Microbial Regulation of Glucose Metabolism and Insulin Resistance

Microbiota metabolism of intestinal amino acids impacts host nutrient homeostasis and physiology

The intestine and liver are thought to metabolize dietary nutrients and regulate host nutrient homeostasis. Here, we find that the gut microbiota also reshapes the host amino acid (aa) landscape via efficiently metabolizing intestinal aa. To identify the responsible microbes/genes, we developed a metabolomics-based assay to screen 104 commensals and identified candidates that efficiently utilize aa. Using genetics, we identified multiple responsible metabolic genes in phylogenetically diverse microbes. By colonizing germ-free mice with the wild-type strain and their isogenic mutant deficient in individual aa-metabolizing genes, we found that these genes regulate the availability of gut and circulatory aa. Notably, microbiota genes for branched-chain amino acids (BCAAs) and tryptophan metabolism indirectly affect host glucose homeostasis via peripheral serotonin. Collectively, at single-gene level, this work characterizes a microbiota-encoded metabolic activity that affects host nutrient homeostasis and provides a roadmap to interrogate microbiota-dependent activity to improve human health.

Metabolomics reveals the role of Lactobacillus plantarum SHY130 in hepatic metabolic regulation in a mouse model of type 2 diabetes

BACKGROUND

Among type 2 diabetes (T2D) patients, the incidence rate of liver metabolic disorders is much higher than that in healthy subjects. It was observed in our previous research that diabetic symptoms were improved by Lactobacillus plantarum SHY130 (LPSHY130) isolated from yak yogurt in a murine model of T2D. This study sought to investigate the LPSHY130-mediated hepatic metabolic regulation in a murine model of T2D.

RESULTS

Treatment with LPSHY130 improved liver function and pathological damage in diabetic mice. Untargeted metabolome analysis revealed that T2D-induced changes in 11 metabolites were regulated after LPSHY130 treatment, mainly involving purine metabolism, amino acid metabolism, and choline metabolism and pantothenate and coenzyme A biosynthesis pathways. In addition, correlation analysis indicated that hepatic metabolic changes can be adjusted by the intestinal microbiota.

CONCLUSION

Overall, this study suggests that treatment with LPSHY130 relieves liver injury and regulates liver metabolism in a murine model of T2D, thus providing a theoretical basis for the use of probiotics as dietary supplements to regulate hepatic metabolic disorders associated with T2D. © 2023 Society of Chemical Industry.

Composition of the intestinal microbiota and its variations between the second and third trimesters in women with gestational diabetes mellitus and without gestational diabetes mellitus

Objective

This study was designed to explore the composition of the intestinal microbiota and its longitudinal variation between the second trimester (T2) and the third trimester (T3) in women with gestational diabetes mellitus (GDM) and pregnant women with normal glucose tolerance.

Methods

This observational study was conducted at Peking Union Medical College Hospital (PUMCH). Women with GDM and pregnant women with normal glucose tolerance were enrolled in the study, and fecal samples were collected during T2 (weeks 24~28) and T3 (weeks 34~38). Fecal samples were analyzed from 49 women with GDM and 42 pregnant women with normal glucose tolerance. The 16S rRNA gene amplicon libraries were sequenced to analyze the microbiota and QIIME2 was used to analyze microbiome bioinformatics.

Results

The four dominant phyla that Firmicutes, Bacteroidetes, Actinobacteria and Proteobacteria which accomplish about 99% of the total relative abundance did not significantly change between the T2 and T3 in the GDM and healthy groups. At the genus level, the relative abundance of Scardovia (0 vs. 0.25%, P = 0.041) and Propionibacterium (0 vs. 0.29%, P = 0.041) increased significantly in the control group, but not in the GDM group. At the phylum level, the relative abundance of Firmicutes and Actinobacteria was significantly different between women with GDM and pregnant women with normal glucose tolerance in both T2 and T3. In T2 and T3, the relative abundances of unidentified_Lachnospiraceae, Blautia, and Parabacteroides were significantly higher in the GDM group than in the control group (P<0.05). The relative abundance of Bifidobacterium in the GDM group was lower than in the control group in both T2 and T3.

Conclusions

The intestinal microbiota composition was stable from T2 to T3 in the GDM and control groups; however, the intestinal microbiota composition was different between the two groups.

The Implication of Mechanistic Approaches and the Role of the Microbiome in Polycystic Ovary Syndrome (PCOS): A Review

As a complex endocrine and metabolic condition, polycystic ovarian syndrome (PCOS) affects women's reproductive health. These common symptoms include hirsutism, hyperandrogenism, ovulatory dysfunction, irregular menstruation, and infertility. No one knows what causes it or how to stop it yet. Alterations in gut microbiota composition and disruptions in secondary bile acid production appear to play a causative role in developing PCOS. PCOS pathophysiology and phenotypes are tightly related to both enteric and vaginal bacteria. Patients with PCOS exhibit changed microbiome compositions and decreased microbial diversity. Intestinal microorganisms also alter PCOS patient phenotypes by upregulating or downregulating hormone release, gut-brain mediators, and metabolite synthesis. The human body's gut microbiota, also known as the "second genome," can interact with the environment to improve metabolic and immunological function. Inflammation is connected to PCOS and may be caused by dysbiosis in the gut microbiome. This review sheds light on the recently discovered connections between gut microbiota and insulin resistance (IR) and the potential mechanisms of PCOS. This study also describes metabolomic studies to obtain a clear view of PCOS and ways to tackle it.

Christensenella regulated by Huang-Qi-Ling-Hua-San is a key factor by which to improve type 2 diabetes

There is a lot of evidence that oral hypoglycemic drugs work by affecting gut microbes, but the key strains responsible for this effect are not well known. Huang-Qi-Ling-Hua-San (HQLHS), composed of Astragalus Membranaceus, Ganoderma lucidum, Inonotus obliquus, and Momordica charantia L., is a specially designed Chinese medicine formula to treat type 2 diabetes (T2D). In this study, a mouse model of T2D induced by high-fat diet and streptozotocin was used to explore the mechanism of HQLHS in improving hyperglycemia and hyperlipidemia through multiple rounds of animal experiments, such as HQLHS feeding, fecal microbiota transplantation (FMT), and live bacteria feeding, so as to explore the potential target intestinal flora in its hypoglycemic effect. Results show that such specific taxa as Bifidobacterium, Turicibacter, Alistipes, Romboutsia, and Christensenella were identified to be preferably enriched by HQLHS and then assumed to be the target microbes. Herein, FMT was used to test if the upregulated beneficial bacteria by HQLHS play a therapeutic role. The strain Christensenella minuta DSM 22607 and the strain Christensenella timonensis DSM 102800 were selected to test the beneficial effect of Christensenella taxa on T2D. Diabetic animals supplemented with these strains showed the improvement in blood glucose and lipid metabolism, the promotion of GLP-1 secretion, the increase in antioxidant capacity, the inhibition of hepatic gluconeogenesis, the suppression of intestinal glucose absorption, the enhancement of intestinal barrier, reduced LPS-induced inflammation, and the reduction of branched amino acids (BCAAs) content in the liver. Overall, these data demonstrate that Christensenella plays a beneficial role in T2D and is a target for the action of HQLHS therapy.

Modified Banxia Xiexin Decoction Ameliorates Polycystic Ovarian Syndrome With Insulin Resistance by Regulating Intestinal Microbiota

Objective

To analyze the characteristics of the intestinal microbiota of polycystic ovarian syndrome with insulin resistance (PCOS-IR) and explore the possible mechanism of modified Banxia Xiexin Decoction in the treatment of PCOS-IR.

Methods

A total of 17 specific pathogen-free (SPF) female Sprague–Dawley (SD) rats, aged 21 days, were selected and randomly divided into the control group (group Z, n = 6), model group (group M, n = 6), and treatment group (group A, n = 5). Letrozole combined with a high-fat diet was used to induce the PCOS-IR model. Rats in group A were treated with modified Banxia Xiexin Decoction for 2 weeks after the end of modeling; then the characteristics of reproductive, metabolic, inflammatory, and intestinal microbiota were compared among three groups.

Results

The PCOS-IR model had an imbalance of intestinal microbiota, and the enriched microbiota was mainly class Coriobacteria, order Clostridiales, and genus Clostridium_sensu_stricto_1. Modified Banxia Xiexin Decoction can regulate the disorder of intestinal microbiota diversity, significantly increase the abundance of phyla Verrucomicrobiota Proteobacteria and genera Akkermansia and Blautia, and decrease the abundance of genus Clostridium_sensu_stricto_1.

Conclusion

Genus Clostridium_sensu_stricto_1 might be the pivotal pathogenic bacteria of PCOS-IR. Modified Banxia Xiexin Decoction may ameliorate PCOS-IR by regulating intestinal microbiota imbalance and improving metabolic disorders.

A Three-Day Intervention With Granola Containing Cereal Beta-Glucan Improves Glycemic Response and Changes the Gut Microbiota in Healthy Individuals: A Crossover Study

Intake of soluble fibers including beta-glucan, is known to improve post-prandial glycemic response. The mechanisms have been attributed to the viscous gel forming in the stomach and small intestine, giving a longer absorption time. However, recent evidence suggests a link between intake of beta-glucan and improved glycemic regulation at subsequent meals through the gut microbiota. We investigated the short-term effect of granola with different amounts of cereal beta-glucan on glycemic response and gut microbiota. After a two-week run-in period (baseline), fourteen healthy, normal weight adults completed a dose-response dietary crossover study. Different amounts of cereal beta-glucan (low: 0.8 g, medium: 3.2 g and high: 6.6 g) were provided in granola and eaten with 200 ml low-fat milk as an evening meal for three consecutive days. Blood glucose and insulin were measured fasted and after an oral glucose tolerance test (OGTT) the following day, in addition to peptide YY (PYY) and glucagon-like peptide (GLP-2), fasting short chain fatty acids (SCFA) in blood, breath H2, and gut microbiota in feces. Only the intervention with medium amounts of beta-glucan decreased blood glucose and insulin during OGTT compared to baseline. Fasting PYY increased with both medium and high beta-glucan meal compared to the low beta-glucan meal. The microbiota and SCFAs changed after all three interventions compared to baseline, where acetate and butyrate increased, while propionate was unchanged. Highest positive effect size after intake of beta-glucan was found with Haemophilus, followed by Veillonella and Sutterella. Furthermore, we found several correlations between different bacterial taxa and markers of glycemic response. In summary, intake of granola containing 3.2 g cereal beta-glucan as an evening meal for three consecutive days reduced the glycemic response after an OGTT 0-180 min and changed gut microbiota composition. Since we cannot rule out that other fiber types have contributed to the effect, more studies are needed to further explore the effect of cereal beta-glucan on glycemic regulation.

Clinical Trial Registration

[www.clinicaltrials.gov], identifier [NCT03293693].

Gestational Diabetes Mellitus: The Crosslink among Inflammation, Nitroxidative Stress, Intestinal Microbiota and Alternative Therapies

Gestational diabetes mellitus (GDM) is characterized by a set of metabolic complications arising from adaptive failures to the pregnancy period. Estimates point to a prevalence of 3 to 15% of pregnancies. Its etiology includes intrinsic and extrinsic aspects of the progenitress, which may contribute to the pathophysiogenesis of GDM. Recently, researchers have identified that inflammation, oxidative stress, and the gut microbiota participate in the development of the disease, with potentially harmful effects on the health of the maternal-fetal binomial, in the short and long terms. In this context, alternative therapies were investigated from two perspectives: the modulation of the intestinal microbiota, with probiotics and prebiotics, and the use of natural products with antioxidant and anti-inflammatory properties, which may mitigate the endogenous processes of the GDM, favoring the health of the mother and her offspring, and in a future perspective, alleviating this critical public health problem.

Impact of Dietary Sodium Butyrate and Salinomycin on Performance and Intestinal Microbiota in a Broiler Gut Leakage Model

Unfavorable alterations of the commensal gut microbiota and dysbacteriosis is a major health problem in the poultry industry. Understanding how dietary intervention alters the microbial ecology of broiler chickens is important for prevention strategies. A trial was conducted with 672 Ross 308 day-old male broilers fed a basic diet (no additives, control) or the basic diet supplemented with 500 mg/kg encapsulated butyrate or 68 mg/kg salinomycin. Enteric challenge was induced by inclusion of 50 g/kg rye in a grower diet and oral gavage of a 10 times overdose of a vaccine against coccidiosis. Compared to control and butyrate-supplemented birds, salinomycin supplementation alleviated growth depression. Compared to butyrate and non-supplemented control, salinomycin increased potentially beneficial Ruminococcaceae and reduced potentially pathogenic Enterobacteriaceae and counts of Lactobacillus salivarius and Clostridium perfringens. Further, salinomycin supplementation was accompanied by a pH decrease and succinic acid increase in ceca, while coated butyrate (0.5 g/kg) showed no or limited effects. Salinomycin alleviated growth depression and maintained intestinal homeostasis in the challenged broilers, while butyrate in the tested concentration showed limited effects. Thus, further investigations are required to identify optimal dietary inclusion rates for butyrate used as alternative to ionophore coccidiostats in broiler production.

Rectal administration of buttermilk processed with medicinal plants alters gut microbiome in obese individuals

OBJECTIVE

To evaluate the effect of rectal administration of buttermilk processed with medicinal plants on gut microbial composition and thereby on weight in obese individuals.

METHODS

With ethics committee approval, 16 obese individuals in the age group 20-50 years (BMI ≥30 kg/m2) were recruited who received a course of 15-enemas over 15-days. Of these, 1st, 8th and 15th enemas were of sesame-oil administered after food, while other enemas were of buttermilk processed with medicinal plants administered before food. Outcome variables viz. anthropometry, body composition, blood glucose, insulin and lipid profile were evaluated on day 0, 16 and 45. Also, microbial composition of buttermilk preparation and faecal samples of patients collected on day 0, 16 and 45 were studied with the help of 16S rRNA gene sequencing.

RESULTS

The circumferential measures and skinfold-thickness showed a decrease on day 16, which remained lower as compared to baseline till day 45. A gradual decrease in blood-glucose was seen, which was statistically significant on day 45, while insulin levels increased on day 16 and fell to baseline on day 45. There was an overall increase in bacterial diversity on day 16 that settled back to its original composition by day 45.

CONCLUSION

Our findings suggest that buttermilk administration per rectum is effective for a specific period and may have to be repeated for sustained benefits.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40200-021-00879-z.

Qing-Re-Xiao-Zheng Formula Modulates Gut Microbiota and Inhibits Inflammation in Mice With Diabetic Kidney Disease

Evidence indicates that the metabolic inflammation induced by gut microbiota dysbiosis contributes to diabetic kidney disease. Prebiotic supplementations to prevent gut microbiota dysbiosis, inhibit inflammatory responses, and protect the renal function in DKD. Qing-Re-Xiao-Zheng formula (QRXZF) is a Traditional Chinese Medicine (TCM) formula that has been used for DKD treatment in China. Recently, there are growing studies show that regulation of gut microbiota is a potential therapeutic strategy for DKD as it is able to reduce metabolic inflammation associated with DKD. However, it is unknown whether QRXZF is effective for DKD by regulating of gut microbiota. In this study, we investigated the reno-protective effect of QRXZF by exploring its potential mechanism between gut microbiota and downstream inflammatory pathways mediated by gut-derived lipopolysaccharide (LPS) in the kidney. High-fat diet (HFD) and streptozotocin injection-induced DKD mice model was established to assess the QRXZF effect in vivo. Mice treated with QRXZF for 8 weeks had significantly lower levels of urinary albumin, serum cholesterol and triglycerides. The renal injuries observed through histological analysis were attenuated as well. Also, mice in the QRXZF group had higher levels of Zonula occludens protein-1 (ZO-1) expression, lower levels of serum fluorescein-isothiocyanate (FITC)-dextran and less-damaged colonic mucosa as compared to the DKD group, implying the benefit role for the gut barrier integrity. QRXZF treatment also reversed gut dysbiosis and reduced levels of gut-derived LPS. Notably, the expression of toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB), which are important inflammation pathways in DKD, were suppressed in the QRXZF groups. In conclusion, our results indicated that the reno-protective effects of QRXZF was probably associated with modulating gut microbiota and inhibiting inflammatory responses in the kidney.

Gut Microbiota May Mediate the Influence of Periodontitis on Prediabetes

Mounting evidence has shown that periodontitis is associated with diabetes. However, a causal relationship remains to be determined. Recent studies reported that periodontitis may be associated with gut microbiota, which plays an important role in the development of diabetes. Therefore, we hypothesized that gut microbiota might mediate the link between periodontitis and diabetes. Periodontitis was induced by ligatures. Glycemic homeostasis was evaluated through fasting blood glucose (FBG), serum glycosylated hemoglobin (HbA1c), and intraperitoneal glucose tolerance test. Micro-computed tomography and hematoxylin and eosin staining were used to evaluate periodontal destruction. The gut microbiota was analyzed using 16S ribosomal RNA gene sequencing and bioinformatics. Serum endotoxin, interleukin (IL) 6, tumor necrosis factor α (TNF-α), and IL-1β were measured to evaluate the systemic inflammation burden. We found that the levels of FBG, HbA1c, and glucose intolerance were higher in the periodontitis (PD) group than in the control (Con) group (P < 0.05). When periodontitis was eliminated, the FBG significantly decreased (P < 0.05). Several butyrate-producing bacteria were decreased in the gut microbiota of the PD group, including Lachnospiraceae_NK4A136_group, Eubacterium_fissicatena_group, Eubacterium_coprostanoligenes_group, and Ruminococcaceae_UCG-014 (P < 0.05), which were negatively correlated with serum HbA1c (P < 0.05). Subsequently, the gut microbiota was depleted using antibiotics or transplanted through cohousing. Compared with the PD group, the levels of HbA1c and glucose intolerance were decreased in the gut microbiota-depleted mice with periodontitis (PD + Abx) (P < 0.05), as well as the serum levels of endotoxin and IL-6 (P < 0.05). The serum levels of IL-6, TNF-α, and IL-1β in the PD + Abx group were higher than those of the Con group (P < 0.05). Antibiotics exerted a limited impact on the periodontal microbiota. When the PD mice were cohoused with healthy ones, the elevated FBG and HbA1c significantly recovered (P < 0.05), as well as the aforementioned butyrate producers (P < 0.05). Thus, within the limitations of this study, our data indicated that the gut microbiota may mediate the influence of periodontitis on prediabetes.

Evaluation of the effect of insulin sensitivity-enhancing lifestyle- and dietary-related adjuncts on antidepressant treatment response: A systematic review and meta-analysis

Background

Depression is associated with insulin resistance (IR). However, the potential beneficial effect, on antidepressant treatment response, of adjunctive therapy with insulin sensitivity-enhancing lifestyle and dietary interventions (exercise; supplementation with: vitamin D, magnesium, zinc, probiotics or omega-3 fatty acids) has not been systematically explored.

Aims

To determine the effect of the above stated adjuncts on antidepressant treatment response in clinically depressed patients via a systematic review and meta-analysis.

Methods

RCTs which assessed the effect, on antidepressant treatment response of adjunctive therapy with any of the interventions in comparison with treatment as usual were included.

Results

The interventions had a significant antidepressant effect, with SMD for follow-up (end of study) scores and change (from baseline) scores being -0.88, [95% CI: -1.19 to -0.57; P < 0.001] and -1.98 [95% CI -2.86 to -1.10; P < 0.001], respectively. The odds ratio (OR) for remission was 2.28 (95% CI 1.42 to 3.66; P < 0.001). The number-needed-to-treat (NNT) for remission was 6. Subgroup analysis of the follow-up scores revealed age effect: SMD significant in those with mean age ≤50 (-1.02 SMD; 95% CI: -1.40 to -0.64; p < 0.001) and insignificant in those with mean age >50 (-0.38 SMD (95% CI: -0.82 to 0.05; P = 0.08)). Also, the interventions were more beneficial among outpatients- SMD: -0.97 (95% CI: -1.32 to -0.62; P < 0.001) compared to inpatients- SMD: -0.34 (95% CI: -0.88 to 0.20; P = 0.22). Sensitivity analysis did not change the results.

Conclusion

The finding that antidepressant treatment response may be improved using insulin sensitivity-enhancing lifestyle and dietary adjuncts is worthy of further exploration.

Roux-en-Y gastric bypass surgery changes fungal and bacterial microbiota in morbidly obese patients-A pilot study

The Roux-en-Y gastric bypass (RYGB) remains the most effective treatment for morbidly obese patients to lower body weight and improve glycemic control. There is recent evidence that the mycobiome (fungal microbiome) can aggravate disease severity in a number of diseases including inflammatory bowel disease (IBD), irritable bowel syndrome (IBS) and hepatitis; moreover, a dysbiotic fungal microbiota has been reported in the obese. We characterized fungal and bacterial microbial composition in fecal samples of 16 morbidly obese patients before and three months after RYGB surgery and compared with nine healthy controls. We found that RYGB surgery induced a clear alteration in structure and composition of the gut fungal and bacterial microbiota. Beta diversity analysis revealed significant differences in bacterial microbiota between obese patients before surgery and healthy controls (P < 0.005) and a significant, unidirectional shift in RYGB patients after surgery (P < 0.001 vs. before surgery). In contrast, there was no significant difference in fungal microbiota between groups but individually specific changes after RYGB surgery. Interestingly, RYGB surgery induced a significant reduction in fungal alpha diversity namely Chao1, Sobs, and Shannon diversity index (P<0.05, respectively) which contrasts the trend for uniform changes in bacteria towards increased richness and diversity post-surgery. We did not observe any inter-kingdom relations in RYGB patients but in the healthy control cohort and there were several correlations between fungi and bacteria and clinical parameters (P<0.05, respectively) that warrant further research. Our study identifies changes in intestinal fungal communities in RYGB patients that are distinct to changes in the bacterial microbiota.

The Role of Dysfunctional Adipose Tissue in Pancreatic Cancer: A Molecular Perspective

Pancreatic cancer (PC) is a lethal malignancy with rising incidence and limited therapeutic options. Obesity is a well-established risk factor for PC development. Moreover, it negatively affects outcome in PC patients. Excessive fat accumulation in obese, over- and normal-weight individuals induces metabolic and inflammatory changes of adipose tissue microenvironment leading to a dysfunctional adipose “organ”. This may drive the association between abnormal fat accumulation and pancreatic cancer. In this review, we describe several molecular mechanisms that underpin this association at both local and systemic levels. We focus on the role of adipose tissue-derived circulating factors including adipokines, hormones and pro-inflammatory cytokines, as well as on the impact of the local adipose tissue in promoting PC. A discussion on potential therapeutic interventions, interfering with pro-tumorigenic effects of dysfunctional adipose tissue in PC, is included. Considering the raise of global obesity, research efforts to uncover the molecular basis of the relationship between pancreatic cancer and adipose tissue dysfunction may provide novel insights for the prevention of this deadly disease. In addition, these efforts may uncover novel targets for personalized interventional strategies aimed at improving the currently unsatisfactory PC therapeutic options.

Role of gut microbiota in the development of insulin resistance and the mechanism underlying polycystic ovary syndrome: a review

Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder. Typically, it is characterized by hirsutism, hyperandrogenism, ovulatory dysfunction, menstrual disorders and infertility. To date, its pathogenesis remains unclear. However, insulin resistance (IR) is considered as the primary pathological basis for its reproductive dysfunction. On the other hand, a condition in which insulin is over-secreted is called hyperinsulinemia. IR/Hyperinsulinemia is associated with chronic inflammation, hormonal changes, follicular dysplasia, endometrial receptivity changes, and abortion or infertility. Additionally, it increases incidence of complications during pregnancy and has been associated with anxiety, depression, and other psychological disorders. Gut microbiota, the "second genome" acquired by the human body, can promote metabolism, immune response through interaction with the external environment. Gut microbiota dysbiosis can cause IR, which is closely linked to the occurrence of PCOS. This article reviewed recent findings on the roles of gut microbiota in the development of insulin resistance and the mechanism underlying polycystic ovary syndrome.

Adipose Tissue Distribution, Inflammation and Its Metabolic Consequences, Including Diabetes and Cardiovascular Disease

Adipose tissue plays essential roles in maintaining lipid and glucose homeostasis. To date several types of adipose tissue have been identified, namely white, brown, and beige, that reside in various specific anatomical locations throughout the body. The cellular composition, secretome, and location of these adipose depots define their function in health and metabolic disease. In obesity, adipose tissue becomes dysfunctional, promoting a pro-inflammatory, hyperlipidemic and insulin resistant environment that contributes to type 2 diabetes mellitus (T2DM). Concurrently, similar features that result from adipose tissue dysfunction also promote cardiovascular disease (CVD) by mechanisms that can be augmented by T2DM. The mechanisms by which dysfunctional adipose tissue simultaneously promote T2DM and CVD, focusing on adipose tissue depot-specific adipokines, inflammatory profiles, and metabolism, will be the focus of this review. The impact that various T2DM and CVD treatment strategies have on adipose tissue function and body weight also will be discussed.

Association between increased breath hydrogen methane concentration and prevalence of glucose intolerance in acute pancreatitis

Pancreatic damage, in the form of pancreatitis, intestinal bacteria and glucose imbalance could be interrelated. The aim of this study was to investigate the breath hydrogen (H₂) and methane (CH₄), which can indicate small intestinal bacterial overgrowth (SIBO) status, and assess the link between SIBO and glucose tolerance in patients with acute pancreatitis (AP). This prospective study enrolled 75 patients who were admitted for AP. A glucose breath test (GBT) which detects breath hydrogen H₂ and CH₄ for SIBO with an oral glucose tolerance test (OGTT) for 120 min was simultaneously performed to determine SIBO and glucose tolerance. Patient demographic data, laboratory test data, and computed tomography severity index (CTSI) were also evaluated. The levels of total breath H₂ and CH₄ in patients with AP were significantly higher than those in controls, respectively (p < 0.01). There were no significant differences in the incidence of SIBO between patients with AP and controls. The OGTT indicated that blood glucose levels at 30, 60, 90, and 120 min were higher in SIBO-positive patients than in SIBO-negative patients. No significant differences in CTSI, patient demographic data or laboratory test data were observed between the two groups. Breath H₂ and CH₄ concentrations are relatively higher in patients with AP, indicating a correlation between high levels of intestinal bacteria and AP. Furthermore, higher breath H₂ and CH₄ concentrations appear to be associated with oral glucose intolerance, with hyperglycemia occurring in patients with AP.

Immunometabolism in type 2 diabetes mellitus: tissue-specific interactions

The immune system is frequently described in the context of its protective function against infections and its role in the development of autoimmunity. For more than a decade, the interactions between the immune system and metabolic processes have been reported, in effect creating a new research field, termed immunometabolism. Accumulating evidence supports the hypothesis that the development of metabolic diseases may be linked to inflammation, and reflects, in some cases, the activation of immune responses. As such, immunometabolism is defined by 1) inflammation as a driver of disease development and/or 2) metabolic processes stimulating cellular differentiation of the immune components. In this review, the main factors capable of altering the immuno-metabolic communication leading to the development and establishment of obesity and diabetes are comprehensively presented. Tissue-specific immune responses suggested to impair metabolic processes are described, with an emphasis on the adipose tissue, gut, muscle, liver, and pancreas.

Probiotics in Adolescent Prediabetes: A Pilot RCT on Glycemic Control and Intestinal Bacteriome

Dysbiosis of intestinal ecology could be implicated in prediabetes. The aim of this pilot randomized controlled trial (RCT) was to collect preliminary data on the effects of probiotic supplementation (Vivomixx©) on markers of glucose metabolism, intestinal microbiome composition, and intestinal health indices, of prediabetic adolescents. The intervention group was administered probiotic sachets twice daily for 4 months, while both intervention and control groups received weekly consultation sessions for a healthier lifestyle. Thirty-two participants were recruited (1.3 participants per month) and were randomized (16 in control and 16 in intervention group). Fifteen of them signed the inform consent and never entered the study (6 in control and 9 in intervention group). Thus, seventeen participants completed the study (10 in control and 7 in intervention group), with no serious adverse events. After the 4-month intervention, no difference was observed in the markers of glycemic control between the two groups, although a minor effect was observed for fasting glucose at 1-month, probably due to the initial higher adherence to the probiotic supplements. Modifications of the protocol procedures are warranted because of the high attrition rates and suboptimal compliance that were noted. Future studies and further RCTs with larger samples need to be conducted to fully elucidate the potential effects of probiotics in the glycemic control of prediabetic adolescents.

Systems biology perspective for studying the gut microbiota in human physiology and liver diseases

The advancement in high-throughput sequencing technologies and systems biology approaches have revolutionized our understanding of biological systems and opened a new path to investigate unacknowledged biological phenomena. In parallel, the field of human microbiome research has greatly evolved and the relative contribution of the gut microbiome to health and disease have been systematically explored. This review provides an overview of the network-based and translational systems biology-based studies focusing on the function and composition of gut microbiota. We also discussed the association between the gut microbiome and the overall human physiology, as well as hepatic diseases and other metabolic disorders.

Optimized fasting and OGTT-based simple surrogate methods for assessing insulin sensitivity

AIMS

Simple surrogate indices of insulin sensitivity have been conceived to deal with costly and complicated approaches, such as the hyperinsulinemic-euglycemic clamp; however, their use has not been widespread given their variabilities in different populations. In this paper, we present two simple surrogate indices, one that uses fasting glucose and insulin values and the other based on the values from the oral glucose tolerance test.

MATERIALS AND METHODS

The proposed methods integrate easy-to-obtain anthropometric measures. Evolutionary algorithms were used to optimize the proposed methods by maximizing its correlation with the Stumvoll MCR method.

RESULTS AND CONCLUSION

When the proposed indices were applied to three study groups (control subjects, metabolic syndrome, marathon runners), a reduction in the intergroup variability of the insulin sensitivity was obtained. Moreover, the proposed index based on the oral glucose tolerance test (OGTT), which considers the glucose metabolism process and the hepatic and peripheral insulin sensitivity, showed stronger correlations with the Stumvoll method and lower intergroup variability than the fasting one.

Beneficial Effects of Potentilla discolor Bunge Water Extract on Inflammatory Cytokines Release and Gut Microbiota in High-Fat Diet and Streptozotocin-Induced Type 2 Diabetic Mice

Potentilla discolor Bunge (PDB), a perennial herb, has been used as a traditional Chinese medicine in the therapy of many diseases. The aim of the current study was to investigate the effect of PDB water extract on systemic inflammation and gut microbiota in type 2 diabetic (T2D) mice induced by high-fat diet (HFD) and streptozotocin (STZ) injection. C57BL/6J mice were randomly divided into a normal diet (ND) group, T2D group, and PDB group (diabetic mice treated with PDB water extract at a dose of 400 mg/kg body weight). Results showed that PDB significantly decreased the levels of lipopolysaccharide (LPS) and pro-inflammatory cytokines in serum. Further investigation showed that PDB significantly reduced the ratio of Firmicutes/Bacteroidetes and the relative abundance of Proteobacteria in fecal samples of diabetic mice. In addition, PDB notably alleviated intestinal inflammation as evidenced by decreased expression of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), nuclear factor-κB (NF-κB), and inflammatory cytokines. PDB also reversed the decreased expression of intestinal mucosal tight junction proteins including Claudin3, ZO-1, and Occludin. Meanwhile, the levels of fecal acetic acid and butyric acid and their specific receptors including G-protein-coupled receptor (GPR) 41 and 43 expression in the colon were also increased after PDB treatment. Our results indicated that PDB might serve as a potential functional ingredient against diabetes and related inflammation.

Diet-Gut Microbiota Interactions and Gestational Diabetes Mellitus (GDM)

Medical nutritional therapy is the first-line approach in managing gestational diabetes mellitus (GDM). Diet is also a powerful modulator of the gut microbiota, whose impact on insulin resistance and the inflammatory response in the host are well known. Changes in the gut microbiota composition have been described in pregnancies either before the onset of GDM or after its diagnosis. The possible modulation of the gut microbiota by dietary interventions in pregnancy is a topic of emerging interest, in consideration of the potential effects on maternal and consequently neonatal health. To date, very few data from observational studies are available about the associations between diet and the gut microbiota in pregnancy complicated by GDM. In this review, we analyzed the available data and discussed the current knowledge about diet manipulation in order to shape the gut microbiota in pregnancy.

Vitamin D and probiotic co-supplementation affects mental health, hormonal, inflammatory and oxidative stress parameters in women with polycystic ovary syndrome

Objective

The aim of this study was to determine the effect of vitamin D and probiotic co-administration on mental health, hormonal, inflammatory and oxidative stress parameters in women with polycystic ovary syndrome (PCOS).

Methods

This randomized, double-blinded, placebo-controlled clinical trial was carried out on 60 subjects, aged 18–40 years old. Subjects were randomly allocated to take either 50,000 IU vitamin D every 2 weeks plus 8 × 10⁹ CFU/day probiotic (n = 30) or placebo (n = 30) for 12 weeks.

Results

Vitamin D and probiotic co-supplementation, compared with the placebo, significantly improved beck depression inventory [β (difference in the mean of outcomes measures between treatment groups) − 0.58; 95% CI, − 1.15, − 0.02; P = 0.04], general health questionnaire scores (β − 0.93; 95% CI, − 1.78, − 0.08; P = 0.03) and depression, anxiety and stress scale scores (β − 0.90; 95% CI, − 1.67, − 0.13; P = 0.02). Vitamin D and probiotic co-supplementation was associated with a significant reduction in total testosterone (β − 0.19 ng/mL; 95% CI, − 0.28, − 0.10; P < 0.001), hirsutism (β − 0.95; 95% CI, − 1.39, − 0.51; P < 0.001), high-sensitivity C-reactive protein (hs-CRP) (β − 0.67 mg/L; 95% CI, − 0.97, − 0.38; P < 0.001) and malondialdehyde (MDA) levels (β − 0.25 μmol/L; 95% CI, − 0.40, − 0.10; P = 0.001), and a significant increase in total antioxidant capacity (TAC) (β 82.81 mmol/L; 95% CI, 42.86, 122.75; P < 0.001) and total glutathione (GSH) levels (β 40.42 μmol/L; 95% CI, 4.69, 76.19; P = 0.02), compared with the placebo.

Conclusions

Overall, the co-administration of vitamin D and probiotic for 12 weeks to women with PCOS had beneficial effects on mental health parameters, serum total testosterone, hirsutism, hs-CRP, plasma TAC, GSH and MDA levels.

Trial Registration

This study was retrospectively registered in the Iranian website (www.irct.ir) for registration of clinical trials (IRCT20170513033941N37).

Obesity alters composition and diversity of the oral microbiota in patients with type 2 diabetes mellitus independently of glycemic control

Background and objective

The involvement of the oral microbiota as a possible link between periodontitis, type 2 diabetes mellitus and obesity is still not well understood. The objective of the study was to investigate if glycemic control and obesity play a role in modulating the composition and diversity of the oral microbial ecology.

Material and methods

A cohort of patients with type 2 diabetes mellitus (n = 18) was recruited. Participants demonstrating improved glycemic control after 3 months (n = 6) were included in a second examination. A full mouth examination was performed to estimate periodontitis severity followed by sample collection (subgingival plaque and saliva). Generation of large sequence libraries was performed using the high-throughput Illumina MiSeq sequencing platform.

Results

The majority of participants (94.4%, n = 17) presented with moderate or severe forms of periodontitis. Differences in microbial composition and diversity between obese (BMI ≥ 30 kg/m²) and non-obese (BMI < 30 kg/m²) groups were statistically significant. Cross-sectional and longitudinal approaches failed to reveal statistically significant associations between HbA_1c level and species composition or diversity.

Conclusions

Obesity was significantly associated with the oral microbial composition. The impact of glycemic control on oral microbiota, however, could not be assured statistically.

The effects of probiotic and selenium co-supplementation on parameters of mental health, hormonal profiles, and biomarkers of inflammation and oxidative stress in women with polycystic ovary syndrome

Background

The aim of this study was to evaluate the effect of the co-administration of probiotic and selenium on parameters of mental health, hormonal profiles, and biomarkers of inflammation and oxidative stress in women with PCOS. Data on the effects of selenium and probiotic co-supplementation on mental health, hormonal and inflammatory parameters of patients with polycystic ovary syndrome (PCOS) are scarce. This investigation was carried out to evaluate the effects of selenium and probiotic co-supplementation on mental health, hormonal and inflammatory parameters in women with PCOS.

Methods

This randomized, double-blinded, placebo-controlled clinical trial was conducted on 60 subjects, aged 18–40 years old. Participants were randomly allocated into two groups to intake 8 × 10⁹ CFU/day probiotic plus 200 μg/day selenium supplements (n = 30) or placebo (n = 30) for 12 weeks. Hormonal and inflammatory parameters were measured at baseline and after the 12-week intervention.

Results

Probiotic and selenium co-supplementation resulted in a significant improvement in beck depression inventory (β − 0.76; 95% CI, − 1.26, − 0.26; P = 0.003), general health questionnaire scores (β − 1.15; 95% CI, − 1.97, − 0.32; P = 0.007) and depression anxiety and stress scale scores (β − 1.49; 95% CI, − 2.59, − 0.39; P = 0.009) compared with the placebo. Furthermore, probiotic and selenium co-supplementation significantly reduced total testosterone (β − 0.26 ng/mL; 95% CI, − 0.51, − 0.02; P = 0.03), hirsutism (β − 0.43; 95% CI, − 0.74, − 0.11; P = 0.008), high-sensitivity C-reactive protein (hs-CRP) (β − 0.58 mg/L; 95% CI, − 0.97, − 0.19; P = 0.004) and malondialdehyde (MDA) levels (β − 0.29 μmol/L; 95% CI, − 0.56, − 0.02; P = 0.03), and significantly increased total antioxidant capacity (TAC) (β + 84.76 mmol/L; 95% CI, + 48.08, + 121.44; P < 0.001) and total glutathione (GSH) levels (β + 26.78 μmol/L; 95% CI, + 4.33, + 49.23; P = 0.02) compared with the placebo.

Conclusions

Overall, the co-administration of probiotic and selenium for 12 weeks to women with PCOS had beneficial effects on mental health parameters, serum total testosterone, hirsutism, hs-CRP, TAC, GSH and MDA levels.

This study was prospectively registered in the Iranian website (www.irct.ir) for registration of clinical trials (http://www.irct.ir: IRCT20170513033941N22).

Trial registration

IRCT20170513033941N22.

Intestinal dysbiosis activates renal renin-angiotensin system contributing to incipient diabetic nephropathy

Considerable interest nowadays has focused on gut microbiota owing to their pleiotropic roles in human health and diseases. This intestinal community can arouse a variety of activities in the host and function as "a microbial organ" by generating bioactive metabolites and participating in a series of metabolism-dependent pathways. Alternations in the composition of gut microbiota, referred to as intestinal dysbiosis, are reportedly associated with several diseases, especially diabetes mellitus and its complications. Here we focus on the relationship between gut microbiota and diabetic nephropathy (DN), as the latter is one of the major causes of chronic kidney diseases. The activation of renin angiotensin system (RAS) is a critical factor to the onset of DN, and emerging data has demonstrated a provoking and mediating role of gut microbiota for this system in the context of metabolic diseases. The purpose of the current review is to highlight some research updates about the underlying interplay between gut microbiota, their metabolites, and the development and progression of DN, along with exploring innovative approaches to targeting this intestinal community as a therapeutic perspective in clinical management of DN patients.