Role of the gut in visceral fat inflammation and metabolic disorders

Prospects and challenges of tissue-derived extracellular vesicles

Extracellular vesicles (EVs) are considered a vital component of cell-to-cell communication and represent a new frontier in diagnostics and a means to identify pathways for therapeutic intervention. Recently, studies have revealed the importance of tissue-derived EVs (Ti-EVs), which are EVs present in the interstitial spaces between cells, as they better represent the underlying physiology of complex, multicellular tissue microenvironments in biology and disease. EVs are native, lipid bilayer membraned nano-sized particles produced by all cells that are packaged with varied functional biomolecules including proteins, lipids, and nucleic acids. They are implicated in short- and long-range cellular communication and may elicit functional responses in recipient cells. To date, studies have often utilized cultured cells or biological fluids as a source for EVs that do not capture local molecular signatures of the tissue microenvironment. Recent work utilizing Ti-EVs has elucidated novel biomarkers for disease and provided insights into disease mechanisms that may lead to the development of novel therapeutic agents. Still, there are considerable challenges facing current studies. This review explores the vast potential and unique challenges for Ti-EV research and provides considerations for future studies that seek to advance this exciting field.

Microbiome signatures associated with clinical stages of gastric Cancer: whole metagenome shotgun sequencing study

BACKGROUND

Gastric cancer is one of the global health concerns. A series of studies on the stomach have confirmed the role of the microbiome in shaping gastrointestinal diseases. Delineation of microbiome signatures to distinguish chronic gastritis from gastric cancer will provide a non-invasive preventative and treatment strategy. In this study, we performed whole metagenome shotgun sequencing of fecal samples to enhance the detection of rare bacterial species and increase genome sequence coverage. Additionally, we employed multiple bioinformatics approaches to investigate the potential targets of the microbiome as an indicator of differentiating gastric cancer from chronic gastritis.

RESULTS

A total of 65 patients were enrolled, comprising 33 individuals with chronic gastritis and 32 with gastric cancer. Within each group, the chronic gastritis group was sub-grouped into intestinal metaplasia (n = 15) and non-intestinal metaplasia (n = 18); the gastric cancer group, early stage (stages 1 and 2, n = 13) and late stage (stages 3 and 4, n = 19) cancer. No significant differences in alpha and beta diversities were detected among the patient groups. However, in a two-group univariate comparison, higher Fusobacteria abundance was identified in phylum; Fusobacteria presented higher abundance in gastric cancer (LDA scored 4.27, q = 0.041 in LEfSe). Age and sex-adjusted MaAsLin and Random Forest variable of importance (VIMP) analysis in species provided meaningful features; Bacteria_caccae was the most contributing species toward gastric cancer and late-stage cancer (beta:2.43, se:0.891, p:0.008, VIMP score:2.543). In contrast, Bifidobacterium_longum significantly contributed to chronic gastritis (beta:-1.8, se:0.699, p:0.009, VIMP score:1.988). Age, sex, and BMI-adjusted MasAsLin on metabolic pathway analysis showed that GLCMANNANAUT-PWY degradation was higher in gastric cancer and one of the contributing species was Fusobacterium_varium.

CONCLUSION

Microbiomes belonging to the pathogenic phylum Fusobacteria and species Bacteroides_caccae and Streptococcus_anginosus can be significant targets for monitoring the progression of gastric cancer. Whereas Bifidobacterium_longum and Lachnospiraceae_bacterium_5_1_63FAA might be protection biomarkers against gastric cancer.

The Association between Functional Dyspepsia and Metabolic Syndrome-The State of the Art

Functional dyspepsia is a common functional disorder of the gastrointestinal tract that is responsible for many primary care visits. No organic changes have been found to explain its symptoms. We hypothesize that modern lifestyles and environmental factors, especially psychological stress, play a crucial role in the high prevalence of functional dyspepsia and metabolic syndrome. While gastrointestinal tract diseases are rarely linked to metabolic disorders, chronic stress, obesity-related metabolic syndrome, chronic inflammation, intestinal dysbiosis, and functional dyspepsia have significant pathophysiological associations. Functional dyspepsia, often associated with anxiety and chronic psychological stress, can activate the neuroendocrine stress axis and immune system, leading to unhealthy habits that contribute to obesity. Additionally, intestinal dysbiosis, which is commonly present in functional dyspepsia, can exacerbate systemic inflammation and obesity, further promoting metabolic syndrome-related disorders. It is worth noting that the reverse is also true: obesity-related metabolic syndrome can worsen functional dyspepsia and its associated symptoms by triggering systemic inflammation and intestinal dysbiosis, as well as negative emotions (depression) through the brain-gut axis. To understand the pathophysiology and deliver an effective treatment strategy for these two difficult-to-cure disorders, which are challenging for both caregivers and patients, a psychosocial paradigm is essential.

Endotoxin biomarkers, hepatic fat fraction, liver volume and liver stiffness among adolescents at high-risk for non-alcoholic fatty liver disease: The HEROES study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is on the rise among youth. Identifying biomarkers of NAFLD progression/risk can aid in prevention efforts.

AIMS

This pilot study investigated associations of two endotoxin biomarkers-lipopolysaccharide-binding protein (LBP) and anti-endotoxin core immunoglobulin G (EndoCab)-with markers of NAFLD among 99 Latino/Latina adolescents (11-19 years) with obesity.

MATERIALS & METHODS

We used linear regression to examine associations of each endotoxin biomarker (per 1-SD) with hepatic fat fraction (HFF), liver volume, and liver stiffness.

RESULTS

We found positive associations of LBP with HFF and liver volume. Each 1-SD increment in LBP corresponded with 2.35% (95% CI: 0.46%, 4.23%) higher HFF and 0.14 (0.06, 0.23) L greater liver volume after adjusting for age, sex, and maternal education. Accounting for abdominal adiposity and Tanner stage did not change results. Excluding 72 participants with NAFLD attenuated associations of LBP with HFF but associations with liver volume persisted (0.11 [0.01, 0.21] L). EndoCab was not associated with any liver outcomes. Neither endotoxin biomarker predicted liver stiffness.

DISCUSSION/CONCLUSION

While additional research is warranted, our results support LBP as a biomarker of NAFLD risk/progression in high-risk youth.

Effect of Probiotic Supplementation on Intestinal Permeability in Overweight and Obesity: A Systematic Review of Randomized Controlled Trials and Animal Studies

Overweight and obesity are associated with increased intestinal permeability, characterized by loss of gut epithelial integrity, resulting in unregulated passage of lipopolysaccharide (LPS) and other inflammatory triggers into circulation, i.e., metabolic endotoxemia. In obesity, shifts in the gut microbiome negatively impact intestinal permeability. Probiotics are an intervention that can target the gut microbiome by introducing beneficial microbial species, potentially restoring gut barrier integrity. Currently, the role of probiotic supplementation in ameliorating obesity- and overweight-associated increases in gut permeability has not been reviewed. This systematic review aimed to summarize findings from both animal and clinical studies that evaluated the effect of probiotic supplementation on obesity-induced impairment in intestinal permeability (International Prospective Register of Systematic Reviews, CRD42022363538). A literature search was conducted using PubMed (Medline), Web of Science, and CAB Direct from origin until August 2023 using keywords of intestinal permeability, overweight or obesity, and probiotic supplementation. Of 920 records, 26 eligible records were included, comprising 12 animal and 14 clinical studies. Clinical trials ranged from 3 to 26 wk and were mostly parallel-arm (n = 13) or crossover (n = 1) design. In both animal and clinical studies, plasma/serum LPS was the most common measure of intestinal permeability. Eleven of 12 animal studies reported a positive effect of probiotic supplementation in reducing intestinal permeability. However, results from clinical trials were inconsistent, with half reporting reductions in serum LPS and half reporting no differences after probiotic supplementation. Bifidobacterium, Lactobacillus, and Akkermansia emerged as the most common genera in probiotic formulations among the animal and clinical studies that yielded positive results, suggesting that specific bacteria may be more effective at reducing intestinal permeability and improving gut barrier function. However, better standardization of strain use, dosage, duration, and the delivery matrix is needed to fully understand the probiotic impact on intestinal permeability in individuals with overweight and obesity.

Effects of the abdominal fat distribution on the relationship between exposure to air pollutants and thyroid hormones among Korean adult males

BACKGROUND

Several significant associations between air pollution and thyroid function have been reported, but few studies have identified whether these associations differ by obesity, particularly its regional distribution. We assessed the relationship between ambient air pollution and thyroid hormone, and whether this relationship is modified by abdominal adiposity, as indicated by the waist circumference, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and visceral-to-subcutaneous fat ratio (VSR) in Korean men.

METHODS

We included 2440 male adults in the final analysis and used each person's annual average exposure to four air pollutants: particulate matter with an aerodynamic diameter ≤ 10 μm (PM10), nitrogen dioxide, sulfur dioxide (SO2), and carbon monoxide (CO). Abdominal fat deposition was quantified by computed tomography. Serum thyrotropin (TSH) and free thyroxine (FT4) concentrations were measured for thyroid hormone. To evaluate the relationship between air pollution and thyroid hormone according to adiposity, we performed multiple linear regression analysis on the two subgroups stratified by abdominal fat level.

RESULTS

Abdominal adiposity was significantly related to FT4 concentration. The exposures to air pollutants were associated with increased TSH and decreased FT4 concentrations. In stratified analysis using abdominal fat traits, ambient air pollution except for SO2 was significantly related to increased TSH and decreased FT4 concentrations in the high adiposity group (all p < 0.05), but not in the normal adiposity group. Among the air pollutants, PM10 showed an association with an increase of TSH concentration in all group with high adiposity, including high VAT, high SAT, and high VSR groups (all p < 0.05). In case of FT4, CO showed a similar pattern. Among the abdominal fat-related traits, the VSR in the high adiposity group had the largest effect on the relationship between exposure to air pollutants and thyroid hormone.

CONCLUSIONS

This study suggests the first clue that the relationship between air pollution exposure and thyroid hormone differs according to abdominal fat distribution among Korean adult males.

Correlation Between Allergic Rhinitis and Body Mass Index: An Observational Study

Allergic rhinitis is one of the most rampant diseases in the world and many studies have been conducted to find its risk factors. Various studies have shown that there is a correlation between allergic rhinitis and increased Body Mass Index (BMI). Obesity has several effects on the immune system that could play a major role in increasing allergic disease. Allergic rhinitis is known to produce mild eosinophilia. The purpose of this study is to assess the correlation between BMI and allergic rhinitis using the Absolute Eosinophil Count (AEC). Over a period of 6 months, 55 cases of allergic rhinitis were selected. The patients were investigated by Absolute Eosinophil Count and their Body Mass Index values were calculated based on weight and height measurement. There was a positive correlation between Absolute Eosinophil Count and BMI with a p value of < 0.0001 which in turn revealed a positive correlation between BMI and allergy. We conclude that patients with high BMI are more prone to allergic rhinitis and have higher Absolute Eosinophil Counts probably due to the immunological effects of adipose tissue on the progress of the allergic disease.

Associations between ambient air pollution, obesity, and serum vitamin D status in the general population of Korean adults

Background

Although a growing body of evidence suggests air pollution is associated with low serum vitamin D status, few studies have reported whether obesity status affects this relationship. The aim of this study was to identify associations between ambient air pollution exposure, obesity, and serum vitamin D status in the general population of South Korea.

Methods

This study was conducted in a cross-sectional design. A total of 30,242 Korean adults from a nationwide general population survey were included for our final analysis. Air pollutants included particulate matter with an aerodynamic diameter ≤ 10 μm (PM₁₀), nitrogen dioxide (NO₂), and carbon monoxide (CO). We measured serum 25-hydroxyvitamin D concentration to assess vitamin D status for each participant. Multiple linear and logistic regression analyses were performed to identify associations between ambient air pollution and vitamin D status in each subgroup according to body mass index level.

Results

The annual average concentrations of PM₁₀, NO₂, and CO were significantly associated with a lower serum vitamin D concentration and higher risk of vitamin D deficiency. The results show a significant association between serum vitamin D status and PM₁₀ exposure in obese subgroup. Based on the gender, females with obesity showed more strong association (negative) between different air pollutants and low serum vitamin D concentration and a higher risk of vitamin D deficiency. However, this pattern was not observed in men.

Conclusions

This study provides the first evidence that women with obesity may be more vulnerable to vitamin D deficiency in the context of persistent exposure to air pollution.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14164-y.

GDF15 and Cortisol Response to Meal Tolerance Test in Post-Sleeve Gastrectomy Patients with Weight Regain

BACKGROUND

Hormonal factors behind weight regain (WR) after surgical weight loss remain inadequately understood. Growth/differentiation factor 15 (GDF15) has emerged as a potential therapeutic target in obesity treatment. Cortisol, another stress hormone, has also been associated with weight gain at both low and high circulating concentrations. We aimed to compare meal-stimulated GDF15 and cortisol response in adults with and without WR after sleeve gastrectomy (SG). We hypothesized that GDF15 and cortisol response to meal tolerance test (MTT) will be lower in those with versus without WR after SG.

METHODS

Cross-sectional study comprised 21 adults without diabetes, who underwent SG. WR was defined as 100 × (current weight - nadir)/(preoperative weight - nadir) > 10%. GDF15, cortisol, insulin, glucose, and incretins (total glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic polypeptide (GIP) circulating concentrations) were measured during MTT (0-240 min) after 3-6 years post-bariatric surgery.

RESULTS

All participants were 48% White, 85% female, with mean (SD) age: 43(10) years, and BMI: 36.2(7.6) kg/m². Compared to the non-WR group (n = 6), the WR group (n = 15) had significantly higher BMI (WR: 38.6 ± 7.6 kg/m², non-WR: 30.3 ± 3.5 kg/m², p = 0.02) and showed lower GDF15 response (WR AUC vs non-WR AUC (116143 ± 13973 vs 185798 ± 38884 ng*min/L, p = 0.047)) and lower cortisol response (WR AUC vs non-WR AUC (3492 ± 210 vs 4880 ± 655 µg*min/dL, p = 0.015)). Incretin response did not differ between the groups.

CONCLUSIONS

GDF15 and cortisol responses to MTT were lower in those who regained the weight after SG compared to those who did not, suggesting that dysregulation in GDF15 and cortisol response following bariatric surgery.

Endotoxin Biomarkers Are Associated With Adiposity and Cardiometabolic Risk Across 6 Years of Follow-up in Youth

CONTEXT

Metabolic endotoxemia may be a shared mechanism underlying childhood obesity and early-onset metabolic diseases (eg, type 2 diabetes, nonalcoholic fatty liver disease).

OBJECTIVE

Examine prospective associations of serum endotoxin biomarkers lipopolysaccharide (LPS) and its binding protein, LPS binding protein (LBP), and anti-endotoxin core immunoglobulin G (EndoCab IgG) with adiposity and cardiometabolic risk in youth.

DESIGN/SETTING

This prospective study included 393 youth in the Exploring Perinatal Outcomes Among Children cohort in Colorado. Participants were recruited from 2006 to 2009 at age 10 years (baseline) and followed for 6 years (follow-up). We examined associations of endotoxin biomarkers at baseline with adiposity [body mass index (BMI) z-score, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), skinfolds, waist circumference] and cardiometabolic risk (insulin, glucose, adipokines, lipid profile, blood pressure) across both visits using mixed-effects regression, and with hepatic fat fraction (HFF) at follow-up using linear regression.

RESULTS

Higher LPS and LBP predicted greater adiposity across follow-up. Each 1-unit log-transformed LPS corresponded with 0.23 (95% CI 0.03, 0.43) units BMI z-score, 5.66 (95% CI 1.99, 9.33) mm3 VAT, 30.7 (95% CI 8.0, 53.3) mm3 SAT, and 8.26 (95% CI 4.13, 12.40) mm skinfold sum. EndoCab IgG was associated with VAT only [3.03 (95% CI 0.34, 5.71) mm3]. LPS was associated with higher insulin [1.93 (95% CI 0.08, 3.70) µU/mL] and leptin [2.28 (95% CI 0.66, 3.90) ng/mL] and an adverse lipid profile. No association was observed with HFF. Accounting for pubertal status and lifestyle behaviors did not change findings. However, adjustment for prepregnancy BMI and gestational diabetes attenuated most associations.

CONCLUSIONS

Serum endotoxin may be a marker of pathophysiological processes underlying development of childhood obesity and cardiometabolic conditions associated with exposure to fetal overnutrition.

Physical activity and childhood asthma control: Mediation and moderation role of body mass index

BACKGROUND

Physical activity (PA) may be associated with asthma management. Whether PA is associated with childhood asthma control is not well studied, and the role of body mass index (BMI) in this association remains unclarified. This study aimed to evaluate the association between PA and childhood asthma control and investigate the potential mediating and modifying role of BMI in the association.

METHODS

This cross-sectional study involved 303 asthmatic children aged 5-14 years. Information on PA was collected from children. Asthma control was assessed using a valid questionnaire by children and their parents. Height and weight were objectively measured and BMI was calculated and classified. Multiple linear regression, mediation, and moderation analyses were performed.

RESULTS

There was a positive association between PA and childhood asthma control with adjustment for variates (B = 0.144, p = .012). Mediation analysis indicated that BMI status negatively mediated the association (estimate = -0.656, 95% credit interval: -1.645, -0.006), and such indirect effect is lower than the direct effect (indirect effect/direct effect = 58.3%). No evidence of effect modification by BMI was observed (P_interaction = 0.516). Stratified analyses showed that the significant association was only observed in children with overweight/obesity (normal weight: B = 0.863, p = .189; overweight/obese: B = 1.494, p = .044).

CONCLUSIONS

Increased PA is associated with improved childhood asthma control, especially for children with higher BMI. BMI exhibited a negative effect but not effect modification in this association. PA should be encouraged to improve asthma control for asthmatic children. Besides, mechanisms other than weight loss may explain the association.

Maturation of the Visceral (Gut-Adipose-Liver) Network in Response to the Weaning Reaction versus Adult Age and Impact of Maternal High-Fat Diet

Metabolic-associated fatty liver disease is a major cause of chronic pathologies, of which maternal obesity is a frequent risk factor. Gut wall and microbiota, visceral fat, and liver form a pre-systemic network for substrates and pro-inflammatory factors entering the body, undergoing accelerated maturation in early-life when the weaning reaction, i.e., a transitory inflammatory condition, affects lifelong health. We aimed to characterize organ metabolism in the above network, in relation to weaning reaction and maternal obesity. Weaning or 6-months-old offspring of high-fat-diet and normal-diet fed dams underwent in vivo imaging of pre-/post-systemic glucose uptake and tissue radiodensity in the liver, visceral fat, and intestine, a liver histology, and microbiota and metabolic pathway analyses. Weaning mice showed the dominance of gut Clostridia and Bacteroidia members, overexpressing pathways of tissue replication and inflammation; adulthood increased proneness to steatohepatitis, and Desulfovibrio and RF39 bacteria, and lipopolysaccharide, bile acid, glycosaminoglycan, and sphingolipid metabolic pathways. In vivo imaging could track organ maturation, liver inflammation, and protective responses. A maternal high-fat diet amplified the weaning reaction, elevating liver glucose uptake, triglyceride levels, and steatohepatitis susceptibility along the lifespan. The visceral network establishes a balance between metabolism and inflammation, with clear imaging biomarkers, and crucial modulation in the weaning time window.

Dairy consumption and subclinical atherosclerosis: A cross-sectional study among middle-aged Mexican women

BACKGROUND AND AIMS

Many dietary guidelines encourage low-fat dairy products; however, recent studies have found null and inverse associations between high-fat dairy intake and cardiovascular disease (CVD) risk. We examined the association between the intake of total dairy and different types of dairy and carotid intima-media thickness (IMT), a marker of subclinical atherosclerosis, in Mexican women.

METHODS AND RESULTS

Dairy consumption was assessed using a validated food-frequency questionnaire (FFQ) in 1759 women in the Mexican Teachers' Cohort (MTC) study who were free of CVD or cancer. We categorized participants according to total dairy intake and consumption of four mutually exclusive dairy groups: high-fat, low-fat, yogurt, and dairy with added sugars. IMT and atherosclerotic plaque were measured by B-mode ultrasonography. Subclinical atherosclerosis was defined as an IMT ≥0.8 mm and/or the presence of plaque. Multivariable linear regression and logistic regression models were used to respectively assess the mean percentage difference of mean IMT and odds ratios (OR) for subclinical atherosclerosis across quantiles of dairy consumption. Mean (±SD) age was 45.4 ± 5.0 years and the median (interquartile range: IQR) total dairy consumption was 11.0 (6.6, 17.1) servings/week. After adjusting for lifestyle, clinical, and dietary factors, comparing the highest category of consumption, to the lowest, total dairy was associated with increased IMT (2.6%, 95% confidence interval (CI): 0.6, 4.3; p-trend<0.01). Moreover, yogurt consumption was associated with lower odds of subclinical atherosclerosis (OR = 0.65, 95% CI: 0.47, 0.91; p-trend = 0.01).

CONCLUSIONS

While total dairy consumption was associated with carotid wall thickening, yogurt consumption was related to lower subclinical atherosclerosis.

Potential of Nutraceutical Supplementation in the Modulation of White and Brown Fat Tissues in Obesity-Associated Disorders: Role of Inflammatory Signalling

The high incidence of obesity is associated with an increasing risk of several chronic diseases such as cardiovascular disease, type 2 diabetes and non-alcoholic fatty liver disease (NAFLD). Sustained obesity is characterized by a chronic and unsolved inflammation of adipose tissue, which leads to a greater expression of proinflammatory adipokines, excessive lipid storage and adipogenesis. The purpose of this review is to clarify how inflammatory mediators act during adipose tissue dysfunction in the development of insulin resistance and all obesity-associated diseases. In particular, we focused our attention on the role of inflammatory signaling in brown adipose tissue (BAT) thermogenic activity and the browning of white adipose tissue (WAT), which represent a relevant component of adipose alterations during obesity. Furthermore, we reported the most recent evidence in the literature on nutraceutical supplementation in the management of the adipose inflammatory state, and in particular on their potential effect on common inflammatory mediators and pathways, responsible for WAT and BAT dysfunction. Although further research is needed to demonstrate that targeting pro-inflammatory mediators improves adipose tissue dysfunction and activates thermogenesis in BAT and WAT browning during obesity, polyphenols supplementation could represent an innovative therapeutic strategy to prevent progression of obesity and obesity-related metabolic diseases.

Interaction between visceral adiposity and ambient air pollution on LDL cholesterol level in Korean adults

BACKGROUND

Although previous reports have found that obesity intensifies the negative impact of long-term air pollution exposure on the low-density lipoprotein-cholesterol (LDL-C) level, few studies have examined whether the type of abdominal adiposity, such as visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT), and the visceral-to-subcutaneous fat ratio (VSR) affects this relationship. We investigated the association between ambient air pollution and LDL-C in Korean adults and identified whether this association is different by the type of abdominal adiposity.

METHODS

A total of 2737 adults were included. Abdominal fat areas were quantified by computed tomography, and the annual average concentration of air pollutants was included in this analysis.

RESULTS

In the total sample, none of the air pollutants was associated with LDL-C level in either the crude or adjusted model (all p > 0.05). The association was not significant even in subgroups stratified according to the obesity status defined by body mass index, and no interaction on the LDL-C level was also found (all p_int > 0.05). In the subgroup analysis stratified according to adiposity level, particulate matter with an aerodynamic diameter of ≤10 μm (PM₁₀) [β (SE) = 3.58 (1.59); p = 0.0245] and sulfur dioxide (SO₂) exposures [β (SE) = 2.71 (1.27); p = 0.0330] in the high-VAT group were associated with the increased LDL-C level. Interactions on LDL-C level were also found between VAT level and ambient air pollutants such as PM₁₀ and SO₂ (both p_int < 0.05). In the analysis of the VSR, PM₁₀ exposure showed a significant interaction on LDL level (p_int = 0.0032). However, the strength of these associations was not significant across all SAT subgroup (all p_int > 0.05).

CONCLUSIONS

In conclusion, we found that association between air pollution exposure and LDL-C level is different by abdominal fat distribution.

Chronic inflammation in psoriasis promotes visceral adiposity associated with noncalcified coronary burden over time

BACKGROUND

Psoriasis is a chronic inflammatory skin disease associated with increased obesity, noncalcified coronary artery burden (NCB), and incident myocardial infarction. Here, we sought to assess the relationship among inflammation, visceral adipose tissue (VAT), and NCB. Furthermore, we evaluated whether improvement in VAT would be associated with reduction in NCB over time in psoriasis.

METHODS

Consecutive psoriasis patients underwent coronary CT angiography to quantify NCB and abdominal CT to calculate VAT at baseline (n = 237), 1 year (n = 176), and 4 years (n = 50).

RESULTS

Patients with high levels of high-sensitivity C-reactive protein (hs-CRP) had significantly greater visceral adiposity (17,952.9 ± 849.2 cc³ vs. 13370.7 ± 806.8 cc³, P < 0.001) and noncalcified coronary burden (1.26 ± 0.03 vs. 1.07 ± 0.02 mm²) than those with low levels of hs-CRP. Those with higher levels of VAT had more systemic inflammation (hs-CRP, median [IQR], 2.5 mg/L [1.0–5.3 mg/L] vs. 1.2 mg/L [0.6–2.9 mg/L]), with approximately 50% higher NCB (1.42 ± 0.6 mm² vs. 0.91 ± 0.2 mm², P < 0.001). VAT associated with NCB in fully adjusted models (β = 0.47, P < 0.001). At 1-year follow-up, patients who had worsening hs-CRP had an increase in VAT (14,748.7 ± 878.1 cc³ to 15,158.7 ± 881.5 cc³; P = 0.03), whereas those who had improved hs-CRP improved their VAT (16,876.1 ± 915.2 cc³ to 16310.4 ± 889.6 cc³; P = 0.04). At 1 year, there was 10.3% reduction in NCB in those who had decreased VAT (β = 0.26, P < 0.0001), which persisted in a subset of patients at 4 years (β = 0.39, P = 0.003).

CONCLUSIONS

Inflammation drives development of VAT, increased cardiometabolic risk, and NCB in psoriasis. Reduction of inflammation associated with reduction in VAT and associated with longitudinal improvement in NCB. These findings demonstrate the important role of inflammation in the development of VAT in humans and its effect on early atherogenesis.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01778569.

FUNDING

This study was supported by the National Heart, Lung, and Blood Institute Intramural Research Program (HL006193-05), the NIH Medical Research Scholars Program, a public-private partnership supported jointly by the NIH and contributions to the Foundation for the NIH from the Doris Duke Charitable Foundation (no. 2014194), the American Association for Dental Research, the Colgate-Palmolive Company, Genentech, and Elsevier as well as private donors.

Inflammation is associated with development of visceral adiposity and coronary artery disease in humans.

Serum zonulin measured by enzyme-linked immunosorbent assay may not be a reliable marker of small intestinal permeability in healthy adults

The association between intestinal permeability (IP) and body composition remains unclear. The gold standard differential sugar-absorption test is arduous to complete, with zonulin being increasingly used as an independent biomarker of IP. This pilot study aimed to explore the association between small IP, zonulin concentrations, and body composition in healthy adults. The urinary lactulose-rhamnose ratio was used to measure small IP. Serum zonulin, lipopolysaccharide (LPS) and high-sensitivity C-reactive protein (hs-CRP) were analyzed in serum. Body composition was measured using dual-energy X-ray absorptiometry and anthropometric measurements were collected. In total, 34 participants were included (12 males, median age 28 years, body mass index 24 kg/m², waist circumference 77cm). No correlation was observed between the lactulose-rhamnose ratio and zonulin (r = -.016, P = .929). The lactulose-rhamnose ratio displayed a strong positive correlation with LPS (n 20, r = .536, P = .018) but did not correlate with body composition measures. Conversely, zonulin displayed a moderate positive correlation with waist circumference (r = .437, P = .042) in female participants and hs-CRP (r = .485, P = .004) in all participants. These findings raise important considerations for the measurement of small IP, warranting exploration in larger powered studies that address the limitations of the present study.

Role of gut microbiota in sex- and diet-dependent metabolic disorders that lead to early mortality of androgen receptor-deficient male mice

The gut microbiota is involved in metabolic disorders induced by androgen deficiency after sexual maturation in males (late-onset hypogonadism). However, its role in the energy metabolism of congenital androgen deficiency (e.g., androgen-insensitive syndrome) remains elusive. Here, we examined the link between the gut microbiota and metabolic disease symptoms in androgen receptor knockout (ARKO) mouse by administering high-fat diet (HFD) and/or antibiotics. HFD-fed male, but not standard diet-fed male or HFD-fed female, ARKO mice exhibited increased feed efficiency, obesity with increased visceral adipocyte mass and hypertrophy, hepatic steatosis, glucose intolerance, insulin resistance, and loss of thigh muscle. In contrast, subcutaneous fat mass accumulated in ARKO mice irrespective of the diet and sex. Notably, all HFD-dependent metabolic disorders observed in ARKO males were abolished after antibiotics administration. The ratios of fecal weight-to-food weight and cecum weight-to-body weight were specifically reduced by ARKO in HFD-fed males. 16S rRNA sequencing of fecal microbiota from HFD-fed male mice revealed differences in microbiota composition between control and ARKO mice. Several genera or species (e.g., Turicibacter and Lactobacillus reuteri, respectively) were enriched in ARKO mice, and antibiotics treatment spoiled the changes. Furthermore, the life span of HFD-fed ARKO males was shorter than that of control mice, indicating that androgen deficiency causes metabolic dysfunctions leading to early death. These findings also suggest that AR signaling plays a role in the prevention of metabolic dysfunctions, presumably by influencing the gut microbiome, and improve our understanding of health consequences in subjects with hypogonadism and androgen insensitivity.

The parasitic worm product ES-62 promotes health- and life-span in a high calorie diet-accelerated mouse model of ageing

Improvements in hygiene and health management have driven significant increases in human lifespan over the last 50 years. Frustratingly however, this extension of lifespan has not been matched by equivalent improvements in late-life health, not least due to the global pandemic in type-2 diabetes, obesity and cardiovascular disease, all ageing-associated conditions exacerbated and accelerated by widespread adoption of the high calorie Western diet (HCD). Recently, evidence has begun to emerge that parasitic worm infection might protect against such ageing-associated co-morbidities, as a serendipitous side-effect of their evolution of pro-survival, anti-inflammatory mechanisms. As a novel therapeutic strategy, we have therefore investigated the potential of ES-62, an anti-inflammatory secreted product of the filarial nematode Acanthocheilonema viteae, to improve healthspan (the period of life before diseases of ageing appear) by targeting the chronic inflammation that drives metabolic dysregulation underpinning ageing-induced ill-health. We administered ES-62 subcutaneously (at a dose of 1 μg/week) to C57BL/6J mice undergoing HCD-accelerated ageing throughout their lifespan, while subjecting the animals to analysis of 120 immunometabolic responses at various time-points. ES-62 improved a number of inflammatory parameters, but markedly, a range of pathophysiological, metabolic and microbiome parameters of ageing were also successfully targeted. Notably, ES-62-mediated promotion of healthspan in male and female HCD-mice was associated with different mechanisms and reflecting this, machine learning modelling identified sex-specific signatures predictive of ES-62 action against HCD-accelerated ageing. Remarkably, ES-62 substantially increased the median survival of male HCD-mice. This was not the case with female animals and unexpectedly, this difference between the two sexes could not be explained in terms of suppression of the chronic inflammation driving ageing, as ES-62 tended to be more effective in reducing this in female mice. Rather, the difference appeared to be associated with ES-62's additional ability to preferentially promote a healthier gut-metabolic tissue axis in male animals.

Effect of inactivated Bifidobacterium longum intake on obese diabetes model mice (TSOD)

Obesity and diabetes have been increasing at an alarming rate worldwide. Studies have shown the futility of chemical drugs in the treatment of obesity and diabetes. Bifidobacterium longum (BL), a common member of the gut microbiota throughout the human lifespan, has been widely reported to play a role in host health and disease. Here, we evaluated the effects of inactivated cells of BL (IBL) on obesity and blood glucose levels in TSOD mice by administering IBL orally for 5 weeks. The treated mice showed a significant decrease of body weight gain, adipose tissue mass and blood glucose levels, as well as a significant reduction in blood glucose during an oral glucose tolerance test. The treatment also resulted in reduced levels of cholesterol, triglycerides, and NEFA. Moreover, serum and urine analysis showed low creatinine levels in IBL-treated mice. These data demonstrate that IBL may have the potential to prevent obesity and diabetes.

The effects of antibiotics and melatonin on hepato-intestinal inflammation and gut microbial dysbiosis induced by a short-term high-fat diet consumption in rats

High-fat diet (HFD) consumption leads to metabolic disorders, gastrointestinal dysfunction and intestinal dysbiosis. Antibiotics also disrupt the composition of intestinal microbiota. The aim of the present study was to investigate the impact of a short-term feeding with HFD on oxidative status, enteric microbiota, intestinal motility and the effects of antibiotics and/or melatonin treatments on diet-induced hepato-intestinal dysfunction and inflammation. Male Sprague-Dawley rats were pair-fed with either standard chow or HFD (45 % fat) and were given tap water or melatonin (4 mg/kg per d) or melatonin plus antibiotics (ABX; neomycin, ampicillin, metronidazole; each 1 g/l) in drinking water for 2 weeks. On the 14th day, colonic motility was measured and the next day intestinal transit was assessed using charcoal propagation. Trunk blood, liver and intestine samples were removed for biochemical and histopathological evaluations, and faeces were collected for microbiota analysis. A 2-week HFD feeding increased blood glucose level and perirenal fat weight, induced low-level hepatic and intestinal inflammation, delayed intestinal transit, led to deterioration of epithelial tight junctions and overgrowth of colonic bacteria. Melatonin intake in HFD-fed rats reduced ileal inflammation, colonic motility and perirenal fat accumulation. ABX abolished increases in fat accumulation and blood glucose, reduced ileal oxidative damage, suppressed HFD-induced overgrowth in colonic bacteria, and reversed HFD-induced delay in intestinal transit; however, hepatic neutrophil accumulation, hepatic injury and dysfunction were further enhanced. In conclusion, the results demonstrate that even a short-term HFD ingestion results in hepato-intestinal inflammatory state and alterations in bacterial populations, which may be worsened with antibiotic intake, but alleviated by melatonin.

Grape-Seed Proanthocyanidins are Able to Reverse Intestinal Dysfunction and Metabolic Endotoxemia Induced by a Cafeteria Diet in Wistar Rats

We evaluated the effectiveness of pharmacological doses of grape-seed proanthocyanidin extract (GSPE) in reversing intestinal barrier alterations and local inflammation in female Wistar rats fed a long-term obesogenic diet. Animals were fed a 17-week cafeteria diet (CAF diet), supplemented with daily GSPE doses (100 or 500 mg kg⁻¹ body weight) during the final two weeks. CAF diet enhanced the intestinal permeation of an orally administered marker (ovalbumin, OVA) and increased the plasma levels of tumor necrosis factor-α (TNF-α) and lipopolysaccharides (LPS) in 2–3-fold. Ex vivo Ussing chamber assays showed a 55–70% reduction in transepithelial electrical resistance (TEER) and increased the TNF-α secretions in both small and large intestinal sections with a 25-fold increment in the ileum. Ileal tissues also presented a 4-fold increase of myeloperoxidase (MPO) activity. Both GSPE-treatments were able to restitute TEER values in the ileum and colon and to reduce plasma LPS to basal levels without a dose-dependent effect. However, effects on the OVA permeation and TNF-α secretion were dose and section-specific. GSPE also reduced ileal MPO activity and upregulated claudin 1 gene expression. This study provides evidence of the efficacy of GSPE-supplementation ameliorating diet-induced intestinal dysfunction and metabolic endotoxemia when administered at the end of a long-term obesogenic diet.

Effects of abdominal visceral fat compared with those of subcutaneous fat on the association between PM10 and hypertension in Korean men: A cross-sectional study

We assessed whether visceral adipose tissue (VAT) compared with subcutaneous adipose tissue (SAT) has modifying effects on the cross-sectional association between ambient air pollution and hypertension in Korean men. This study included 1,417 adult men who visited a health checkup center. Abdominal fat depots were measured by computed tomography, and we used the annual average concentrations of ambient air pollutants such as particulate matter with an aerodynamic diameter of ≤10 μm (PM₁₀), nitrogen dioxide, sulfur dioxide, and carbon monoxide (CO). The annual mean concentrations of PM₁₀ (odds ratio [OR] = 1.30; 95% confidence interval [CI] = 1.12-1.52) and CO (OR = 1.20; 95% CI = 1.03-1.39) showed a positive association with hypertension. In particular, modifying effects on hypertension were found between PM₁₀ and VAT-related traits such as VAT and visceral-to-subcutaneous fat ratio (VSR). The association between PM₁₀ and hypertension was much stronger in the high-VAT (OR = 1.74; 95% CI = 1.12-2.71) and high-VSR groups (OR = 1.53; 95% CI = 1.23-1.91). However, the strength of association across levels of SAT was not observed (P_int = 0.4615). In conclusion, we found that association between PM₁₀ exposure and hypertension is different by abdominal fat distribution.

Role of androgens in energy metabolism affecting on body composition, metabolic syndrome, type 2 diabetes, cardiovascular disease, and longevity: lessons from a meta-analysis and rodent studies

Testosterone is a sex hormone produced by testicular Leydig cells in males. Blood testosterone concentrations increase at three time-periods in male life-fetal, neonatal (which can be separated into newborn and infant periods), and pubertal stages. After peaking in the early 20s, the blood bioactive testosterone level declines by 1-2% each year. It is increasingly apparent that a low testosterone level impairs general physical and mental health in men. Here, this review summarizes recent systematic reviews and meta-analyses of epidemiological studies in males (including cross-sectional, longitudinal, and androgen deprivation studies, and randomized controlled testosterone replacement trials) in relation to testosterone and obesity,  body composition, metabolic syndrome, type 2 diabetes, cardiovascular disease, and longevity. Furthermore, underlying mechanisms are discussed using data from rodent studies involving castration or androgen receptor knockout. This review provides an update understanding of the role of testosterone in energy metabolism. Abbreviations AR: androgen receptor; CV: cardiovascular; FDA: US Food and Drug Administration; HFD: high-fat diet; KO: knockout; MetS: metabolic syndrome; RCT: randomized controlled trial; SHBG: sex hormone binding globulin; SRMA: systematic review and meta-analysis; TRT: testosterone replacement therapy; T2DM:type 2 diabetes mellitus.

High Fructose Intake During Pregnancy in Rats Influences the Maternal Microbiome and Gut Development in the Offspring

Studies in pregnant women indicate the maternal microbiome changes during pregnancy so as to benefit the mother and fetus. In contrast, disruption of the maternal microbiota around birth can compromise normal bacterial colonisation of the infant's gastrointestinal tract. This may then inhibit development of the gut so as to increase susceptibility to inflammation and reduce barrier function. The impact of modulating fructose intake on the maternal microbiome through pregnancy is unknown, therefore we examined the effect of fructose supplementation on the maternal microbiome together with the immediate and next generation effects in the offspring. Wistar rat dams were divided into control and fructose fed groups that received 10% fructose in their drinking water from 8 weeks of age and throughout pregnancy (10-13 weeks). Maternal fecal and blood samples were collected pre-mating (9 weeks) and during early (gestational day 4-7) and late pregnancy (gestational day 19-21). We show supplementation of the maternal diet with fructose appears to significantly modulate the maternal microbiome, with a significant reduction in Lactobacillus and Bacteroides. In offspring maintained on this diet up to pregnancy and term there was a reduction in gene expression of markers of gut barrier function that could adversely affect its function. An exacerbated insulin response to pregnancy, reduced birth weight, but increased fat mass was also observed in these offspring. In conclusion dietary supplementation with fructose modulates the maternal microbiome in ways that could adversely affect fetal growth and later gut development.

Sterilized bifidobacteria suppressed fat accumulation and blood glucose level

Probiotics such as Lactobacillus and Bifidobacterium improve the balance of intestinal microflora and have various physiological functions beneficial to human health. It is not always known whether the ingested microbial cells are viable- or killed. However, even sterilized bacterial cells are functional. Bacterial cell functions are strain-specific and their modes of action are still poorly understood. The aim of this study was to elucidate the roles of sterilized bifidobacteria in obesity and lipid metabolism. To this end, mice were orally ingested sterilized bacteria. Male C57BL/6J mice aged 7 wks were raised on a high-fat diet and received oral sterilized bifidobacteria for 4 wks. Although the amount of food they ingested did not change in response to bifidobacteria administration, both weight gain and epididymal body fat mass were significantly reduced. In addition, the elevated blood glucose, triglyceride, and total cholesterol levels observed in the mice on the high-fat diet all decreased in response to bifidobacteria treatment. Hepatic triglyceride levels also decreased. Furthermore, oral glucose tolerance and insulin resistance tests indicated that sterilized bifidobacteria improved glucose tolerance and diminished insulin resistance. Sterilized bifidobacteria also decreased blood lipopolysaccharides and altered intestinal flora. The present study indicates that in mice on a high-fat diet, sterilized bifidobacteria suppressed fat accumulation, improved insulin resistance, and lowered blood glucose levels.

Cranial Irradiation Induces Hypothalamic Injury and Late-Onset Metabolic Disturbances in Juvenile Female Rats

Cranial radiotherapy is one of the most effective tools for treating children with brain tumors. However, radiotherapy-induced late-onset side effects have a significant impact on patients' quality of life. The purpose of this study was to investigate the effects of irradiation on metabolism and the possible molecular and cellular mechanisms behind such effects. Female Wistar rats were subjected to a single dose of 6-Gy whole-brain irradiation on postnatal day 11. The animals were sacrificed 6 h or 20 weeks after irradiation. Cell death and proliferation, microglial activation, and inflammation were analyzed and RNA sequencing was performed. We found that irradiation led to a significantly increased body weight from 15 weeks (p < 0.05) along with white adipose tissue accumulation and adipocyte hypertrophy at 20 weeks, and these changes were accompanied by glucose and lipid metabolic disturbances as indicated by reduced glucose tolerance, increased insulin resistance, increased serum triglycerides, and an increased leptin/adiponectin ratio. Furthermore, irradiation induced cell death, microglial activation, inflammation, and persistent astrocyte reactivity in the hypothalamus. Hypothalamic transcriptome analysis showed that 865 genes were downregulated and 290 genes were upregulated in the irradiated group 20 weeks after irradiation, and further pathway analysis showed that the insulin resistance-related PI3K-Akt signaling pathway and the energy expenditure-related adipocytokine signaling pathway were downregulated. Gene Ontology enrichment analysis showed that the expression of fatty acid metabolism-related proteins and effector proteins was significantly different in the irradiation group. This study demonstrates that ionizing radiation to the juvenile female brain induces hypothalamic damage that is likely to be associated with delayed metabolic abnormalities, and this critical vulnerability of the hypothalamus to irradiation should be taken into consideration in the development of future protective strategies for radiotherapy.

Adiposity and Asthma in a Nationwide Study of Children and Adults in the United States

RATIONALE

Although obesity has been associated with asthma, body mass index is suboptimal to fully characterize adiposity.

OBJECTIVES

We examined the relation between adiposity and asthma in a large sample of the U.S. population, using indices defined by dual-energy X-ray absorptiometry.

METHODS

We analyzed data from 8,886 children (aged 8-19 yr) and 12,795 adults (aged 20-69 yr) from the 2001 to 2006 National Health and Nutrition Examination Survey. In addition to body mass index, percent body fat, waist circumference, and waist-to-height ratio, dual-energy X-ray absorptiometry was used to calculate whole-body and local adiposity indices: fat mass index; total, trunk, and legs percent fat; and trunk-to-total fat mass ratio, legs-to-total fat mass ratio, and trunk-to-legs fat mass ratios. Logistic regression was used for the analysis of adiposity measures and asthma.

RESULTS

Among children, general adiposity was significantly associated with asthma, with no major differences by sex. Results were driven by nonatopic children, in whom trunk-predominant (central) adiposity (assessed by waist circumference, waist-to-height ratio, trunk-to-total fat mass ratio, and trunk-to-legs fat mass ratio) was also associated with asthma. There were no significant associations among atopic children. Among adults, all adiposity indices were associated with asthma, with central adiposity significant only among women. The results in adults were driven by atopy, especially in women.

CONCLUSIONS

Adiposity measured by dual-energy X-ray absorptiometry provides similar information to that obtained by using anthropometric indices among children of both sexes and among adult men. However, dual-energy X-ray absorptiometry provides additional information in adult women, in whom dual-energy X-ray absorptiometry-measured central adiposity is significantly associated with asthma, particularly atopic asthma.

Adipose tissue extrinsic factor: Obesity-induced inflammation and the role of the visceral lymph node

Obesity-related adverse health consequences occur predominately in individuals with upper body fat distribution commonly associated with increased central adiposity. Visceral adipose tissue accumulation is described to be the greatest driver of obesity-induced inflammation, however evidence also supports that the intestines fundamentally contribute to the development of obesity-induced metabolic disease. The visceral adipose depot shares the same vasculature and lymph drainage as the small intestine. We hypothesize that the visceral lymph node, which drains adipose tissue and the gastrointestinal tract, is central to the exacerbation of systemic pro-inflammation. Male C57BL/6 mice were fed CHOW or high fat diet (HFD) for 7 weeks. At termination the mesenteric depot, visceral lymph node and ileum, jejunum and Peyer's patches were collected. Cytokine concentration was determined in adipose tissue whereas immune cell populations where investigated in the visceral lymph node and intestinal segments by flow cytometry. Visceral adipose tissue and the gastrointestinal tract mutually influence immune cells enclosed within the visceral lymph node. HFD increased visceral lymph node immune cell number. This likely resulted from 1.) an increase in immune cells migration from the small intestines likely from activated dendritic cells that travel to the lymph node and 2.) cytokine effluent from visceral adipose tissue that promoted expansion, survival and retention of pro-inflammatory immune cells. Overall, the visceral lymph node, the immune nexus of visceral adipose tissue and the small intestines, likely plays a fundamental role in exacerbation of systemic pro-inflammation by HFD-induced obesity. The research of Tim Bartness greatly enhanced the understanding of adipose tissue regulation. Studies from his laboratory significantly contributed to our awareness of extrinsic factors that influence body fatness levels. Specifically, the work he produced eloquently demonstrated that adipose tissue was more complex than an insulating storage center; it was connected to our brains via the sympathetic and sensory nervous system. Mapping studies demonstrated that adipose tissue both receives and sends information to the brain. Further, his lab demonstrated that nervous system connections contributed to lipolysis, thermogenesis and adipocyte proliferation and growth. The work of Tim Bartness will continue to influence adipose tissue research. As such, Tim Bartness directly inspired the following research. Adipose tissue extrinsic factors are not limited to the peripheral nervous system. The lymphatic system is an additional extrinsic factor that cross talks with adipose tissue, however its role in this context is under emphasized. Here we begin to elucidate how the lymphatic system may contribute to the comorbidities associated with visceral adipose tissue accumulation.

Intake of Fish Oil Specifically Modulates Colonic Muc2 Expression in Middle-Aged Rats by Suppressing the Glycosylation Process

SCOPE

Dietary fats have been shown to affect gut microbiota composition and aging gene expression of middle-aged rats at a normal dose, but little is known about such an effect on gut barrier. In this study, the changes in colonic Muc2 expression are investigated and the underlying mechanism is also proposed.

METHODS AND RESULTS

36 middle-aged Sprague-Dawley rats are assigned to one of the diets containing soybean oil, lard, or fish oil (4%). The rats are fed for 5 weeks and then goblet cells, Muc2 expression, and inflammatory cytokines in the colon are measured. Proteome analysis is performed. Compared with the lard and soybean oil diet groups, intake of fish oil decreases the number of goblet cells, and inhibits Muc2 and TLRs expression in the colon of middle-aged rats, which would impair mucus barrier. Several key enzymes involved in glycosylation process, including Agr2, Gale, Gne, Pmm2, Pdxdc1, Plch1, Pfkp, Cmpk1, and Rexo2, show the lowest abundance in the fish oil diet group.

CONCLUSION

Intake of fish oil at a normal dose downregulates colonic Muc2 expression. This negative effect of fish oil may involve the suppression of mucin glycosylation process.

High fat diet consumption differentially affects adipose tissue inflammation and adipocyte size in obesity-prone and obesity-resistant rats

Background/Objectives

Expanding visceral adiposity is associated with increased inflammation and increased risk for developing obesity-related comorbidities. The goal of this study was to examine high fat diet (HFD)-induced differences in adipocyte size and cytokine/chemokine expression in visceral and subcutaneous adipose depots in obesity-prone (OP) and obesity-resistant (OR) rats.

Methods

OP and OR rats were fed either a low fat diet (LFD, 10% kilocalories from fat) or HFD (60% kilocalories from fat) for 7 weeks. Adipocyte size and the presence of crown-like structures in epididymal and inguinal adipose tissue were determined. A multiplex cytokine/chemokine panel was used to assess the expression of inflammatory markers in epididymal and inguinal adipose tissues.

Results

A higher percentage of large adipocytes (> 5000 μm²) was detected in the epididymal and inguinal adipose tissues of OP rats and a higher percentage of small adipocytes (< 4000 μm²) was detected in the epididymal and inguinal adipose tissues of OR rats. More crown-like structures were identified in epididymal adipose tissue of OP rats fed a LFD, compared to OR rats. Consumption of a HFD increased the number of crown-like structures in OR, but not OP rats. Epididymal expression of pro-inflammatory cytokines (IL-1β, TNF-α) was higher in OP rats, compared to OR rats fed LFD. HFD consumption increased epididymal expression of GM-CSF, IL-1α, IL-1β, IL-6, MIP-2, and TNF-α in OP and OR rats. Inguinal expression of pro-inflammatory cytokines (IL-1α, IL-1β, TNF-α) was higher in OP rats, compared to OR rats.

Conclusions

Overall, these data suggest that a higher susceptibility to developing obesity is characterized by large adipocytes and increased visceral adipose inflammation. Interestingly, in OR rats, the detrimental effects of HFD consumption on visceral adipose inflammation are evident with only small increases in weight and adiposity, suggesting that HFD also increases the risk for obesity-related comorbidities in OR rats.

Are the Gut Bacteria Telling Us to Eat or Not to Eat? Reviewing the Role of Gut Microbiota in the Etiology, Disease Progression and Treatment of Eating Disorders

Traditionally recognized as mental illnesses, eating disorders are increasingly appreciated to be biologically-driven. There is a growing body of literature that implicates a role of the gut microbiota in the etiology and progression of these conditions. Gut bacteria may act on the gut–brain axis to alter appetite control and brain function as part of the genesis of eating disorders. As the illnesses progress, extreme feeding patterns and psychological stress potentially feed back to the gut ecosystem that can further compromise physiological, cognitive, and social functioning. Given the established causality between dysbiosis and metabolic diseases, an altered gut microbial profile is likely to play a role in the co-morbidities of eating disorders with altered immune function, short-chain fatty acid production, and the gut barrier being the key mechanistic links. Understanding the role of the gut ecosystem in the pathophysiology of eating disorders will provide critical insights into improving current treatments and developing novel microbiome-based interventions that will benefit patients with eating disorders.

Endotoxins are associated with visceral fat mass in type 1 diabetes

Bacterial lipopolysaccharides (LPS), potent inducers of inflammation, have been associated with chronic metabolic disturbances. Obesity is linked to dyslipidemia, increased body adiposity, and endotoxemia. We investigated the cross-sectional relationships between serum LPS activity and body adiposity as well as inflammation in 242 subjects with type 1 diabetes. Body fat distribution was measured by DXA and serum LPS activity by the limulus amebocyte lysate end-point assay. Since no interaction between visceral fat mass and sex was observed, data were pooled for the subsequent analyses. LPS was independently associated with visceral fat mass, when adjusted for traditional risk factors (age, sex, kidney status, hsCRP, insulin sensitivity). In the multivariate analysis, serum LPS activity and triglyceride concentrations had a joint effect on visceral fat mass, independent of these factors alone. A combination of high LPS and high hsCRP concentrations was also observed in those with the largest visceral fat mass. In conclusion, high serum LPS activity levels were associated with visceral fat mass in subjects with type 1 diabetes strengthening its role in the development of central obesity, inflammation and insulin resistance.

Aging, low-grade systemic inflammation and vitamin D: a mini-review

We conducted a mini-review of the literature, focusing on aging-related systemic inflammation and its association with vitamin D (VitD). As main findings, data indicate that inflammation in aging seems to have multiple origins, including immunosenescence, and from intestinal and adipose tissue, where VitD may modulate these three factors, through mechanisms not totally known. From the selected studies, three randomized clinical trials of VitD supplementation showed improvements in inflammatory status, whereas two studies did not. Ten epidemiological studies showed associations between VitD and inflammation, whereas two studies did not. One case study reinforced this association. As such, we can assume a reasonable association between VitD and inflammation in the elderly, and a promising role of supplementation in some situations. However, most studies did not take into account environmental and individual factors such as the season of the year, latitude, skin color or even the use of some medicines; in addition, the doses, time of intervention and the sample sizes differed between the studies. In conclusion, although more controlled VitD studies, both clinical and epidemiological, are necessary, it is important to remember the network of factors involved in systemic inflammation in the elderly; an understanding of the dietetic and non-dietetic factors is needed to offer a realistic approach.

Hypogonadism alters cecal and fecal microbiota in male mice

Low testosterone levels increase the risk for cardiovascular disease in men and lead to shorter life spans. Our recent study showed that androgen deprivation via castration altered fecal microbiota and exacerbated risk factors for cardiovascular disease, including obesity, impaired fasting glucose, excess hepatic triglyceride accumulation, and thigh muscle weight loss only in high-fat diet (HFD)-fed male mice. However, when mice were administered antibiotics that disrupted the gut microbiota, castration did not increase cardiovascular risks or decrease the ratio of dried feces to food intake. Here, we show that changes in cecal microbiota (e.g., an increased Firmicutes/Bacteroidetes ratio and number of Lactobacillus species) were consistent with changes in feces and that there was a decreased cecal content secondary to castration in HFD mice. Castration increased rectal body temperature and plasma adiponectin, irrespective of diet. Changes in the gut microbiome may provide novel insight into hypogonadism-induced cardiovascular diseases.

Recent advances in the modification of taste and food preferences following bariatric surgery

There is a large body of evidence indicating that bariatric surgery provides durable weight loss and health benefits to patients who are obese and have comorbidities such as type 2 diabetes (T2D). However, there are still many questions related to mechanisms of metabolic improvement, predictors of success/failure, and long term consequences, which need to be answered. More recently, there has been a particular interest in the modulation of taste and food preferences that occurs after bariatric surgery and how this affects weight loss in different individuals. Animal models as well as human studies have shed some light on the role of taste in changing food preferences and how these changes may affect weight loss after surgery. The goal of this review is to discuss the physiological and behavioral consequences of bariatric surgery as a treatment for obesity and T2D, with particular emphasis on recent studies describing bariatric surgery-induced modifications in taste perception and food preferences.

Influence of GABA and GABA-producing Lactobacillus brevis DPC 6108 on the development of diabetes in a streptozotocin rat model

The aim of this study was to investigate if dietary administration of γ-aminobutyric acid (GABA)-producing Lactobacillus brevis DPC 6108 and pure GABA exert protective effects against the development of diabetes in streptozotocin (STZ)-induced diabetic Sprague Dawley rats. In a first experiment, healthy rats were divided in 3 groups (n=10/group) receiving placebo, 2.6 mg/kg body weight (bw) pure GABA or L. brevis DPC 6108 (~10(9)microorganisms). In a second experiment, rats (n=15/group) were randomised to five groups and four of these received an injection of STZ to induce type 1 diabetes. Diabetic and non-diabetic controls received placebo [4% (w/v) yeast extract in dH2O], while the other three diabetic groups received one of the following dietary supplements: 2.6 mg/kg bw GABA (low GABA), 200 mg/kg bw GABA (high GABA) or ~10(9) L. brevis DPC 6108. L. brevis DPC 6108 supplementation was associated with increased serum insulin levels (P<0.05), but did not alter other metabolic markers in healthy rats. Diabetes induced by STZ injection decreased body weight (P<0.05), increased intestinal length (P<0.05) and stimulated water and food intake. Insulin was decreased (P<0.05), whereas glucose was increased (P<0.001) in all diabetic groups, compared with non-diabetic controls. A decrease (P<0.01) in glucose levels was observed in diabetic rats receiving L. brevis DPC 6108, compared with diabetic-controls. Both the composition and diversity of the intestinal microbiota were affected by diabetes. Microbial diversity in diabetic rats supplemented with low GABA was not reduced (P>0.05), compared with non-diabetic controls while all other diabetic groups displayed reduced diversity (P<0.05). L. brevis DPC 6108 attenuated hyperglycaemia induced by diabetes but additional studies are needed to understand the mechanisms involved in this reduction.

Castration influences intestinal microflora and induces abdominal obesity in high-fat diet-fed mice

Late-onset hypogonadism (i.e. androgen deficiency) raises the risk for abdominal obesity in men. The mechanism for this obesity is unclear. Here, we demonstrated that hypogonadism after castration caused abdominal obesity in high-fat diet (HFD)-fed, but not in standard diet (SD)-fed, C57BL/6J mice. Furthermore, the phenotype was not induced in mice treated with antibiotics that disrupt the intestinal microflora. In HFD-fed mice, castration increased feed efficiency and decreased fecal weight per food intake. Castration also induced in an increase of visceral fat mass only in the absence of antibiotics in HFD-fed mice, whereas subcutaneous fat mass was increased by castration irrespective of antibiotics. Castration reduced the expression in the mesenteric fat of both adipose triglyceride lipase and hormone-sensitive lipase in HFD-fed mice, which was not observed in the presence of antibiotics. Castration decreased thigh muscle (i.e. quadriceps and hamstrings) mass, elevated fasting blood glucose levels, and increased liver triglyceride levels in a HFD-dependent manner, whereas these changes were not observed in castrated mice treated with antibiotics. The Firmicutes/Bacteroidetes ratio and Lactobacillus species increased in the feces of HFD-fed castrated mice. These results show that androgen (e.g. testosterone) deficiency can alter the intestinal microbiome and induce abdominal obesity in a diet-dependent manner.

Characterization of Phenolic Compounds and Antioxidant and Anti-inflammatory Activities from Mamuyo (Styrax ramirezii Greenm.) Fruit

Extracts of Styrax ramirezii Greenm., a fruit traditionally valued for health and wellness in Mexico, were analyzed phytochemically and evaluated for antioxidant and anti-inflammatory activity. Six norneolignans were identified by HPLC-TOF-MS, and the two major compounds were isolated for further evaluation. The effects of the isolated norneolignans, egonol and homoegonol, on lipopolysaccharide (LPS)-induced nitric oxide (NO) production, reactive oxygen species (ROS) production, and biomarkers of inflammation were evaluated. Of the tested compounds, egonol potently inhibited the production of NO and also significantly reduced the release of ROS. Consistent with these observations, the mRNA expression levels of inducible nitric oxide synthase (iNOS) (0.668 ± 0.108), cyclooxygenase-2 (COX-2) (0.553 ± 0.007), interleukin-1β (IL-1β) (0.093 ± 0.005), and interleukin-6 (IL-6) (0.298 ± 0.076) were reduced by egonol. The activity for both egonol and homoegonol increased in a concentration-dependent manner. These results suggest the potential of S. ramirezii Greenm. fruit to contribute to a healthy diet, rich in antioxidant and anti-inflammatory compounds.

Gut Microbiota and Energy Expenditure in Health and Obesity

The contribution of intestinal bacterial strains (gut microbiota) to the development of obesity and obesity-related disorders is increasingly recognized as a potential diagnostic and pharmacologic target. Alterations in the intestinal bacterial composition have been associated with presence of chronic low-grade inflammation, a known feature of insulin resistance and type 2 diabetes mellitus. However, causality still needs to be proven. Fecal transplantation studies in germ-free mice have provided crucial insight into the causality of gut microbiota in development of obesity and obesity-related disorders. Moreover, fecal transplantation studies in conjunction with fecal sampling in prospectively followed cohorts will help identify causally involved intestinal bacterial strains in human obesity. Results from these studies will lead to characterization of novel diagnostic markers as well as therapeutic strategies that aim to treat obesity and obesity-related disorders.

Nutrient availability, the microbiome, and intestinal transport during pregnancy

Adequate adaptation of the gastrointestinal tract is important during pregnancy to ensure that the increased metabolic demands by the developing fetus are met. These include changes in surface area mediated by villus hypertrophy and enhanced functional capacity of individual nutrient receptors, including those transporting glucose, fructose, leucine, and calcium. These processes are regulated either by the enhanced nutrient demand or are facilitated by changes in the secretion of pregnancy hormones. Our review also covers recent research into the microbiome, and how pregnancy could lead to microbial adaptations, which are beneficial to the mother, yet are also similar to those seen in the metabolic syndrome. The potential role of diet in modulating the microbiome during pregnancy, as well as the potential for the intestinal microbiota to induce pregnancy complications, are examined. Gaps in the current literature are highlighted, including those where only historical evidence is available, and we suggest areas that should be a priority for further research. In summary, although a significant degree of adaptation has been described, there are both well-established processes and more recent discoveries, such as changes within the maternal microbiome, that pose new questions as to how the gastrointestinal tract effectively adapts to pregnancy, especially in conjunction with maternal obesity.

Adipose Tissue Is a Neglected Viral Reservoir and an Inflammatory Site during Chronic HIV and SIV Infection

Two of the crucial aspects of human immunodeficiency virus (HIV) infection are (i) viral persistence in reservoirs (precluding viral eradication) and (ii) chronic inflammation (directly associated with all-cause morbidities in antiretroviral therapy (ART)-controlled HIV-infected patients). The objective of the present study was to assess the potential involvement of adipose tissue in these two aspects. Adipose tissue is composed of adipocytes and the stromal vascular fraction (SVF); the latter comprises immune cells such as CD4+ T cells and macrophages (both of which are important target cells for HIV). The inflammatory potential of adipose tissue has been extensively described in the context of obesity. During HIV infection, the inflammatory profile of adipose tissue has been revealed by the occurrence of lipodystrophies (primarily related to ART). Data on the impact of HIV on the SVF (especially in individuals not receiving ART) are scarce. We first analyzed the impact of simian immunodeficiency virus (SIV) infection on abdominal subcutaneous and visceral adipose tissues in SIVmac251 infected macaques and found that both adipocytes and adipose tissue immune cells were affected. The adipocyte density was elevated, and adipose tissue immune cells presented enhanced immune activation and/or inflammatory profiles. We detected cell-associated SIV DNA and RNA in the SVF and in sorted CD4+ T cells and macrophages from adipose tissue. We demonstrated that SVF cells (including CD4+ T cells) are infected in ART-controlled HIV-infected patients. Importantly, the production of HIV RNA was detected by in situ hybridization, and after the in vitro reactivation of sorted CD4+ T cells from adipose tissue. We thus identified adipose tissue as a crucial cofactor in both viral persistence and chronic immune activation/inflammation during HIV infection. These observations open up new therapeutic strategies for limiting the size of the viral reservoir and decreasing low-grade chronic inflammation via the modulation of adipose tissue-related pathways.

Fermented dairy food and CVD risk

Fermented dairy foods such as yoghurt and cheese are commonly found in the Mediterranean diet. Recent landmark research has confirmed the effect of the Mediterranean diet on reducing the CVD risk, but the relative contributions of fermented dairy foods have not been fully articulated. The present study provides a review of the relationship between fermented dairy foods consumption and CVD risk in the context of the whole diet. Studies show that people who eat healthier diets may be more likely to consume yoghurt, so there is a challenge in attributing separate effects to yoghurt. Analyses from large population studies list yoghurt as the food most negatively associated with the risk of weight gain (a problem that may lead to CVD). There is some suggestion that fermented dairy foods consumption (yoghurt or cheese) may be associated with reduced inflammatory biomarkers associated with the development of CVD. Dietary trials suggest that cheese may not have the same effect on raising LDL-cholesterol levels as butter with the same saturated fat content. The same might be stated for yoghurt. The use of different probiotic cultures and other aspects of study design remain a problem for research. Nevertheless, population studies from a range of countries have shown that a reduced risk of CVD occurs with the consumption of fermented dairy foods. A combination of evidence is necessary, and more research is always valuable, but indications remain that fermented dairy foods such as cheese and yoghurt are integral to diets that are protective against CVD.

Gut permeability, its interaction with gut microflora and effects on metabolic health are mediated by the lymphatics system, liver and bile acid

There is evidence to link obesity (and metabolic syndrome) with alterations in gut permeability and microbiota. The underlying mechanisms have been questioned and have prompted this review. We propose that the gut barrier function is a primary driver in maintaining metabolic health with poor health being linked to ‘gut leakiness'. This review will highlight changes in intestinal permeability and how it may change gut microflora and subsequently affect metabolic health by influencing the functioning of major bodily organs/organ systems: the lymphatic system, liver and pancreas. We also discuss the likelihood that metabolic syndrome undergoes a cyclic worsening facilitated by an increase in intestinal permeability leading to gut dysbiosis, culminating in ongoing poor health leading to further exacerbated gut leakiness.