ObjectiveTo assess the adipogenic potential and mitochondrial bioenergetics of umbilical cord mesenchymal stem cells (UC-MSCs) derived from infants born to mothers with divergent body mass index and to evaluate the associations between maternal BMI and adipogenic gene expression.MethodsUC-MSCs were isolated and cultured from infants born to mothers with normal weight (22.2 ± 0.3 kg/m2; NW-MSCs) or with overweight or obesity (29.3 ± 0.6 kg/m2; OW/OB-MSCs). Cells were collected at baseline (day 0) and after 7 and 14 days of differentiation to assess gene expression, protein levels, and mitochondrial respiration.ResultsOW/OB-MSCs exhibited an impaired adipogenic phenotype, characterized by reduced protein levels of Cebpa and Pparg during differentiation, along with diminished mitochondrial flexibility, as evidenced by a trend toward lower maximal respiration and spare respiratory capacity compared to NW-MSCs. In addition, relationships between body mass index and expressions of Cebpa and Pparg in OW/OB-MSCs differed from NW-MSCs, particularly by day 14.ConclusionsPrenatal exposure to maternal obesity may disrupt programming of adipose precursors in offspring, impairing their adipogenic capacity and mitochondrial function, and potentially predisposing them to metabolically compromised adipose tissue later in life.

Osteocytes, the most abundant bone cells, are central regulators of bone remodeling that also exert endocrine control over systemic metabolism. Among the factors they produce, Lipocalin-2 (LCN2) has emerged as a cytokine linking bone and energy homeostasis, yet its local role within the skeleton remains elusive. Here, we identify that LCN2 promotes intracellular iron accumulation, mitochondrial dysfunction, and lipid peroxidation through its receptor SLC22A17, and drives ferroptotic cell death. Dmp1-Cre–mediated deletion of Lcn2 preserves mitochondrial integrity, reduces intracellular iron and lipid peroxidation, and enhances osteocyte dendricity and lacunocanalicular connectivity. Mechanistically, loss of Lcn2 suppresses Wnt antagonists DKK1 and SOST, thereby promoting Wnt/β-catenin signaling and stimulating osteoblast-mediated bone formation. Notably, Dmp1-Cre-mediated deletion of Lcn2 does not alter systemic energy balance, underscoring LCN2’s local skeletal function. These findings define the LCN2–SLC22A17 axis as a local regulator of osteocyte ferroptosis, Wnt/β-catenin signaling, and skeletal fragility.

Primary aging associates with an imbalanced gut microbiome and cardiovascular disease (CVD) risk in mice and humans. Strong evidence from clinical and preclinical studies supports that habitual physical exercise improves cardiovascular function and intestinal health in adults. Here we tested the hypothesis that exercise training, even when initiated late-in-life, reestablishes a beneficial and cooperative intestinal microbiome to an extent that associates with reduced risk for CVD. At 21 mo of age, male C57BL/6 mice started a progressive resistance treadmill training program 6 days per week (Old + ETR) for 12 wk. Twenty-one-month-old (Old) and 4-mo-old (Adult) male mice remained sedentary. First, reductions in exercise capacity and soleus muscle citrate synthase activity displayed by Old vs. Adult mice were restored in Old + ETR animals. Next, systolic function [fractional shortening (FS)], diastolic function (E/A ratio), and overall left-ventricular function [myocardial performance index (MPI)] otherwise depressed in Old vs. Adult mice were normalized in Old + ETR animals. Third, elevated trimethylamine (TMA) and TMA N-oxide (TMAO), and heightened inflammatory markers [e.g., interferon (IFN)-γ and keratinocyte-derived chemokine (KC)], observed in Old vs. Adult mice were lowered in Old + ETR animals. Importantly, the abundance of beneficial microbial features, including Bacteroides, Muribaculaceae, Parabacteroides, and the Rikenellaceae RC9 gut group, otherwise depressed by aging, was normalized in Old + ETR mice. Finally, the Rikenellaceae RC9 gut group was positively correlated with FS, and Parabacteroides was negatively correlated with IFN-γ. These findings support that late-in-life exercise training beneficially remodels the gut microbiome to an extent that associates with reduced CVD risk in male mice.NEW & NOTEWORTHY It is unknown whether exercise training, if started late-in-life, reestablishes a beneficial and cooperative intestinal microbiome. Here we demonstrate that a 12-wk treadmill running program in older mice rejuvenates the gut microbiome and attenuates markers of cardiovascular disease (CVD) risk. Notably, specific microbial taxa correlate with activity-induced improvements in overall myocardial performance and inflammation, highlighting the importance of gut health on CVD and illustrating the restorative benefits that can be attained from a low-cost lifestyle intervention.

Introduction:Ambient temperature significantly influences physiological and metabolic processes in rodents, affecting obesity and related disorders. Mice housed below thermoneutral temperatures exhibit increased energy expenditure and sympathetic-driven brown fat activation, whereas thermoneutral housing (~30°C) reduces these responses. This study aimed to determine whether short-term exposure to altered housing temperatures before and during pregnancy induces lasting changes in maternal adipose tissue. We hypothesized that even brief exposure during this critical window could cause persistent structural and molecular alterations in adipose tissue. Methods:Female C57BL/6J mice were housed at cold (CE, 8°C), thermoneutral (TN, 30°C), or standard room temperature (RT, 22°C) conditions for one week before and throughout pregnancy. All mice were returned to RT post-delivery. Phenotypic assessments-including glucose tolerance, energy expenditure, histology, and proteomics-were performed after lactation. Results:Temperature exposure did not significantly affect litter size or pup survival. CE-exposed mice showed increased total body weight driven by lean mass gains and reduced fat mass. Adipose tissue showed smaller adipocytes in iWAT and increased vascularity in BAT, though no persistent changes in thermogenic gene expression or glucose homeostasis were observed. Proteomic analysis of iWAT identified 38 differentially expressed proteins, with enrichment of pathways related to mitochondrial function and mTOR signaling. Discussion:Short-term cold exposure induced lasting histological and proteomic changes in iWAT and BAT without sustained effects on energy metabolism, likely due to reversion to RT and limited sample size. Conclusion:Brief temperature manipulation around pregnancy can durably alter maternal adipose tissue architecture and molecular signatures, underscoring ambient temperature as an important modulator of maternal metabolic adaptation.

Maternal weight and diet before and during pregnancy have a substantial impact on offspring metabolic health, though sex-specific differences in metabolic and adipose tissue adaptations to maternal overnutrition remain insufficiently understood. Using a mouse model of maternal high-fat (HF) diet-induced obesity, this study assessed the sexually dimorphic responses on offspring adiposity, physiology, and adipose tissue function. Male offspring of HF diet-fed dams exhibited greater weight gain and adiposity, impaired glucose homeostasis, elevated serum levels of insulin, leptin, and cholesterol, along with increased adipogenic and heat shock proteins (HSPs) gene expression in white adipose tissue compared to female offspring. In established adipocyte cell lines independent of experimental animals, the expression of HSPs during differentiation was higher in white than in brown adipocytes. Also, expression of Hsp90ab1 in human umbilical cord mesenchymal stem cells tended to positively correlate with maternal body mass index in male, but not in female infants. This finding was generated independently of the animal model and were intended to strengthen the translational perspective of our work. Together, these results suggest a potential link between maternal diet, HSPs, and adipose tissue function.

This review takes a close look at the biology of brown and beige fat, not just as thermogenic tissues, but as active metabolic organs influenced by sex, hormones, age, and even environment. Brown adipose tissue (BAT) and beige adipocytes differ in their origins, gene expression, and regulation. These differences are especially relevant when considering how they behave in males and females. Across both animal and human studies, females show higher BAT volume and more efficient thermogenic activity. Estrogen, acting mainly through estrogen receptor alpha (ERα), increases uncoupling protein 1(UCP1) expression, promotes mitochondrial biogenesis, and supports the formation of beige fat within white adipose tissue. In contrast, testosterone and glucocorticoids tend to reduce thermogenic gene expression and shift fat storage toward visceral depots, which increases metabolic risk, particularly in men. These hormone-driven effects are not limited to adulthood. Puberty, pregnancy, menopause, and andropause all influence thermogenic capacity in sex-specific ways. We also outline the key signaling pathways behind beiging such as PR domain-containing 16 (PRDM16), Peroxisome proliferator activated receptor gamma coactivator 1-alpha (PGC-1α), and β3-adrenergic signaling and how they interact with sex hormones to shape thermogenic responses. Findings from Positron Emission Tomography with Computed Tomography (PET/CT) imaging, genetic models, and molecular profiling show that beige and brown fat are regulated by distinct mechanisms and developmental cues depending on sex. We also review how BAT activity is linked to a lower risk of type 2 diabetes, cardiovascular disease, and inflammation, particularly in women with obesity. Conditions like Polycystic Ovary Syndrome (PCOS), hormone therapy, and exposure to endocrine-disrupting chemicals further influence BAT function in sex dependent ways. Understanding how brown and beige fat respond differently in men and women to internal and external signals, is critical. These differences have clear implications for developing targeted, more effective strategies to treat obesity and metabolic disease.

Evidence suggests that a healthy gut microbiome is essential for metabolizing dietary phytochemicals. However, the microbiome’s role in metabolite production and the influence of gut dysbiosis on this process remain unclear. Further, studies on the relationship among gut microbes, metabolites, and biological activities of phytochemicals are limited. We addressed this knowledge gap using strawberry phytochemicals as a model. C57BL/6J mice were fed a standard diet [C]; strawberry-supplemented diet (~2 human servings) [CS]; strawberry-supplemented diet and treated with antibiotics (to deplete gut microbes) [CSA]; high-fat diet (HFD) [HF]; strawberry-supplemented HFD [HS]; and strawberry-supplemented HFD and treated with antibiotics [HSA] for 12 weeks. First, antibiotic treatment suppressed the production of selected metabolites (CSA vs. CS), and p-coumaric acid was identified as a strawberry-derived microbial metabolite. Second, HFD-induced dysbiosis negatively affected metabolite production (HS vs. HF), and hippuric acid was identified as a microbial metabolite in HFD conditions. Third, dietary strawberries improved HFD-induced vascular inflammation (HS vs. HF). However, antibiotic treatment reduced metabolite production and abolished the vascular effects of strawberries (HSA vs. HS), indicating the importance of gut microbes in mediating the vascular benefits of strawberries via metabolites. Fourth, strawberry supplementation decreased Coprobacillus that was positively associated with vascular inflammation, whereas it increased Lachnospiraceae that was negatively associated with vascular inflammation and positively associated with hippuric acid. Fifth, hippuric acid was negatively associated with vascular inflammation. Our study fills in some pieces of the giant puzzle regarding the influence of gut microbes on the biological activities of phytochemicals. HFD-induced gut dysbiosis negatively impacts metabolite production and a strong association exists among gut microbes, strawberry-derived microbial metabolites, and the vascular benefits of dietary strawberries. Further, our study provides significant proof of concept to warrant future research on the use of strawberries as a nutritional strategy to prevent vascular complications.

Proton pump inhibitors (PPIs) are commonly used to treat heartburn and acid-related disorders. However, their misuse and prolonged use contribute to gut dysbiosis. This study investigated whether well-known prebiotic dietary sources, blueberries or strawberries, can reverse PPI (omeprazole) induced dysbiosis and gut inflammation by modulating gut microbes. Male C57BL/6J mice (7 weeks old) were fed a diet with or without omeprazole (40 mg/kg diet), blueberry (3.7% in the diet; ∼1.5 human servings) or strawberry (2.35% in the diet; ∼2 human servings) for 12 weeks. Metabolic parameters, gut microbes (in the cecum and colon), and inflammatory markers were assessed. In this study, no changes were observed in metabolic parameters in mice fed a diet supplemented with omeprazole or berries. Second, blueberry or strawberry supplementation at nutritional dosages improved alterations in gut microbial ecology induced by omeprazole, with effects varying between the cecum and colon. Third, strawberry supplementation reduced omeprazole-induced gut inflammation. Fourth, selected genera were either positively or negatively associated with markers of gut inflammation, suggesting that dietary berries can ameliorate inflammatory signaling through modifications in the gut microbiome. Dietary berries represent a potential nutritional strategy for improving PPI-induced gut dysbiosis and inflammation.

Alzheimer's Disease (AD) is a debilitating neurocognitive disorder with an unclear underlying mechanism. Recent studies have implicated gut microbiota dysbiosis with the onset and progression of AD. The connection between gut microbiota and AD can significantly affect the prevention and treatment of AD patients. This systematic review summarizes primary outcomes of human and mouse AD models concerning gut microbiota alterations. A systematic literature search in February through March 2023 was conducted on PubMed, Embase, and Web of Science. We identified 711 as potential manuscripts of which 672 were excluded because of irrelevance to the identified search criteria. Primary outcomes include microbiota compositions of control and AD models in humans and mice. In total, 39 studies were included (19 mouse and 20 human studies), published between 2017 and 2023. We included studies involving well-established mice models of AD (5xFAD, 3xTg-AD, APP/PS1, Tg2576, and APPPS2) which harbor mutations and genes that drive the formation of Aß plaques. All human studies were included on those with AD or mild cognitive impairment. Among alterations in gut microbiota, most studies found a decreased abundance of the phyla Firmicutes and Bifidobacteria, a genus of the phylum Actinomycetota. An increased abundance of the phyla Bacteroidetes and Proteobacteria were identified in animal and human studies. Studies indicated that gut microbiota alter the pathogenesis of AD through its impact on neuroinflammation and permeability of the gastrointestinal tract. The ensuing increase in blood-brain barrier permeability may accelerate Aβ penetrance and formation of neuritic plaques that align with the amyloid hypothesis of AD pathogenesis. Further studies should assess the relationship between gut microbiota and AD progression and therapy preserving beneficial gut microbiota.

Background/Aim: This study examined the effects of tocotrienols (TT) in conjunction with statin on glucose homeostasis, bone microstructure, gut microbiome, and systemic and liver inflammatory markers in obese C57BL/6J mice. Materials and Methods: Forty male C57BL/6J mice were fed a high -fat diet (HFD) and assigned into four groups in a 2 (no statin vs. 120 mg statin/kg diet)x2 (no TT vs. 400 mg TT/kg diet) factorial design for 14 weeks. Results: Statin and TT improved glucose tolerance only when each was given alone, and only statin supplementation decreased insulin resistance. Consistently, only statin supplementation decreased serum insulin levels and HOMA-IR. Pancreatic insulin was also increased with statin treatment. Statin and TT, alone or in combination, reduced the levels of serum IL6, but only TT attenuated the increased serum leptin levels induced by a HFD. Statin supplementation increased bone area/total area and connectivity density at LV-4, while TT supplementation increased bone area/total area and trabecular number, but decreased trabecular separation at the distal femur. Statin supplementation, but not TT, reduced hepatic inflammatory cytokine gene expression. Neither TT supplementation nor statin supplementation statistically altered microbiome species evenness or richness. However, they altered the relative abundance of certain microbiome species. Most notably, both TT and statin supplementation increased the relative abundance of Lachnospiraceae UCG006. Conclusion: TT and statin collectively benefit bone microstructure, glucose homeostasis, and microbial ecology in obese mice. Such changes may be, in part, associated with suppression of inflammation in the host.

Background: Low cardiorespiratory fitness due to genetics increases the risk for cardiometabolic disease. Endurance exercise training promotes cardiorespiratory fitness and improves cardiometabolic risk factors, but with great heterogeneity. Here, we tested the hypothesis that the metabolic phenotype imparted by low parental (inborn) cardiorespiratory fitness would be overcome by early-life exercise training, and that exercise adaptations would be influenced in part by inborn fitness. Methods: At 26 days of age, male and female rat low-capacity runners (LCR, n=20) and high-capacity runners (HCR, n=20) generated by artificial selection were assigned to either sedentary control (CTRL, n=10) or voluntary wheel running (VWR, n=10) for 6 weeks. Post-intervention, whole-body metabolic phenotyping was performed, and the respiratory function of isolated skeletal muscle and liver mitochondria assayed. Transcriptomics and proteomics were performed on skeletal muscle and liver tissue using RNA-sequencing and mass spectrometry, respectively. Results: Daily VWR volume was 1.8-fold higher in HCR-VWR compared to LCR-VWR. In LCR, VWR reduced adiposity and enhanced glucose tolerance, coincident with elevated total energy expenditure. While intrinsic skeletal muscle mitochondrial respiratory function was unaffected by VWR, estimated skeletal muscle oxidative capacity increased in VWR groups owing to greater mitochondrial content. In the liver, both maximal oxidative capacity and ATP-linked respiration were higher in HCR-VWR than HCR-CTRL. Transcriptomic and proteomic profiling revealed extensive remodeling of skeletal muscle and liver tissue by VWR, elements of which were both shared and distinct based on inborn fitness. Summary: Early-life exercise training partially overcomes the metabolic phenotype imparted by low inborn cardiorespiratory fitness. However, molecular adaptations to VWR are partly influenced by inborn fitness, which may have implications for personalized exercise medicine. ### Competing Interest Statement The authors have declared no competing interest.

AbstractAlterations in the gut microbiome have been linked to obesity, with maternal high‐fat diet (HF) playing a role in shaping offspring microbiome composition. However, the sex‐specific responses to maternal HF diet and the impact of subsequent dietary challenges remain unclear. This study investigated the effects of maternal HF diet on offspring gut microbiota structure and predicted functional profile in response to short‐term postnatal HF diet exposure with a focus on sex‐specific responses. Female and male offspring of maternal control (C) diet or maternal HF diet were weaned onto C diet or HF diet. Offspring were euthanized at 13 weeks of age and cecal contents were collected for bacterial taxonomic profiling. Maternal HF diet reduced α‐diversity, notably in male offspring weaned onto HF diet. Sex‐specific differences were observed in the gut microbial composition and predicted functional potential. Furthermore, the influence of maternal diet on bacterial community structure and functional potential varied depending on postnatal diet. Maternal HF diet led to increased relative abundance of Corynebacterium in female offspring and decreased abundance of Akkermansia and Roseburia in male offspring. These findings underscore the sexually dimorphic nature of maternal HF diet effects on gut microbiota composition and function, with implications for developmental programming and metabolic health.

Gut microbes play a pivotal role in host physiology by producing beneficial or detrimental metabolites. Gut bacteria metabolize dietary choline and L-carnitine to trimethylamine (TMA) which is then converted to trimethylamine-N-oxide (TMAO). An elevated circulating TMAO is associated with diabetes, obesity, cardiovascular disease, and cancer in humans. In the present study, we investigated the effect of dietary blueberries and strawberries at a nutritional dosage on TMA/TMAO production and the possible role of gut microbes. Blueberry cohort mice received a control (C) or freeze-dried blueberry supplemented (CB) diet for 12 weeks and subgroups received an antibiotics cocktail (CA and CBA). Strawberry cohort mice received a control (N) or strawberry-supplemented (NS) diet and subgroups received antibiotics (NA and NSA). Metabolic parameters, choline, TMA, and TMAO were assessed in addition to microbial profiling and characterization of berry powders. Blueberry supplementation (equivalent to 1.5 human servings) reduced circulating TMAO in CB versus C mice (~48%) without changing choline or TMA. This effect was not mediated through alterations in metabolic parameters. Dietary strawberries did not reduce choline, TMA, or TMAO. Depleting gut microbes with antibiotics in these cohorts drastically reduced TMA and TMAO to not-quantified levels. Further, dietary blueberries increased the abundance of bacterial taxa that are negatively associated with circulating TMA/TMAO suggesting the role of gut microbes. Our phenolic profiling indicates that this effect could be due to chlorogenic acid and increased phenolic contents in blueberries. Our study provides evidence for considering dietary blueberries to reduce TMAO and prevent TMAO-induced complications.

Activation of thermogenic adipose tissue depots has been linked to improved metabolism and weight loss. To study the molecular regulation of adipocyte thermogenesis, we performed RNA‐Seq on brown adipose tissue (BAT), gonadal white adipose tissue (gWAT), and inguinal white adipose tissue (iWAT) from mice treated with β3‐adrenoreceptor agonist CL316,243 (CL). Our analysis revealed diverse transcriptional profile and identified pathways in response to CL treatment. Differentially expressed genes (DEGs) in iWATCL were associated with the upregulation of pathways involved in cellular immune responses and with the upregulation of the browning program. We identified 39 DEGs in beige adipose which included certain heat shock proteins (Hspa1a and Hspa1b), and others suggesting potential associations with browning. Our results highlight transcriptional heterogeneity across adipose tissues and reveal genes specifically regulated in beige adipose, potentially aiding in identifying novel browning pathways.

Evidence from our lab and others indicates the vascular effects of dietary blueberries. In the present study, we determined dietary blueberries' dose- and time-dependent effects on diabetic vasculature and their association with gut microbes. Seven-week-old db/db diabetic male mice were fed a diet supplemented with ± freeze-dried wild blueberry powder (FD-BB) for 4, 8, or 12 weeks (three cohorts). Diets contained 0%, 1.23%, 2.46%, and 3.7% of FD-BB, equivalent to 0, ½, 1, and 1.5 human servings of wild blueberries, respectively. The non-diabetic db/+ mice fed a standard diet served as controls. Metabolic parameters, vascular inflammation, and gut microbiome were assessed. Dietary supplementation of 3.7% FD-BB improved vascular inflammation in diabetic mice without improving systemic milieu in all three cohorts. Blueberries improved diabetes-induced gut dysbiosis depending on blueberry dosage and treatment duration. Spearman's correlation indicated that the opportunistic microbes and commensal microbes were positively and negatively associated with indices of vascular inflammation, respectively. Dietary blueberries reduced the opportunistic microbe that was positively associated with vascular inflammation (Desulfovibrio), and increased the commensal microbe that was negatively associated with vascular inflammation (Akkermansia). Dietary blueberries could be a potential adjunct strategy to beneficially modulate gut microbes and improve vascular complications in diabetes.

SCOPE:Gut microbiota depletion using antibiotics in drinking water is a valuable tool to investigate the role of gut microbes and microbial metabolites in health and disease. However, there are challenges associated with this model. Animals avoid drinking water because of the antibiotic bitterness, which affects their metabolic health. The present study develops an efficient strategy to deplete gut microbes without affecting metabolic parameters. METHODS AND RESULTS:Male C57BL/6J mice (7 weeks old) are fed a control (C) or high-fat (HF) diet. Subgroups of C and HF mice receive an antibiotic cocktail in drinking water (CA and HA). The antibiotic dosage is gradually increased so that the animals adapt to the taste of antibiotics. Metabolic parameters, gut microbiome, and microbial metabolites are assessed after 12 weeks treatment. Culture methods and 16s rRNA amplification confirm the depletion of gut microbes in antibiotic groups (CA and HA). Further, antibiotic treatment does not alter metabolic parameters (body weight, body fat, lean body mass, blood glucose, and glucose/insulin tolerance), whereas it suppresses the production of diet-derived microbial metabolites (trimethylamine and trimethylamine-N-oxide). CONCLUSION:This strategy effectively depletes gut microbes and suppresses the production of microbial metabolites in mice without affecting their metabolic health.