Effect of inulin and oligofructose enrichment of the diet on rats suffering thiamine deficiency

Role of gut commensal bacteria in juvenile developmental growth of the host: insights from Drosophila studies

The gut microbiome plays a crucial role in maintaining health in a variety of organisms, from insects to humans. Further, beneficial symbiotic microbes are believed to contribute to improving the quality of life of the host. Drosophila is an optimal model for studying host-commensal microbe interactions because it allows for convenient manipulation of intestinal microbial composition. Fly microbiota has a simple taxonomic composition and can be cultivated and genetically tracked. This permits functional studies and analyses of the molecular mechanisms underlying their effects on host physiological processes. In this context, we briefly introduce the principle of juvenile developmental growth in Drosophila. Then, we discuss the current understanding of the molecular mechanisms underlying the effects of gut commensal bacteria, such as Lactiplantibacillus plantarum and Acetobacter pomorum, in the fly gut microbiome on Drosophila juvenile growth, including specific actions of gut hormones and metabolites in conserved cellular signaling systems, such as the insulin/insulin-like (IIS) and the target of rapamycin (TOR) pathways. Given the similarities in tissue function/structure, as well as the high conservation of physiological systems between Drosophila and mammals, findings from the Drosophila model system will have significant implications for understanding the mechanisms underlying the interaction between the host and the gut microbiome in metazoans.

Effect of thiamine supplementation on glycaemic outcomes in adults with type 2 diabetes: a systematic review and meta-analysis

BACKGROUND

Patients with type 2 diabetes mellitus (T2DM) have been shown to have thiamine deficiency. Dietary supplementation is an economic strategy to control blood glucose. Objective: To evaluate effectiveness of thiamine supplementation on glycaemic outcomes in patients with T2DM.

METHODS

Eligibility criteria: Studies that assessed effect of thiamine supplementation in adults with T2DM which measured glycaemic outcomes-HbA1c, fasting blood glucose (FBG) and/or postprandial blood glucose (PPG) were included. Information sources: PUBMED, Tripdatabase, the Cochrane Central Register, National Institute of Health Clinical Database and Google Scholar were searched until December 2021 for RCTs. Risk of bias: It was assessed using standardised critical appraisal instruments from the Joanna Briggs Institute for RCTs. Synthesis of results: Where possible, studies were pooled in a meta-analysis. Results were presented in a narrative format if statistical pooling was not possible.

RESULTS

Included studies: Six trials involving 364 participants. Synthesis of results: No significant beneficial effects were observed on glycaemic outcomes with 100-900 mg/day of thiamine or benfotiamine for up to 3 months (HbA1c: MD, -0.02%, 95% CI: -0.35 to 0.31; FBG: MD,-0.20 mmol/L; 95% CI: -0.69 to 0.29; PPG: MD, - 0.20 mmol/L, 95% CI: -2.05 to 1.65 (mean difference, MD)). There was a significant increase in high-density lipoprotein (HDL) (MD, 0.10; 95% CI: 0.10 to 0.20) at 3-month follow-up. Benfotiamine reduced triglyceride level (MD, -1.10; 95% CI: -1.90 to -0.30) in 120 mg/day dose as compared with placebo 150 mg/day, however this was not demonstrated in higher doses.

DISCUSSION

Limitations of evidence: Inclusion of single-centre trials published only in English, small sample sizes of included studies, lack of trials investigating outcomes for same comparisons and varying follow-up periods. Interpretation: Thiamine supplementation does not affect glycaemic outcomes, however reduces triglycerides while increasing HDL. Multicentre well-designed RCT with higher doses of thiamine and a follow-up period of 1-2 years will provide better evidence.

PROSPERO REGISTRATION NUMBER

CRD42020170520.

The role of pancreas to improve hyperglycemia in STZ-induced diabetic rats by thiamine disulfide

Background

The present study investigated the effect of thiamine disulfide (TD) on the pancreas in terms of hyperglycemia improvement and insulin sensitivity increase in diabetic male rats. We also aimed to study the function of Pdx1 (pancreatic and duodenal homeobox 1) and Glut2 (glucose transporter 2) genes in pancreatic tissue.

Methods

Type 1 diabetes was induced through injection of 60 mg/kg streptozotocin (STZ). The diabetic rats were divided into four groups, namely diabetic control (DC), diabetic treated with thiamine disulfide (D-TD), diabetic treated with insulin (D-insulin), and diabetic treated with TD and insulin (D-insulin+TD). The non-diabetic (NDC) and diabetic groups received a normal diet (14 weeks). Blood glucose level and body weight were measured weekly; insulin tolerance test (ITT) and glucagon tolerance test (GTT) were performed in the last month of the study. The level of serum insulin and glucagon were measured monthly and a hyperglycemic clamp (Insulin Infusion rate (IIR)) was done for all the groups. Pancreas tissue was isolated so that Pdx1and Glut2 genes expression could be measured.

Results

We observed that TD therapy decreased blood glucose level, ITT, and serum glucagon levels in comparison with those of the DC group; it also increased serum insulin levels, IIR, and expression of Pdx1 and Glut2 genes in comparison with those of the DC group.

Conclusion

Administration of TD could improve hyperglycemia in type 1 diabetic animals through improved pancreas function. Therefore, not only does TD have a significant effect on controlling and reducing hyperglycemia in diabetes, but it also has the potential to decrease the dose of insulin administration.

The role of yoghurt consumption in the management of type II diabetes

Enrichment of yoghurt with specific ingrdients beneficially affects the management of Type II Diabetes Mellitus (DMII). As far as the role of yoghurt in the management of DMII is concerned, the limited number of randomized clinical trials (RCTs) which have been conducted suggest that daily intake of yoghurt enriched with vitamin D and/or calcium as well as probiotics positively influences glycemic regulation and may contribute to more effective control of the disease. It is argued that the various ingredients which are already contained in the complex matrix of food, such as bioactive peptides, calcium, B-complex vitamins and beneficial microbes, as well as the fact that it can be used as a vehicle for the inclusion of other effective ingredients can have an impact on the metabolic control of diabetic patients. The aim of this review is to present the RCTs which have been conducted in the last decade in patients with DMII in an attempt to highlight the positive effects of yoghurt in the management of the disease.

Thiamine deficiency affects glucose transport and β-oxidation in rats

Thiamine is recognized as a cofactor for many enzymes involved in intermediary metabolism responsible for energy production. Animal model of thiamine deficiency (TD) included direct evaluation of glucose uptake by estimation of ³H‐deoxyglucose transport across red blood cells membranes and β‐oxidation of fatty acids in isolated leucocytes. Feeding of animals with the thiamine‐deficient diet (0.018 mg/kg diet) for 30 days resulted in disturbances in energy production. The thiamine intake was limited not only by vitamin B₁ deficiency in the diet, but also by time‐dependent drop of feed consumption by rats fed this diet. At the end of experiment, diet consumption in this group of rats was 52% lower than in the control group. This was accompanied by low glucose uptake by erythrocytes of rats suffering vitamin B₁ deficiency for longer time. At the end of experimental period, glucose uptake was over 2 times lower in TD erythrocytes than in control RBC. Such drop of energy production was not compensated by delivery of energy from fatty acid degradation. In leucocytes from TD rats, the β‐oxidation was also suppressed. Observed significant decrease of serum insulin from 2.25 ± 0.25 ng/ml (day 0) to 1.94 ± 0.17 ng/ml (day 30) might have significant impact on observed energy production disorders. The results from this study indicate that the thiamine deficiency significantly reduces feed intake and causes modest abnormalities in glucose and fatty acid utilization.

Effects of α-Lipoic Acid, Carnosine, and Thiamine Supplementation in Obese Patients with Type 2 Diabetes Mellitus: A Randomized, Double-Blind Study

Type 2 diabetes mellitus (T2DM) is evolving to an epidemic of the modern world. T2DM is associated with a number of pathological complications, including cardiovascular disease that is mostly promoted by the increased oxidative stress in type 2 diabetic patients. We performed a randomized double-blind placebo-controlled trial to investigate the effectiveness of an individualized oral supplementation with α-lipoic acid (ALA), carnosine, and thiamine. For that purpose, 82 obese type 2 diabetic patients were randomly assigned to 2 groups, and were either supplemented daily with 7 mg ALA/kg body weight, 6 mg carnosine/kg body weight, and 1 mg thiamine/kg body weight or placebo for 8 weeks. An array of biochemical tests including the estimation of oxidative stress and platelet aggregation were performed at baseline and at follow-up. Moreover, the antiplatelet activity of each of the supplement's components was determined ex vivo at human and washed rabbit platelets. Glucose and HbA_1c levels were significantly reduced after supplementation (135.7 ± 19.5 mg/dL vs. 126.5 ± 16.8 mg/dL and 8.3% ± 0.3% vs. 6.03% ± 0.58%, respectively, P < .05); however, insulin was significantly increased (3.6 ± 0.7 μIU/mL vs. 6.8 ± 0.2 μIU/mL, P < .05). The patients treated with the supplement recorded higher follow-up values for HOMA-IR and HOMA-β, and a significant drop in serum hydroperoxide level. Only ALA inhibited platelets aggregation ex vivo through ADP, platelet activating factor, arachidonic acid, epinephrine, collagen, and thrombin pathways. Daily supplementation with an individualized ALA, carnosine, and thiamine supplement effectively reduced glucose concentration in type 2 diabetic patients, probably by increasing insulin production from the pancreas. In addition to that, the reduction of oxidative stress and inhibition of platelet aggregation could potentially provide greater cardiovascular protection. Further studies are needed to fine-tune the supplementation dose-response effects in T2DM patients.

Effect of Pregnancy and Stage of Lactation on Energy Processes in Isolated Blood Cells of Dairy Cows

Introduction

The transition period is the most challenging time for dairy cattle, which is characterised not only by negative energy balance but also by fatty tissue mobilisation.

Material and Methods

The efficiency of energy pathways, β-oxidation in WBC and glycolysis in RBC (based on deoxyglucose transmembrane transport) were estimated. Insulin in blood plasma was determined using ELISA.

Results

After calving and up to one month after delivery, a significant drop in blood plasma level was noticed, simultaneously with a rise in β-oxidation from 18.93 ±3.64 to 30.32 ±5.28 pmol/min/mg protein in WBC. A strong negative correlation between these two indices (r = -0.68) was found. During the period of transition to lactation an increase in glucose cross-membrane transportation from 41.44 ±4.92 to 50.49 ±6.41 μmol/h/g Hb was observed. A strong positive correlation between glucose transportation in RBC and β-oxidation in WBC (r = 0.71) was noticed. These data are in agreement with results of studies on dairy cows using liver slices from dairy cows in late pregnancy and different stages of lactation, in which changes in gene expression were analysed.

Conclusion

It seems that measuring fatty acids oxidation and glycolysis using isolated blood cells may be an adequate and relatively simple method for energy state analysis to estimate the state of dairy cow metabolism and animal health.

The impact of thiamine treatment in the diabetes mellitus

Thiamine acts as a coenzyme for transketolase (Tk) and for the pyruvate dehydrogenase and α-ketoglutarate dehydrogenase complexes, enzymes which play a fundamental role for intracellular glucose metabolism. The relationship between thiamine and diabetes mellitus (DM) has been reported in the literature. Thiamine levels and thiamine-dependent enzyme activities have been reduced in DM. Genetic studies provide opportunity to link the relationship between thiamine and DM (such as Tk, SLC19A2 gene, transcription factor Sp1, α-1-antitrypsin, and p53). Thiamine and its derivatives have been demonstrated to prevent the activation of the biochemical pathways (increased flux through the polyol pathway, formation of advanced glycation end-products, activation of protein kinase C, and increased flux through the hexosamine biosynthesis pathway) induced by hyperglycemia in DM.Thiamine definitively has a role in the diabetic endothelial vascular diseases (micro and macroangiopathy), lipid profile, retinopathy, nephropathy, cardiopathy, and neuropathy.