Low Glucose Research Articles

Comparison of Metabolic Control in Children and Adolescents Treated with Insulin Pumps.

While insulin pumps remain the most common form of therapy for youths with type 1 diabetes (T1DM), they differ in the extent to which they utilize data from continuous glucose monitoring (CGM) and automate insulin delivery. The aim of the study was to compare metabolic control in patients using different models of insulin pumps. This retrospective single-center study randomly sampled 30 patients for each of the following treatments: Medtronic 720G without PLGS (predictive low glucose suspend), Medtronic 640G or 740G with PLGS and Medtronic 780G. In the whole study group, we used CGM systems to assess patients' metabolic control, and we collected lipid profiles. In three groups of patients, we utilized CGM sensors (Guardian 3, Guardian 4, Libre 2 and Dexcom G6) to measure the following glycemic variability proxy values: time in range (TIR), time below 70 mg/dL (TBR), time above 180 mg/dL (TAR), coefficient of variation (CV) and mean sensor glucose. Medtronic 640G or 740G and 780G users were more likely to achieve a target time in the target range 70-180 mg/dL (≥80%) [Medtronic 720G = 4 users (13.3%) vs. Medtronic 640G/740G = 10 users (33.3%) vs. Medtronic 780G = 13 users (43.3%); p = 0.0357)] or low glucose variability [Medtronic 720G = 9 users (30%) vs. Medtronic 640G/740G = 18 users (60%) vs. Medtronic 780G = 19 users (63.3%); p = 0.0175)]. Any integration between the insulin pump and CGM was associated with better glycemic control. More advanced technologies and artificial intelligence in diabetes help patients maintain better glycemia by eliminating various factors affecting postprandial glycemia.

The complications of long time treatment of insulin therapy in type-2 diabetes patients: A Review

Diabetes is a chronic metabolic disease characterized by elevated blood sugar levels. It can also mean long-term problems with the metabolism of carbohydrates caused by insulin deficiency, which leads to hyperglycemia and glycosuria. Weight gain is a common side effect of insulin therapy and other oral antidiabetic medications for diabetic patients, which can hinder their ability to meet strict glycemic targets and potentially reduce treatment success. Insulin-related weight gain is attributed to anabolic effects, appetite increases, and reduced glycosuria. Insulin therapy has been linked to increased cardiovascular risk and mortality in type 2 diabetes patients, as well as inflammation, atherosclerosis, hypertension, dyslipidemia, heart failure, and arrhythmias. Large-scale evaluations suggest that insulin therapy has a poorer short- and long-term safety profile than other anti-T2D therapies. To treat diabetes, a variety of insulin formulations are available, each acting at a distinct pace. Whether they are long-acting, intermediate-acting, or rapid-acting, there are similar adverse effects to be mindful of. Weight gain, injection site responses, and hypoglycemia (low blood glucose) are common side effects of insulin. Lipodystrophy, or improper fat distribution, and limb edema are uncommon adverse effects of insulin. When it comes to insulin introduction, titration, and follow-up treatment, doctors can manage patients with type 2 diabetes mellitus more effectively by employing simple algorithms. Primary care doctors and other medical professionals can manage patients with type 2 diabetes mellitus more easily by using streamlined insulin introduction and titration protocols.

The role and mechanism of action of miR-483-3p in mediating the effects of IGF-1 on human renal tubular epithelial cells induced by high glucose

This study aimed to elucidate the influence of miR-483-3p on human renal tubular epithelial cells (HK-2) under high glucose conditions and to understand its mechanism. Human proximal tubular epithelial cells (HK-2) were exposed to 50 mmol/L glucose for 48 h to establish a renal tubular epithelial cell injury model, denoted as the high glucose group (HG group). Cells were also cultured for 48 h in a medium containing 5.5 mmol/L glucose, serving as the low glucose group. Transfection was performed in various groups: HK-2 + low glucose (control group), high glucose (50 mM) (HG group), high glucose + miR-483-3p mimics (HG + mimics group), high glucose +miR-483-3p inhibitor (HG + inhibitor group), and corresponding negative controls. Real-time quantitative polymerase chain reaction (qPCR) assessed the mRNA expression of miR-483-3p, bax, bcl-2, and caspase-3. Western blot determined the corresponding protein levels. Proliferation was assessed using the CCK-8 assay, and cell apoptosis was analyzed using the fluorescence TUNEL method. Western blot and Masson’s staining were conducted to observe alterations in cell fibrosis post miR-483-3p transfection. Furthermore, a dual-luciferase assay investigated the targeting relationship between miR-483-3p and IGF-1. The CCK8 assay demonstrated that the HG + mimics group inhibited HK-2 cell proliferation, while the fluorescent TUNEL method revealed induced cell apoptosis in this group. Conversely, the HG + inhibitor group promoted cell proliferation and suppressed cell apoptosis. The HG + mimics group upregulated mRNA and protein expression of pro-apoptotic markers (bax and caspase-3), while downregulating anti-apoptotic marker (bcl-2) expression. In contrast, the HG + inhibitor group showed opposite effects. Collagen I and FN protein levels were significantly elevated in the HG + mimics group compared to controls (P < 0.05). Conversely, in the HG + inhibitor group, the protein expression of Collagen I and FN was notably reduced compared to the HG group (P < 0.05). The dual luciferase reporter assay confirmed that miR-483-3p could inhibit the luciferase activity of IGF-1’s 3′-UTR region (P < 0.05). miR-483-3p exerts targeted regulation on IGF-1, promoting apoptosis and fibrosis in renal tubular epithelial cells induced by high glucose conditions.

Oral glucose tolerance test-The imperfect gold standard for gestational diabetes screening: A qualitative study involving clinicians in regional, rural and remote areas of Western Australia.

The oral glucose tolerance test is the 'gold standard' for detecting gestational diabetes in Australian and International guidelines. Test completion in regional, rural and remote regions may be as low as 50%. We explored challenges and enablers for regional, rural and remote antenatal clinicians providing gestational diabetes screening to better understand low oral glucose tolerance test completion. We conducted a qualitative descriptive study using semi-structured interviews. Participants eligible for the study were doctors or midwives providing antenatal care in regional, rural and remote Western Australia, between August 2019 and November 2020. Interviews were recorded digitally and transcribed into a Word document. We conducted a thematic analysis after initial categorisation and deduction of themes through workshops involving the research team. We found a diversity of viewpoints on oral glucose tolerance test reliability for detecting gestational diabetes. Themes that emerged were; good collaboration between antenatal clinicians is required for successful screening; screening occurs throughout pregnancy using various tests; clinicians make significant efforts to address barriers; clinicians prioritise therapeutic relationships. Effective universal screening for gestational diabetes in regional, rural and remote Western Australia is difficult and more complex in practice than guidelines imply. Detecting gestational diabetes requires creative solutions, early identification of at risk women and trust and collaboration between clinicians and women. SO WHAT?: Detection of gestational diabetes in regional, rural and remote Western Australia remains poorly completed. New strategies are required to adequately identify women at risk of adverse birth outcomes relating to hyperglycaemia in pregnancy.

Ketomimetic Medium Promotes Metastatic Disposition and Chemoresistance in Breast Cancer Cells through Hypersialylation and Lipid Synthesis.

Although metastasis accounts for the vast majority of cancer-related fatalities, the triggers for the metastatic transformation of breast cancer (BC) cells remain unknown. Recent evidence suggests that a common feature of invasive and resistant cells could be their metabolic state. However, attempts to control metabolic state via nutrient intake, e.g., ketogenic or low carbohydrate diets, have shown inconsistent results with respect to improving chemotherapy efficacy and curbing metastasis. Aiming to decode the molecular mechanisms that alter cell phenotype upon nutrient alteration, we study how a ketomimetic (ketone body-rich, low glucose) medium affects Doxorubicin (DOX) susceptibility and invasive disposition of BC cells. We quantified glycocalyx sialylation and found an inverse correlation with DOX-induced cytotoxicity and DOX internalization. These measurements were coupled with single-cell metabolic imaging, bulk migration studies, and transcriptomic and metabolomic analyses to map the mechanisms involved in ketone body-driven BC cell metabolic maneuvering. Our findings revealed that a ketomimetic medium enhances chemoresistance and invasive disposition of BC cells via two main oncogenic pathways: hypersialylation and lipid accumulation. We propose that the crosstalk between these pathways leads to synthesis of the glycan precursor UDP-GlcNAc, which leads to advancement of a metastatic phenotype in BC cells under ketomimetic conditions.

Single-cell transcriptomic profiling of human pancreatic islets reveals genes responsive to glucose exposure over 24 h

Aims/hypothesisDisruption of pancreatic islet function and glucose homeostasis can lead to the development of sustained hyperglycaemia, beta cell glucotoxicity and subsequently type 2 diabetes. In this study, we explored the effects of in vitro hyperglycaemic conditions on human pancreatic islet gene expression across 24 h in six pancreatic cell types: alpha; beta; gamma; delta; ductal; and acinar. We hypothesised that genes associated with hyperglycaemic conditions may be relevant to the onset and progression of diabetes.MethodsWe exposed human pancreatic islets from two donors to low (2.8 mmol/l) and high (15.0 mmol/l) glucose concentrations over 24 h in vitro. To assess the transcriptome, we performed single-cell RNA-seq (scRNA-seq) at seven time points. We modelled time as both a discrete and continuous variable to determine momentary and longitudinal changes in transcription associated with islet time in culture or glucose exposure. Additionally, we integrated genomic features and genetic summary statistics to nominate candidate effector genes. For three of these genes, we functionally characterised the effect on insulin production and secretion using CRISPR interference to knock down gene expression in EndoC-βH1 cells, followed by a glucose-stimulated insulin secretion assay.ResultsIn the discrete time models, we identified 1344 genes associated with time and 668 genes associated with glucose exposure across all cell types and time points. In the continuous time models, we identified 1311 genes associated with time, 345 genes associated with glucose exposure and 418 genes associated with interaction effects between time and glucose across all cell types. By integrating these expression profiles with summary statistics from genetic association studies, we identified 2449 candidate effector genes for type 2 diabetes, HbA1c, random blood glucose and fasting blood glucose. Of these candidate effector genes, we showed that three (ERO1B, HNRNPA2B1 and RHOBTB3) exhibited an effect on glucose-stimulated insulin production and secretion in EndoC-βH1 cells.Conclusions/interpretationThe findings of our study provide an in-depth characterisation of the 24 h transcriptomic response of human pancreatic islets to glucose exposure at a single-cell resolution. By integrating differentially expressed genes with genetic signals for type 2 diabetes and glucose-related traits, we provide insights into the molecular mechanisms underlying glucose homeostasis. Finally, we provide functional evidence to support the role of three candidate effector genes in insulin secretion and production.Data availabilityThe scRNA-seq data from the 24 h glucose exposure experiment performed in this study are available in the database of Genotypes and Phenotypes (dbGap; https://www.ncbi.nlm.nih.gov/gap/) with accession no. phs001188.v3.p1. Study metadata and summary statistics for the differential expression, gene set enrichment and candidate effector gene prediction analyses are available in the Zenodo data repository (https://zenodo.org/) under accession number 11123248. The code used in this study is publicly available at https://github.com/CollinsLabBioComp/publication-islet_glucose_timecourse.Graphical

Healthy and diabetic primary human osteoblasts exhibit varying phenotypic profiles in high and low glucose environments on 3D-printed titanium surfaces.

The revolution of orthopedic implant manufacturing is being driven by 3D printing of titanium implants for large bony defects such as those caused by diabetic Charcot arthropathy. Unlike traditional subtractive manufacturing of orthopedic implants, 3D printing fuses titanium powder layer-by-layer, creating a unique surface roughness that could potentially enhance osseointegration. However, the metabolic impairments caused by diabetes, including negative alterations of bone metabolism, can lead to nonunion and decreased osseointegration with traditionally manufactured orthopedic implants. This study aimed to characterize the response of both healthy and diabetic primary human osteoblasts cultured on a medical-grade 3D-printed titanium surface under high and low glucose conditions. Bone samples were obtained from six patients, three with Type 2 Diabetes Mellitus and three without. Primary osteoblasts were isolated and cultured on 3D-printed titanium discs in high (4.5 g/L D-glucose) and low glucose (1 g/L D-Glucose) media. Cellular morphology, matrix deposition, and mineralization were assessed using scanning electron microscopy and alizarin red staining. Alkaline phosphatase activity and L-lactate concentration was measured in vitro to assess functional osteoblastic activity and cellular metabolism. Osteogenic gene expression of BGLAP, COL1A1, and BMP7 was analyzed using reverse-transcription quantitative polymerase chain reaction. Diabetic osteoblasts were nonresponsive to variations in glucose levels compared to their healthy counterparts. Alkaline phosphatase activity, L-lactate production, mineral deposition, and osteogenic gene expression remained unchanged in diabetic osteoblasts under both glucose conditions. In contrast, healthy osteoblasts exhibited enhanced functional responsiveness in a high glucose environment and showed a significant increase in osteogenic gene expression of BGLAP, COL1A1, and BMP7 (p<.05). Our findings suggest that diabetic osteoblasts exhibit impaired responsiveness to variations in glucose concentrations, emphasizing potential osteoblast dysfunction in diabetes. This could have implications for post-surgery glucose management strategies in patients with diabetes. Despite the potential benefits of 3D printing for orthopedic implants, particularly for diabetic Charcot collapse, our results call for further research to optimize these interventions for improved patient outcomes.

Extracellular glucose triggers metabolic reprogramming of cultured human bronchial epithelial cells and indirect fibroblast activation.

Glucose is essential for energy metabolism, and its usage can determine other cellular functions, depending on the cell type. In some pathological conditions, cells are exposed to high concentrations of glucose for extended periods. In this study, we investigated metabolic, oxidative stress, and cellular senescence pathways in human bronchial epithelial cells (HBECs) cultured in media with physiologically low (5 mm) and high (12.5 mm) glucose concentrations. HBECs exposed to 12.5 mm glucose showed increased glucose routing toward the pentose phosphate pathway, lactate synthesis, and glycogen, but not triglyceride synthesis. These metabolic shifts were not associated with changes in cell proliferation rates, oxidative stress, or cellular senescence pathways. Since hyperglycemia is associated with fibrosis in the lung, we asked whether HBECS could activate fibroblasts. Primary human lung fibroblasts cultured in media conditioned by 12.5 mm glucose-exposed HBECs showed a 1.3-fold increase in the gene expression of COL1A1 and COL1A2, along with twofold increased protein levels of smooth muscle cell actin and 2.4-fold of COL1A1. Consistently, HBECs cultured with 12.5 mm glucose secreted proteins associated with inflammation and fibrosis, such as interleukins IL-1β, IL-10, and IL-13, CC chemokine ligands CCL2 and CCL24, and with extracellular matrix remodeling, such as metalloproteinases (MMP)-1, MMP-3, MMP-9, and MMP-13 and tissue inhibitors of MMPs (TIMP)-1 and -2. This study shows that HBECs undergo metabolic reprogramming and increase the secretion of profibrotic mediators following exposure to high concentrations of glucose, and it contributes to the understanding of the metabolic crosstalk of neighboring cells in diabetes-associated pulmonary fibrosis.

Trends in Presentation and Management of Endogenous Hyperinsulinaemic Hypoglycaemia Over the Last Three Decades at a Tertiary Care Centre (1992-2022).

Endogenous hyperinsulinaemic hypoglycaemia (EHH) is characterized by inappropriate insulin secretion from pancreatic beta cells despite low blood glucose concentrations. We aimed to evaluate the secular changes in presentation and management of EHH due to insulinoma/non-insulinoma pancreatogenous hypoglycaemia syndrome (NIPHS) at our centre. This was a single-centre ambispective study (2014-2022). The clinical, biochemical, hormonal and radiological parameters (n = 63) collected as part of this study were compared with our earlier studies (1992-2005, n = 31; and 2006-2013, n = 35) and with other centres across the world. A total of 63 patients (39 males) with a preoperative diagnosis of EHH (insulinoma, n = 58; and NIPHS, n = 5) and a mean age of 40.7 years were studied. The mean lag time from the onset of symptoms to diagnosis decreased from 4.6 years during the first study period to 1.9 years during this study period. However, the majority presented with fasting hypoglycaemia of 98.4%, and both fasting and postprandial hypoglycaemia of 32%. Exclusive postprandial hypoglycaemia was present in 1.7% of insulinoma. A histopathological diagnosis of insulinoma was made in 52 patients and nesidioblastosis in two patients. Intraoperative ultrasonography (IOUS) and intraoperative palpation (IOP) yielded 100% sensitivity, while endoscopic ultrasonography (EUS) and 68Ga-DOTA-Exendin-4 positron emission tomography/computed tomography (PET/CT) yielded sensitivity of 86% and 85%, respectively, for localizing insulinoma. Resolution of hypoglycaemia was noted in 53 of 57 (93%) patients who underwent surgery with a preoperative diagnosis of insulinoma. We observed a trend towards earlier diagnosis of EHH, increased patient numbers and availability of nuclear imaging techniques for preoperative localization in the last decade compared to earlier.

Burden and Coping Strategies of Hypoglycemia in People with Diabetes.

Hypoglycemia is a limiting adverse effect of glucose-lowering medications and particularly insulin replacement therapy. This review provides insights into the burden of hypoglycemia in the management of diabetes and outlines strategies available to reduce the risk of hypoglycemia and improve patients' well-being. People with type 1 diabetes are primarily affected by hypoglycemic episodes which are associated with direct physical harms like injuries and cardiac events as well as indirect psychosocial consequences including constant anxiety, absenteeism, increased healthcare costs and overall poorer quality of life. These complications are more prominent amongst individuals with hypoglycemia unawareness or overnight hypoglycemia and could even extend to caregivers such as parents of children with diabetes. Patients experiencing frequent or severe hypoglycemic events might also develop a pathological fear of hypoglycemia and adopt aberrant behaviors intending to maintain higher blood glucose levels. Modern pharmaceutical options with a safer profile in terms of hypoglycemia are available including novel basal insulins with lower rates of nocturnal hypoglycemia along with ultra-rapid-acting insulin analogs with a shorter duration of action that might avert late post-meal hypoglycemia. Continuous glucose monitoring and sensor-augmented insulin pump therapy with low glucose suspend technology can also prevent hypoglycemia, although concerns about cost and patient satisfaction remain. Advancements in insulin therapy and technological modalities should be coupled with ongoing education and support for patients to become co-managers of their disease and reduce the risk of hypoglycemia.

Beta-Hydroxybutyrate Promotes Basal Insulin Secretion While Decreasing Glucagon Secretion in Mouse and Human Islets.

Dietary carbohydrates raise blood glucose levels, and limiting carbohydrate intake improves glycemia in patients with type 2 diabetes. Low carbohydrate intake (< 25 g) allows the body to utilize fat as its primary fuel. As a consequence of increased fatty acid oxidation, the liver produces ketones to serve as an alternative energy source. β-Hydroxybutyrate (βHB) is the most abundant ketone. While βHB has a wide range of functions outside of the pancreas, its direct effects on islet cell function remain understudied. We examined human islet secretory response to acute racemic βHB treatment and observed increased insulin secretion at a low glucose concentration of 3 mM. Because βHB is a chiral molecule, existing as both R and S forms, we further studied insulin and glucagon secretion following acute treatment with individual βHB enantiomers in human and C57BL/6J mouse islets. We found that acute treatment with R-βHB increased insulin secretion and decreased glucagon secretion at physiological glucose concentrations in both human and mouse islets. Proteomic analysis of human islets treated with R-βHB over 72 hours showed altered abundance of proteins that may promote islet cell health and survival. Collectively, our data show that physiological concentrations of βHB influence hormone secretion and signaling within pancreatic islets.

Impaired GK-GKRP interaction rather than direct GK activation worsens lipid profiles and contributes to long-term complications: a Mendelian randomization study

BackgroundGlucokinase (GK) plays a key role in glucose metabolism. In the liver, GK is regulated by GK regulatory protein (GKRP) with nuclear sequestration at low plasma glucose level. Some GK activators (GKAs) disrupt GK-GKRP interaction which increases hepatic cytoplasmic GK level. Excess hepatic GK activity may exceed the capacity of glycogen synthesis with excess triglyceride formation. It remains uncertain whether hypertriglyceridemia associated with some GKAs in previous clinical trials was due to direct GK activation or impaired GK-GKRP interaction.MethodsUsing publicly available genome-wide association study summary statistics, we selected independent genetic variants of GCKR and GCK associated with fasting plasma glucose (FPG) as instrumental variables, to mimic the effects of impaired GK-GKRP interaction and direct GK activation, respectively. We applied two-sample Mendelian Randomization (MR) framework to assess their causal associations with lipid-related traits, risks of metabolic dysfunction-associated steatotic liver disease (MASLD) and cardiovascular diseases. We verified these findings in one-sample MR analysis using individual-level statistics from the Hong Kong Diabetes Register (HKDR).ResultsGenetically-proxied impaired GK-GKRP interaction increased plasma triglycerides, low-density lipoprotein cholesterol and apolipoprotein B levels with increased odds ratio (OR) of 14.6 (95% CI 4.57–46.4) per 1 mmol/L lower FPG for MASLD and OR of 2.92 (95% CI 1.78–4.81) for coronary artery disease (CAD). Genetically-proxied GK activation was associated with decreased risk of CAD (OR 0.69, 95% CI 0.54–0.88) and not with dyslipidemia. One-sample MR validation in HKDR showed consistent results.ConclusionsImpaired GK-GKRP interaction, rather than direct GK activation, may worsen lipid profiles and increase risks of MASLD and CAD. Development of future GKAs should avoid interfering with GK-GKRP interaction.

Recent Advances in Glycemic Management for Hospitalized Diabetic Patients

With the increase in the number of diabetic patients, hospitalized diabetes management has become very important. During hospitalization, diabetic patients are prone to high or low blood glucose levels, which pose significant risks and challenges for treatment and recovery. Therefore, glycemic management of diabetic patients during hospitalization is critical. This article reviews the latest research progress in glycemic management of hospitalized diabetic patients from several aspects, develops individualized treatment plans, and uses various methods to manage and control blood glucose in hospitalized diabetic patients.

Metabolic flexibility ensures proper neuronal network function in moderate neuroinflammation

Microglia, brain-resident macrophages, can acquire distinct functional phenotypes, which are supported by differential reprogramming of cell metabolism. These adaptations include remodeling in glycolytic and mitochondrial metabolic fluxes, potentially altering energy substrate availability at the tissue level. This phenomenon may be highly relevant in the brain, where metabolism must be precisely regulated to maintain appropriate neuronal excitability and synaptic transmission. Direct evidence that microglia can impact on neuronal energy metabolism has been widely lacking, however. Combining molecular profiling, electrophysiology, oxygen microsensor recordings and mathematical modeling, we investigated microglia-mediated disturbances in brain energetics during neuroinflammation. Our results suggest that proinflammatory microglia showing enhanced nitric oxide release and decreased CX3CR1 expression transiently increase the tissue lactate/glucose ratio that depends on transcriptional reprogramming in microglia, not in neurons. In this condition, neuronal network activity such as gamma oscillations (30–70 Hz) can be fueled by increased ATP production in mitochondria, which is reflected by elevated oxygen consumption. During dysregulated inflammation, high energy demand and low glucose availability can be boundary conditions for neuronal metabolic fitness as revealed by kinetic modeling of single neuron energetics. Collectively, these findings indicate that metabolic flexibility protects neuronal network function against alterations in local substrate availability during moderate neuroinflammation.

AMPK targets PDZD8 to trigger carbon source shift from glucose to glutamine

The shift of carbon utilization from primarily glucose to other nutrients is a fundamental metabolic adaptation to cope with decreased blood glucose levels and the consequent decline in glucose oxidation. AMP-activated protein kinase (AMPK) plays crucial roles in this metabolic adaptation. However, the underlying mechanism is not fully understood. Here, we show that PDZ domain containing 8 (PDZD8), which we identify as a new substrate of AMPK activated in low glucose, is required for the low glucose-promoted glutaminolysis. AMPK phosphorylates PDZD8 at threonine 527 (T527) and promotes the interaction of PDZD8 with and activation of glutaminase 1 (GLS1), a rate-limiting enzyme of glutaminolysis. In vivo, the AMPK-PDZD8-GLS1 axis is required for the enhancement of glutaminolysis as tested in the skeletal muscle tissues, which occurs earlier than the increase in fatty acid utilization during fasting. The enhanced glutaminolysis is also observed in macrophages in low glucose or under acute lipopolysaccharide (LPS) treatment. Consistent with a requirement of heightened glutaminolysis, the PDZD8-T527A mutation dampens the secretion of pro-inflammatory cytokines in macrophages in mice treated with LPS. Together, we have revealed an AMPK-PDZD8-GLS1 axis that promotes glutaminolysis ahead of increased fatty acid utilization under glucose shortage.

2G-lactic acid from olive oil supply chain waste: olive leaves upcycling via Lactobacillus casei fermentation

The transition towards a sustainable model, particularly the circular economy, emphasizes the importance of redefining waste as a valuable resource, paving the way for innovative upcycling strategies. The olive oil industry, with its significant output of agricultural waste, offers a promising avenue for high-value biomass conversion into useful products through microbial processes. This study focuses on exploring new, high-value applications for olive leaves waste, utilizing a biotechnological approach with Lactobacillus casei for the production of second-generation lactic acid. Contrary to initial expectations, the inherent high polyphenol content and low fermentable glucose levels in olive leaves posed challenges for fermentation. Addressing this, an enzymatic hydrolysis step, following a preliminary extraction process, was implemented to increase glucose availability. Subsequent small-scale fermentation tests were conducted with and without nutrient supplements, identifying the medium that yielded the highest lactic acid production for scale-up. The scaled-up batch fermentation process achieved an enhanced conversion rate (83.58%) and specific productivity (0.26 g/L·h). This research confirms the feasibility of repurposing olive waste leaves for the production of lactic acid, contributing to the advancement of a greener economy through the valorization of agricultural waste.Key points• Olive leaves slurry as it did not allow L. casei to ferment.• High concentrations of polyphenols inhibit fermentation of L. casei.• Enzymatic hydrolysis combined to organosolv extraction is the best pretreatment for lactic acid production starting from leaves and olive pruning waste.Graphical

Enhancing probiotic impact: engineering Saccharomyces boulardii for optimal acetic acid production and gastric passage tolerance.

Saccharomyces boulardii has been a subject of growing interest due to its potential as a probiotic microorganism with applications in gastrointestinal health, but the molecular cause for its probiotic potency has remained elusive. The recent discovery that S. boulardii contains unique mutations causing high acetic acid accumulation and inhibition of bacterial growth provides a possible clue. The natural S. boulardii isolates Sb.P and Sb.A are homozygous for the recessive mutation whi2S270* and accumulate unusually high amounts of acetic acid, which strongly inhibit bacterial growth. However, the homozygous whi2S270* mutation also leads to acetic acid sensitivity and acid sensitivity in general. In the present study, we have constructed a new S. boulardii strain, derived from the widely therapeutically used CMCN I-745 strain (isolated from the pharmaceutical product Enterol), producing even higher levels of acetic acid while keeping the same tolerance toward low pH as the parent Enterol (ENT) strain. This newly engineered strain, named ENT3, has a homozygous deletion of ACH1 and strong overexpression of ALD4. It is also able to accumulate much higher acetic acid concentrations when growing on low glucose levels, in contrast to the ENT wild-type and Sb.P strains. Moreover, we show the antimicrobial capacity of ENT3 against gut pathogens in vitro and observed that higher acetic acid production might correlate with better persistence in the gut in healthy mice. These findings underscore the possible role of the unique acetic acid production and its potential for improvement of the probiotic action of S. boulardii.IMPORTANCESuperior variants of the probiotic yeast Saccharomyces boulardii produce high levels of acetic acid, which inhibit the growth of bacterial pathogens. However, these strains also show increased acid sensitivity, which can compromise the viability of the cells during their passage through the stomach. In this work, we have developed by genetic engineering a variant of Saccharomyces boulardii that produces even higher levels of acetic acid and does not show enhanced acid sensitivity. We also show that the S. boulardii yeasts with higher acetic acid production persist longer in the gut, in agreement with a previous work indicating competition between probiotic yeast and bacteria for residence in the gut.

Accuracy evaluation of Roche Accu‐Chek Performa blood glucose meters at low glucose concentrations: A nine‐year retrospective study

AbstractObjectiveTo evaluate the accuracy of Roche Accu‐Chek Performa glucose meters at a low glucose concentration of &lt;5.55 mmol/L (100 mg/dL) over a 9‐year period.MethodsThe accuracy of the Roche Accu‐Chek Performa glucose meters at low glucose concentrations was evaluated using annual comparison data for 9 consecutive years from 2015 to 2023, according to the acceptability criteria specified in International Organization for Standardization (ISO) 15197:2013. Blood samples with low glucose concentrations of &lt;5.55 mmol/L were prepared by incubation and glycolysis. The glucose concentration was detected using Roche Accu‐Chek Performa glucose meters and a biochemical analyzer in the central laboratory.ResultsA total of 2978 pairs of comparison results from 211 glucose meters at a low glucose concentration of &lt;5.55 mmol/L were retrospectively analyzed from 2015 to 2023. The clinical use duration spanned from 1 to 9 years and 40.76% (86 out of 211 glucose meters) had been used for more than 2 years. The correlation coefficient r between glucose meter measurements and laboratory reference values was 0.98 (p &lt; 0.001). The mean according to Roche Accu‐Chek Performa glucose meters was 0.05 mmol/L (0.9 mg/dL) higher than that of the biochemical analyzer (Z = −13.82, p &lt; 0.0001). The results showed that 100.00% (211 out of 211) of the Roche Accu‐Chek Performa glucose meters met the acceptability criteria specified in ISO 15197:2013. At a low glucose concentration of &lt;5.55 mmol/L, 99.90% (2975 out of 2978) of the comparative data pairs in the error distribution fell within the range of ±0.83 mmol/L (15 mg/dL). Parkes consensus error grid analysis showed that 100.00% (2978 out of 2978) of comparative data pairs fell within region A.ConclusionsThis study demonstrated that Roche Accu‐Chek Performa glucose meters successfully met the accuracy standards of ISO 15197:2013 for measuring blood glucose within the hypoglycemic range. Greater attention should be given to the performance of blood glucose monitoring systems in the low glycemic range, especially for patients with diabetes who are prone to hypoglycemia and require precise measurements.

Changes in adiponectin levels of subclinical ketosis cows and their effects on steroid hormone secretion and proliferation in follicular granulosa cells

In dairy cows, the occurrence of subclinical ketosis (SCK) is particularly high during early lactation. Previously, we documented alterations in the abundance of adiponectin (ADPN) in anestrus cows with SCK in comparison to cows in estrus. In the present study, 60 cows were divided into two groups: control (C, n = 30) and SCK (n = 30). Based on cow’s estrus situation in two group at 55–60 days postpartum, 15 anestrus SCK cows and estrus cows were designated the SCK-A group and C-E group, respectively. The SCK-A group had downregulated serum and follicular fluid ADPN levels compared with the C-E group. The serum ADPN level was positively correlated with the insulin level and follicle growth rate, and there was a positive correlation between ADPN and glucose in the follicular fluid. Primary culture of dairy cow granulosa cells (GCs) was established to observe the effect of low glucose (Glu) and/or ADPN on GCs cyclins and proteins important for steroid synthesis. The results showed that the addition of 1 µg/mL ADPN alleviated the negative effects of low Glu treatment on the proliferation of GCs and the expression of steroid secretion related protein proteins. Treatment with LY294002 (PI3K inhibitor) four experimental GCs groups: control (0 µg/mL ADPN), 1 µg/mL ADPN, LY294002 inhibitor, and 1 µg/mL ADPN+LY294002. The results showed that ADPN promotes the secretion of steroid hormones by GCs through the PI3K–AKT. In summary, ADPN plays a crucial role in ameliorating postpartum anestrus in dairy cows with SCK.

Accuracy of FreeStyle Libre flash glucose monitoring in patients with type 2 diabetes who migrated from highlands to plains

BACKGROUND The FreeStyle Libre flash glucose monitoring (FGM) system entered the Chinese market in 2017 to complement the self-monitoring of blood glucose. Due to its increased usage in clinics, the number of studies investigating its accuracy has increased. However, its accuracy has not been investigated in highland popu-lations in China. AIM To evaluate measurements recorded using the FreeStyle Libre FGM system compared with capillary blood glucose measured using the enzyme electrode method in patients with type 2 diabetes (T2D) who had migrated within 3 mo from highlands to plains. METHODS Overall, 68 patients with T2D, selected from those who had recently migrated from highlands to plains (within 3 mo), were hospitalized at the Department of Endocrinology from August to October 2017 and underwent continuous glucose monitoring (CGM) with the FreeStyle Libre FGM system for 14 d. Throughout the study period, fingertip capillary blood glucose was measured daily using the enzyme electrode method (Super GL, China), and blood glucose levels were read from the scanning probe during fasting and 2 h after all three meals. Moreover, the time interval between reading the data from the scanning probe and collecting fingertip capillary blood was controlled to &lt; 5 min. The accuracy of the FGM system was evaluated according to the CGM guidelines. Subsequently, the factors influencing the mean absolute relative difference (MARD) of this system were analyzed by a multiple linear regression method. RESULTS Pearson’s correlation analysis showed that the fingertip and scanned glucose levels were positively correlated (R = 0.86, P = 0.00). The aggregated MARD of scanned glucose was 14.28 ± 13.40%. Parker's error analysis showed that 99.30% of the data pairs were located in areas A and B. According to the probe wear time of the FreeStyle Libre FGM system, MARD1 d and MARD2–14 d were 16.55% and 14.35%, respectively (t = 1.23, P = 0.22). Multiple stepwise regression analysis showed that MARD did not correlate with blood glucose when the largest amplitude of glycemic excursion (LAGE) was &lt; 5.80 mmol/L but negatively correlated with blood glucose when the LAGE was ≥ 5.80 mmol/L. CONCLUSION The FreeStyle Libre FGM system has good accuracy in patients with T2D who had recently migrated from highlands to plains. This system might be ideal for avoiding the effects of high hematocrit on blood glucose monitoring in populations that recently migrated to plains. MARD is mainly influenced by glucose levels and fluctuations, and the accuracy of the system is higher when the blood glucose fluctuation is small. In case of higher blood glucose level fluctuations, deviation in the scanned glucose levels is the highest at extremely low blood glucose levels.