A New Light on Vitamin D in Obesity: A Novel Association with Trimethylamine-N-Oxide (TMAO)

Comparison of the role of vitamin D in normal organs and those affected by COVID-19

The outbreak of COVID-19 has opened up new avenues for exploring the importance of vitamin D in immunity, in addition to its role in calcium absorption. Recently, vitamin D supplementation has been found to enhance T regulatory lymphocytes, which are reduced in individuals with COVID-19. Increased risk of pneumonia and increases in inflammatory cytokines have been reported to be major threats associated with vitamin-D deficiency. Although vaccination reduces the threat of COVID-19 to a certain extent, herd immunity is the long-term solution to overcoming such diseases. Co-administration of vitamin D with certain inactivated vaccines has been reported to enhance the systemic immune response through stimulation of the production of antigen-specific mucosal immunity. COVID-19 was found to induce multiple organ damage, and vitamin D has a beneficial role in various organs, such as the intestines, pancreas, prostate, kidneys, liver, heart, brain, and immune cells. The consequences that occur after COVID-19 infection known as long COVID-19 are also a concern as they accumulate and target multiple organs, leading to immune dysregulation. The present review covers the overall role and impact of vitamin D and its deficiency for various organs in normal conditions and after COVID-19 infection, which is still a serious issue.

Circulating TMAO, the gut microbiome and cardiometabolic disease risk: an exploration in key precursor disorders

BACKGROUND

Elevations in the gut metabolite trimethylamine-N-oxide (TMAO) have been linked to cardiovascular and metabolic diseases. Whether elevated TMAO levels reflect early mechanistic involvement or a sequela of evolving disease awaits elucidation. The purpose of this study was to further explore these potential associations.

METHODS

We investigated relationships between circulating levels of TMAO and its pre-cursor substrates, dietary factors, gut microbiome profiles and disease risk in individuals with a Healthy BMI (18.5 < BMI < 25, n = 41) or key precursor states for cardiometabolic disease: Overweight (25 < BMI < 30 kg/m2, n = 33), Obese (BMI > 30, n = 27) and Metabolic Syndrome (MetS; ≥ 3 ATPIII report criteria, n = 39).

RESULTS

Unexpectedly, plasma [TMAO] did not vary substantially between groups (means of 3-4 µM; p > 0.05), although carnitine was elevated in participants with MetS. Gut microbial diversity and Firmicutes were also significantly reduced in the MetS group (p < 0.05). Exploratory analysis across diverse parameters reveals significant correlations between circulating [TMAO] and seafood intake (p = 0.007), gut microbial diversity (p = 0.017-0.048), and plasma [trimethylamine] (TMA; p = 0.001). No associations were evident with anthropometric parameters or cardiometabolic disease risk. Most variance in [TMAO] within and between groups remained unexplained.

CONCLUSIONS

Data indicate that circulating [TMAO] may be significantly linked to seafood intake, levels of TMA substrate and gut microbial diversity across healthy and early disease phenotypes. However, mean concentrations remain < 5 µM, with little evidence of links between TMAO and cardiometabolic disease risk. These observations suggest circulating TMAO may not participate mechanistically in cardiometabolic disease development, with later elevations likely a detrimental sequela of extant disease.

Vitamin D is involved in the effects of the intestinal flora and its related metabolite TMAO on perirenal fat and kidneys in mice with DKD

BACKGROUND

Vitamin D was shown to directly exert a protective effect on diabetic kidney disease (DKD) in our previous study. However, whether it has an effect on perirenal adipose tissue (PRAT) or the intestinal flora and its metabolites (trimethylamine N-oxide, TMAO) is unclear.

METHODS

DKD mice were received different concentrations of 1,25-(OH)2D3 for 2 weeks. Serum TNF-α levels and TMAO levels were detected. 16S rRNA sequencing was used to analyze gut microbiota. qPCR was used to detect the expression of TLR4, NF-Κb, PGC1α, and UCP-1 in kidney and adipose tissue. Histological changes in kidney and perirenal adipose tissue were observed using HE, PAS, Masson and oil red staining. Immunofluorescence and immunohistochemistry were used to detect the expression of VDR, PGC1α, podocin, and UCP-1 in kidney and adipose tissue. Electron microscopy was used to observe the pathological changes in the kidney. VDR knockout mice were constructed to observe the changes in the gut and adipose tissue, and immunofluorescence and immunohistochemistry were used to detect the expression of UCP-1 and collagen IV in the kidney.

RESULTS

1,25-(OH)2D3 could improve the dysbiosis of the intestinal flora of mice with DKD, increase the abundance of beneficial bacteria, decrease the abundance of harmful bacteria, reduce the pathological changes in the kidney, reduce fat infiltration, and downregulate the expression of TLR4 and NF-κB in kidneys. The serum TMAO concentration in mice with DKD was significantly higher than that of the control group, and was significantly positively correlated with the urine ACR. In addition, vitamin D stimulated the expression of the surface markers PGC1α, UCP-1 and VDR in the PRAT in DKD mice, and TMAO downregulated the expression of PRAT and renal VDR.

CONCLUSIONS

The protective effect of 1,25-(OH)2D3 in DKD mice may affect the intestinal flora and its related metabolite TMAO on perirenal fat and kidneys.

Research Progress on the Correlation Between Hypertension and Gut Microbiota

Among cardiovascular diseases, hypertension is the most important risk factor for morbidity and mortality worldwide, and its pathogenesis is complex, involving genetic, dietary and environmental factors. The characteristics of the gut microbiota can vary in response to increased blood pressure (BP) and influence the development and progression of hypertension. This paper describes five aspects of the relationship between hypertension and the gut microbiota, namely, the different types of gut microbiota, metabolites of the gut microbiota, sympathetic activation, gut-brain interactions, the effects of exercise and dietary patterns and the treatment of the gut microbiota through probiotics, faecal microbiota transplantation (FMT) and herbal remedies, providing new clues for the future prevention of hypertension. Diet, exercise and traditional Chinese medicine may contribute to long-term improvements in hypertension, although the effects of probiotics and FMT still need to be validated in large populations.

Interplay between metabolic dysfunction-associated fatty liver disease and renal function: An intriguing pediatric perspective

Over recent years, the nomenclature of non-alcoholic fatty liver disease has undergone significant changes. Indeed, in 2020, an expert consensus panel proposed the term "Metabolic (dysfunction) associated fatty liver disease" (MAFLD) to underscore the close association of fatty liver with metabolic abnormalities, thereby highlighting the cardiometabolic risks (such as metabolic syndrome, type 2 diabetes, insulin resistance, and cardiovascular disease) faced by these patients since childhood. More recently, this term has been further replaced with metabolic associated steatotic liver disease. It is worth noting that emerging evidence not only supports a close and independent association of MAFLD with chronic kidney disease in adults but also indicates its interplay with metabolic impairments. However, comparable pediatric data remain limited. Given the progressive and chronic nature of both diseases and their prognostic cardiometabolic implications, this editorial aims to provide a pediatric perspective on the intriguing relationship between MAFLD and renal function in childhood.

Dietary betaine and/or TMAO affect hepatic lipid accumulation and glycometabolism of Megalobrama amblycephala exposed to a high-carbohydrate diet

A 12-week experiment was conducted to explore the effects of betaine and/or TMAO on growth, hepatic health, gut microbiota, and serum metabolites in Megalobrama amblycephala fed with high-carbohydrate diets. The diets were as follows: CD group (control diet, 28.5% carbohydrate), HCD group (high-carbohydrate diet, 38.2% carbohydrate), HBD group (betaine-added diet, 38.3% carbohydrate + 1.2% betaine), HTD group (TMAO-added diet, 38.2% carbohydrate + 0.2% TMAO), and HBT group (diet added with both betaine and TMAO, 38.2% carbohydrate + 1.2% betaine + 0.2% TMAO). The results showed that the hepatosomatic index (HSI); whole-body crude fat; hepatic lipid accumulation; messenger RNA expression levels of gk, fpbase, g6pase, ahas, and bcat; serum branched-chain amino acids (BCAAs); ratio of Firmicutes-to-Bacteroidetes; and abundance of the genus Aeromonas were all significantly increased, while the abundance levels of the genus Lactobacillus and phyla Tenericutes and Bacteroidetes were drastically decreased in the HCD group. Compared with the HCD group, the HSI; whole-body crude fat; hepatic lipid accumulation; expression levels of fbpase, g6pase, pepck, ahas, and bcat; circulating BCAA; ratio of Firmicutes-to-Bacteroidetes; and abundance levels of the genus Aeromonas and phyla Tenericutes and Bacteroidetes were significantly downregulated in the HBD, HTD, and HBT groups. Meanwhile, the expression levels of pk were drastically upregulated in the HBD, HTD, and HBT groups as well as the abundance of Lactobacillus in the HBT group. These results indicated that the supplementation of betaine and/or TMAO in high-carbohydrate diets could affect the hepatic lipid accumulation and glycometabolism of M. amblycephala by promoting glycolysis, inhibiting gluconeogenesis and biosynthesis of BCAA, and mitigating the negative alteration of gut microbiota. Among them, the combination of betaine and TMAO had the best effect.

Connections between serum Trimethylamine N-Oxide (TMAO), a gut-derived metabolite, and vascular biomarkers evaluating arterial stiffness and subclinical atherosclerosis in children with obesity

Introduction

Childhood obesity leads to early subclinical atherosclerosis and arterial stiffness. Studying biomarkers like trimethylamine N-oxide (TMAO), linked to cardio-metabolic disorders in adults, is crucial to prevent long-term cardiovascular issues.

Methods

The study involved 70 children aged 4 to 18 (50 obese, 20 normal-weight). Clinical examination included BMI, waist measurements, puberty stage, the presence of acanthosis nigricans, and irregular menstrual cycles. Subclinical atherosclerosis was assessed by measuring the carotid intima-media thickness (CIMT), and the arterial stiffness was evaluated through surrogate markers like the pulse wave velocity (PWV), augmentation index (AIx), and peripheral and central blood pressures. The blood biomarkers included determining the values of TMAO, HOMA-IR, and other usual biomarkers investigating metabolism.

Results

The study detected significantly elevated levels of TMAO in obese children compared to controls. TMAO presented positive correlations to BMI, waist circumference and waist-to-height ratio and was also observed as an independent predictor of all three parameters. Significant correlations were observed between TMAO and vascular markers such as CIMT, PWV, and peripheral BP levels. TMAO independently predicts CIMT, PWV, peripheral BP, and central SBP levels, even after adding BMI, waist circumference, waist-to-height ratio, puberty development and age in the regression model. Obese children with high HOMA-IR presented a greater weight excess and significantly higher vascular markers, but TMAO levels did not differ significantly from the obese with HOMA-IR

Conclusion

Our study provides compelling evidence supporting the link between serum TMAO, obesity, and vascular damage in children. These findings highlight the importance of further research to unravel the underlying mechanisms of this connection.

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Key Words

• TMAO
• arterial stiffness
• atherosclerosis
• cardiovascular risk
• carotid intima-media thickness
• childhood obesity
• high blood pressure
• pulse wave velocity

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MESH Headings

• Adult
• Female
• Humans
• Child
• Pediatric Obesity/complications
• Carotid Intima-Media Thickness
• Vascular Stiffness/physiology
• Pulse Wave Analysis
• Acanthosis Nigricans
• Atherosclerosis/diagnosis
• Atherosclerosis/etiology
• Biomarkers

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Affiliation(s)

Monica Simina Mihuta Department of Doctoral Studies, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania Center of Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania
Corina Paul Department of Pediatrics, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania
Andreea Borlea Center of Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania 2nd Department of Internal Medicine, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania
Cristina Mihaela Roi Department of Doctoral Studies, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania Center of Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania
Denisa Pescari Department of Doctoral Studies, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania
Oana-Alexandra Velea-Barta 3rd Department of Odontotherapy and Endodontics, Faculty of Dental Medicine, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania
Ioana Mozos Department of Functional Sciences—Pathophysiology, Center for Translational Research and Systems Medicine, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania
Dana Stoian Center of Molecular Research in Nephrology and Vascular Disease, Faculty of Medicine, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania 2nd Department of Internal Medicine, Victor Babes University of Medicine and Pharmacy, Timisoara, Romania

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Gut microbiota in heart failure and related interventions

Heart failure (HF) is a sophisticated syndrome with structural or functional impairment of ventricular filling or ejection of blood, either causing symptoms and signs or being asymptomatic. HF is a major global health issue affecting about 64.3 million people worldwide. The gut microbiota refers to the complex ecosystem of microorganisms, mainly bacteria, in the gut. Studies have revealed that the gut microbiota is associated with many diseases ranging from neurodegenerative diseases to inflammatory bowel disease and cardiovascular diseases. The gut hypothesis of HF suggests that low cardiac output and systemic circulation congestion would cause insufficient intestinal perfusion, leading to ischemia and intestinal barrier dysfunction. The resulting bacterial translocation would contribute to inflammation. Recent studies have refined the hypothesis that changes of metabolites in the gut microbiota have a close relationship with HF. Thus, the gut microbiota has emerged as a potential therapeutic target for HF due to both its critical role in regulating host physiology and metabolism and its pivotal role in the development of HF. This review article aims to provide an overview of the current understanding of the gut microbiota's involvement in HF, including the introduction of the gut hypothesis of HF, its association with HF progression, the potential mechanisms involved mediated by the gut microbiota metabolites, and the impact of various interventions on the gut microbiota, including dietary interventions, probiotic therapy, fecal microbiota transplantation, antibiotics, and so on. While the gut hypothesis of HF is refined with up-to-date knowledge and the gut microbiota presents a promising target for HF therapy, further research is still needed to further understand the underlying mechanisms between gut microbiota and HF, the efficacy of these interventions, and contribute to the health of HF patients.

ZeXieYin Formula alleviates TMAO-induced cognitive impairment by restoring synaptic plasticity damage

ETHNOPHARMACOLOGICAL RELEVANCE

Treating cognitive impairment is a challenging and necessary research topic. ZeXieYin Formula (ZXYF), is a traditional herbal formula documented in the book of HuangDiNeiJing. Our previous studies demonstrated the ameliorative effects of ZXYF on atherosclerosis by reducing the plasma trimethylamine oxide (TMAO) level. TMAO is a metabolite of gut microorganisms, our recent research found that the increasing level of TMAO may have adverse effects on cognitive functions.

AIM OF THE STUDY

Our study mainly focused on the therapeutic effects of ZXYF on TMAO-induced cognitive impairment in mice and explored its underlying mechanism.

MATERIALS AND METHODS

After the TMAO-induced cognitive impairment mice models were established, we applied behavioral tests to estimate the learning and memory ability of the ZXYF intervention mice. Liquid chromatography-mass spectrometry (LC-MS) was used to quantify the TMAO levels in plasma and the brain. The effects of ZXYF on the hippocampal synaptic structure and the neurons were observed by transmission electron microscopy (TEM) and Nissl staining. In addition, western-blotting (WB) and immunohistochemical (IHC) staining were used to detect the level of related proteins in the synaptic structure and further verify the changes in synaptic plasticity and the mTOR pathway after ZXYF administration.

RESULTS

Behavioral tests showed that the learning and memory ability of mice impaired after a period of TMAO intervention and ZXYF could alleviate these changes. A series of results showed that ZXYF partly restored the damage of hippocampal synapse and neurons in TMAO-induced mice, at the same time, the expression of synapse-related proteins and mTOR pathway-related proteins were significantly regulated compared with the damage caused by TMAO.

CONCLUSION

ZXYF could alleviate TMAO-induced cognitive impairment by improving synaptic function, reducing neuronal damage, regulating synapse-associated proteins, and regulating the mTOR signaling pathway.

Vitamin C and vitamin D3 alleviate metabolic-associated fatty liver disease by regulating the gut microbiota and bile acid metabolism via the gut-liver axis

Background: Previous studies have demonstrated that both vitamin C (VC) and vitamin D3 (VD3) have therapeutic potential against metabolic disorders, including obesity, diabetes, and metabolic-associated fatty liver disease (MAFLD). However, it is unclear whether VC supplementation is associated with improving the intestinal flora and regulating the metabolism of bile acids via the gut-liver axis in MAFLD. There is still no direct comparison or combination study of these two vitamins on these effects.

Methods: In this study, we employed biochemical, histological, 16S rDNA-based microbiological, non-targeted liver metabolomic, and quantitative real-time polymerase chain reaction analyses to explore the intervening effect and mechanism of VC and VD3 on MAFLD by using a high-fat diet (HFD)-induced obese mouse model.

Results: Treatment of mice with VC and VD3 efficiently reversed the characteristics of MAFLD, such as obesity, dyslipidemia, insulin resistance, hepatic steatosis, and inflammation. VC and VD3 showed similar beneficial effects as mentioned above in HFD-induced obese mice. Interestingly, VC and VD3 reshaped the gut microbiota composition; improved gut barrier integrity; ameliorated oxidative stress and inflammation in the gut-liver axis; inhibited bile acid salt reflux-related ASBT; activated bile acid synthesis-related CYP7A1, bile acid receptor FXR, and bile acid transportation-related BSEP in the gut-liver axis; and improved bile secretion, thus decreasing the expression of FAS in the liver and efficiently ameliorating MAFLD in mice.

Conclusion: Together, the results indicate that the anti-MAFLD activities of VC and VD3 are linked to improved gut-liver interactions via regulation of the gut microbiota and bile acid metabolism, and they may therefore prove useful in treating MAFLD clinically.

Evening chronotype is associated with hormonal and metabolic disorders in polycystic ovary syndrome

Despite current treatments for polycystic ovary syndrome (PCOS), a considerable number of women with this syndrome do not reach the treatment goal, suggesting the presence of other probable misdiagnosed features of this syndrome that are not taken into account in the assessment and therefore in the therapeutical approach. The aim of this study was to investigate the prevalence of chronotype categories in women with PCOS and their role in determining hormonal and metabolic aspects of PCOS. This observational case-control study was conducted on 112 women with PCOS and 112 healthy women matched for age and body mass index (BMI). At baseline anthropometric parameters such as weight, height, BMI and waist circumference, clinical parameters such as Ferriman-Gallwey (FG) score, biochemical parameters such as fasting plasma glucose, insulin levels and assessment of the homeostasis model of insulin resistance (HoMA-IR), inflammatory parameters such as C-reactive protein (CRP) and hormonal parameters such as testosterone levels were evaluated. Women with PCOS had a lower chronotype score (p < .001) which indicates a higher prevalence of evening chronotype (EC) category (p = .037) compared to controls. After adjustment for BMI, chronotype score was significantly negatively correlated with CRP levels (r = -0.418, p < .001), testosterone levels (r = -0.543, p < .001) and FG score (r = -0.514, p < .001). Linear regression analysis showed that high testosterone levels were among the factors most associated with a lower chronotype score (p < .001), followed by BMI (p < .001) and HoMA-IR (p < .05). In conclusion, there is a higher prevalence of EC in women with PCOS than in women without the condition, which in turn was associated with a worse hormonal and metabolic profile. These findings provide support for the relevance of including chronotype assessment in the treatment of women with PCOS.

Contribution of Trimethylamine N-Oxide (TMAO) to Chronic Inflammatory and Degenerative Diseases

Trimethylamine N-oxide (TMAO) is a metabolite produced by the gut microbiota and has been mainly associated with an increased incidence of cardiovascular diseases (CVDs) in humans. There are factors that affect one's TMAO level, such as diet, drugs, age, and hormones, among others. Gut dysbiosis in the host has been studied recently as a new approach to understanding chronic inflammatory and degenerative diseases, including cardiovascular diseases, metabolic diseases, and Alzheimer's disease. These disease types as well as COVID-19 are known to modulate host immunity. Diabetic and obese patients have been observed to have an increase in their level of TMAO, which has a direct correlation with CVDs. This metabolite is attributed to enhancing the inflammatory pathways through cholesterol and bile acid dysregulation, promoting foam cell formation. Additionally, TMAO activates the transcription factor NF-κB, which, in turn, triggers cytokine production. The result can be an exaggerated inflammatory response capable of inducing endoplasmic reticulum stress, which is responsible for various diseases. Due to the deleterious effects that this metabolite causes in its host, it is important to search for new therapeutic agents that allow a reduction in the TMAO levels of patients and that, thus, allow patients to be able to avoid a severe cardiovascular event. The present review discussed the synthesis of TMAO and its contribution to the pathogenesis of various inflammatory diseases.

Serum Vitamin D Level and Gut Microbiota in Women

Obesity and vitamin D deficiency are two major public health concerns. Evidence suggests that alteration in gut microbiota composition is a possible risk factor for obesity. Additionally, altered vitamin D status has a potential role in shaping the gut microbial community. Further, the prevalence of obesity has been rising in the Middle East, especially among women of reproductive age, which is of specific concern due to its adverse effects on the health of their offspring. To date, limited evidence is available on the association between gut microbiota composition and vitamin D levels in Arab women. This study aims to identify the associations between serum vitamin D, gut microbiota, and obesity among Saudi females. The current study is a case-control study including 92 women aged 18 to 25 years, (n = 48) with normal weight and (n = 44) with obesity. Anthropometric, biochemical, lifestyle data, and fecal samples were collected and analyzed. We used shotgun metagenomic sequencing to characterize microbial communities of stool samples. Vitamin D levels were significantly associated with alpha and beta diversities. Serum vitamin D levels were positively associated with bacteria known to regulate immunological responses; Bacteroides thetaiotaomicron in the normal weight group (r = 0.34, p = 0.03) and Bifidobacterium adolescentis in the obesity group (r = 0.33, p = 0.04). In conclusion, the findings suggest that vitamin D status may play a role in regulating the gut microbiota composition by inhibiting the growth of pathogenic bacteria while nourishing the beneficial strains.

The modification of individual factors on association between serum 25(OH)D and incident type 2 diabetes: Results from a prospective cohort study

Several epidemiological studies have suggested an association between low vitamin D status and increased risk for type 2 diabetes (T2D). This study aimed to explore the dose-response relationship of serum 25-hydroxyvitamin D [25(OH)D] concentrations with incident T2D and the interaction between serum 25(OH)D with individual factors on T2D risk. A total of 1,926 adults without diabetes (mean age: 52.08 ± 13.82 years; 42% men) were prospectively followed for 36 months. Cox proportional hazards model and restricted cubic spline analysis were performed to assess the association and dose-response relationship between serum 25(OH)D and T2D incidence. Both additive and multiplicative interactions were calculated between serum 25(OH)D and individual factors. The net reclassification index (NRI) was used to evaluate the improvement of risk prediction of T2D by adding serum 25(OH)D to traditional risk factors. There were 114 new T2D cases over a mean follow-up of 36 months. Serum 25(OH)D was not associated with T2D incidence, and no significant dose-response relationship was found in the total population. However, stratified analyses suggested a non-linear inverse relationship among individuals with baseline fasting plasma glucose (FPG) <5.6 mmol/L (P _overall = 0.061, P _non-linear = 0.048). And a significant multiplicative interaction was observed between serum 25(OH)D and FPG on T2D risk (P = 0.005). In addition, we found a significant additive interaction of low serum 25(OH)D with older age (RERI = 0.897, 95% CI: 0.080-1.714; AP = 0.468, 95% CI: 0.054-0.881), male (AP = 0.441, 95% CI: 0.010-0.871), and insufficient physical activity (RERI = 0.875, 95% CI: 0.204-1.545; AP = 0.575, 95% CI: 0.039-1.111) on T2D risk. Significant additive interactions were also observed between vitamin D deficiency/insufficiency with male, overweight/obesity, and insufficient physical activity on T2D risk. Moreover, adding low serum 25(OH)D to a model containing established risk factors yielded significant improvements in the risk reclassification of T2D (NRI = 0.205, 95% CI: 0.019-0.391). Our results indicated a non-linear relationship of serum 25(OH)D concentrations with T2D risk among individuals with normal FPG and additive interactions of serum 25(OH)D with gender, overweight/obesity, and physical activity on T2D risk, suggesting the importance of outdoor exercise.

Mediterranean Diet and Obesity-related Disorders: What is the Evidence?

PURPOSE OF REVIEW

Obesity is a chronic disease, a major public health problem due to its association with non-communicable diseases and all-cause mortality. Indeed, people with obesity are at increased risk for a variety of obesity-related disorders including hypertension, dyslipidemia, type 2 diabetes mellitus, cardiovascular disease, and several cancers. Many popular diets with very different macronutrient composition, including the Mediterranean diet (MD), have been used, proposed, and studied for prevention and management of obesity. In particular, MD has been the subject of countless studies over the years and now boasts a large body of scientific literature. In this review, we aimed to update current knowledge by summarizing the most recent evidence on the effect of MD on obesity and obesity-related disorders.

RECENT FINDINGS

The negative effects of obesity are partly reversed by substantial weight loss that can be achieved with MD, especially when low-calorie and in combination with adequate physical activity. In addition, the composition of MD has been correlated with an excellent effect on reducing dyslipidemia. It also positively modulates the gut microbiota and immune system, significantly decreasing inflammatory mediators, a common ground for many obesity-related disorders. People with obesity are at increased risk for a variety of medical disorders including hypertension, dyslipidemia, type 2 diabetes mellitus, and cardiovascular disease. Therefore, there is an inevitable need for measures to manage obesity and its related disorders. At this point, MD has been proposed as a valuable nutritional intervention. It is characterized by a high consumption of vegetables, fruit, nuts, cereals, whole grains, and extra virgin olive oil, as well as a moderate consumption of fish and poultry, and a limited intake of sweets, red meat, and dairy products. MD proves to be the healthiest dietary pattern available to tackle obesity and prevent several non-communicable diseases, including cardiovascular disease and type 2 diabetes.

Cholecalciferol supplementation lowers leptin and TMAO but increases NO and VEGF-A levels in obese vitamin D deficient patients: Is it one of the potential cardioprotective mechanisms of vitamin D?

Background

Vitamin D deficiency is one of the most common health issues in developed countries. Obese patients are most at risk of having serum 25-hydroxyvitamin D₃ (25(OH)D₃) levels that are too low due to the accumulation of vitamin D in adipose tissue. While the effects of a deficiency on the skeletal or immune system are known, the effects on the cardiovascular system are not yet clear. Our study investigates the effect of cholecalciferol supplementation in obese patients on selected biomarkers associated with cardiovascular diseases (CVDs).

Methods

The study enrolled 33 obese patients with insufficient 25(OH)D₃ levels. For three months, the subjects supplemented with cholecalciferol at a dose of 2000 IU/day. Concentrations of nitric oxide (NO), vascular endothelial growth factor A (VEGF-A), leptin, trimethylamine N-oxide (TMAO) and soluble suppression of tumorigenicity 2 (sST2) were measured in baseline samples using ELISA (BioTek EPOCH). 25(OH)D₃ levels measured on Beckman Coulter DXI 800 by chemiluminescence method.

Results

After supplementation, 25(OH)D₃ levels increased significantly. Normal levels were achieved in most patients. A statistically significant reduction leptin and TMAO levels was observed. At the same time, NO and VEGF-A levels increased statistically significantly.

Conclusion

This study indicates that restoring normal 25(OH)D₃ levels in obese people reduces the concentration of pro-inflammatory factors associated with cardiovascular diseases. Reducing inflammation and the potential impact on vascular reactivity leads to the conclusion that cholecalciferol supplementation in obese patients may benefit the cardiovascular system.

Vitamin D: A Role Also in Long COVID-19?

Coronavirus disease 2019 (COVID-19) has quickly become a global pandemic. Reports from different parts of the world indicate that a significant proportion of people who have recovered from COVID-19 are suffering from various health problems collectively referred to as “long COVID-19”. Common symptoms include fatigue, shortness of breath, cough, joint pain, chest pain, muscle aches, headaches, and so on. Vitamin D is an immunomodulatory hormone with proven efficacy against various upper respiratory tract infections. Vitamin D can inhibit hyperinflammatory reactions and accelerate the healing process in the affected areas, especially in lung tissue. Moreover, vitamin D deficiency has been associated with the severity and mortality of COVID-19 cases, with a high prevalence of hypovitaminosis D found in patients with COVID-19 and acute respiratory failure. Thus, there are promising reasons to promote research into the effects of vitamin D supplementation in COVID-19 patients. However, no studies to date have found that vitamin D affects post-COVID-19 symptoms or biomarkers. Based on this scenario, this review aims to provide an up-to-date overview of the potential role of vitamin D in long COVID-19 and of the current literature on this topic.

Balancing the Equation: A Natural History of Trimethylamine and Trimethylamine-N-oxide

Trimethylamine (TMA) and its N-oxide (TMAO) are ubiquitous in prokaryote and eukaryote organisms as well as in the environment, reflecting their fundamental importance in evolutionary biology, and their diverse biochemical functions. Both metabolites have multiple biological roles including cell-signaling. Much attention has focused on the significance of serum and urinary TMAO in cardiovascular disease risk, yet this is only one of the many facets of a deeper TMA-TMAO partnership that reflects the significance of these metabolites in multiple biological processes spanning animals, plants, bacteria, and fungi. We report on analytical methods for measuring TMA and TMAO and attempt to critically synthesize and map the global functions of TMA and TMAO in a systems biology framework.

Chronotype: A Tool to Screen Eating Habits in Polycystic Ovary Syndrome?

Polycystic ovary syndrome (PCOS) is the most common endocrine disorders in women of reproductive age, whose lifestyle approach is an essential part of the treatment. Recently, chronotype, i.e., a trait that determines individual’s circadian preference in behavioral and biological rhythms, has been reported to play a role in determining nutrition preferences and the risk of developing chronic diseases. Thus, the aim of this study was to investigate if chronotype categories (morning, evening, and neither) could be used as tool to screen eating habits in women with PCOS. In this observational cross-sectional study, we assessed anthropometric measurements, lifestyle habits, chronotype categories, adherence to the Mediterranean Diet, dietary pattern, and metabolic parameters in 112 women with PCOS. Chronotype was classified as morning in 27.7%, evening in 42.9%, and neither in 29.5% of subjects. Women with PCOS with evening chronotype showed significantly higher percentages of grade I (p = 0.003) and grade II obesity (p = 0.001), did less regular exercise (p < 0.001), and most of them were smokers (p < 0.001) compared to those with neither and morning chronotypes. Women with PCOS with evening chronotype were significantly more insulin resistant (Homeostatic Model Assessment of Insulin Resistance (HoMA-IR) cut off > 2.5) than other two chronotypes (p < 0.001). Women with PCOS with evening chronotype had the lowest PREvención con DIetaMEDiterránea (PREDIMED) score, consumed more calories (p < 0.001), total (p < 0.001) and simple carbohydrates (p < 0.001), total fat (p < 0.001) and saturated fatty acids (p < 0.001), polyunsaturated fatty acids (p < 0.001) and n-6 polyunsaturated fatty acids (p < 0.001), and less fiber (p < 0.001) than women with PCOS with other chronotypes. In addition, women with PCOS with evening chronotype consumed less extra virgin olive oil (p = 0.001), legumes (p = 0.038), fish/seafood (p < 0.001), and tree nuts (p = 0.041) than women with PCOS of the other two chronotype categories and less red wine (p < 0.001) and more red/processed meat (p < 0.001) than women with PCOS with morning chronotype. In conclusion, in women with PCOS, evening chronotype has been associated with a most severe insulin resistance and unhealthiest eating habits. Thus, chronotype assessment could be an effective tool to screen the eating habits, and more generally the lifestyle, of women with PCOS.

"Forever young at the table": metabolic effects of eating speed in obesity

Background

Cardiometabolic diseases (CMD) are recognized as the main causes of morbidity and mortality in developed countries. In recent years eating speed (ES) has been of particular interest since some studies have associated it with the development of obesity and CMD. However, the different impact of the ES at which main meals are eaten on the risk of developing these diseases has not yet been identified. Thus, we aimed to investigate the effect of ES at the main meals (breakfast, lunch, and dinner) on the risk of developing cardiometabolic diseases (type 2 diabetes mellitus, dyslipidaemia and hypertension) in middle-aged Caucasian subjects with obesity.

Methods

For this purpose we carried out a cross-sectional, observational study. One hundred and eighty-seven middle-aged subjects aged 43.6 ± 16 years were enrolled of which anthropometric parameters and lifestyle habits were studied. A dietary interview was performed to collect information about meal duration and eating habits at the main meals. According to median value of meal duration, meals were classified in two groups: fast eating group (FEG) and slow eating group (SEG).

Results

The prevalence of dyslipidaemia was more than twice in FEG compared to SEG at lunch and dinner. For all main meals, FEG had a significantly higher risk of dyslipidaemia than SEG (p < 0.05) in unadjusted model. However, when the model was adjusted for age, BMI, physical activity, smoking and alcohol use and medication, the result remained significant for lunch and dinner (p < 0.05).

Conclusion

The results of our study suggest that fast eating increases at lunch and dinner increase the risk of developing dyslipidaemia in obesity.

Metabolically Healthy Obesity (MHO) vs. Metabolically Unhealthy Obesity (MUO) Phenotypes in PCOS: Association with Endocrine-Metabolic Profile, Adherence to the Mediterranean Diet, and Body Composition

Obesity and obesity-related low-grade inflammation are common findings in polycystic ovary syndrome (PCOS), the most common endocrine-metabolic disorder-affecting women in reproductive age. The terms metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO) have been introduced to define individuals with obesity in whom cardio-metabolic risk factors are absent or present, respectively. To date, evidence investigating differences in body composition and adherence to the Mediterranean diet (MD) between MHO and MUO-PCOS women are lacking. Aim of this study was to better characterize the determinants of the metabolic health status in PCOS patients with obesity according to MHO and MUO phenotypes by evaluating endocrine-metabolic profile, inflammatory status, adherence to the MD, and body composition. The study population consisted of 94 treatment-naïve women with PCOS and obesity (BMI = 38.23 ± 6.62 kg/m² and age = 24.12 ± 3.68 years). Compared PCOS MHO with PCOS MUO patients, the latter had higher levels of high-sensitivity C-reactive protein (hs-CRP) (p < 0.001), testosterone (p < 0.001), and insulin (p < 0.001), worse metabolic parameters, and higher Homeostatic Model Assessment of Insulin Resistance (HoMA-IR), Visceral Adiposity Index (VAI), and Fatty liver Index (FLI) (p < 0.001). Furthermore, PCOS MUO patients had lower adherence to the MD (p < 0.001) in spite of the same total energy intake (p = 0.102) as compared to PCOS MHO. The presence of MUO was associated with highest hs-CRP levels (OR = 1.49, p < 0.001), more severe hyperandrogenism and cardio-metabolic indices (p < 0.001). On the contrary, being PCOS MUO was associated with lower adherence to the MD (OR = 0.28, p < 0.001), and smaller PhAs (OR = 0.04, p < 0.001). Using a regression linear analysis model PREDIMED score entered at the first step (p < 0.001), followed by VAI (p < 0.001), and FLI (p = 0.032) in this analysis. At ROC analysis, a PREDIMED score of ≤4 (p < 0.001, AUC 0.926) could serve as a threshold for a significantly increased risk of presence the MUO-PCOS phenotype. To the best of our knowledge, this is the first study that characterized MHO and MUO-PCOS women on the basis of their adherence to the MD, body composition, and cardio-metabolic indices, providing evidence of the usefulness of adjunctive diagnostic parameters to better differentiate the MHO/MHO phenotypes in this cohort of PCOS patients with obesity.

Trimethylamine-N-Oxide Pathway: A Potential Target for the Treatment of MAFLD

Trimethylamine-N-oxide (TMAO) is a molecular metabolite derived from the gut flora, which has recently emerged as a candidate risk factor for metabolic dysfunction-associated fatty liver disease (MAFLD). TMAO is mainly derived from gut, where the gut microbiota converts TMA precursors into TMA, which is absorbed into the bloodstream through the intestinal mucosa, and then transformed into TMAO by hepatic flavin monooxygenases (FMOs) in the liver. High-nutrient diets rich in TMA precursors, such as red meat, eggs, and fish, are the main sources of TMAO. Excessively consuming such diets not only directly affects energy metabolism in liver, but also increases the concentration of TMAO in plasma, which promotes the development of MAFLD by affecting bile acid metabolism, unfolded protein response, and oxidative stress. In this review, we focused on the relationship between TMAO and MAFLD and summarized intervention strategies for reducing circulating TMAO concentration, aiming at providing new targets for the prevention and treatment of MAFLD.

Circulating trimethylamine-N-oxide is associated with all-cause mortality in subjects with nonalcoholic fatty liver disease

BACKGROUND AND AIMS

Trimethylamine-N-oxide (TMAO), a gut microbiota-liver metabolite, has been associated with cardiometabolic disease. However, whether TMAO is associated with nonalcoholic fatty liver disease (NAFLD) and NAFLD-related health outcomes remains unclear. We aimed to investigate the association of TMAO with NAFLD and to assess the extent to which the association of TMAO with all-cause mortality is dependent on the presence of NAFLD in the general population.

METHODS

We included 5292 participants enrolled in the Prevention of Renal and Vascular End-stage Disease (PREVEND) cohort study. Cox proportional-hazards regression analyses were performed to study the association of TMAO with all-cause mortality in subjects with and without a fatty liver index (FLI) ≥60, which was used as a proxy of NAFLD.

RESULTS

During a median follow-up of 8.2 years, 307 subjects died, of whom 133 were classified with NAFLD. TMAO was positively and independently associated with baseline FLI (Std β 0.08, 95% CI 0.05, 0.11, P < .001). Higher TMAO was associated with increased risk of all-cause mortality in subjects with NAFLD, in crude analysis (hazard ratio [HR] per 1 SD, 2.55, 95% CI 1.60, 4.05, P < .001) and after full adjustment (_adj HR 1.90, 95% CI 1.18, 3.04, P = .008). Such an association was not present in subjects without NAFLD (crude HR 1.14, 95% CI 0.81, 1.71, P = .39; _adj HR 0.95, 95% CI 0.65, 1.39, P = .78).

CONCLUSION

This prospective study revealed that plasma concentrations of TMAO were associated with all-cause mortality in subjects with NAFLD, independently of traditional risk factors.

Polycystic ovary syndrome and cardiovascular risk. Could trimethylamine N-oxide (TMAO) be a major player? A potential upgrade forward in the DOGMA theory

Several studies reported an increase in cardiovascular risk (CVR) in women with polycystic ovary syndrome (PCOS), considered primarily as the result of the combination of all the clinical features that characterize the syndrome, including hyperandrogenism, insulin resistance, diabetes, obesity chronic low-grade inflammation. Interestingly, in 2012 it has been proposed the so-called DOGMA theory, suggesting the pivotal role played by microbiota alteration in the development of PCOS. Subsequently, several authors evidenced the existence in PCOS women of a marked dysbiosis, which is related to the development of metabolic diseases and cardiovascular complications, mainly due to the production of bacteria-derived metabolites that interfere with various pathways. Among these, trimethylamine-N-oxide (TMAO) is emerging as one of the most important and studied microbiota-derived metabolites related to the increase in CVR, due to its pro-atherosclerotic effect. The purpose of the present review is to summarize the evidence in order to support the hypothesis that, in women with PCOS, dysbiosis might be further involved in enhancement of the CVR via contributing to the increase of circulating TMAO. Although no observational studies on a large number of patients directly investigated the serum levels of TMAO in PCOS women, this manuscript aimed to drive future studies in this field, concurring in providing a novel approach for both comprehension and treatment of the CVR in PCOS.

Relationship between 25 Hydroxyvitamin D, Overweight/Obesity Status, Pro-Inflammatory and Oxidative Stress Markers in Patients with Type 2 Diabetes: A Simplified Empirical Path Model

Vitamin D deficiency is highly prevalent in patients with overweight/obesity and type 2 diabetes (T2DM). Herein, we investigated the relationship between vitamin D status and overweight/obesity status, insulin resistance (IR), systemic inflammation as well as oxidative stress (OS). Anthropometric and laboratory assessments of 25-hydroxyvitamin D (25(OH)D) and glycemic, pro-inflammatory and OS biomarkers were performed in a sample of 47 patients with T2DM who were divided into categories based on overweight and degree of obesity. The main findings were: the overweight/obesity status correlated negatively with the degree of serum 25(OH)D deficiency (ρ = −0.27) with a trend towards statistical significance (p = 0.069); the homeostasis model assessment of insulin resistance (HOMA-IR) was significantly different (p = 0.024) in patients with 25(OH)D deficiency, as was total oxidant status (TOS) and oxidative stress index (OSI) in patients with severe serum 25(OH)D deficiency as compared to those with 25(OH)D over 20 ng/mL (TOS: p = 0.007, OSI: p = 0.008); and 25(OH)D had a negative indirect effect on TOS by body mass index (BMI), but BMI was not a significant mediator of the studied relationship. In a setting of overweight and increasing degree of obesity, patients with T2DM did not display decreasing values of 25(OH)D. Subjects with the lowest values of 25(OH)D presented the highest values of BMI. Patients with 25(OH)D deficiency were more insulin resistant and showed increased OS but no elevated systemic inflammation. The negative effect of 25(OH)D on TOS did not seem to involve BMI as a mediator.

Chronotype: what role in the context of gastroenteropancreatic neuroendocrine tumors?

BACKGROUND

Chronotype is defined as a trait determining the subject circadian preference in behavioral and biological rhythms relative to external light-dark cycle. Although individual differences in chronotype have been associated with an increased risk of developing some types of cancer, no studies have been carried out in gastroenteropancreatic neuroendocrine tumors (GEP-NET).

MATERIALS

We investigate the differences in chronotype between 109 GEP-NET and 109 healthy subjects, gender-, age-, and BMI-matched; and its correlation with tumor aggressiveness.

RESULTS

GEP-NET patients have a lower chronotype score (p = 0.035) and a higher percentage of evening chronotype (p = 0.003) than controls. GEP-NET patients with morning chronotype had lower BMI, waist circumference, and higher percentage of MetS (p < 0.001) than evening type. Interestingly, considering the clinical pathological characteristics, patients with the presence of metastasis, grading G2, and in progressive disease presented the lower chronotype score (p = 0.004, p < 0.001, and p = 0.002; respectively) compared to other categories. Chronotype score was negatively associated with anthropometric measurements, metabolic profile, percentage of MetS, and Ki67 index (p < 0.001 for all).

CONCLUSIONS

GEP-NET patients have an unhealthy metabolic profile and present more commonly an evening chronotype. These results support the importance of including the assessment of chronotype in an adjunctive tool for the prevention of metabolic alterations and tumor aggressiveness of GEP-NET.

Taurisolo®, a Grape Pomace Polyphenol Nutraceutical Reducing the Levels of Serum Biomarkers Associated With Atherosclerosis

Trimethylamine-N-oxide (TMAO) is a gut microbiota-derived metabolite recognized as strongly related to cardiovascular diseases (CVD), mainly increasing the risk of atherosclerosis development. Currently, no pharmacological approaches have been licensed for reduction of TMAO serum levels and conventional anti-atherosclerosis treatments only target the traditional risk factors, and the cardiovascular risk (CVR) still persist. This underlines the need to find novel targeted strategies for management of atherosclerosis. In this study we tested the ability of a novel nutraceutical formulation based on grape pomace polyphenols (Taurisolo®) in reducing both the serum levels of TMAO and oxidative stress-related biomarkers in humans (n = 213). After chronic treatment with Taurisolo® we observed significantly reduced levels of TMAO (−49.78 and −75.80%, after 4-week and 8-week treatment, respectively), oxidized LDL (oxLDL; −43.12 and −65.05%, after 4-week and 8-week treatment, respectively), and reactive oxygen species (D-ROMs; −34.37 and −49.68%, after 4-week and 8-week treatment, respectively). On the other hand, no significant changes were observed in control group. Such promising, the results observed allow indicating Taurisolo® as an effective nutraceutical strategy for prevention of atherosclerosis.

Clinical Trial Registration: This study is listed on the ISRCTN registry with ID ISRCTN10794277 (doi: 10.1186/ISRCTN10794277).

The neuroprotective effects of polyphenols, their role in innate immunity and the interplay with the microbiota

Neurodegenerative disorders, particularly in the elderly population, represent one of the most pressing social and health-care problems in the world. Besides the well-established role of both oxidative stress and inflammation, alterations of the immune response have been found to be closely linked to the development of neurodegenerative diseases. Interestingly, various scientific evidence reported that an altered gut microbiota composition may contribute to the development of neuroinflammatory disorders. This leads to the proposal of the concept of the gut-brain-immune axis. In this scenario, polyphenols play a pivotal role due to their ability to exert neuroprotective, immunomodulatory and microbiota-remodeling activities. In the present review, we summarized the available literature to provide a scientific evidence regarding this neuroprotective and immunomodulatory effects and the interaction with gut microbiota of polyphenols and, the main signaling pathways involved that can explain their potential therapeutic application in neurodegenerative diseases.

Association of Trimethylamine N-Oxide (TMAO) with the Clinical Severity of Hidradenitis Suppurativa (Acne Inversa)

In this case-control, cross-sectional, observational study, we evaluated circulating trimethylamine n-oxide (TMAO) levels, a gut-derived metabolite associated with inflammation and cardiometabolic risk, in patients with hidradenitis suppurativa (HS), a highly disabling inflammatory skin disease associated with an elevated prevalence of comorbidities, especially cardiovascular and metabolic diseases. In this study, we enrolled 35 naive-treatment patients with HS and 35 controls, matched for sex, age, and body mass index (BMI). HS Sartorius score was 49.0 (33.0–75.0), while according to the Harley system 12 and 23 patients presented grade 1 and grade 2 severity, respectively. HS patients had a lower adherence to the Mediterranean diet (MD) (p = 0.002), lower phase angle (PhA) (p < 0.001), and higher circulating TMAO levels (p < 0.001) than the control group. HS patients with grade 2 rather than grade 1 of Harley grade severity showed a higher BMI (p = 0.007), waist circumference (p = 0.016), total energy intake (p = 0.005), and lower PhA (p < 0.001) and adherence to the MD (p = 0.003). Of interest, patients with Hurley grade 2 of severity exhibited higher circulating TMAO levels (p < 0.001) compared to grade 1. Circulating TMAO levels showed a positive correlation with HS Sartorius score even after adjustment for confounding covariates, including BMI, waist circumference, adherence to the MD, total energy intake, and PhA (r = 0.570, p = 0.001). Using a linear regression model, circulating TMAO levels and PhA were the main predictors of the clinical severity of HS.

Association of the Chronotype Score with Circulating Trimethylamine N-Oxide (TMAO) Concentrations

Individual differences in the chronotype, an attitude that best expresses the individual circadian preference in behavioral and biological rhythms, have been associated with cardiometabolic risk and gut dysbiosis. Up to now, there are no studies evaluating the association between chronotypes and circulating TMAO concentrations, a predictor of cardiometabolic risk and a useful marker of gut dysbiosis. In this study population (147 females and 100 males), subjects with the morning chronotype had the lowest BMI and waist circumference (p < 0.001), and a better metabolic profile compared to the other chronotypes. In addition, the morning chronotype had the highest adherence to the Mediterranean diet (p < 0.001) and the lowest circulating TMAO concentrations (p < 0.001). After adjusting for BMI and adherence to the Mediterranean diet, the correlation between circulating TMAO concentrations and chronotype score was still kept (r = -0.627, p < 0.001). Using a linear regression analysis, higher chronotype scores were mostly associated with lower circulating TMAO concentrations (β = -0.479, t = -12.08, and p < 0.001). Using a restricted cubic spline analysis, we found that a chronotype score ≥59 (p < 0.001, R2 = -0.824) demonstrated a more significant inverse linear relationship with circulating TMAO concentrations compared with knots <59 (neither chronotype) and <41 (evening chronotype). The current study reported the first evidence that higher circulating TMAO concentrations were associated with the evening chronotype that, in turn, is usually linked to an unhealthy lifestyle mostly characterized by low adherence to the MD.

Phase angle and Mediterranean diet in patients with acne: Two easy tools for assessing the clinical severity of disease

BACKGROUND

Acne is a chronic, inflammatory and debilitating skin disorder. Dietary factors and nutritional status are among the exacerbating factors of acne. Phase angle (PhA), a direct measure of Bioelectrical Impedance Analysis (BIA), represents an indicator of the chronic inflammatory state. The Mediterranean diet (MD) is a healthy dietary pattern that can exert anti-inflammatory effects in several inflammatory diseases. We aimed to investigate the difference in PhA and adherence to the MD and their associations with the severity of acne in a sample of naïve treatment patients with acne compared to control group.

MATERIALS

In this cross-sectional, case-control, observational study, we enrolled 51 patients with acne and 51 control individuals. Body composition was evaluated by a BIA phase-sensitive system (50 kHz BIA 101 RJL, Akern Bioresearch, Florence, Italy, Akern). For adherence to the MD, we have used the PREvención con DIeta MEDiterránea (PREDIMED) questionnaire. The clinical severity of acne was assessed by using the global acne grading system (GAGS), a quantitative scoring system to assess acne severity.

RESULTS

Patients with acne had a worse body composition, in particular smaller PhA (p = 0.003), and a lower adherence to the MD (p < 0.001) than the control group, in spite of no differences in gender, age and BMI between the two groups. Stratifying patients with acne according to GAGS categories, both PhA (p = 0.006) and PREDIMED score (p = 0.007) decreased significantly in severe acne than mild/moderate acne. The GAGS score was negative correlations with PhA (r = - 0.478, p < 0.001) and PREDIMED score (r = - 0.504, p < 0.001). The results of the multivariate analysis showed PhA and PREDIMED score were the major determinants of GAGS score (p < 0.001). The receiver operator characteristic (ROC) analysis reporting a value of PhA of ≤ 6.1° and a PREDIMED score of ≤ 9 identified patients with acne with the highest clinical severity of the disease.

CONCLUSIONS

Novel correlations were reported between PhA and the degree of adherence to the MD with acne severity. Of interest, PhA and PREDIMED scores might represent possible markers of the severity of acne in a clinical setting. This study highlights how a cooperation between dermatologist and nutritionists might provide a combination key in the complex management of acne patients.

Phase Angle as an Easy Diagnostic Tool of Meta-Inflammation for the Nutritionist

Phase angle (PhA), a noninvasive bioimpedance marker, is a useful tool for nutritional screening in several diseases. C-reactive protein (CRP), a strong risk factor for metabolic and cardiovascular diseases, is a commonly used biomarker of meta-inflammation. As both PhA and CRP are influenced by age, BMI, and nutritional status, and exhibit a clear sex dimorphism, we examined the association between PhA and CRP levels in 1855 subjects (680 males and 1175 females), aged 18-59 years, with BMIs ranging from 19.5 to 69.4 kg/m², stratified according to sex. PhA values and CRP levels were significantly lower in females than males (p < 0.001), while the adherence to the Mediterranean diet (MD) was lower in males compared to females (p < 0.001). After adjusting for age, physical activity, BMI, waist circumference, and adherence to the MD, PhA remained negatively associated with CRP levels in both genders (p < 0.001). In the ROC analysis, PhA ≤ 5.5° in males and ≤5.4° in females were the threshold values predicting increased hs-CRP levels. These results suggested that PhA might represent a valid predictor of CRP levels in both sexes regardless of body weight and adherence to the MD, which avoids the collection of blood sampling and expensive biochemical assays.

Variations in biomarkers of dyslipidemia and dysbiosis during the menstrual cycle: a pilot study in healthy volunteers

BACKGROUND

Dyslipidemia in metabolic syndrome may introduce an underestimation of the risk for cardiovascular disease (CVD) using Low-Density Lipoprotein-Cholesterol (LDL-C) as a surrogate marker. Recently, non-High-Density Lipoprotein-Cholesterol (non-HDL-C), Apolipoprotein B (ApoB) and remnant-Cholesterol (remnant-C) have been suggested as better biomarkers for dyslipidemia. In addition, the microbial metabolites trimethylamine-N-oxide (TMAO), betaine and choline have been associated with CVD and suggested as markers for dysbiosis. There is a lack of knowledge on potential alterations in these biomarkers during the menstrual cycle. The aim of this single center, prospective non-interventional study, was to investigate variations in biomarkers of dyslipidemia and dysbiosis in healthy volunteers during the menstrual cycle.

METHOD

Serum samples were collected from 17 healthy, regularly menstruating women during two menstrual cycles, including the follicular, ovulatory and luteal phases. Levels of lipoproteins, lipoprotein ratios and microbial metabolites were analyzed in a total of 90 samples (30 complete menstrual cycles).

RESULTS

ApoB, ApoB/HDL and non-HDL-C/HDL ratios were significantly higher in the follicular phase compared to the ovulatory and luteal phases (p < 0.05). Remnant-C were higher during the luteal phase (p < 0.05). TMAO did not vary during the different phases and did not correlate with estrogen levels.

CONCLUSION

Our data support that biomarkers for dyslipidemia vary during the menstrual cycle. Thus, to avoid an underestimation of cardiovascular risk, sampling during the follicular phase, when levels of pro-atherogenic lipids are higher, may be considered.

Association of serum 25-hydroxy vitamin D with obesity-related indices in Chinese adults: A cross-sectional study

Obesity has been a well-known risk factor of low-level serum vitamin D. Compared with the traditional obesity-related indicator (body mass index, BMI), associations for two novel anthropometric indices, a body shape index (ABSI) and body roundness index (BRI) with vitamin D deficiency or insufficiency, still remain unclear. This study aimed to assess the associations of serum 25-hydroxy vitamin D (25(OH)D) status with these three obesity-related indices among Chinese adults. A total of 1666 individuals were included. Anthropometric measurements were performed to calculate the indices, and fasting blood was collected to determine serum 25(OH)D deficiency (<12 ng/ml) and insufficiency (12-20 ng/ml). Deficiency or insufficiency of 25(OH)D was found in 37.5% and 43.1% of the participants, respectively. After adjustment for potential confounders, a significantly increased prevalence of 25(OH)D deficiency was observed for higher ABSI (OR Q4 vs Q1 2.334, 95% CI 1.458-3.734; p trend = 0.002) and BRI (OR Q4 vs Q1 2. 215, 95%CI 1.365-3.594; p trend = 0.010), and for higher BMI in men. Regarding 25(OH)D insufficiency, a significant association was also found for ABSI (OR Q4 vs Q1 2.372, 95%CI 1.558-3.612; p trend = 0.001). The area under the ROC of ABSI (0.731, 95%CI 0.687-0.774) for predicting a low level of 25(OH)D was significantly larger than that of BMI (0.695, 95%CI 0.649-0.741) in men, but not in women. A positive association between obesity and lower 25(OH)D serum concentration was found among Chinese adults. Besides BMI, novel obesity-related indicator, ABSI and BRI were associated with lower serum 25(OH)D to some extent, and further studies are needed to clarify their potential to be used as screening tools in clinical practice.

Chronotype and cardio metabolic health in obesity: does nutrition matter?

The aim of the study was to investigate the association of chronotype categories with type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD) in 172 middle-aged adults (71.5% females; 51.8 ± 15.7 years). Anthropometric parameters, lifestyle habits, adherence to the Mediterranean Diet (MD), sleep quality, chronotype and the presence of T2DM and CVD were studied. Chronotype was classified as morning in 58.1% of subjects, evening in 12.8% and intermediate in 28.1%. Subjects with evening chronotype followed an unhealthier lifestyle than other chronotypes; indeed, they significantly performed less regular activity and were more frequently smokers. Furthermore, they had significantly higher risk to have T2DM [Odds Ratio (OR)=3.36 95% confidence interval (CI) 1.14-35.42; p = 0.03] and CVD [Odds Ratio (OR)= 5.89 95% CI 1.14-30.60; p = 0.035](CI) 2.24-407.54); p = 0.01] compared to morning chronotype after adjustment for gender, body mass index (BMI), sleep quality and adherence to the MD. The confidence intervals were wide, indicating that the sample size was too small. Thus, these data need to be replicated in a larger sample size. In addition, nutritional assessment was limited since only PREDIMED questionnaire was carried out. However, the main strengths of this study included a random sample and a population-based approach, although the cross-sectional design cannot establish causality. Although study population was unbalanced per gender and smoking and age group representing only middle-aged people,we adjusted the statistical analysis for potential confounding factors. In conclusion, the evening chronotype has an increased risk to be associated to T2DM and CVD.

High animal protein diet and gut microbiota in human health

The role of the intestinal flora in health and disease has become a research hotspot. Compared with carbohydrates and fats, proteins are metabolized primarily by microbial fermentation in the intestine. The production of protein fermentation products and metabolites depends on the composition, diversity, and metabolism of the gut microbiota. Several protein fermentation products, including indoles, phenols, polyamines, hydrogen sulfide (H₂S), amines, and carnitine, are toxic. This study analyzes the relationship between high-protein diets (HPDs), the intestinal microbiota, and human health and disease. Long-term HPDs increase the risk of intestinal diseases, type 2 diabetes (T2DM), obesity, central nervous system (CNS) diseases, and cardiovascular diseases (CVD) by producing toxic metabolites in the colon, including amines, H₂S, and ammonia. Short-term HPDs have little effect on the metabolism of healthy individuals under 65 years old. However, meeting the protein requirements of individuals over 65 years old using HPDs is more challenging. The adverse effects of HPDs on athletes are minimal. Natural compounds (plant extracts, whose main constituents are polysaccharides and polyphenols), prebiotics, probiotics, and regular physical exercise improve gut dysbiosis and reduce disease risk.

Use of dietary phytochemicals for inhibition of trimethylamine N-oxide formation

Trimethylamine-N-oxide (TMAO) has been reported as a risk factor for atherosclerosis development, as well as for other cardiovascular disease (CVD) pathologies. The objective of this review is to provide a useful summary on the use of phytochemicals as TMAO-reducing agents. This review discusses the main mechanisms by which TMAO promotes CVD, including the modulation of lipid and bile acid metabolism, and the promotion of endothelial dysfunction and oxidative stress. Current knowledge on the available strategies to reduce TMAO formation are discussed, highlighting the effect and potential of phytochemicals. Overall, phytochemicals (i.e., phenolic compounds or glucosinolates) reduce TMAO formation by modulating gut microbiota composition and/or function, inhibiting host's capacity to metabolize TMA to TMAO, or a combination of both. Perspectives for design of future studies involving phytochemicals as TMAO-reducing agents are discussed. Overall, the information provided by this review outlines the current state of the art of the role of phytochemicals as TMAO reducing agents, providing valuable insight to further advance in this field of study.

Can diet modulate trimethylamine N-oxide (TMAO) production? What do we know so far?

BACKGROUND

Trimethylamine N-oxide (TMAO) is a metabolite that has attracted attention due to its positive association with several chronic non-communicable diseases such as insulin resistance, atherosclerotic plaque formation, diabetes, cancer, heart failure, hypertension, chronic kidney disease, liver steatosis, cardiac fibrosis, endothelial injury, neural degeneration and Alzheimer's disease. TMAO production results from the fermentation by the gut microbiota of dietary nutrients such as choline and carnitine, which are transformed to trimethylamine (TMA) and converted into TMAO in the liver by flavin-containing monooxygenase 1 and 3 (FMO1 and FMO3). Considering that TMAO is involved in the development of many chronic diseases, strategies have been found to enhance a healthy gut microbiota. In this context, some studies have shown that nutrients and bioactive compounds from food can modulate the gut microbiota and possibly reduce TMAO production.

OBJECTIVE

This review has as main objective to discuss the studies that demonstrated the effects of food on the reduction of this harmful metabolite.

METHODS

All relevant articles until November 2020 were included. The articles were searched in Medline through PubMed.

RESULTS

Both the food is eaten acutely and chronically, by altering the nature of the gut microbiota, influencing colonic TMA production. Furthermore, hepatic production of TMAO by the flavin monooxygenases in the liver may also be influenced by phenolic compounds present in foods.

CONCLUSION

The evidence presented in this review shows that TMAO levels can be reduced by some bioactive compounds. However, it is crucial to notice that there is significant variation among the studies. Further clinical studies should be conducted to evaluate these dietary components' effectiveness, dose, and intervention time on TMAO levels and its precursors.

Cardio-Metabolic Indices and Metabolic Syndrome as Predictors of Clinical Severity of Gastroenteropancreatic Neuroendocrine Tumors

BACKGROUND

Obesity, mainly visceral obesity, and metabolic syndrome (MetS) are major risk factors for the development of type 2 diabetes, cardiovascular diseases, and cancer. Data analyzing the association of obesity and MetS with gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) are lacking. Fatty liver index (FLI) is a non-invasive tool for identifying individuals with non-alcoholic fatty liver disease (NAFLD). Visceral adiposity index (VAI) has been suggested as a gender-specific indicator of adipose dysfunction. Both indexes have been proposed as early predictors of MetS. This study aimed to investigate the association of FLI VAI as early predictors of MetS with gastroenteropancreatic neuroendocrine tumors (GEP-NETs).

METHODS

A cross-sectional, case-control, observational study was carried out at the ENETS Centers of Excellence Multidisciplinary Group for Neuroendocrine Tumors, University "Federico II". VAI and FLI were calculated.

RESULTS

We enrolled 109 patients with histologically confirmed G1/G2 GEP-NET (53 M; 57.06 ± 15.96 years), as well as 109 healthy subjects, age, sex- and body mass index-matched. Forty-four GEP-NET patients were G2, of which 21 were with progressive disease, and 27 patients had metastases. GEP-NET patients had a higher value of VAI (p < 0.001) and FLI (p = 0.049) and higher MetS presence (p < 0.001) compared with controls. VAI and FLI values and MetS presence were higher in G2 than in G1 patients (p < 0.001), in patients with progressive disease, and in metastatic vs non-metastatic patients (p < 0.001). In addition, higher values of VAI and FLI and higher MetS presence were significantly correlated with the worst clinical severity of NENs. The cut-off values for the FLI and MetS to predict high grading of GEP-NETs and the presence of metastasis were also provided.

CONCLUSIONS

This is the first study investigating an association between VAI and FLI as early predictors of MetS and GEP-NET. Our findings report that the worsening of clinicopathological characteristics in GEP-NET is associated with higher presence of MetS, NAFLD, evaluated by FLI, and visceral adiposity dysfunction, evaluated by VAI. Addressing the clinical evaluation of MetS presence, NAFLD, and visceral adiposity dysfunction might be of crucial relevance to establish targeted preventive and treatment interventions of NEN-related metabolic comorbidities.

Vitamin D in obesity and obesity-related diseases: an overview

Hypovitaminosis D and obesity represent two pandemic conditions sometimes associated with each other. Although it is known that there is a close relationship between these two health problems, the underlying pathophysiological mechanism has not yet been fully clarified. In fact, on the one hand, obesity per se seems to involve low circulating levels of vitamin D due to low sun exposure, physical activity, and intake of foods rich in vitamin D, volumetric dilution and sequestration in the adipose tissue. Conversely, since preadipocytes and adipocytes express the receptors and are involved in the metabolism of vitamin D it would seem that low levels of this vitamin may be involved in adipogenesis and therefore in the development of obesity. This connection is extremely important when considering obesity-related diseases. In fact, low vitamin D levels and severe obesity are significantly associated with some cardio-metabolic risk factors, including high Body Mass Index, waist circumference, blood pressure, impaired lipid and glycemic profile and insulin resistance, as they would seem associated with worse cardiovascular outcomes and higher cancer incidence and mortality. Therefore, the purpose of this review was to examine the recent evidence linking low vitamin D status, obesity and obesity-related diseases, highlighting the scientific achievements and the gaps to be filled with further investigations.

Microbial Metabolites: Critical Regulators in NAFLD

Non-alcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease throughout the world. The relationship between gut microbiota and NAFLD has been extensively investigated. The gut microbiota is involved in the regulation of NAFLD by participating in the fermentation of indigestible food, interacting with the intestinal mucosal immune system, and influencing the intestinal barrier function, leading to signaling alteration. Meanwhile, the microbial metabolites not only affect the signal transduction pathway in the gut but also reach the liver far away from gut. In this review, we focus on the effects of certain key microbial metabolites such as short-chain fatty acids, trimethylamine-N-oxide, bile acids, and endogenous ethanol and indole in NAFLD, and also summarize several potential therapies targeting the gut-liver axis and modulation of gut microbiota metabolites including antibiotics, prebiotics, probiotics, bile acid regulation, and fecal microbiota transplantation. Understanding the complex interactions between microbial metabolites and NAFLD may provide crucial insight into the pathogenesis and treatment of NAFLD.

Alisma orientalis Beverage Treats Atherosclerosis by Regulating Gut Microbiota in ApoE-/- Mice

Background

Alisma orientalis beverage (AOB) is a Chinese traditional medicine formulated with a diversity of medicinal plants and used for treating metabolic syndrome and atherosclerosis (AS) since time ago. Given the current limited biological research on AOB, the mechanism by which AOB treats AS is unknown. This study investigats the role of AOB-induced gut microbiota regulation in the expansion of AS.

Methods

We established an AS model in male apolipoprotein E-deficient (ApoE^−/−) mice that are fed with a high-fat diet (HFD), treated with numerous interventions, and evaluated the inflammatory cytokines and serum biochemical indices. The root of the aorta was stained with oil red O, and the proportion of the lesion area was quantified. Trimethylamine N-oxide (TMAO) and trimethylamine (TMA) levels in serum were evaluated through liquid chromatography with mass spectrometry. Flavin−containing monooxygenase 3 (FMO3) liver protein expression was assessed by Western blotting. 16S rDNA sequencing technique was adopted to establish the changes in the microbiota structure.

Results

After 8 weeks of HFD feeding, an inflammatory cytokine, and AS development expression were significantly decreased in mice treated with AOB; the same parameters in the mice treated with the antibiotics cocktail did not change. In the gut microbiota study, mice treated with AOB had a markedly different gut microbiota than the HFD-fed mice. Additionally, AOB also decreased serum TMAO and hepatic FMO3 expression.

Conclusion

The antiatherosclerotic effects of AOB were found associated with changes in the content of gut microbiota and a reduction in TMAO, a gut microbiota metabolite, suggesting that AOB has potential therapeutic value in the treatment of AS.

Mediterranean diet as tool to manage obesity in menopause: A narrative review

Menopause is a physiological event in a woman's life characterized by the cessation of spontaneous menstrual cycles caused by a reduction in the sex hormones estrogen and progesterone and a consequent increase of gonadotropins, which occurs when the stocks of ovarian follicles end. Weight gain is a common phenomenon in menopause and age of onset is influenced by several factors. Among modifiable risk factors are sedentary lifestyle and unhealthy nutritional patterns, which often result in obesity that in turn contributes to an increase in cardiovascular risk in menopause, mostly through low-grade inflammation. The Mediterranean diet (MedD) is a healthy dietary pattern characterized by an adequate consumption of vegetables, fruits, whole grains, and legumes with a reduction of saturated animal fats in favor of unsaturated vegetable fats and a high intake of bioactive compounds including polyphenols and ω-3 fatty acids with anti-inflammatory and antioxidant potency. Because of its palatability and long-term sustainability, the MedD, especially if hypocaloric, combined with physical activity, has shown promising results in terms of weight loss in individuals with obesity, as well as similar beneficial effects in menopause-related obesity. It has been observed that greater adherence to the MedD in menopause is associated with reduced risk for becoming overweight/obese, better cardiometabolic profile, and an improvement in menopausal symptoms. Although it is necessary to confirm these data with future large intervention trials, the MedD can be considered a safe and healthy approach in the management of menopause-related obesity and its cardiometabolic complications.

Does Sars-Cov-2 threaten our dreams? Effect of quarantine on sleep quality and body mass index

Background

COVID 19-related quarantine led to a sudden and radical lifestyle changes, in particular in eating habits. Objectives of the study were to investigate the effect of quarantine on sleep quality (SQ) and body mass index (BMI), and if change in SQ was related to working modalities.

Materials

We enrolled 121 adults (age 44.9 ± 13.3 years and 35.5% males). Anthropometric parameters, working modalities and physical activity were studied. Sleep quality was evaluated by the Pittsburgh Sleep Quality Index (PSQI) questionnaire. At baseline, the enrolled subjects were assessed in outpatient clinic and after 40 days of quarantine/lockdown by phone interview.

Results

Overall, 49.6% of the subjects were good sleepers (PSQI < 5) at the baseline and significantly decreased after quarantine (p < 0.001). In detail, sleep onset latency (p < 0.001), sleep efficiency (p = 0.03), sleep disturbances (p < 0.001), and daytime dysfunction (p < 0.001) significantly worsened. There was also a significant increase in BMI values in normal weight (p = 0.023), in subjects grade I (p = 0.027) and II obesity (p = 0.020). In all cohort, physical activity was significantly decreased (p = 0.004). However, analyzing the data according gender difference, males significantly decreased physical activity as well as females in which there was only a trend without reaching statistical significance (53.5% vs 25.6%; p = 0.015 and 50.0% vs 35.9%, p = 0.106; in males and females, respectively). In addition, smart working activity resulted in a significant worsening of SQ, particularly in males (p < 0.001).

Conclusions

Quarantine was associated to a worsening of SQ, particularly in males doing smart working, and to an increase in BMI values.

Nutrition and immune system: from the Mediterranean diet to dietary supplementary through the microbiota

The interaction between nutrition and the immune system is very complex. In particular, at every stage of the immune response, specific micronutrients, including vitamins and minerals play a key role and often synergistic, and the deficiency of only one essential nutrient may impair immunity. An individual's overall nutrition status and pattern of dietary intake (comprised of nutrients and non-nutritive bioactive compounds and food) and any supplementation with nutraceuticals including vitamins and minerals, can influence positively or negatively the function of the immune system. This influence can occur at various levels from the innate immune system and adaptive immune system to the microbiome. Although there are conflicting evidence, the current results point out that dietary supplementation with some nutrients such as vitamin D and zinc may modulate immune function. An update on the complex relationship between nutrition, diet, and the immune system through gut microbiota is the aim of this current review. Indeed, we will provide the overview of the link among immune function, nutrition and gut microbiota, paying particular attention at the effect of the Mediterranean diet on the immune system, and finally we will speculate the possible role of the main one functional supplements on immune function.

New-generation anti-obesity drugs: naltrexone/bupropion and liraglutide. An update for endocrinologists and nutritionists

The prevalence of obesity increases worldwide and has a significant economic impact on health care systems. A comprehensive program of lifestyle modification, including diet, exercise, and behavior therapy is considered the first option for achieving the significant weight loss. However, the intrinsic difficulties associated with maintenance of lifestyle changes contribute to the unsatisfactory long-term outcomes reported and weight regain in the obesity management. In this context, pharmacological approaches are useful to maximize non-pharmacological interventions in the long-term management of obesity. As add-on to lifestyle modification, pharmacological interventions are useful to facilitate clinically weight loss. In the past, anti-obesity drugs were limited. To date, the landscape has changed and naltrexone/bupropion and liraglutide have been recently added as new-generation anti-obesity drugs on obesity treatment and could represent important tools to manage of obesity. Liraglutide is a glucagon-like peptide 1 (GLP-1) receptor agonist that shares 97% homology to native GLP-1 with effects on the limbic system. The treatment with liraglutide 3.0 mg, in combination with a hypocaloric diet and increased physical activity, provides a clinically meaningful weight loss. The combination of naltrexone 32 mg and bupropion 360 mg acts on the mesolimbic reward pathway and the hypothalamic hunger system, two areas of the central nervous system. The combination of naltrexone/bupropion, an adjunct to a hypocaloric diet and increased physical activity, is approved for chronic weight management in adults with obesity or overweight and ≥1 weight-related comorbidity. In the present review, we have focused on the current evidence on two new-generation anti-obesity drugs, naltrexone/bupropion and liraglutide 3.0 mg addressing the main studies that investigated these two new drugs for obesity treatment. Furthermore, evidence on semaglutide, currently in the pipeline for potential future therapeutic use for weight loss, are reported.

Effect and mechanism of vitamin D on the development of colorectal cancer based on intestinal flora disorder

BACKGROUND

To investigate the correlation between the level of circulating vitamin D and the development of colorectal cancer (CRC) and to clarify the effect and mechanism of vitamin D on the development of CRC.

METHODS

Serum samples from 63 patients with CRC (CRC group) and 61 healthy volunteers (normal group) were collected. Azoxymethane + dextran sodium sulfate-induced CRC mouse model and dietary models with different doses of vitamin D were established to verify whether vitamin D supplementation could reverse the occurrence and development of CRC at the overall animal level. Intestinal barrier integrity and microbial defense response were evaluated by detection of intestinal flora and expression of related genes.

RESULTS

In the clinical serum samples, compared with the normal group, the level of 25 (OH) D3 in the CRC group was relatively low (P < 0.01), which was consistent with the clinical situation in mice. Vitamin D deficiency aggravated the deterioration of enteritis and intestinal cancer in CRC mice, whereas the overall condition of CRC mice improved after vitamin D supplementation. Vitamin D has a significant regulatory effect on the homeostasis of the intestinal flora, particularly in the regulation of intestinal probiotics, Akkermansia muciniphila-mediated colon barrier integrity.

CONCLUSIONS

Vitamin D deficiency is closely related to the high incidence of CRC, and vitamin D supplementation can inhibit the occurrence and development of CRC. Vitamin D plays a role in the reversal of CRC mainly through the regulation of intestinal flora, especially the regulation of A. muciniphila-mediated colon barrier integrity.

Influence of the Mediterranean Diet on 25- Hydroxyvitamin D Levels in Adults

The Mediterranean diet (MD) is a dietary pattern effective in terms of prevention of obesity-related diseases, and represents the gold standard in preventive medicine, due to the synergistic action of many nutrients with antioxidant and anti-inflammatory properties. In addition, excess body weight significantly increases the risk of hypovitaminosis D, a well-recognized common feature of individuals with obesity. It is well-known that there is a clear gender difference in the adherence to the MD. The aim of this study was to investigate the association between adherence to the MD and 25-hydroxyvitamin D (25OHD) levels in adults, according to gender. Study population consisted of 617 participants; 296 were males and 321 were females, matched by age and body mass index (BMI). A validated 14-item questionnaire PREDIMED (Prevención con dieta Mediterránea) was used for the assessment of adherence to the MD. The 25OHD levels were determined by a direct competitive chemiluminescence immunoassay. Females have a higher PREDIMED score than males (7.4 ± 2.8 vs. 6.7 ± 3.1 score, p = 0.001), and according to PREDIMED categories, a greater percentage of males had low adherence to the MD compared to their female counterparts (40.2% vs. 37.1%; χ² = 8.94, p = 0.003). The 25OHD levels were higher in males than in females (18.3 ± 7.3 vs. 16.8 ± 7.8 ng/mL, p = 0.01), and a higher percentage of males had sufficient 25OHD levels (>30 ng/mL) than their female counterparts (10.5% vs. 3.4%, χ² = 10.96, p < 0.001). Stratifying the sample population according to 25OHD categories, BMI decreased and PREDIMED score increased significantly along with the increased 25OHD levels, in both males and females, respectively (p < 0.001). Looking at the bivariate correlations, PREDIMED score was positively correlated with 25OHD levels after adjusting for age and BMI, in both males (r = 0.21, p < 0.001) and females (r = 0.30, p < 0.001). At the bivariate proportional odds ratio (OR) model, 25OHD levels presented the highest OR values in the category low adherence vs. high adherence to the MD, in both genders (OR 1.21 and OR 1.31, in males and females, respectively). Receiver operator characteristic (ROC) analysis was performed to determine the cut-off values of PREDIMED scores predictive of 25OHD levels: PREDIMED score >5 in males (p < 0.001) and >7 in females (p < 0.001) could serve as thresholds for 25OHD levels above the median. The results of our study highlighted a novel positive association between adherence to the MD and 25OHD levels in both genders. Although 25OHD levels were higher in males than females, 69.7% were deficient. To the best of our knowledge, this is the first study to show that high adherence to the MD is associated with low BMI and high 25OHD levels in both genders, probably through the anti-inflammatory and anti-oxidant effects that are synergistically exerted by either MD or vitamin D on body weight.

The Sun's Vitamin in Adult Patients Affected by Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a genetic disorder characterized by hyperphagia with progressive, severe obesity, and an increased risk of obesity-related comorbidities in adult life. Although low dietary vitamin D intake and low 25-hydroxy vitamin D (25OHD) levels are commonly reported in PWS in the context of bone metabolism, the association of low 25OHD levels with fat mass has not been extensively evaluated in PWS adults. The aims of this study were to investigate the following in PWS adults: (1) 25OHD levels and the dietary vitamin D intake; (2) associations among 25OHD levels with anthropometric measurements and fat mass; (3) specific cut-off values for body mass index (BMI) and fat mass predictive of the 25OHD levels. In this cross-sectional, single-center study we enrolled 30 participants, 15 PWS adults (age 19-41 years and 40% males) and 15 control subjects matched by age, sex, and BMI from the same geographical area (latitude 40° 49' N; elevation 17 m). Fat mass was assessed using a bioelectrical impedance analysis (BIA) phase-sensitive system. The 25OHD levels were determined by a direct competitive chemiluminescence immunoassay. Dietary vitamin D intake data was collected by three-day food records. The 25OHD levels in the PWS adults were constantly lower across all categories of BMI and fat mass compared with their obese counterpart. The 25OHD levels were negatively associated with BMI (p = 0.04), waist circumference (p = 0.03), fat mass (p = 0.04), and dietary vitamin D intake (p < 0.001). During multiple regression analysis, dietary vitamin D intake was entered at the first step (p < 0.001), thus explaining 84% of 25OHD level variability. The threshold values of BMI and fat mass predicting the lowest decrease in the 25OHD levels were found at BMI ≥ 42 kg/m2 (p = 0.01) and fat mass ≥ 42 Kg (p = 0.003). In conclusion, our data indicate that: (i) 25OHD levels and dietary vitamin D intake were lower in PWS adults than in the control, independent of body fat differences; (ii) 25OHD levels were inversely associated with BMI, waist circumference, and fat mass, but low dietary vitamin D intake was the major determinant of low vitamin D status in these patients; (iii) sample-specific cut-off values of BMI and fat mass might help to predict risks of the lowest 25OHD level decreases in PWS adults. The presence of trained nutritionists in the integrated care teams of PWS adults is strongly suggested in order to provide an accurate nutritional assessment and tailored vitamin D supplementations.

Microencapsulation as a tool to counteract the typical low bioavailability of polyphenols in the management of diabetes

Polyphenols are secondary metabolites widely distributed in many plant foods, such a tea, coffee, chocolate and fruits. The consumption of these compounds is related to the improvement or amelioration of many diseases, including diabetes. Nevertheless, the great barrier to the therapeutic use of polyphenols is the low bioavailability of these compounds once ingested. For that reason, the encapsulation of polyphenols in different matrices may protect them from digestion and improve their release and subsequent absorption to obtain target-specific health effects. Some studies have reported the beneficial effect of encapsulation to increase both bioavailability and bioaccessibility. However, these works have mostly been carried out in vitro and few studies are specifically addressed at improving diabetes. In the current work, an overview of the knowledge related to nanoparticles and their use in the diabetic condition has been reviewed.