Hepatic Steatosis Can Be Partly Generated by the Gut Microbiota-Mitochondria Axis via 2-Oleoyl Glycerol and Reversed by a Combination of Soy Protein, Chia Oil, Curcumin and Nopal

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a serious health problem, and recent evidence indicates that gut microbiota plays a key role in its development. It is known that 2-oleoyl glycerol (2-OG) produced by the gut microbiota is associated with hepatic fibrosis, but it is not known whether this metabolite is involved in the development of hepatic steatosis. The aim of this study was to evaluate how a high-fat-sucrose diet (HFS) increases 2-OG production through gut microbiota dysbiosis and to identify whether this metabolite modifies hepatic lipogenesis and mitochondrial activity for the development of hepatic steatosis as well as whether a combination of functional foods can reverse this process. Wistar rats were fed the HFS diet for 7 months. At the end of the study, body composition, biochemical parameters, gut microbiota, protein abundance, lipogenic and antioxidant enzymes, hepatic 2-OG measurement, and mitochondrial function of the rats were evaluated. Also, the effect of the consumption of functional food with an HFS diet was assessed. In humans with MASLD, we analyzed gut microbiota and serum 2-OG. Consumption of the HFS diet in Wistar rats caused oxidative stress, hepatic steatosis, and gut microbiota dysbiosis, decreasing α-diversity and increased Blautia producta abundance, which increased 2-OG. This metabolite increased de novo lipogenesis through ChREBP and SREBP-1. 2-OG significantly increased mitochondrial dysfunction. The addition of functional foods to the diet modified the gut microbiota, reducing Blautia producta and 2-OG levels, leading to a decrease in body weight gain, body fat mass, serum glucose, insulin, cholesterol, triglycerides, fatty liver formation, and increased mitochondrial function. To use 2-OG as a biomarker, this metabolite was measured in healthy subjects or with MASLD, and it was observed that subjects with hepatic steatosis II and III had significantly higher 2-OG than healthy subjects, suggesting that the abundance of this circulating metabolite could be a predictor marker of hepatic steatosis.

Intermittent fasting, calorie restriction, and a ketogenic diet improve mitochondrial function by reducing lipopolysaccharide signaling in monocytes during obesity: A randomized clinical trial

BACKGROUND

Mitochondrial dysfunction occurs in monocytes during obesity and contributes to a low-grade inflammatory state; therefore, maintaining good mitochondrial conditions is a key aspect of maintaining health. Dietary interventions are primary strategies for treating obesity, but little is known about their impact on monocyte bioenergetics. Thus, the aim of this study was to evaluate the effects of calorie restriction (CR), intermittent fasting (IF), a ketogenic diet (KD), and an ad libitum habitual diet (AL) on mitochondrial function in monocytes and its modulation by the gut microbiota.

METHODS AND FINDINGS

A randomized controlled clinical trial was conducted in which individuals with obesity were assigned to one of the 4 groups for 1 month. Subsequently, the subjects received rifaximin and continued with the assigned diet for another month. The oxygen consumption rate (OCR) was evaluated in isolated monocytes, as was the gut microbiota composition in feces and anthropometric and biochemical parameters. Forty-four subjects completed the study, and those who underwent CR, IF and KD interventions had an increase in the maximal respiration OCR (p = 0.025, n2p = 0.159 [0.05, 0.27] 95% confidence interval) in monocytes compared to that in the AL group. The improvement in mitochondrial function was associated with a decrease in monocyte dependence on glycolysis after the IF and KD interventions. Together, diet and rifaximin increased the gut microbiota diversity in the IF and KD groups (p = 0.0001), enriched the abundance of Phascolarctobacterium faecium (p = 0.019) in the CR group and Ruminococcus bromii (p = 0.020) in the CR and KD groups, and reduced the abundance of lipopolysaccharide (LPS)-producing bacteria after CR, IF and KD interventions compared to the AL group at the end of the study according to ANCOVA with covariate adjustment. Spearman's correlation between the variables measured highlighted LPS as a potential modulator of the observed effects. In line with this findings, serum LPS and intracellular signaling in monocytes decreased with the three interventions (CR, p = 0.002; IF, p = 0.001; and KD, p = 0.001) compared to those in the AL group at the end of the study.

CONCLUSIONS

We conclude that these dietary interventions positively regulate mitochondrial bioenergetic health and improve the metabolic profile of monocytes in individuals with obesity via modulation of the gut microbiota. Moreover, the evaluation of mitochondrial function in monocytes could be used as an indicator of metabolic and inflammatory status, with potential applications in future clinical trials.

TRIAL REGISTRATION

This trial was registered with ClinicalTrials.gov (NCT05200468).

Acute Effects of Dietary Protein Consumption on the Postprandial Metabolic Response, Amino Acid Levels and Circulating MicroRNAs in Patients with Obesity and Insulin Resistance

The post-nutritional intervention modulation of miRNA expression has been previously investigated; however, post-acute dietary-ingestion-related miRNA expression dynamics in individuals with obesity and insulin resistance (IR) are unknown. We aimed to determine the acute effects of protein ingestion from different dietary sources on the postprandial metabolic response, amino acid levels, and circulating miRNA expression in adults with obesity and IR. This clinical trial included adults with obesity and IR who consumed (1) animal-source protein (AP; calcium caseinate) or (2) vegetable-source protein (VP; soy protein isolate). Glycaemic, insulinaemic, and glucagon responses, amino acid levels, and exosomal microRNAs isolated from plasma were analysed. Post-AP ingestion, the area under the curve (AUC) of insulin (p = 0.04) and the plasma concentrations of branched-chain (p = 0.007) and gluconeogenic (p = 0.01) amino acids increased. The effects of different types of proteins on the concentration of miRNAs were evaluated by measuring their plasma circulating levels. Compared with the baseline, the AP group presented increased circulating levels of miR-27a-3p, miR-29b-3p, and miR-122-5p (p < 0.05). Subsequent analysis over time at 0, 30, and 60 min revealed the same pattern and differences between treatments. We demonstrated that a single dose of dietary protein has acute effects on hormonal and metabolic regulation and increases exosomal miRNA expression in individuals with obesity and IR.

Epigenetic reprogramming of H3K4me3 in adipose-derived stem cells by HFS diet consumption leads to a disturbed transcriptomic profile in adipocytes

Adipose tissue metabolism is actively involved in the regulation of energy balance. Adipose-derived stem cells (ASCs) play a critical role in maintaining adipose tissue function through their differentiation into mature adipocytes (Ad). This study aimed to investigate the impact of an obesogenic environment on the epigenetic landscape of ASCs and its impact on adipocyte differentiation and its metabolic consequences. Our results showed that ASCs from rats on a high-fat sucrose (HFS) diet displayed reduced adipogenic capacity, increased fat accumulation, and formed larger adipocytes than the control (C) group. Mitochondrial analysis revealed heightened activity in undifferentiated ASC-HFS but decreased respiratory and glycolytic capacity in mature adipocytes. The HFS diet significantly altered the H3K4me3 profile in ASCs on genes related to adipogenesis, mitochondrial function, inflammation, and immunomodulation. After differentiation, adipocytes retained H3K4me3 alterations, confirming the upregulation of genes associated with inflammatory and immunomodulatory pathways. RNA-seq confirmed the upregulation of genes associated with inflammatory and immunomodulatory pathways in adipocytes. Overall, the HFS diet induced significant epigenetic and transcriptomic changes in ASCs, impairing differentiation and causing dysfunctional adipocyte formation.NEW & NOTEWORTHY Obesity is associated with the development of chronic diseases like metabolic syndrome and type 2 diabetes, and adipose tissue plays a crucial role. In a rat model, our study reveals how an obesogenic environment primes adipocyte precursor cells, leading to epigenetic changes that affect inflammation, adipogenesis, and mitochondrial activity after differentiation. We highlight the importance of histone modifications, especially the trimethylation of histone H3 to lysine 4 (H3K4me3), showing its influence on adipocyte expression profiles.

Observation of magnet-induced star-like radiation of a plasma created from cancer cells in a laser trap

We present a new phenomenon resulting from the interaction of magnetic beads with cancer cells in a laser trap formed on a slide containing a depression 16.5 mm in diameter and 0.78 mm of maximum depth. This phenomenon includes the apparent formation and expansion of a dark bubble that attracts and incinerates surrounding matter when it explodes, which leads to a plasma emitting intense radiation that has the appearance of a star on a microscopic scale. We have observed the star-like phenomenon for more than 4 years, and the intensity depends on the laser's power. Measuring the laser power of the dark bubble shows the entrapment of electromagnetic energy as it expands.

Modulation of MicroRNAs and Exosomal MicroRNAs after Dietary Interventions for Obesity and Insulin Resistance: A Narrative Review

MicroRNAs (miRNAs) are small noncoding RNAs approximately 22 nucleotides in length. Their main function is to regulate gene expression at the posttranscriptional level by inhibiting the translation of messenger RNAs (mRNAs). miRNAs originate in the cell nucleus from specific genes, where they can perform their function. However, they can also be found in serum, plasma, or other body fluids travelling within vesicles called exosomes and/or bound to proteins or other particles such as lipoproteins. miRNAs can form complexes outside the cell where they are synthesized, mediating paracrine and endocrine communication between different tissues. In this way, they can modulate the gene expression and function of distal cells. It is known that the expression of miRNAs can be affected by multiple factors, such as the nutritional or pathological state of the individual, or even in conditions such as obesity, insulin resistance, or after any dietary intervention. In this review, we will analyse miRNAs whose expression and circulation are affected in conditions of obesity and insulin resistance, as well as the changes generated after a dietary intervention, with the purpose of identifying new possible biomarkers of early response to nutritional treatment in these conditions.

An adenosine derivative prevents the alterations observed in metabolic syndrome in a rat model induced by a rich high-fat diet and sucrose supplementation

Metabolic syndrome is a multifactorial disease with high prevalence worldwide. It is related to cardiovascular disease, diabetes, and obesity. Approximately 80% of patients with metabolic syndrome have some degree of fatty liver disease. An adenosine derivative (IFC-305) has been shown to exert protective effects in models of liver damage as well as on elements involved in central metabolism; therefore, here, we evaluated the effect of IFC-305 in an experimental model of metabolic syndrome in rats induced by a high-fat diet and 10% sucrose in drinking water for 18 weeks. We also determined changes in fatty acid uptake in the Huh-7 cell line. In the experimental model, increases in body mass, serum triglycerides and proinflammatory cytokines were induced in rats, and the adenosine derivative significantly prevented these changes. Interestingly, IFC-305 prevented alterations in glucose and insulin tolerance, enabling the regulation of glucose levels in the same way as in the control group. Histologically, the alterations, including mitochondrial morphological changes, observed in response to the high-fat diet were prevented by administration of the adenosine derivative. This compound exerted protective effects against metabolic syndrome, likely due to its action in metabolic regulation, such as in the regulation of glucose blood levels and hepatocyte fatty acid uptake.

Genistein-mediated thermogenesis and white-to-beige adipocyte differentiation involve transcriptional activation of cAMP response elements in the Ucp1 promoter

Genistein is an isoflavone present in soybeans and is considered a bioactive compound due to its widely reported biological activity. We have previously shown that intraperitoneal genistein administration and diet supplementation activates the thermogenic program in rats and mice subcutaneous white adipose tissue (scWAT) under multiple environmental cues, including cold exposure and high-fat diet feeding. However, the mechanistic insights of this process were not previously unveiled. Uncoupling protein 1 (UCP1), a mitochondrial membrane polypeptide responsible for dissipating energy into heat, is considered the most relevant thermogenic marker; thus, we aimed to evaluate whether genistein regulates UCP1 transcription. Here we show that genistein administration to thermoneutral-housed mice leads to the appearance of beige adipocyte markers, including a sharp upregulation of UCP1 expression and protein abundance in scWAT. Reporter assays showed an increase in UCP1 promoter activity after genistein stimulation, and in silico analysis revealed the presence of estrogen (ERE) and cAMP (CRE) response elements as putative candidates of genistein activation. Mutation of the CRE but not the ERE reduced genistein-induced promoter activity by 51%. Additionally, in vitro and in vivo ChIP assays demonstrated the binding of CREB to the UCP1 promoter after acute genistein administration. Taken together, these data elucidate the mechanism of genistein-mediated UCP1 induction and confirm its potential applications in managing metabolic disorders.

Amino Acid Catabolism: An Overlooked Area of Metabolism

Amino acids have been extensively studied in nutrition, mainly as key elements for maintaining optimal protein synthesis in the body as well as precursors of various nitrogen-containing compounds. However, it is now known that amino acid catabolism is an important element for the metabolic control of different biological processes, although it is still a developing field to have a deeper understanding of its biological implications. The mechanisms involved in the regulation of amino acid catabolism now include the contribution of the gut microbiota to amino acid oxidation and metabolite generation in the intestine, the molecular mechanisms of transcriptional control, and the participation of specific miRNAs involved in the regulation of amino acid degrading enzymes. In addition, molecules derived from amino acid catabolism play a role in metabolism as they are used in the epigenetic regulation of many genes. Thus, this review aims to examine the mechanisms of amino acid catabolism and to support the idea that this process is associated with the immune response, abnormalities during obesity, in particular insulin resistance, and the regulation of thermogenesis.

Edible and medicinal mushrooms (Pleurotus ostreatus, Ustilago maydis, Ganoderma lucidum) reduce endoplasmic reticulum stress and inflammation in adipose tissue of obese Wistar rats fed with a high fat plus saccharose diet

Obesity is an increasing global public health problem. A strategy to treat obesity is the use of functional foods. Edible and medicinal mushrooms contain diverse bioactive compounds showing important antihyperlipidemic, antioxidant, and prebiotic properties. We analysed the effects of adding (10%) of Pleurotus ostreatus (Po, basidiomata), Ganoderma lucidum (Gl, basidiomata), or Ustilago maydis (Um, galls), milled, to a high fat plus saccharose diet (HFD + S) for 6 months in a model of obesity with Wistar rats. We assessed weight gain, body composition, lipid parameters, endoplasmic reticulum stress (proteins and inflammatory markers: BiP, XBP-1, JNK, p-JNK, TNF-α), and adiponectin in subcutaneous adipose tissue (SAT). The consumption of edible and medicinal mushrooms decreased weight gain (-17.2-30.1%) and fat mass (-23.7-43.1%), maintained fat-free mass, reduced levels of serum biochemical parameters (TC: -40.1-44.1%, TG: -37.7-51.6%, LDL-C: -64.5-71.1%), and prevented adipocyte hypertrophy (-30.9-36.9%) and collagen deposition (-70.9-73.7%) in SAT. Compared with the HFD + S group, mushroom consumption by Wistar rats significantly reduced the expression of proteins associated with endoplasmic reticulum stress and inflammation (BiP: -72.2-88.2%; XBP-1: -71.5-81.8%; JNK: -71.2-90.0%; p-JNK: -37.3-81.0%; TNF-α: -80.7-91.5%), whereas significantly increased adiponectin protein expression (246.4-654.2%) in SAT. These effects outperformed those obtained through the commercial lipid-lowering drug atorvastatin, contributing synergistically to prevent further obesity-related dysfunctions, such as insulin resistance derived from inflammation and ER stress in adipose tissue. Bioactive compounds from edible, functional and medicinal mushrooms represent new emerging therapies for obesity treatments using natural products.

Chaya (Cnidoscolus aconitifolius (Mill.) I.M. Johnst) leaf extracts regulate mitochondrial bioenergetics and fatty acid oxidation in C2C12 myotubes and primary hepatocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Chaya (Cnidoscolus aconitifolius (Mill.) I.M. Johnst) is an important component of the regular diet and traditional medicine of indigenous communities in Mexico. Customarily, Chaya is consumed as a beverage made of macerated leaf, cooked, or prepared in teas or infusions to empirically treat obesity, diabetes, gastrointestinal disorders, and kidney stones. The beneficial effects of Chaya can be attributed to the presence of protein, dietary fiber, vitamins, and especially polyphenols, which regulate mitochondrial function. Therefore, polyphenols present in Chaya extracts could be used to develop novel strategies to prevent and treat metabolic alterations related to mitochondrial dysfunction in the muscle and liver of subjects with obesity, type 2 diabetes, and cardiovascular diseases. However, limited information is available concerning the effect of Chaya extracts on mitochondrial activity in those tissues.

AIM OF THE STUDY

The aim of this study was to evaluate the antioxidant capacity of an aqueous extract (AE) or mixed (methanol/acetone/water) extract (ME) of Chaya leaf and their effect on C2C12 myotubes and primary hepatocyte mitochondrial bioenergetics and fatty acid oxidation (FAO).

MATERIALS AND METHODS

Total polyphenol content and antioxidant activity were determined using the Folin-Ciocalteu method and the oxygen radical absorbance capacity assay, respectively. The effect of AE and ME from Chaya leaf on mitochondrial activity and FAO of C2C12 myotubes and primary hepatocytes was evaluated using an extracellular flux analyzer.

RESULTS

The AE and ME from Chaya leaf exhibited antioxidant activity and a polyphenol content similar to nopal, another plant used in Mexican traditional medicine. AE significantly (p < 0.05) decreased the maximal respiration and spare respiratory capacity (SRC) of C2C12 cells, whereas ME had little effect on C2C12 mitochondrial function. Conversely, ME significantly (p < 0.05) decreased SRC in primary hepatocytes, whereas AE increased maximal respiration and SRC at low doses (5 and 10 μM). Moreover, low doses of Chaya AE significantly (p < 0.05) increased AMPK phosphorylation, acyl-coenzyme A oxidase protein abundance, and palmitate oxidation in primary hepatocytes.

CONCLUSION

The AE of Chaya leaf increases mitochondrial function and FAO of primary hepatocytes, indicating its potential to treat hepatic mitochondrial dysfunction underlying metabolic diseases.

A New Approach to Personalized Nutrition: Postprandial Glycemic Response and its Relationship to Gut Microbiota

A prolonged and elevated postprandial glucose response (PPGR) is now considered a main factor contributing for the development of metabolic syndrome and type 2 diabetes, which could be prevented by dietary interventions. However, dietary recommendations to prevent alterations in PPGR have not always been successful. New evidence has supported that PPGR is not only dependent of dietary factors like the content of carbohydrates, or the glycemic index of the foods, but is also dependent on genetics, body composition, gut microbiota, among others. In recent years, continuous glucose monitoring has made it possible to establish predictions on the effect of different dietary foods on PPGRs through machine learning methods, which use algorithms that integrate genetic, biochemical, physiological and gut microbiota variables for identifying associations between them and clinical variables with aim of personalize dietary recommendations. This has allowed to improve the concept of personalized nutrition, since it is now possible to recommend through these predictions specific dietary foods to prevent elevated PPGRs that are highly variable among individuals. Additional components that can enrich the predictive algorithms are findings of nutrigenomics, nutrigenetics and metabolomics. Thus, this review aims to summarize the evidence of the components that integrate personalized nutrition focused on the prevention of PPGRs, and to show the future of personalized nutrition by laying the groundwork for the development of individualized dietary management and its impact on the improvement of metabolic diseases.

A metagenomic study identifies a Prevotella copri enriched microbial profile associated with non-alcoholic steatohepatitis in subjects with obesity

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of liver disease. Increasing evidence indicates that the gut microbiota can play an important role in the pathophysiology of NAFLD. Recently, several studies have tested the predictive value of gut microbiome profiles in NAFLD progression; however, comparisons of microbial signatures in NAFLD or non-alcoholic steatohepatitis (NASH) have produced discrepant results, possibly due to ethnic and environmental factors. Thus, we aimed to characterize the gut metagenome composition of patients with fatty liver disease.

METHODS

Gut microbiome of 45 well-characterized patients with obesity and biopsy-proven NAFLD was evaluated using shot-gun sequencing: 11 non-alcoholic fatty liver controls (non-NAFL), 11 with fatty liver, and 23 with NASH.

RESULTS

Our study showed that Parabacteroides distasonis and Alistipes putredenis were enriched in fatty liver but not in NASH patients. Notably, in a hierarchical clustering analysis, microbial profiles were differentially distributed among groups, and membership to a Prevotella copri dominant cluster was associated with a greater risk of developing NASH. Functional analyses showed that although no differences in LPS biosynthesis pathways were observed, Prevotella-dominant subjects had higher circulating levels of LPS and a lower abundance of pathways encoding butyrate production.

CONCLUSIONS

Our findings suggest that a Prevotella copri dominant bacterial community is associated with a greater risk for NAFLD disease progression, probably linked to higher intestinal permeability and lower capacity for butyrate production.

The Gut Microbiota-Brain Axis during Aging, Mild Cognitive Impairment and Dementia: Role of Tau Protein, β-Amyloid and LPS in Serum and Curli Protein in Stool

Currently, there is an increasing number of people with mild cognitive (MCI) impairment and dementia (D). In the present work we studied the role of tau protein, β-amyloid, LPS (lipopolysaccharide), and curli protein of elderly adults with MCI or D and the contribution of gut microbiota. Four groups were studied: young subjects, healthy adults older than 60 years (A), elderly adults with MCI (MCI), and elderly adults with dementia (D). A preclinical study was conducted in old male Wistar rats to evaluate the impact of gut microbiota on curli protein abundance in feces and brain. The results showed that with increasing age, tau protein, β-amyloid, and LPS significantly increased in serum during MCI and D, and this was associated with an increase in the abundance of E. coli that synthesize the amyloid protein curli, that may promote the aggregation of amyloid proteins. Rats showed a clear increase in the abundance of curli protein in the brain during aging. Thus, cognitive impairment and dementia are in part due to an alteration in the gut microbiota-brain axis via increase in curli protein and LPS leading to an increase in tau and β-amyloid protein.

Effects of Mexican Ganoderma lucidum extracts on liver, kidney, and the gut microbiota of Wistar rats: A repeated dose oral toxicity study

Well-characterized and standardized extracts of a Mexican genotype of Ganoderma lucidum (Gl), a medicinal mushroom, cultivated on oak sawdust (Gl-1) or oak sawdust plus acetylsalicylic acid (Gl-2, ASA), have been shown to exert antioxidant, hypocholesterolemic, anti-inflammatory, prebiotic, and anticancer properties. However, toxicity analyses still need to be carried out. Different doses of these Gl-1 or Gl-2 extracts were administered to Wistar rats for 14 days in a repeated dose oral toxicity study. We assessed the external clinical signs, biochemical parameters, liver and kidney tissues, injury and inflammation biomarkers, gene expression, inflammatory responses, proinflammatory mediators, and gut microbiota. Gl extracts had no significant adverse, toxic or harmful effects on male and female rats compared to the control groups. No injury or dysfunction were recorded in the kidney or liver, as there were no significant abnormal variations in organ weight, tissue histopathology, serum biochemical parameters (C-reactive protein, creatinine, urea, glucose, ALT and AST transaminases, TC, LDL-c, TG, HDL-c), urinary parameters (creatinine, urea nitrogen, albumin, the albumin-to-creatinine ratio, glucose), injury and inflammatory biomarkers (KIM-1/TIM-1, TLR4, and NF-кB protein expression; IL-1β, TNF-α and IL-6 gene expression), or the expression of genes linked to cholesterol metabolism (HMG-CoA, Srebp2, Ldlr). Gl-1 and Gl-2 extracts showed prebiotic effects on the gut microbiota of male and female Wistar rats. Bacterial diversity and relative bacterial abundance (BRA) increased, positively modulating the Firmicutes/Bacteroidetes ratio. The ASA (10 mM) added to the substrate used for mushroom cultivation changed properties and effects of the Gl-2 extract on Wistar rats. The no-observed-adverse-effect-level (NOAEL) was 1000 mg/kg body weight/day of Gl-1 or Gl-2 extracts. Clinical trials are recommended for further exploring the potential therapeutic applications of studied extracts.

Establishment of triple-negative breast cancer cells based on BMI: A novel model in the correlation between obesity and breast cancer

Introduction

Obesity has been associated with an increased risk of biologically aggressive variants in breast cancer. Women with obesity often have tumors diagnosed at later stages of the disease, associated with a poorer prognosis and a different response to treatment. Human cell lines have been derived from specific subtypes of breast cancer and have served to define the cell physiology of corresponding breast cancer subtypes. However, there are no current cell lines for breast cancer specifically derived from patients with different BMIs. The availability of those breast cancer cell lines should allow to describe and unravel functional alterations linked to these comorbidities.

Methods

Cell cultures were established from tumor explants. Once generated, the triple negative subtype in a patient with obesity and a patient with a normal BMI were chosen for comparison. For cellular characterization, the following assays were conducted: proliferation assays, chemo - sensitivity assays for doxorubicin and paclitaxel, wound healing motility assays, matrix invasion assays, breast cancer cell growth to estradiol by chronic exposure to leptin, induction of endothelial permeability and tumorigenic potential in athymic mice with normo - versus hypercaloric diets with an evaluation of the epithelium - mesenchymal transformation proteins.

Results

Two different cell lines, were established from patients with breast cancer: DSG-BC1, with a BMI of 21.9 kg/m2 and DSG-BC2, with a BMI of 31.5 kg/m2. In vitro, these two cell lines show differential growth rates, motility, chemosensitivity, vascular permeability, response to leptin with an activation of the JAK2/STAT3/AKT signaling pathway. In vivo, they displayed distinct tumorigenic potential. In particular, DSG-BC2, presented higher tumorigenicity when implanted in mice fed with a hypercaloric diet.

Discussion

To our knowledge, these primary cultures are the first in vitro representation of both breast cancer and obesity. DSG - BC2 presented a more aggressive in vivo and in vitro phenotype. These results support the hypothesis that breast cancer generated in an obese metabolic state may represent a contrasting variant within the same disease. This new model will allow both further comprehension, functional studies and the analysis of altered molecular mechanisms under the comorbidity of obesity and breast cancer.

Dietary Fiber Modulates the Release of Gut Bacterial Products Preventing Cognitive Decline in an Alzheimer's Mouse Model

Fiber intake is associated with a lower risk for Alzheimer´s disease (AD) in older adults. Intake of plant-based diets rich in soluble fiber promotes the production of short-chain fatty acids (SCFAs: butyrate, acetate, propionate) by gut bacteria. Butyrate administration has antiinflammatory actions, but propionate promotes neuroinflammation. In AD patients, gut microbiota dysbiosis is a common feature even in the prodromal stages of the disease. It is unclear whether the neuroprotective effects of fiber intake rely on gut microbiota modifications and specific actions of SCFAs in brain cells. Here, we show that restoration of the gut microbiota dysbiosis through the intake of soluble fiber resulted in lower propionate and higher butyrate production, reduced astrocyte activation and improved cognitive function in 6-month-old male APP/PS1 mice. The neuroprotective effects were lost in antibiotic-treated mice. Moreover, propionate promoted higher glycolysis and mitochondrial respiration in astrocytes, while butyrate induced a more quiescent metabolism. Therefore, fiber intake neuroprotective action depends on the modulation of butyrate/propionate production by gut bacteria. Our data further support and provide a mechanism to explain the beneficial effects of dietary interventions rich in soluble fiber to prevent dementia and AD. Fiber intake restored the concentration of propionate and butyrate by modulating the composition of gut microbiota in male transgenic (Tg) mice with Alzheimer´s disease. Gut dysbiosis was associated with intestinal damage and high propionate levels in control diet fed-Tg mice. Fiber-rich diet restored intestinal integrity and promoted the abundance of butyrate-producing bacteria. Butyrate concentration was associated with better cognitive performance in fiber-fed Tg mice. A fiber-rich diet may prevent the development of a dysbiotic microbiome and the related cognitive dysfunction in people at risk of developing Alzheimer´s disease.

P-740 Social disparities in pregnancy awareness among individuals in the general U.S. population

Study question

What are socio-demographic and lifestyle characteristics of pregnant individuals who were aware versus those who were unaware of pregnancy status in the general U.S. population.

Summary answer

Women unaware of their pregnancy status were more likely to be Non-Hispanic Black, living below the poverty line, and unmarried.

What is known already

The early weeks of pregnancy are critical for fetal programming of organ systems and consequently long-term offspring health. Individuals who are unaware of pregnancy are at risk of poor nutrition, inadvertent environmental chemical exposures and risky behaviors/lifestyles that contribute to inadequate prenatal care. Lack of pregnancy awareness increases the risk of pregnancy complications and misses opportunities for early intervention.

Study design, size, duration

We included 842 individuals aged between 20 to 44 years who had a positive urine pregnancy test result at time of the cross-sectional National Health and Examination Survey (NHANES), 2003-2016 cycles.

Participants/materials, setting, methods

The urine pregnancy tests and reproductive health interviews were conducted concurrently in medical examination center. We defined participants with a positive urine pregnancy test result but who reported not being pregnant during the interview as being unaware of their pregnancy status. Information on demographic, socio-economic, and lifestyle characteristics were collected by questionnaires. We employed student t test and chi-square test to compare the characteristics between individuals who were aware vs. unaware of the pregnancy.

Main results and the role of chance

Among 842 pregnant individuals, 62 (7.36%) were unaware of their pregnancy status. The mean (SE) ages (years) were similar between individuals who were unaware vs. those aware of their pregnancy status (Unaware: 28.05 (0.96) vs. Aware: 28.48 (0.32)). Compared with aware individuals, a higher proportion of the unaware group were Non-Hispanic Black (Unaware: 36.31% vs. Aware: 13.06%; p &lt; 0.001), living in poverty (Unaware: 30.03% vs. Aware: 18.95%; p = 0.09), and unmarried (Unaware: 68.12% vs. Aware: 30.45%; p &lt; 0.001). No significant differences were found for education (College degree and above: Unaware: 60.73% vs. Aware: 67.73%; p = 0.33) and smoking behavior between the two groups (Current smoker: Unaware: 4.97% vs. Aware: 8.88%; p = 0.38).

Limitations, reasons for caution

The sample size of this study was relatively small. Findings may not be representative of population characteristics.

Wider implications of the findings

Our findings point to significant social disparities in pregnancy awareness and have important implications for clinical practice and early identification of high-risk pregnancies.

Trial registration number

not applicable

Genistein Stimulation of White Adipose Tissue Thermogenesis is Partially Dependent on GPR30 in Mice

SCOPE

Genistein increases whole body energy expenditure by stimulating white adipose tissue (WAT) browning and thermogenesis. G-Coupled receptor GPR30 can mediate some actions of genistein, however, it is not known whether it is involved in the activation of WAT-thermogenesis. Thus, the aim of the study was to determine whether genistein activates thermogenesis coupled to an increase in WAT browning and mitochondrial activity, in GPR30^+/+ and GPR30^-/- mice.

METHODS AND RESULTS

GPR30^+/+ and GPR30^-/- mice were fed control or high fat sucrose diets containing or not genistein for 8 weeks. Body weight and composition, energy expenditure, glucose tolerance and browning markers in WAT, and oxygen consumption rate, 3', 5'-cyclic adenosine monophosphate (cAMP) concentration and browning markers in adipocytes were evaluated. Genistein consumption reduced body weight and fat mass gain in a different extent in both genotypes, however, energy expenditure was lower in GPR30^-/- compared to GPR30^+/+ mice, accompanied by a reduction in browning markers, maximal mitochondrial respiration, cAMP concentration and browning markers in cultured adipocytes from GPR30^-/- mice. Genistein improved glucose tolerance in GPR30^+/+ , but this was partially observed in GPR30^-/- mice.

CONCLUSION

Our results showed that GPR30 partially mediates genistein stimulation of WAT thermogenesis and the improvement of glucose tolerance. This article is protected by copyright. All rights reserved.

Modulation of gut microbiota by Mantequilla and Melipona honeys decrease low-grade inflammation caused by high fructose corn syrup or sucrose in rats

Several studies have shown that consumption of honey is associated with various health benefits. However, there is scarce evidence on whether honeys modify the intestinal microbiota by preventing the inflammatory response in the host. Therefore, the aim of the present work was to study the effect of Melipona (Mel) and Mantequilla (Mtq) honeys, which contain different bioactive compounds and antioxidant capacity on gut microbiota and metabolic consequences in comparison with other sweeteners, in particular sucrose (S) and high fructose corn syrup (HFCS) in rats. The results of the present work showed that both honeys have polyphenols, flavonoids, antioxidant and bactericidal activities. Rats fed with both honeys gained less weight and body fat by increasing energy expenditure compared to S or HFCS and increased gene expression of antioxidant enzymes mediated by the transcription factor Nrf2. Analysis of the gut microbiota showed that consumption of both honeys modified the beta-diversity compared to those fed S or HFCS resulting in increased abundance of a specific cluster of bacteria of the Clostridium genus particularly Coprococcus eutactus, Defluviitalea saccharophila, Ruminicoccus gnavus and Ruminicoccus flavefaciens. As a result of the changes in the gut microbiota, there was a decrease in LPS- and TLR4-mediated low-grade inflammation and an increase in sIgA. Consumption of both honeys prevented glucose intolerance and increased adipocyte size compared to S or HFCS. In conclusion, consumption of MtqH or MelH can reduce metabolic endotoxemia by modifying the gut microbiota to prevent glucose intolerance.

Association of BCAT2 and BCKDH polymorphisms with clinical, anthropometric and biochemical parameters in young adults

BACKGROUND AND AIM

Circulating amino acids are modified by sex, body mass index (BMI) and insulin resistance (IR). However, whether the presence of genetic variants in branched-chain amino acid (BCAA) catabolic enzymes modifies circulating amino acids is still unknown. Thus, we determined the frequency of two genetic variants, one in the branched-chain aminotransferase 2 (BCAT2) gene (rs11548193), and one in the branched-chain ketoacid dehydrogenase (BCKDH) gene (rs45500792), and elucidated their impact on circulating amino acid levels together with clinical, anthropometric and biochemical parameters.

METHODS AND RESULTS

We performed a cross-sectional comparative study in which we recruited 1612 young adults (749 women and 863 men) aged 19.7 ± 2.1 years and with a BMI of 24.9 ± 4.7 kg/m². Participants underwent clinical evaluation and provided blood samples for DNA extraction and biochemical analysis. The single nucleotide polymorphisms (SNPs) were determined by allelic discrimination using real-time polymerase chain reaction (PCR). The frequencies of the less common alleles were 15.2 % for BCAT2 and 9.83 % for BCKDH. The subjects with either the BCAT2 or BCKDH SNPs displayed no differences in the evaluated parameters compared with subjects homozygotes for the most common allele at each SNP. However, subjects with both SNPs had higher body weight, BMI, blood pressure, glucose, and circulating levels of aspartate, isoleucine, methionine, and proline than the subjects homozygotes for the most common allele (P < 0.05, One-way ANOVA).

CONCLUSION

Our findings suggest that the joint presence of both the BCAT2 rs11548193 and BCKDH rs45500792 SNPs induces metabolic alterations that are not observed in subjects without either SNP.