Gut microbiota: closely tied to the regulation of circadian clock in the development of type 2 diabetes mellitus

Chronodisruption and Gut Microbiota: Triggering Glycemic Imbalance in People with Type 2 Diabetes

The desynchronization of physiological and behavioral mechanisms influences the gut microbiota and eating behavior in mammals, as shown in both rodents and humans, leading to the development of pathologies such as Type 2 diabetes (T2D), obesity, and metabolic syndrome. Recent studies propose resynchronization as a key input controlling metabolic cycles and contributing to reducing the risk of suffering some chronic diseases such as diabetes, obesity, or metabolic syndrome. In this analytical review, we present an overview of how desynchronization and its implications for the gut microbiome make people vulnerable to intestinal dysbiosis and consequent chronic diseases. In particular, we explore the eubiosis-dysbiosis phenomenon and, finally, propose some topics aimed at addressing chronotherapy as a key strategy in the prevention of chronic diseases.

A State-of-Art Review of the Vicious Circle of Sleep Disorders, Diabetes and Neurodegeneration Involving Metabolism and Microbiota Alterations

In the context of neurodegenerative disorders, cognitive decline is frequently reported in older population. Recently, numerous metabolic pathways have been implicated in neurodegeneration, including signaling disruption of insulin and other glucose-regulating hormones. In fact, Alzheimer's disease has now been considered as "type-3 diabetes". In this review, we tried to clarify the role of sleep impairment as the third major player in the complex relationship between metabolic and neurodegenerative diseases. Altered sleep may trigger or perpetuate these vicious mechanisms, leading to the development of both dementia and type 2 diabetes mellitus. Finally, we analyzed these reciprocal interactions considering the emerging role of the gut microbiota in modulating the same processes. Conditions of dysbiosis have been linked to circadian rhythm disruption, metabolic alterations, and release of neurotoxic products, all contributing to neurodegeneration. In a future prospective, gut microbiota could provide a major contribution in explaining the tangled relationship between sleep disorders, dementia and diabetes.

Changes in the Microbiota and their Roles in Patients with Type 2 Diabetes Mellitus

An association between type 2 diabetes mellitus (T2DM) and gut microbiota is well established, but the results of related studies are inconsistent. The purpose of this investigation is to elucidate the characteristics of the gut microbiota in T2DM and non-diabetic subjects. Forty-five subjects were recruited for this study, including 29 T2DM patients and 16 non-diabetic subjects. Biochemical parameters, including body mass index (BMI), fasting plasma glucose (FPG), serum total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL), and hemoglobin A1c (HbA1c), were analyzed and correlated with the gut microbiota. Bacterial community composition and diversity were detected in fecal samples using direct smear, sequencing, and real-time polymerase chain reaction (PCR). In this study, it was observed that indicators such as BMI, FPG, HbA1c, TC, and TG in T2DM patients were on the rise, concurrent with dysbiosis of the microbiota. We observed an increase in Enterococci and a decrease in Bacteroides, Bifidobacteria, and Lactobacilli in patients with T2DM. Meanwhile, total short-chain fatty acids (SCFAs) and D-lactate concentrations were decreased in the T2DM group. In addition, FPG was positively correlated with Enterococcus and negatively correlated with Bifidobacteria, Bacteroides, and Lactobacilli. This study reveals that microbiota dysbiosis is associated with disease severity in patients with T2DM. The limitation of this study is that only common bacteria were noted in this study, and more in-depth related studies are urgently needed.

Composition of the intestinal microbiota of infant rhesus macaques at different ages before and after weaning

Background

Rhesus macaques and humans are closely related genetically and share similar physiological and pathological characteristics. Exploring the impact of diet on the early establishment of gut microbiota in non-human primates can provide relevant clinical models for healthy infant growth and development. At present, few writers have focused on the composition and changes of the intestinal microbes of infant rhesus macaques throughout their progression from birth to formula feeding after weaning. In this study, we used 16S rRNA sequencing technology to explore the composition of the intestinal flora of rhesus macaques at different ages and analyzed the trends in the microbial changes.

Results

The results showed that the relative abundance of Bifidobacterium and Lactobacillus in the intestinal flora of infant rhesus macaques significantly decreased, and Prevotella increased with age. Bifidobacterium longum and Bifidobacterium breve are effective biomarkers to predict grouping. The metabolic pathways enriched in early life mainly concentrated in glycosphingolipid biosynthesis (lacto and neolacto series) and the degradation and metabolism of alcohols and esters.

Conclusions

We found that age was an important factor that affected the changes in the intestinal flora. This study revealed the change trend of flora in breastfed and formula-fed infant rhesus monkeys in different growth months, and found that the dominant flora changed greatly. This research provides a medically relevant theoretical basis for understanding the healthy development of infants.

The Role of Maternal Vitamin D Deficiency in Offspring Obesity: A Narrative Review

Currently, vitamin D (VD) deficiency during pregnancy is widespread globally, causing unfavorable pregnancy outcomes for both mothers and infants for a longer time than expected, based on the Developmental Origins of Health and Disease (DOHaD) theory. As VD plays a key role in maintaining normal glucose and lipid metabolism, maternal VD deficiency may lead to obesity and other obesity-related diseases among offspring later in life. This review mainly focuses on the effect of maternal VD deficiency on offspring lipid metabolism, reviewing previous clinical and animal studies to determine the effects of maternal VD deficit on offspring obesity and potential mechanisms involved in the progression of offspring obesity. Emerging clinical evidence shows that a low VD level may lead to abnormal growth (either growth restriction or largeness for gestational age) and lipid and glucose metabolism disorders in offspring. Here, we also outline the link between maternal VD deficiency and life-long offspring effects, including the disorder of adipogenesis, the secretion of adipocytokines (including leptin, resistin, and adiponectin), activated systemic inflammation, increased oxidative reactions in adipose tissue, insulin resistance, and abnormal intestinal gut microbiota. Thus, there is an urgent need to take active steps to address maternal VD deficiency to relieve the global burden of obesity.

A time-restricted feeding intervention in children and adolescents with obesity: The TRansForm study protocol

Obesity during childhood is of special concern as adiposity is typically tracked into adult life and it constitutes a major risk factor for future obesity and associated metabolic disorders. Recent studies indicate that time-restricted feeding (TRF) interventions may provide a promising strategy for obesity treatment. However, TRF interventions have only been tested in adult subjects. This study aims to determine both short- and long-term effects of a TRF intervention in children and adolescents with obesity. We will also investigate potential mechanisms mediating the response to the intervention, including the circadian rhythm and the gut microbiota composition. We have designed a randomized-controlled parallel-group clinical study in which children and adolescents (age range 8–18 year-old) with obesity will be subjected to time-restricted eating or no time restrictions for 2 months. Follow-up visits will allow for long-term effect assessments. We will measure anthropometric (BMI, body composition) and metabolic parameters (glucose and lipid metabolism), indicators of the circadian rhythm, and gut microbiota composition will be analyzed. This study will (1) determine safety and effectiveness of the TRF intervention in children and adolescents; (2) assess its long-term effects; and (3) evaluate potential mechanisms involved in the response to the intervention.

Clinical trial registration

[www.ClinicalTrials.gov], identifier [NCT05174871].

Characteristics of Probiotic Preparations and Their Applications

The probiotics market is one of the fastest growing segments of the food industry as there is growing scientific evidence of the positive health effects of probiotics on consumers. Currently, there are various forms of probiotic products and they can be categorized according to dosage form and the site of action. To increase the effectiveness of probiotic preparations, they need to be specifically designed so they can target different sites, such as the oral, upper respiratory or gastrointestinal tracts. Here we review the characteristics of different dosage forms of probiotics and discuss methods to improve their bioavailability in detail, in the hope that this article will provide a reference for the development of probiotic products.

The Effect and Potential Mechanism of Maternal Micronutrient Intake on Offspring Glucose Metabolism: An Emerging Field

Diabetes has become the most common metabolic disease around the world. In addition to genetic and environmental factors in adulthood, the early life environment is critical to the progression of diabetes in adults, especially the environment during the fetal period; this concept is called “fetal programming.” Substantial evidence has illustrated the key role of early life macronutrient in programming metabolic diseases. Recently, the effect of maternal micronutrient intake on offspring glucose metabolism during later life has become an emerging field. This review focuses on updated human and animal evidence about the effect of maternal micronutrient status on offspring glucose metabolism and the underlying mechanism.

Potential contribution of the gut microbiota to hypoglycemia after gastric bypass surgery

Obesity has become a global health problem. Lifestyle modification and medical treatment only appear to yield short-term weight loss. Roux-en-Y gastric bypass (RYGB) is the most popular bariatric procedure, and it sustains weight reduction and results in the remission of obesity-associated comorbidities for obese individuals. However, patients who undergo this surgery may develop hypoglycemia. To date, the diagnosis is challenging and the prevalence of post-RYGB hypoglycemia (PRH) is unclear. RYGB alters the anatomy of the upper gastrointestinal tract and has a combined effect of caloric intake restriction and nutrient malabsorption. Nevertheless, the physiologic changes after RYGB are complex. Although hyperinsulinemia, incretin effects, dysfunction of β-cells and α-cells, and some other factors have been widely investigated and are reported to be possible mediators of PRH, the pathogenesis is still not completely understood. In light of the important role of the gut microbiome in metabolism, we hypothesized that the gut microbiome might also be a critical link between RYGB and hypoglycemia. In this review, we mainly highlight the current possible factors predisposing individuals to PRH, particularly related to the gut microbiota, which may yield significant insights into the intestinal regulation of glucose metabolic homeostasis and provide novel clues to improve the treatment of type 2 diabetes mellitus.