediabetes: A Literature Review

Given the growing global threat and rising prevalence of type 2 diabetes mellitus (T2DM), addressing this metabolic disease is imperative. T2DM is preceded by prediabetes (PD), an intermediate hyperglycaemia that goes unnoticed for years in patients. Several studies have shown that gut microbial diversity and glucose homeostasis in PD or T2DM patients are affected. Therefore, this review aims to synthesize the existing literature to elucidate the association between high-calorie diets, intestinal permeability and their correlation with PD or T2DM. Moreover, it discusses the beneficial effects of different dietary interventions on improving gut health and glucose metabolism. The primary factor contributing to complications seen in PD or T2DM patients is the chronic consumption of high-calorie diets, which alters the gut microbial composition and increases the translocation of toxic substances from the intestinal lumen into the bloodstream. This causes an increase in inflammatory response that further impairs glucose regulation. Several dietary approaches or interventions have been implemented. However, only a few are currently in use and have shown promising results in improving beneficial microbiomes and glucose metabolism. Therefore, additional well-designed studies are still necessary to thoroughly investigate whether improving gut health using other types of dietary interventions can potentially manage or reverse PD, thereby preventing the onset of T2DM.

Gut microbiota in insulin resistance: a bibliometric analysis

Background

Insulin resistance (IR) is considered the pathogenic driver of diabetes, and can lead to obesity, hypertension, coronary artery disease, metabolic syndrome, and other metabolic disorders. Accumulating evidence indicates that the connection between gut microbiota and IR. This bibliometric analysis aimed to summarize the knowledge structure of gut microbiota in IR.

Methods

Articles and reviews related to gut microbiota in IR from 2013 to 2022 were retrieved from the Web of Science Core Collection (WoSCC), and the bibliometric analysis and visualization were performed by Microsoft Excel, Origin, R package (bibliometrix), Citespace, and VOSviewer.

Results

A total of 4 749 publications from WoSCC were retrieved, including 3 050 articles and 1 699 reviews. The majority of publications were from China and USA. The University Copenhagen and Shanghai Jiao Tong University were the most active institutions. The journal of Nutrients published the most papers, while Nature was the top 1 co-cited journal, and the major area of these publications was molecular, biology, and immunology. Nieuwdorp M published the highest number of papers, and Cani PD had the highest co-citations. Keyword analysis showed that the most frequently occurring keywords were "gut microbiota", "insulin-resistance", "obesity", and "inflammation". Trend topics and thematic maps showed that serum metabolome and natural products, such as resveratrol, flavonoids were the research hotspots in this field.

Conclusion

This bibliometric analysis summarised the hotspots, frontiers, pathogenesis, and treatment strategies, providing a clear and comprehensive profile of gut microbiota in IR.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01342-x.

The Improvement and Related Mechanism of Microecologics on the Sports Performance and Post-Exercise Recovery of Athletes: A Narrative Review

The diversity and functionality of gut microbiota may play a crucial role in the function of human motor-related systems. In addition to traditional nutritional supplements, there is growing interest in microecologics due to their potential to enhance sports performance and facilitate post-exercise recovery by modulating the gut microecological environment. However, there is a lack of relevant reviews on this topic. This review provides a comprehensive overview of studies investigating the effects of various types of microecologics, such as probiotics, prebiotics, synbiotics, and postbiotics, on enhancing sports performance and facilitating post-exercise recovery by regulating energy metabolism, mitigating oxidative-stress-induced damage, modulating immune responses, and attenuating bone loss. Although further investigations are warranted to elucidate the underlying mechanisms through which microecologics exert their effects. In summary, this study aims to provide scientific evidence for the future development of microecologics in athletics.

Two-Month Consumption of Orange Juice Enriched with Vitamin D3 and Probiotics Decreases Body Weight, Insulin Resistance, Blood Lipids, and Arterial Blood Pressure in High-Cardiometabolic-Risk Patients on a Westernized Type Diet: Results from a Randomized Clinical Trial

This study examined the effects of orange juice (OJ) supplemented with vitamin D3 (2000 IU) and probiotics (Lacticaseibacillus casei Shirota and Lacticaseibacillus rhamnosus GG, 108 cfu/mL) on cardiometabolic risk factors in overweight and obese adults following a Westernized-type diet. Fifty-three high-risk individuals were randomly assigned to one of two groups. Over 8 weeks, one group consumed a vitamin D3 and probiotic-enriched OJ and the other regular OJ (control). Diets remained unchanged and were documented through food diaries. Measures of metabolic and inflammatory markers and blood pressure were measured at the start and end of the study. Post-intervention, the enriched OJ group showed the following significant metabolic improvements (without changes in triglycerides, inflammation, or central blood pressure): reduced fasting insulin, peripheral blood pressure, body weight (-1.4 kg 95% CI: -2.4, -0.4), energy (-270 kcal 95% CI: -553.2, -13.7), macronutrient (dietary fat -238 kcal 95% CI: -11.9, -1.0; carbohydrates -155 kcal 95% CI: -282.4, -27.3; sugars -16.1 g 95% CI: -11.9, -1.0) intake, and better lipid profiles (total cholesterol -10.3 mg/dL 95% CI: -21.4, 0.9; LDL-C -7 mg/dL 95% CI: -13.5, -0.5). The enriched OJ led to weight loss, less energy/macronutrient consumption, improved lipid profiles, and increased insulin sensitivity after 8 weeks in those following a Westernized diet, thus indicating potential benefits for cardiometabolic risk. This study was a part of FunJuice-T2EDK-01922, which was funded by the EU Regional Development Fund and Greek National Resources.

Nutritional therapy bridges the critical cut-off point for the closed-loop role of type 2 diabetes and bone homeostasis: A narrative review

Currently, osteoporosis-related fractures become the most cutting-edge problem of diabetes-related complications. Rational diet is not only the basis of glycemic management in type 2 diabetes patients, but also the direction of diabetic bone health. This review highlights the importance of micronutrient supplementation (including calcium, magnesium, zinc, vitamin D, vitamin K, and vitamin C) for patients with T2DM, as well as describing the constructive intermediary role of gut flora between T2DM and bone through nutrients predominantly high in dietary fiber. In addition, it is recommended to combine the Mediterranean dietary pattern with other diversified management approaches to prevent OP. Therefore, this provides a theoretical basis for the potential role of islet β-cells in promoting bone health.

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

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

Gut microbiota and female health

The gut microbiota is recognized as an endocrine organ with the capacity to influence distant organs and associated biological pathways. Recent advancements underscore the critical role of gut microbial homeostasis in female health; with dysbiosis potentially leading to diseases among women such as polycystic ovarian syndrome, endometriosis, breast cancer, cervical cancer, and ovarian cancer etc. Despite this, there has been limited discussion on the underlying mechanisms. This editorial explores the three potential mechanisms through which gut microbiota dysbiosis may impact the development of diseases among women, namely, the immune system, the gut microbiota-estrogen axis, and the metabolite pathway. We focused on approaches for treating diseases in women by addressing gut microbiota imbalances through probiotics, prebiotics supplementation, and fecal microbiota transplantation (FMT). Future studies should focus on determining the molecular mechanisms underlying associations between dysbiosis of gut microbiota and female diseases to realize precision medicine, with FMT emerging as a promising intervention.

Gestational Diabetes and the Gut Microbiota: Fibre and Polyphenol Supplementation as a Therapeutic Strategy

Gestational diabetes mellitus (GDM) is an escalating public health concern due to its association with short- and long-term adverse maternal and child health outcomes. Dysbiosis of microbiota within the gastrointestinal tract has been linked to the development of GDM. Modification of microbiota dysbiosis through dietary adjustments has attracted considerable attention as adjunct strategies to improve metabolic disease. Diets high in fibre and polyphenol content are associated with increased gut microbiota alpha diversity, reduced inflammation and oxidative processes and improved intestinal barrier function. This review explores the potential of fibre and polyphenol supplementation to prevent GDM by investigating their impact on gut microbiota composition and function.

Gut dysbiosis is linked to metabolic syndrome in obese Egyptian women: potential treatment by probiotics and high fiber diets regimen

Metabolic syndrome (MetS) is defined as a cluster of glucose intolerance, hypertension, dyslipidemia, and central obesity with insulin resistance. The role of gut microbiota in metabolic disorders is increasingly considered. To investigate the effects of probiotic supplements and hypocaloric high fiber regimen on MetS in obese Egyptian women. A longitudinal follow-up intervention study included 58 obese Egyptian women, with a mean age of 41.62 ± 10.70 years. They were grouped according to the criteria of MetS into 2 groups; 23 obese women with MetS and 35 ones without MetS. They followed a hypocaloric high fiber regimen weight loss program, light physical exercise, and received a probiotic supplement daily for 3 months. For each participating woman, blood pressure, anthropometric measurements, basal metabolic rate (BMR), dietary recalls, laboratory investigations, and microbiota analysis were acquired before and after 3 months of follow-up. After intervention by the probiotic and hypocaloric high fiber regimen and light exercise, reduction ranged from numerical to significant difference in the anthropometric parameters, blood pressure, and BMR was reported. All the biochemical parameters characterized by MetS decreased significantly at p ≤ 0.05-0.01. Before the intervention, results revealed abundant of Bacteroidetes bacteria over Firmicutes with a low Firmicutes/Bacteroidetes ratio. After the intervention, Log Lactobacillus, Log Bifidobacteria, and Log Bacteroidetes increased significantly in both groups, while Log Firmicutes and the Firmicutes/Bacteroidetes Ratio revealed a significant decrease. In conclusion, this study's results highlight a positive trend of probiotics supplementation with hypocaloric high-fiber diets in amelioration of the criteria of the Mets in obese Egyptian women.

Hypoglycemic effect of recrystallized resistant starch on high-fat diet- and streptozotocin-induced type 2 diabetic mice via gut microbiota modulation

The hypoglycemic effects of two recrystallized resistant starches, A-type (ARS) and B-type (BRS), were investigated in type 2 diabetic mice. Mice were treated with low-, medium-, or high-dose ARS, high-dose BRS, or high-dose ARS combined with BRS (ABRS). After 10 weeks of continuous intervention, the medium-dose ARS group showed a significant reduction in fasting blood glucose, area under the curve of glucose, triglyceride (P < 0.01), and low-density lipoprotein (P < 0.05) levels compared to the model group and an increase in high-density lipoprotein levels (P < 0.01). The peptide YY and glucagon-like peptide-1 levels in the high-dose ARS, BRS, and ABRS groups and the butyric acid yield in the medium-dose ARS and BRS groups were significantly increased (P < 0.01) compared to those in the model group. Medium- and high-dose ARS intervention efficiently increased the relative abundance of beneficial Bacteroidetes, Lactobacillus, Lachnospiraceae_NK4A136_group, and Faecalibaculum, and lowered the ratio of Firmicutes to Bacteroidetes. Overall, ARS exhibited greater advantages than BRS in lowering blood sugar levels.

Probing the microbial diversity and probiotic candidates from Pakistani foods: isolation, characterization, and functional profiling

Probiotics represent beneficial living microorganisms that confer physiological, nutritional, and functional advantages to human health, holding significant potential for development of functional foods. This research aimed to isolate, identify, and characterize potential probiotic bacterial strains sourced from fermented and non-fermented foods from Pakistan. A total of 341 bacterial strains were isolated from diverse food samples (81) collected from various regions of Pakistan. Strains were identified using 16S rRNA gene sequencing and phylogenetic analysis. The identified strains belonged to genera Bacillus, Staphylococcus, Microbacterium, Shigella, Micrococcus, Enterococcus, Sporosarcina, Paenibacillus, Limosilactobacillus, Kosakonia, Dietzia, Leclercia, Lacticaseibacillus, Levilactobacillus, Kluyvera, Providencia, Enterobacter, Neisseria, Streptococcus, Acinetobacter, Corynebacterium, Pantoea, Mammaliicoccus, Pseudomonas, Burkholderia, and Alkalihalobacillus. Selected strains were chosen for probiotic assessment, employing existing literature as a guideline. Among these selections, six strains exhibited hemolytic activity, and seven strains displayed resistance to multiple antibiotics, prompting their exclusion from subsequent evaluations. The remaining strains demonstrated auto-aggregation capacities spanning 3.39-79.7%, and displayed coaggregation capabilities with reported food-borne pathogens. Furthermore, nine strains exhibited antimicrobial properties against food-borne pathogens. The assessment encompassed diverse characteristics such as cell surface hydrophobicity, survival rates under varying conditions, cholesterol reduction ability, casein digestion capability, and antioxidant activity. Phylogenomic analysis, digital-DNA DNA hybridization (digi-DDH), and average nucleotide identity (ANI) calculations unveiled novel species potentially belonging to the genera Sporosarcina and Dietzia. Based on these findings, we advocate for the consideration of Staphylococcus cohnii subsp. cohnii NCCP-2414, Lacticaseibacillus rhamnosus NCCP-2569 and Levilactobacillus brevis NCCP-2574 as prime probiotic candidates with the potential for integration into formulation of functional foods.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03903-6.

Inulin prebiotic ameliorates type 1 diabetes dictating regulatory T cell homing via CCR4 to pancreatic islets and butyrogenic gut microbiota in murine model

Gut dysbiosis is linked to type 1 diabetes mellitus (T1D). Inulin (INU), a prebiotic, modulates the gut microbiota, promoting beneficial bacteria that produce essential short-chain fatty acids for immune regulation. However, how INU affects T1D remains uncertain. Using a streptozotocin-induced (STZ) mouse model, we studied INU's protective effects. Remarkably, STZ + INU mice resisted T1D, with none developing the disease. They had lower blood glucose, reduced pancreatic inflammation, and normalized serum insulin compared with STZ + SD mice. STZ + INU mice also had enhanced mucus production, abundant Bifidobacterium, Clostridium cluster IV, Akkermansia muciniphila, and increased fecal butyrate. In cecal lymph nodes, we observed fewer CD4+Foxp3+ regulatory T cells expressing CCR4 and more Foxp3+CCR4+ cells in pancreatic islets, with higher CCL17 expression. This phenotype was absent in CCR4-deficient mice on INU. INU supplementation effectively protects against experimental T1D by recruiting CCR4+ regulatory T cells via CCL17 into the pancreas and altering the butyrate-producing microbiota.

The effects of 6 wk of resistance training on the gut microbiome and cardiometabolic health in young adults with overweight and obesity

Obesity is a known risk factor for the development of insulin resistance and other cardiometabolic disorders. Recently, the gut microbiome has been associated with obesity and subsequent health complications. Exercise has been regularly utilized as a therapeutic intervention to treat obesity and its associated comorbidities. This study examined the effects of a 6-wk resistance training exercise program (RT) on the diversity, composition, and metabolic pathways of the gut microbiome. Sedentary young adults (age 18-35 yr) with overweight and obesity (BMI 25-45 kg/m2) were recruited to participate in this randomized controlled trial. Participants were randomized to RT (n = 16), a 6-wk resistance training program (3 days/wk), or control (CT) (n = 16), a nonexercising control. Main outcomes of the study included gut microbiome measures (taxa abundances, diversity, and predicted function) and cardiometabolic outcomes [blood pressure (BP) and glucoregulation]. Increased abundances of Roseburia, a short-chain fatty acid (SCFA) producer were observed over 6 wk (W6) with RT compared with CT (group × week, P < 0.05, q < 0.25). RT also induced marginal alterations in predicted microbial metabolic and cell motility pathways compared with CT (group × week, P < 0.05, q < 0.25). However, RT did not significantly impact overall microbial diversity. Furthermore, RT resulted in higher quantitative insulin-sensitivity check index (QUICKI) and lower diastolic BP at W6 compared with CT [baseline (BL)-adjusted P < 0.05]. RT had mixed effects on the gut microbiome. Although RT increased abundances of Roseburia and induced minor changes in microbial pathways, it is important to consider these changes in the context of the overall stability observed in the microbiome composition.NEW & NOTEWORTHY Resistance training induces mixed changes in the gut microbiome, including an increase in the abundances of the Roseburia genus and minor alterations in microbial pathways. However, it is vital to interpret these changes in light of the broader context, where we observe stability in the overall microbiome composition. This stability may be attributed to the microbiome's resilience, demonstrating its capacity to withstand short-term physiological stressors.

From Birth to Weaning: A Window of Opportunity for Microbiota

(1) Background: The first 1000 days of life constitute a critical window of opportunity for microbiota development. Nutrients play a crucial role in enriching and diversifying the microbiota, derived not only from solid food but also from maternal dietary patterns during gestation. (2) Methods: We conducted a comprehensive literature review using the PubMed database, covering eleven years (2013-2023). We included English-language reviews, original research papers, and meta-analyses, while excluding case reports and letters. (3) Results: Consensus in the literature emphasizes that our interaction with a multitude of microorganisms begins in the intrauterine environment and continues throughout our lives. The existing data suggest that early nutritional education programs, initiated during pregnancy and guiding infant diets during development, may influence the shaping of the gut microbiota, promoting long-term health. (4) Conclusions: Further research is necessary in the coming years to assess potential interventions and early nutritional models aimed at modulating the pediatric microbiota, especially in vulnerable populations such as premature newborns.

Recent advances in the extraction, purification, structural-property correlations, and antiobesity mechanism of traditional Chinese medicine-derived polysaccharides: a review

Traditional Chinese medicine (TCM) has displayed preventive and therapeutic effects on many complex diseases. As natural biological macromolecules, TCM-derived antiobesogenic polysaccharides (TCMPOs) exhibit notable weight-loss effects and are seen to be a viable tactic in the fight against obesity. Current studies demonstrate that the antiobesity activity of TCMPOs is closely related to their structural characteristics, which could be affected by the extraction and purification methods. Therefore, the extraction, purification and structural-property correlations of TCMPOs were discussed. Investigation of the antiobesity mechanism of TCMPOs is also essential for their improved application. Herein, the possible antiobesity mechanisms of TCMPOs are systematically summarized: (1) modulation of appetite and satiety effects, (2) suppression of fat absorption and synthesis, (3) alteration of the gut microbiota and their metabolites, and (4) protection of intestinal barriers. This collated information could provide some insights and offer a new therapeutic approach for the management and prevention of obesity.

The effects of the interplay between vitamins, antibiotics, and gut microbiota on the pathogenesis and progression of dementia: A systematic review and meta-analysis

Background

Given that there is already evidence of a neural network that connects the brain and gut and that the gut microbiota actively modulates gut health, it is crucial to know which foods, supplements, and medications to use or avoid when treating any disease that causes dementia or cognitive impairment. Previous research has examined the relationships between vitamins, antibiotics, and gut microbiota and the correlations between these factors and dementia. The question arises of how these three factors interact together and if evidence suggests one element is more important than the others in the pathogenesis and development of dementia.

Methods

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) standards were followed when conducting this review. The papers' publication dates varied from (2012-2022). Cochrane/EMBASE, PEDro, and PubMed/Medline databases were searched. The precise terms "gut microbiota," vitamins," antibiotics," and "dementia" were included in the search method, along with the conjunctions "OR" and "AND."

Results

Gut dysbiosis has a significant impact on cognition, brain function, and the development and progression of dementia. The two most popular probiotics used in studies linked to cognition benefits were Lactobacillus and Bifidobacterium. Numerous scales were used to evaluate cognition, but the mini-mental state examination was the most popular, and the most prevalent impairment was Alzheimer's disease. The supplements with the most significant impact on gut microbiota were vitamin B-12 and folic acid.

Conclusion

This systematic review concluded that vitamins, gut microbiota and antibiotics have a close association with the development of dementia. More research is required to establish causality and elucidate the underlying mechanisms because there is still little evidence connecting the interactions of vitamins, medications, and microbiota with dementia. The complexity of interactions between genetics, lifestyle factors, and comorbidities, as well as the heterogeneity of dementia, may make it more challenging to interpret the findings.

Carboxymethyl chitosan-TK resistant starch complex ameliorates type 2 diabetes by regulating the gut microbiota

Carboxymethyl chitosan and resistant starch exhibit good performance in diabetes regulation. We prepared carboxymethyl chitosan - resistant starch complex. Test the properties of composite resistant starch by using X-ray diffraction, water contact angle, infrared spectroscopy, and scanning electron microscopy, interactions with intestinal microbiota and mouse experiments were also conducted. The results indicated that the composite resistant starch had a good effect on promoting the proliferation of probiotics on Bifidobacterium and a significant inhibitory effect on Escherichia coli than resistant starch (P < 0.05). After administration, the water intake and weight of diabetic mice were significantly reduced. The blood glucose of diabetic mice was also reduced, and oral glucose tolerance showed that the glucose degradation rates of composite resistant starch were significantly improved compared to model mice. Cholesterol, triglycerides, high-density lipoprotein and low-density lipoprotein were significantly lower than those in the diabetes group (P < 0.05). The diversity of the gut microbiota was also proven.

The effect of different prebiotics on intestinal probiotics in newly diagnosed diabetic patients

Prebiotics exert favorable effects on the host through interactions with probiotics, and their beneficial impacts have been extensively validated across various chronic ailments, including diabetes. This study presents findings from a case-control investigation involving 10 individuals with type 2 diabetes mellitus (T2DM) and 10 healthy counterparts. Fresh stool specimens were collected from all participants. Following a 24-h fermentation period in mediums containing xylitol and mannitol, the observed increase in Lactobacillus abundance within the case group exceeded that of the control group. Similarly, in mediums containing soluble starch, choline, and L-carnitine, the augmentation of Bifidobacterium within the case group surpassed that of the controls. Notably, a statistically significant divergence in sugar degradation rate emerged between the case and control groups, specifically in the medium harboring lactulose and isomalto-oligosaccharides. Remarkably, the degradation rate of lactulose exhibited a positive correlation with the expansion of Bifidobacterium (R 2 = .147, p = .037). Likewise, the degradation rate of isomalto-oligosaccharides demonstrated a positive correlation with Bifidobacterium proliferation (R 2 = .165, p = .041). In conclusion, prebiotics like xylitol and mannitol exhibit the capacity to enhance intestinal probiotic populations in individuals newly diagnosed with diabetes. The modifications in the intestinal flora homeostasis of diabetic patients may be evidenced by alterations in the degradation rate of specific prebiotic substrates.

Lactiplantibacillus plantarum GL001 alleviates jejunal oxidative damage induced by intestinal ischemia-reperfusion injury by influencing jejunal tissue metabolism through the improvement of jejunal microbial composition

Intestinal ischemia-reperfusion (IIR) injury is associated with inflammation and oxidative stress, yet its precise mechanisms remain not fully understood. IIR injury is closely linked to the gut microbiota and its metabolites. The anti-inflammatory and antioxidant effects of Lactiplantibacillus plantarum are specific to IIR. In our study, we conducted a 30-day pre-treatment of SD rats with both a standard strain of Lactiplantibacillus plantarum and Lactiplantibacillus plantarum GL001. After a 7-day cessation of treatment, we induced an IIR injury model to investigate the mechanisms by which Lactiplantibacillus plantarum alleviates IIR damage. The results demonstrate that Lactiplantibacillus plantarum effectively mitigates the inflammatory and oxidative stress damage induced by IIR. Lactiplantibacillus plantarum GL001 can improve the gut microbiota by reducing the abundance of harmful bacteria and increasing the abundance of beneficial bacteria. In IIR intestinal tissue, the levels of secondary bile acids are elevated. The content of the bacterial metabolite Calcimycin increases. Annotations of metabolic pathways suggest that Lactiplantibacillus plantarum GL001 can alleviate IIR damage by modulating calcium-phosphorus homeostasis through the regulation of parathyroid hormone synthesis, secretion, and action. Microbiota-metabolite correlation analysis reveals a significant negative correlation between calcimycin and Lactonacillus and a significant positive correlation between calcimycin and Shigella. There is also a significant positive correlation between calcimycin and secondary bile acids. Lactiplantibacillus plantarum GL001 can alleviate oxidative damage induced by IIR through improvements in gut microbiota and intestinal tissue metabolism.

Gut microbiome in healthy aging versus those associated with frailty

As the proportion of older people in the world's population steadily increases, there is an urgent need to identify ways to support healthy aging. The gut microbiome has been proposed to be involved in aging-related diseases and has become an attractive target for improving health in older people. Herein, we cover the relationship between the gut microbiome and chronological age in adults, and then, we discuss the gut microbiome features associated with frailty, as a hallmark of unhealthy aging in older people. Furthermore, we describe the effects of microbiome-targeted interventions, such as dietary patterns and consumption of probiotics, prebiotics, and synbiotics, on modulating the gut microbiome composition and further promoting healthy aging. Further studies are needed to explore the underlying mechanisms of gut microbiome-induced aging complications and to develop personalized microbiome-based strategies for reducing the severity of frailty or preventing the onset of frailty in older adults.

The Effect of Probiotic Supplements on Metabolic Parameters of People with Type 2 Diabetes in Greece-A Randomized, Double-Blind, Placebo-Controlled Study

The role of probiotic supplementation in type 2 diabetes (T2D) treatment is controversial. The present study aimed to assess the effects of a multi-strain probiotic supplement (LactoLevureR (containing Lactobacillus acidophilus, Lactobacillus plantarum, Bifidobacterium lactis, and Saccharomyces boulardii)) over 6 months, primarily on glycemic control as well as on lipid levels and alterations in the gut microbiome, among individuals with T2D residing in Greece. A total of 91 adults with T2D (mean age [±SD] 65.12 ± 10.92 years, 62.6% males) were randomized to receive the probiotic supplement or a matching placebo capsule, once daily, for 6 months. Blood chemistries and anthropometric parameters were conducted every 3 months, and stool samples were collected at baseline and at 6 months. Significant reductions in HbA1c, fasting blood glucose, and total cholesterol were observed in participants treated with the probiotic supplement (n = 46) compared to the controls (n = 45), even after adjustment for a greater decrease in adiposity (waist circumference). Although there were no statistically significant differences in the diversity of the gut microbiome (α and β diversity), the administration of probiotics did influence several genera, metabolites, and key enzymes associated with diabetes. Overall, the administration of the multi-strain probiotic LactoLevureR over a 6-month period in individuals with T2D was well-tolerated and had a positive impact on metabolic parameters, alongside improvements in indices of adiposity.

Effects of probiotics in patients with morbid obesity undergoing bariatric surgery: a systematic review and meta-analysis

BACKGROUND

Probiotics are commonly used after bariatric surgery. However, uncertainty remains regarding their effects. The purpose of this systematic review was to assess the effect of probiotics in patients with morbid obesity undergoing bariatric surgery.

METHODS

PubMed, Cochrane Library, Embase, Science Direct, and Web of Science were searched from inception to April 4, 2023. No language restrictions were applied. Relevant randomized controlled trials and controlled clinical trials were included. We used the aggregated data extracted from the trials and assessed the heterogeneity. When severe heterogeneity was detected, a random effect model was used. All stages of the review were done by independent authors.

RESULTS

We screened 2024 references and included 11 randomized controlled trials and controlled clinical trials. Compared with the protocol groups, probiotics showed significant effects on regulating aspartate amino transferase level (MD = -4.32 U/L; 95% CI [-7.10, -1.53], p = 0.002), triglycerides (MD = -20.16 mg/dL; 95% CI [-34.51, -5.82], p = 0.006), weight (MD = -1.99 kg; 95% CI [-3.97, -0.01], p = 0.05), vitamin B12 (MD = 2.24 pg/dL; 95% CI [-0.02, 4.51], p = 0.05), dietary energy (MD = -151.03 kcal; 95% CI [-215.68, -86.37], p < 0.00001), dietary protein (MD = -4.48 g/day, 95% CI [-8.76, -0.20], p = 0.04), dietary carbohydrate (MD = -34.25 g/day, 95% CI [-44.87, -23.62], p < 0.00001), and dietary fiber (MD = -2.17 g/day, 95% CI [-3.21, -1.14], p < 0.0001). There were no severe side effects related to probiotics.

CONCLUSIONS

Our meta-analysis suggested that probiotics may delay the progression of liver function injury, improve lipid metabolism, reduce weight, and reduce food intake, although the effects on other indicators were insignificant. Probiotics may be helpful for patients undergoing bariatric surgery. The review was registered on PROSPERO (International prospective register of systematic reviews): CRD42023407970. No primary source of funding.

Integrated Gut Microbiota and Urine Metabolite Analyses of T2DM with NAFLD Rat Model

Globally 80% type 2 diabetes mellitus (T2DM) patients suffer nonalcoholic fatty liver disease (NAFLD). The interplay of gut microbiota and endogenous metabolic networks has not yet been reported in the setting of T2DM with NAFLD. As such, this study utilized 16S rRNA gene sequencing to assess the changes in intestinal flora and nuclear magnetic resonance spectroscopy (1H NMR) to identify potential metabolites in a T2DM with NAFLD rat model. Spearman correlation analysis was performed to explore the relationship between gut microbiota and metabolites. Results revealed that among T2DM with NAFLD rats, diversity indexes of intestinal microbiota were distinctly decreased while levels of 18 bacterial genera within the intestinal tract were significantly altered. In addition, levels of eight metabolites mainly involved in the synthesis and degradation of ketone bodies, the TCA cycle, and butanoate metabolism were altered. Correlation analysis revealed that gut bacteria such as Blautia, Ruminococcus torques group, Allobaculum, and Lachnoclostridium strongly associate with 3-hydroxybutyrate, acetone, acetoacetate, 2-oxoglutarate, citrate, creatinine, hippurate, and allantoin. Our findings can provide a basis for future development of targeted treatments.

Lactobacillus coryniformis subsp. torquens T3 alleviates non-alcoholic fatty liver disease via reconstruction of the gut microbiota and redox system

BACKGROUND

A high-fat diet (HFD) that induces obesity has become the most common type of diet worldwide, leading to serious global health issues. Obesity is associated with an increased risk of non-alcoholic fatty liver disease (NAFLD). Probiotic supplements have been shown to help alleviate obesity. The present study aimed to investigate the mechanism by which Lactobacillus coryniformis supsp. torquens T3 (T3L) alleviated NAFLD induced by HFD via reconstruction of the gut microbiota and redox system.

RESULTS

The results showed that, compared with the HFD group, T3L inhibited obesity and relieved fat accumulation in the liver of mice with NAFLD. In addition, T3L inhibited liver inflammation and oxidative stress injury in NAFLD mice by regulating the lipopolysaccharide (LPS) inflammatory pathway in the liver. Furthermore, T3L changed the composition of the intestinal flora, reduced the abundance of harmful bacteria in the intestinal tract, enhanced the mechanical function of the intestinal barrier, and increased the short-chain fatty acid contents, thus inhibiting the secondary metabolite LPS, which directly causes liver damage through the portal vein.

CONCLUSION

In summary, T3L ameliorated NAFLD induced by obesity through the liver-gut axis pathway, thus reducing oxidative stress and liver injury. © 2023 Society of Chemical Industry.

The Effect of Theaflavins on the Gut Microbiome and Metabolites in Diabetic Mice

With the development of diabetes, the gut microbiome falls into a state of dysbiosis, further affecting its progression. Theaflavins (TFs), a type of tea polyphenol derivative, show anti-diabetic properties, but their effect on the gut microbiome in diabetic mice is unclear. It is unknown whether the improvement of TFs on hyperglycemia and hyperlipidemia in diabetic mice is related to gut microbiota. Therefore, in this study, different concentrations of TFs were intragastrically administered to mice with diabetes induced by a high-fat-diet to investigate their effects on blood glucose, blood lipid, and the gut microbiome in diabetic mice, and the plausible mechanism underlying improvement in diabetes was explored from the perspective of the gut microbiome. The results showed that the TFs intervention significantly improved the hyperglycemia and hyperlipidemia of diabetic mice and affected the structure of the gut microbiome by promoting the growth of bacteria positively related to diabetes and inhibiting those negatively related to diabetes. The changes in short-chain fatty acids in mice with diabetes and functional prediction analysis suggested that TFs may affect carbohydrate metabolism and lipid metabolism by regulating the gut microbiome. These findings emphasize the ability of TFs to shape the diversity and structure of the gut microbiome in mice with diabetes induced by a high-fat diet combined with streptozotocin and have practical implications for the development of functional foods with TFs.

Dietary Fiber and Its Potential Role in Obesity: A Focus on Modulating the Gut Microbiota

Dietary fiber is a carbohydrate polymer with ten or more monomeric units that are resistant to digestion by human digestive enzymes, and it has gained widespread attention due to its significant role in health improvement through regulating gut microbiota. In this review, we summarized the interaction between dietary fiber, gut microbiota, and obesity, and the beneficial effects of dietary fiber on obesity through the modulation of microbiota, such as modifying selective microbial composition, producing starch-degrading enzymes, improving gut barrier function, reducing the inflammatory response, reducing trimethylamine N-oxide, and promoting the production of gut microbial metabolites (e.g., short chain fatty acids, bile acids, ferulic acid, and succinate). In addition, factors affecting the gut microbiota composition and metabolites by dietary fiber (length of the chain, monosaccharide composition, glycosidic bonds) were also concluded. Moreover, strategies for enhancing the biological activity of dietary fiber (fermentation technology, ultrasonic modification, nanotechnology, and microfluidization) were subsequently discussed. This review may provide clues for deeply exploring the structure-activity relationship between dietary fiber and antiobesity properties by targeting specific gut microbiota.

Attenuation of Hyperglycemia in Diabetic Rats Assisted by Immobilized Probiotic in Sodium Alginate

Diabetes mellitus type 2 (DM2) is the most common chronic disease worldwide, characterized mainly by increased glucose concentration in the blood and affecting several organs' functionality. The daily consumption of probiotic bacteria can help control diabetes and reduce the damage caused. Cell immobilization techniques are a powerful tool that provides physical cell protection to such probiotic bacteria against gastrointestinal conditions. We suggest that cell immobilization could be a significant vector for delivering a high quantity of viable probiotics to the gut, helping attenuate hyperglycemia in diabetic rats. Seventy male Wistar rats were used in this work. Nicotinamide was administrated via intraperitoneal injection 15 minutes before inducing type 2 diabetes (DM2), followed by a second intraperitoneal injection of streptozotocin to induce DM2. Rats were divided into seven groups. For 45 days, a specific treatment was applied to each group. The group of rats, supplied with immobilized Lactobacillus casei, showed a serum glucose concentration of 137 mg/dL, which was close to the one observed in the groups of healthy rats (117 mg/dL) and rats treated with metformin (155 mg/dL). The diabetic rats without treatment presented a higher serum glucose concentration (461 mg/dL). In the rats treated with immobilized L. casei, there was no biochemical parameter alteration, and the cell morphology of the analyzed tissues was similar to those of the healthy group. The consumption of immobilized L. casei could allow a high quantity of viable probiotics to be delivered to the gut, reducing serum glucose concentration by up to 70% compared to diabetic rats and reducing organ damage caused by diabetes.

A Metabolite Perspective on the Involvement of the Gut Microbiota in Type 2 Diabetes

Type 2 diabetes (T2D) is a commonly diagnosed condition that has been extensively studied. The composition and activity of gut microbes, as well as the metabolites they produce (such as short-chain fatty acids, lipopolysaccharides, trimethylamine N-oxide, and bile acids) can significantly impact diabetes development. Treatment options, including medication, can enhance the gut microbiome and its metabolites, and even reverse intestinal epithelial dysfunction. Both animal and human studies have demonstrated the role of microbiota metabolites in influencing diabetes, as well as their complex chemical interactions with signaling molecules. This article focuses on the importance of microbiota metabolites in type 2 diabetes and provides an overview of various pharmacological and dietary components that can serve as therapeutic tools for reducing the risk of developing diabetes. A deeper understanding of the link between gut microbial metabolites and T2D will enhance our knowledge of the disease and may offer new treatment approaches. Although many animal studies have investigated the palliative and attenuating effects of gut microbial metabolites on T2D, few have established a complete cure. Therefore, conducting more systematic studies in the future is necessary.

Canagliflozin alters the gut, oral, and ocular surface microbiota of patients with type 2 diabetes mellitus

Background

Modifications in the gut microbiota may be a crucial factor in the efficacy of canagliflozin (Cana) in managing patients with type 2 diabetes mellitus (T2DM). However, the interplay between oral and ocular surface microbiota and this treatment remains poorly explored.

Aim

This study aimed to assess alterations in the gut, oral, and ocular surface microbiota pre- and post-Cana treatment in patients with T2DM.

Methods

In this 30-day, controlled before-and-after study, 21 treatment-naïve patients with T2DM received sole treatment with Cana (100 mg/day), and were matched with 10 healthy controls based on gender and age. Using 16S rRNA sequencing, changes in the gut, oral, and ocular surface microbiota pre- and post-Cana treatment were assessed and compared with those of healthy controls. Concurrently, diabetes-related clinical parameters were recorded over the study period. The trial was registered in the Chinese Clinical Trial Registry (ChiCTR200034878).

Results

A noticeable shift was observed in the gut, oral, and ocular surface microbiota pre- and post-Cana treatment. The post-Cana treatment gut microbiota was more similar to that of the healthy controls. Network correlation analysis revealed that modifications in the gut, oral, and ocular surface microbiota were related to changes in clinical parameters, especially for the ocular surface microbiota.

Clinical parameters

A significant decrease in fasting plasma glucose (8.22 ± 2.19 vs 6.87 ± 1.09 mmol/L), glycated serum protein [291.00 (264.00, 353.00) vs 275.00 (251.00, 342.50) μmol/L], hemoglobin A1c (7.39 ± 1.18 vs 7.12 ± 1.33%), body mass index (25.32 ± 2.99 vs 24.83 ± 2.95 kg/m2), systolic blood pressure (129.05 ± 17.51 vs 123.43 ± 14.82 mmHg), and urinary creatinine [158.40 (74.75, 219.15) vs 79.70 (56.25, 138.10) μmmol/kg] levels was noted after 30-day Cana monotherapy (P < 0.05).

Gut microbiome

Treatment with Cana resulted in an increase in the relative abundance of short-chain fatty acid (SCFA)-producing bacteria, particularly Lachnospiraceae UCG 004, Bacteroides, and Lachnospiraceae NK4A136 group.

Oral microbiota

After Cana treatment, a significant increase of Prevotella and Veillonella, both of which are known to be closely associated with SCFAs, was observed.

Ocular surface microbiota

Post-Cana administration, the ocular surface microbiota exhibited the most distinct changes in structure and composition. Remarkably, the majority of the increased ocular surface microbiota could produce SCFAs within the gut microbiota.

Conclusion

Cana effectively improved the dysregulated glucose metabolism in patients with T2DM. This improvement can potentially be attributed to the restoration of balance among the gut, oral, and ocular surface microbial communities.

Clinical trial registration

https://www.chictr.org.cn/showproj.html?proj=56487, identifier ChiCTR2000034878.

Lactobacillus rhamnosus GG administration partially prevents diet-induced insulin resistance in rats: a comparison with its heat-inactivated parabiotic

Insulin resistance and type 2 diabetes are obesity-related health alterations, featuring an ever-increasing prevalence. Besides inadequate feeding patterns, gut microbiota alterations stand out as potential contributors to these metabolic disturbances. The aim of this study was to investigate whether the administration of a probiotic (Lactobacillus rhamnosus GG) effectively prevents diet-induced insulin resistance in rats and to compare these potential effects with those exerted by its heat-inactivated parabiotic. For this purpose, 34 male Wistar rats were fed a standard or a high-fat high-fructose diet, alone or supplemented with viable or heat-inactivated Lactobacillus rhamnosus GG. The body and white adipose tissue weight increases, induced by the obesogenic diet, were prevented by probiotic and parabiotic administration. The trend towards higher basal glucose levels and significantly higher serum insulin concentration observed in the non-treated animals fed with the obesogenic diet were effectively reverted by both treatments. Similar results were also found for serum adiponectin and leptin, whose levels were brought back by the probiotic and parabiotic administration to values similar to those of the control animals. Noteworthily, parabiotic administration significantly reduced skeletal muscle triglyceride content and activated CPT-1b compared to the non-treated animals. Finally, both treatments enhanced Akt and AS160 phosphorylation in the skeletal muscle compared to the non-treated animals; however, only parabiotic administration increased GLUT-4 protein expression in this tissue. These results suggest that heat-inactivated Lactobacillus rhamnosus GG seem to be more effective than its probiotic of origin in preventing high-fat high-fructose diet-induced insulin resistance in rats.

The Importance of Dietary Fiber for Metabolic Health

Dietary fiber are non-digestible carbohydrates that are diverse, have varied functions, and are acquired by consuming plant-based foods. Some forms of fiber are digested by the gut microbiota and produce bioactive metabolites called short chain fatty acids-butyrate, acetate, and propionate. Dietary fiber is able to alter human physiology through multiple mechanisms that can result in health benefits. Unfortunately, nearly 19 out of 20 Americans do not consume the minimum recommended amount of fiber each day. This bears profound relevance to public health because at least six of the ten leading causes of death are potentially preventable or clinically improved through dietary means. Additionally, these same conditions share a common underlying pathophysiology-metabolic dysfunction. This can manifest as abdominal obesity, high blood pressure, insulin resistance, dyslipidemia, or collectively as metabolic syndrome. In this review, we will assess the evidence that consumption of dietary fiber undermines these forms of metabolic dysfunction, examine the mechanism of action for these physiologic effects, and consider the potential for dietary fiber to improve human health on a public health level by simply encouraging our patients to consume more plant-based foods in abundance and diversity.

The Effect of Probiotic Supplementation on Glucolipid Metabolism in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis

PURPOSE

Type 2 diabetes mellitus (T2DM) is a persistent metabolic condition with an unknown pathophysiology. Moreover, T2DM remains a serious health risk despite advances in medication and preventive care. Randomised controlled trials (RCTs) have provided evidence that probiotics may have positive effects on glucolipid metabolism. Therefore, we performed a meta-analysis of RCTs to measure the effect of probiotic therapy on glucolipid metabolism in patients with T2DM.

METHODS

With no constraints on the language used in the literature, Excerpta Medica Database, PubMed, the Cochrane Library, and the Web of Science were searched for pertinent RCTs published between the date of creation and 18 August 2022. Stringent inclusion and exclusion criteria were applied by two reviewers to independently examine the literature. The risk of bias associated with the inclusion of the original studies was assessed using the Cochrane risk-of-bias tool, and Stata 15.0 was used to perform the meta-analysis.

RESULTS

Thirty-seven publications containing a total of 2502 research participants were included in the meta-analysis. The results showed that after a probiotic intervention, the experimental group showed a significant decrease in body mass index (standardised mean difference (SMD) = -0.42, 95% confidence interval (CI) [-0.76, -0.08]), fasting glucose concentration (SMD = -0.73, 95% CI [-0.97, -0.48]), fasting insulin concentration (SMD = -0.67, 95% CI [-0.99, -0.36]), glycated haemoglobin concentration (SMD = -0.55, 95% CI [-0.75, -0.35]), Homeostatic Model Assessment for Insulin Resistance score (SMD = -0.88, 95% CI [-1.17, -0.59]), triglyceride concentration (SMD = -0.30, 95% CI [-0.43, -0.17]), total cholesterol concentration (SMD = -0.27, 95% CI [-0.43, -0.11]), and low-density lipoprotein concentration (SMD = -0.20, 95% CI [-0.37, -0.04]), and an increase in high-density lipoprotein concentration (SMD = 0.31, 95% CI [0.08, 0.54]). Moreover, subgroup analyses showed that patients with a longer intervention time, or those who were treated with multiple strains of probiotics, may benefit more than those with a shorter intervention time or those who were treated with a single probiotic strain, respectively.

CONCLUSION

Probiotic supplementation improves glucolipid metabolism in patients with T2DM, offering an alternative approach for the treatment of these patients.

Gut Microbiota and Critical Metabolites: Potential Target in Preventing Gestational Diabetes Mellitus?

Gestational diabetes mellitus (GDM) is an intractable issue that negatively impacts the quality of pregnancy. The incidence of GDM is on the rise, becoming a major health burden for both mothers and children. However, the specific etiology and pathophysiology of GDM remain unknown. Recently, the importance of gut microbiota and related metabolic molecules has gained prominence. Studies have indicated that women with GDM have significantly distinct gut microbiota and gut metabolites than healthy pregnant women. Given that the metabolic pathways of gut flora and related metabolites have a substantial impact on inflammation, insulin signaling, glucose, and lipid metabolism, and so on, gut microbiota or its metabolites, such as short-chain fatty acids, may play a significant role in both pathogenesis and progression of GDM. Whereas the role of intestinal flora during pregnancy is still in its infancy, this review aims to summarize the effects and mechanisms of gut microbiota and related metabolic molecules involved in GDM, thus providing potential intervention targets.

Effects of probiotics on non-alcoholic fatty liver disease: a review of human clinical trials

Non-alcoholic fatty liver disease (NAFLD) is a global public health issue, of which the prevalence is about 25% worldwide. The incidence of NAFLD is increasing in patients with obesity, type 2 diabetes (T2DM) and the metabolic syndrome. The crosstalk between gut microbiota and metabolism-related diseases has been raised great concern. Patients with NAPLD were observed with disruption of gut microbiota. Several researches showed that gut microbiota was the determination in the progression of NAFLD by the experiments using fecal microbiota transplants. The application of probiotics, as one of the most important strategies for the regulation of gut microbiota disorder, have been explored whether it is beneficial to gut-related diseases of intestine-distal organs. Some probiotics were showed to improve the liver parameters and phenotype in patients with NAFLD. The oral intake of them might become the effective management for the prevention and treatment of NAFLD. In this review, we summarized the human clinical trials focusing on the effects of probiotics on NAFLD to give some evidential reference for the administration of NAFLD.

Dose-dependent effects of xylooligosaccharides on glycemic regulation with L. rhamnosus CCFM1060 in diabetic mice

Dietary intervention with the probiotic Lactobacillus rhamnosus CCFM1060 has been proved to be effective on glycemic regulation in diabetic mice. Therefore characterization of the potential symbiotic effect of prebiotic xylooligosaccharides (XOS) with L. rhamnosus CCFM1060 would be desirable. In this study, we evaluated any dose-dependent relationship between XOS and L. rhamnosus CCFM1060, and the potential impact on glycemic regulation. Diabetic mice were randomly assigned to receive 5 × 10⁹ CFU mL^-1L. rhamnosus CCFM1060, 5 × 10⁹ CFU mL^-1L. rhamnosus CCFM1060 with 250 mg kg^-1 XOS (L-LXOS), or 5 × 10⁹ CFU mL^-1L. rhamnosus CCFM1060 with 500 mg kg^-1 XOS (L-HXOS) for 7 weeks. In addition to characterization of the host metabolism, the intestinal microbiota were analyzed using 16S rRNA gene sequencing. The results showed that L. rhamnosus alone and L-LXOS intervention significantly alleviated diabetes symptoms and increased the populations of short-chain fatty acid (SCFA)-producing bacteria. The intake of L-HXOS had an adverse effect on glucose metabolism, causing increased insulin resistance and inflammation. Although a significant increase in the relative abundance of Bifidobacterium was observed in the L-HXOS group, the abundance of SCFA-producing bacteria, such as Romboutsia and Clostrudium sensu stricto 1, decreased. KEGG pathway analysis revealed that the adverse effects of L-HXOS intervention might be attributed to the metabolic pathways involved in amino acid, cofactor, and vitamin metabolism. This study revealed that L. rhamnosus CCFM1060 combined with different doses of XOS exerted dose-dependent effects on glucose metabolism. Therefore, the type and dose of prebiotics should be carefully evaluated when developing individualized symbiotic formula.

Neurodegenerative and Neurodevelopmental Diseases and the Gut-Brain Axis: The Potential of Therapeutic Targeting of the Microbiome

The human gut microbiome contains the largest number of bacteria in the body and has the potential to greatly influence metabolism, not only locally but also systemically. There is an established link between a healthy, balanced, and diverse microbiome and overall health. When the gut microbiome becomes unbalanced (dysbiosis) through dietary changes, medication use, lifestyle choices, environmental factors, and ageing, this has a profound effect on our health and is linked to many diseases, including lifestyle diseases, metabolic diseases, inflammatory diseases, and neurological diseases. While this link in humans is largely an association of dysbiosis with disease, in animal models, a causative link can be demonstrated. The link between the gut and the brain is particularly important in maintaining brain health, with a strong association between dysbiosis in the gut and neurodegenerative and neurodevelopmental diseases. This link suggests not only that the gut microbiota composition can be used to make an early diagnosis of neurodegenerative and neurodevelopmental diseases but also that modifying the gut microbiome to influence the microbiome-gut-brain axis might present a therapeutic target for diseases that have proved intractable, with the aim of altering the trajectory of neurodegenerative and neurodevelopmental diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, autism spectrum disorder, and attention-deficit hyperactivity disorder, among others. There is also a microbiome-gut-brain link to other potentially reversible neurological diseases, such as migraine, post-operative cognitive dysfunction, and long COVID, which might be considered models of therapy for neurodegenerative disease. The role of traditional methods in altering the microbiome, as well as newer, more novel treatments such as faecal microbiome transplants and photobiomodulation, are discussed.

Microbiota-Liver-Bile Salts Axis, a Novel Mechanism Involved in the Contrasting Effects of Sodium Selenite and Selenium-Nanoparticle Supplementation on Adipose Tissue Development in Adolescent Rats

Adolescence is a period during which body composition changes deeply. Selenium (Se) is an excellent antioxidant trace element related to cell growth and endocrine function. In adolescent rats, low Se supplementation affects adipocyte development differently depending on its form of administration (selenite or Se nanoparticles (SeNPs). Despite this effect being related to oxidative, insulin-signaling and autophagy processes, the whole mechanism is not elucidated. The microbiota-liver-bile salts secretion axis is related to lipid homeostasis and adipose tissue development. Therefore, the colonic microbiota and total bile salts homeostasis were explored in four experimental groups of male adolescent rats: control, low-sodium selenite supplementation, low SeNP supplementation and moderate SeNPs supplementation. SeNPs were obtained by reducing Se tetrachloride in the presence of ascorbic acid. Supplementation was received orally through water intake; low-Se rats received twice more Se than control animals and moderate-Se rats tenfold more. Supplementation with low doses of Se clearly affected anaerobic colonic microbiota profile and bile salts homeostasis. However, these effects were different depending on the Se administration form. Selenite supplementation primarily affected liver by decreasing farnesoid X receptor hepatic function, leading to the accumulation of hepatic bile salts together to increase in the ratio Firmicutes/Bacteroidetes and glucagon-like peptide-1 (GLP-1) secretion. In contrast, low SeNP levels mainly affected microbiota, moving them towards a more prominent Gram-negative profile in which the relative abundance of Akkermansia and Muribaculaceae was clearly enhanced and the Firmicutes/Bacteroidetes ratio decreased. This bacterial profile is directly related to lower adipose tissue mass. Moreover, low SeNP administration did not modify bile salts pool in serum circulation. In addition, specific gut microbiota was regulated upon administration of low levels of Se in the forms of selenite or SeNPs, which are properly discussed. On its side, moderate-SeNPs administration led to great dysbiosis and enhanced the abundance of pathogenic bacteria, being considered toxic. These results strongly correlate with the deep change in adipose mass previously found in these animals, indicating that the microbiota-liver-bile salts axis is also mechanistically involved in these changes.

Impact of Dietary Fiber on Inflammation and Insulin Resistance in Older Patients: A Narrative Review

The beneficial impact of dietary fiber on the prevention and management of several chronic conditions associated with aging, including diabetes, neurodegenerative, cardiovascular diseases, and cancer, is well-known. High fiber intake has been associated with reduced inflammatory mediators counteracting the low-grade chronic inflammation typical of older age. In addition, dietary fiber improves postprandial glucose response and insulin resistance. In contrast, during acute diseases, its effects on insulin resistance and modulation of immune response are unclear. The aim of this narrative is to summarize the evidence for the potential impact of dietary fiber on inflammation and insulin resistance in older adults, with a particular focus on those acutely ill. Available evidence suggests that dietary fiber has the potential to counteract acute inflammation and to improve metabolic health. In addition, modulation of gut microbiota composition may contribute to improved immune function, particularly in the setting of aging-associated dysbiosis. This phenomenon has relevant implications in those acutely ill, in whom dysbiosis can be exacerbated. Our review leads to the conclusion that dietary interventions based on fiber manipulation could exploit its beneficial effects on inflammation and insulin resistance, if conducted from a precision nutrition perspective. This could also be true for the acutely ill patient, even though strong evidence is lacking.

Short-Chain Fatty-Acid-Producing Bacteria: Key Components of the Human Gut Microbiota

Short-chain fatty acids (SCFAs) play a key role in health and disease, as they regulate gut homeostasis and their deficiency is involved in the pathogenesis of several disorders, including inflammatory bowel diseases, colorectal cancer, and cardiometabolic disorders. SCFAs are metabolites of specific bacterial taxa of the human gut microbiota, and their production is influenced by specific foods or food supplements, mainly prebiotics, by the direct fostering of these taxa. This Review provides an overview of SCFAs' roles and functions, and of SCFA-producing bacteria, from their microbiological characteristics and taxonomy to the biochemical process that lead to the release of SCFAs. Moreover, we will describe the potential therapeutic approaches to boost the levels of SCFAs in the human gut and treat different related diseases.

Microbiota-derived short-chain fatty acids mediate the effects of dengzhan shengmai in ameliorating cerebral ischemia via the gut-brain axis

ETHNOPHARMACOLOGICAL RELEVANCE

Dengzhan shengmai (DZSM) formula, composed of four herbal medicines (Erigeron breviscapus, Panax ginseng, Schisandra chinensis, and Ophiopogon japonicus), is widely used in the recovery period of ischemic cerebrovascular diseases; however, the associated molecular mechanism remains unclear.

AIM OF THE STUDY

The purpose of this study was to uncover the links between the microbiota-gut-brain axis and the efficacy of DZSM in ameliorating cerebral ischemic diseases.

MATERIALS AND METHODS

The effects of DZSM on the gut microbiota community and bacteria-derived short-chain fatty acid (SCFA) production were evaluated in vivo using a rat model of cerebral ischemia and in vitro through the anaerobic incubation with fresh feces derived from model animals. Subsequently, the mechanism underlying the role of SCFAs in the DZSM-mediated treatment of cerebral ischemia was explored.

RESULTS

We found that DZSM treatment significantly altered the composition of the gut microbiota and markedly enhanced SCFA production. The consequent increase in SCFA levels led to the upregulation of the expression of monocarboxylate transporters and facilitated the transportation of intestinal SCFAs into the brain, thereby inhibiting the apoptosis of neurocytes via the regulation of the PI3K/AKT/caspase-3 pathway. The increased intestinal SCFA levels also contributed to the repair of the 2VO-induced disruption of gut barrier integrity and inhibited the translocation of lipopolysaccharide from the intestine to the brain, thus attenuating neuroinflammation. Consequently, cerebral neuropathy and oxidative stress were significantly improved in 2VO model rats, leading to the amelioration of cerebral ischemia-induced cognitive dysfunction. Finally, fecal microbiota transplantation could reproduce the beneficial effects of DZSM on SCFA production and cerebral ischemia.

CONCLUSIONS

Our findings suggested that SCFAs mediate the effects of DZSM in ameliorating cerebral ischemia via the gut microbiota-gut-brain axis.

Food, gut barrier dysfunction, and related diseases: A new target for future individualized disease prevention and management

Dysfunction of gut barrier is known as "leaky gut" or increased intestinal permeability. Numerous recent scientific evidences showed the association between gut dysfunction and multiple gastrointestinal tract (GI) and non-GI diseases. Research also demonstrated that food plays a crucial role to cause or remedy gut dysfunction related to diseases. We reviewed recent articles from electronic databases, mainly PubMed. The data were based on animal models, cell models, and human research in vivo and in vitro models. In this comprehensive review, our aim focused on the relationship between dietary factors, intestinal permeability dysfunction, and related diseases. This review synthesizes currently available literature and is discussed in three parts: (a) the mechanism of gut barrier and function, (b) food and dietary supplements that may promote gut health, and food or medication that may alter gut function, and (c) a table that organizes the synthesized information by general mechanisms for diseases related to leaky gut/intestinal permeability and associated dietary influences. With future research, dietary intervention could be a new target for individualized disease prevention and management.

Nutritional and lifestyle management of the aging journey: A narrative review

With age, the physiological responses to occasional or regular stressors from a broad range of functions tend to change and adjust at a different pace and restoring these functions in the normal healthy range becomes increasingly challenging. Even if this natural decline is somehow unavoidable, opportunities exist to slow down and attenuate the impact of advancing age on major physiological processes which, when weakened, constitute the hallmarks of aging. This narrative review revisits the current knowledge related to the aging process and its impact on key metabolic functions including immune, digestive, nervous, musculoskeletal, and cardiovascular functions; and revisits insights into the important biological targets that could inspire effective strategies to promote healthy aging.

Surrogate fostering of mice prevents prenatal estradiol-induced insulin resistance via modulation of the microbiota-gut-brain axis

Introduction

Prenatal and early postnatal development are known to influence future health. We previously reported that prenatal high estradiol (HE) exposure induces insulin resistance in male mice by disrupting hypothalamus development. Because a foster dam can modify a pup's gut microbiota and affect its health later in life, we explored whether surrogate fostering could also influence glucose metabolism in HE offspring and examined mechanisms that might be involved.

Methods

We performed a surrogate fostering experiment in mice and examined the relationship between the metabolic markers associated to insulin resistance and the composition of the gut microbiota.

Results

HE pups raised by HE foster dams (HE-HE) developed insulin resistance, but HE pups fostered by negative control dams (NC-HE) did not. The gut microbiota composition of HE-HE mice differed from that of NC mice raised by NC foster dams (NC-NC), whereas the composition in NC-HE mice was similar to that of NC-NC mice. Compared with NC-NC mice, HE-HE mice had decreased levels of fecal short-chain fatty acids and serum intestinal hormones, increased food intake, and increased hypothalamic neuropeptide Y expression. In contrast, none of these indices differed between NC-HE and NC-NC mice. Spearman correlation analysis revealed a significant correlation between the altered gut microbiota composition and the insulin resistance-related metabolic indicators, indicating involvement of the microbiota-gut-brain axis.

Discussion

Our findings suggest that alterations in the early growth environment may prevent fetal-programmed glucose metabolic disorder via modulation of the microbiota-gut-brain axis. These findings offer direction for development of translational solutions for adult diseases associated with aberrant microbial communities in early life.

The crucial role and mechanism of insulin resistance in metabolic disease

Insulin resistance (IR) plays a crucial role in the development and progression of metabolism-related diseases such as diabetes, hypertension, tumors, and nonalcoholic fatty liver disease, and provides the basis for a common understanding of these chronic diseases. In this study, we provide a systematic review of the causes, mechanisms, and treatments of IR. The pathogenesis of IR depends on genetics, obesity, age, disease, and drug effects. Mechanistically, any factor leading to abnormalities in the insulin signaling pathway leads to the development of IR in the host, including insulin receptor abnormalities, disturbances in the internal environment (regarding inflammation, hypoxia, lipotoxicity, and immunity), metabolic function of the liver and organelles, and other abnormalities. The available therapeutic strategies for IR are mainly exercise and dietary habit improvement, and chemotherapy based on biguanides and glucagon-like peptide-1, and traditional Chinese medicine treatments (e.g., herbs and acupuncture) can also be helpful. Based on the current understanding of IR mechanisms, there are still some vacancies to follow up and consider, and there is also a need to define more precise biomarkers for different chronic diseases and lifestyle interventions, and to explore natural or synthetic drugs targeting IR treatment. This could enable the treatment of patients with multiple combined metabolic diseases, with the aim of treating the disease holistically to reduce healthcare expenditures and to improve the quality of life of patients to some extent.

The associations of gut microbiota, endocrine system and bone metabolism

Gut microbiota is of great importance in human health, and its roles in the maintenance of skeletal homeostasis have long been recognized as the "gut-bone axis." Recent evidence has indicated intercorrelations between gut microbiota, endocrine system and bone metabolism. This review article discussed the complex interactions between gut microbiota and bone metabolism-related hormones, including sex steroids, insulin-like growth factors, 5-hydroxytryptamine, parathyroid hormone, glucagon-like peptides, peptide YY, etc. Although the underlying mechanisms still need further investigation, the regulatory effect of gut microbiota on bone health via interplaying with endocrine system may provide a new paradigm for the better management of musculoskeletal disorders.