Pregnancy is a dynamic physiological state characterized by extensive metabolic changes. The development of insulin resistance later in gestation is a normal adaptation that supports fetal growth and a physiological response in pregnancy. However, if metabolic aberrations occur above the normal insulin resistance, gestational diabetes mellitus, a form of diabetes that appears during pregnancy, can develop. Multi-omics approaches are powerful tools to uncover the mechanisms that drive metabolic changes in different physiological and pathological states. A recent multi-omics mouse study collected pregnancy-specific physiological and metabolic profiles, 16S rRNA microbiome, and plasma untargeted LC-MS metabolome data from 3 genetically diverse strains of mice (C57BL/6J, CD1, and NIH-Swiss) over 6 timepoints: gestational days 0, 10, 15, and 19, and postpartum days 3 and 20, totaling 60 samples for each strain. To facilitate the utilization of these impactful data by other researchers, we developed Multi-omics Metabolic & Microbiome Profiling of Mouse Pregnancy (MOMMI-MP), a database that provides an easy-to-use platform to browse and search differentially abundant microbial taxa, metabolites, metabolic pathways, and predicted micro-metabolite interactions using an array of state-of-the-art statistical and machine learning models. Our analysis revealed a previously unrecognized gut microbial–host metabolic pathway involving indoleamine 2,3-dioxygenase 1 (IDO1) and kynurenine, which plays a crucial role in mediating pregnancy-related metabolic adaptations, as well as other significant microbiome and metabolic changes. The computational results are presented in various tables and plots, organized in MOMMI-MP, to empower exploratory analyses by other researchers. Representing a significant new resource, MOMMI-MP provides a tool for researchers to facilitate the investigation of novel mechanisms governing metabolic changes during pregnancy. Received: 17 August 2025 | Revised: 9 November 2025 | Accepted: 4 January 2026 Conflicts of Interest The authors declare that they have no conflicts of interest to this work. Data Availability Statement The data that support the findings of this study are openly available in the MOMMI-MP database at https://mommi-mp.github.io/Plots/index.html. Author Contribution Statement Kaustubh K. Pachpor: Methodology, Software, Validation, Formal analysis, Investigation, Resources, Data curation, Writing – original draft, Visualization. Julianne Jorgensen: Methodology, Formal analysis, Investigation, Resources, Data curation, Writing – review & editing, Visualization. Medha Priyadarshini: Methodology, Validation, Formal analysis, Investigation, Resources, Data curation. Derek J. Reiman: Methodology, Formal analysis, Investigation, Resources, Data curation. Brian T. Layden: Conceptualization, Investigation, Resources, Writing – review & editing, Supervision, Project administration. Yang Dai: Conceptualization, Methodology, Software, Investigation, Resources, Data curation, Writing – review & editing, Supervision, Project administration.

Changes in gut microbiota composition due to diet impact health. Fiber-rich diets promote beneficial microbiota and reduce the risk of metabolic diseases, while low-fiber, calorie-dense diets are linked to dysbiosis and increased disease risk. This study examines the effects of a Western diet (WD) and explores dietary fiber supplements as potential modifiers of those effects. 10-week-old C57Bl/6J male mice were fed control (low-fat) or WD (high-fat, high-sucrose) containing 0% fermentable fiber (FF) or WD supplemented with 20% FF (fructooligosaccharides, FOS; guar gum, GG, or pectin, Pec). After 19 weeks, analysis of the cecal metagenome using whole-genome shotgun sequencing, metabolome by untargeted and targeted LC-MS/MS, and tissue RNA and protein expression by RT-PCR and immunoblotting was undertaken. WD-FF reduced metabolic derangements from WD while also improving GM diversity and altering cecal metabolites, particularly tryptophan metabolism. A profound increase in cecal indole levels (targeted metabolomics) was noted in WD vs WD-FF groups. As the primary indole-oxidizing enzyme, CYP2E1 generates indoxyl sulfate, which contributes to oxidative stress and a leaky gut. Mice on WD displayed higher expression of Cyp2e1 mRNA in the gut. In the liver, the levels of both CYP2E1 protein and mRNA were higher in the WD group compared to the WD-FOS group, with protein levels also higher than in the WD-Pec group and mRNA levels higher than in the WD-GG group. mRNA expression of markers of oxidative stress, inflammation, and leaky barrier was significantly higher in the liver and intestine of the WD vs the WD-FF groups. FFs reduced high plasma indoxyl sulfate levels (except in WD-GG), and boosted short-chain fatty acids and indole acetic acid. Our data suggest that WD disrupts GM tryptophan metabolism, possibly by altering the balance between indole-producing and utilizing gut bacteria. Dietary fiber supplementation exerts protective effects, in part, by mitigating this imbalance.

Heart failure with preserved ejection fraction (HFpEF) is a multisystemic syndrome that accounts for more than half of all heart failure cases and causes a substantial burden of morbidity and mortality. In contrast to heart failure with reduced ejection fraction (HFrEF), few disease-modifying therapies exist for HFpEF, reflecting differences in pathophysiology. Low fermentable fiber (FF) intake, gut dysbiosis, and depletion of short-chain fatty acids (SCFAs), microbial metabolites central to immune, metabolic, and vascular homeostasis, are increasingly linked to the pathophysiology of HFpEF. Here, we synthesize preclinical and clinical evidence on FF and SCFAs and evaluate their therapeutic relevance to HFpEF. Preclinical studies demonstrate that FF supplementation or direct SCFA administration improves cardiometabolic function and attenuates cardiac remodeling through SCFA receptor signaling, enhanced nitric oxide bioavailability, reduced inflammation, and metabolic support of the energy-starved failing heart. Supporting the translational relevance of these findings, a systematic review of 27 human randomized controlled trials showed that FF interventions exert microbiome-mediated effects, enriching SCFA-producing taxa and augmenting fecal and circulating SCFA levels, while improving insulin sensitivity and reducing abdominal adiposity and LDL cholesterol. Direct SCFA supplementation increases SCFA availability and provides modest metabolic benefits, including reduced adiposity and liver fat. However, its effects are inconsistent. Collectively, these findings provide a mechanistic and translational rationale for FF-based interventions in HFpEF. To date, no clinical trials have evaluated the effects of FF on HFpEF-specific outcomes. Clinical studies are therefore needed to determine whether increasing FF intake can improve symptoms, cardiac function, and disease progression in HFpEF.

Abstract Obesity and related metabolic disorders are often characterized by chronic adipose tissue inflammation, driving systemic insulin resistance and general metabolic dysfunction. Free Fatty Acid Receptor 2 (FFA2) has emerged as a potential modulator of adipocyte function, inflammation, and metabolism. To investigate the role of FFA2 expressed in the adipose tissue, we generated adipose‐specific FFA2 knockout mice (Adipoq‐F2‐KO) and assessed metabolic outcomes under standard laboratory chow and high‐fat, high‐sugar Western diet conditions, with and without dietary fiber supplementation. We found that adipose‐specific FFA2 deletion had minimal metabolic consequences under standard dietary conditions but significantly reduced body weight and adiposity when mice were fed a fiber (fructooligosaccharide)‐supplemented Western diet. Subsequent fecal analyses and transcriptomic profiling indicated impaired intestinal lipid absorption as the primary driver of reduced adiposity, suggesting disrupted adipose‐intestinal communication. Unexpectedly, the lighter Adipoq‐F2‐KO mice also exhibited heightened adipose inflammation, characterized by increased macrophage infiltration and pro‐inflammatory cytokine expression. Furthermore, in vitro loss‐of‐function experiments in adipocytes revealed that FFA2 knockdown impaired adipocyte maturation, lipid storage, and anti‐inflammatory signaling. Additional studies using intestinal epithelial cells exposed to adipocyte‐conditioned media implicated adipose‐derived signals in driving intestinal dysfunction. Collectively, our findings highlight adipose‐specific FFA2 as critical in regulating adipose tissue inflammation, lipid metabolism, and inter‐organ communication.

Muscle tissue is highly exposed to free radicals owing to oxidative stress as a result of strenuous exercise. Damaged proteins are often functionally inactive and their unfolding is associated with enhanced susceptibility to proteinases. An investigation was carried out in which we exposed muscle cystatin to free radicals and also explored the anti-oxidant potential of green tea flavonoids epicatechin (EC) and epigallocatechin gallate (ECGC). The experiments were focused on examining the effect of reactive species on muscle cystatin and also investigating the potential of EGCG and EC to protect its damage against deleterious effects of the radicals by analysing papain inhibitory activity along with intrinsic fluorescence behaviour of treated muscle cystatin. Nitric oxide (NO) was generated from sodium nitroprusside (SNP) (nitric oxide donor) and measured by the Griess reaction. The treatment of cystatin purified from muscle with the NO-generating compound SNP causes concentration and time-dependent loss of enzyme activity. The modification of the microenvironment of aromatic residues of muscle cystatin in the presence of NO was studied by monitoring the changes in intensity and wavelength of emission maximum as a function of SNP concentration. Fluorescence spectra of muscle cystatin in the presence of NO showed quenching of fluorescence intensity coupled with 5 nm red shift. It was found that EGCG prevented NO-induced functional and structural damage of muscle cystatin while for reclamation to similar extent approximately 3 times concentration of EC was required as indicated by activity and fluorescence measurements. Fluorescence studies have proved that EGCG inhibits oxidative stress strongly and in a concentration-dependent manner. However, the NO scavenging effect depicted the order EGCG > EC. Thus, the widespread dietary consumption of green tea by the human population provides a rather inexpensive therapeutic option against oxidative injury.

The global prevalence of Metabolic Dysfunction-Associated Steatohepatitis (MASH) has been rising sharply, closely mirroring the increasing rates of obesity and metabolic syndrome. MASH exhibits a strong sexual dimorphism where females are affected with more severe forms after menopause. Hexokinase domain-containing protein 1 (HKDC1) has recently been recognized for its role in liver diseases, where its expression is minimal under normal conditions but significantly increases in response to metabolic stressors like obesity and liver injury. This selective upregulation suggests HKDC1's potential specialization in hepatic glucose and lipid dysregulation, linking it closely to the progression of MASH. This study aims to clarify the role of HKDC1 in Western diet-induced MASH in female mice by examining its impact on hepatic glucose and lipid metabolism, offering insights into its potential as a therapeutic target and addressing the need for sex-specific research in liver disease. This study reveals that HKDC1 expression is elevated in obese women with MASH and correlates with liver pathology. In a mouse model, liver-specific HKDC1 knockout (HKDC1LKO) protected against Western diet-induced obesity, glucose intolerance, and MASH features, including steatosis, inflammation, and fibrosis. Transcriptomic analysis showed that HKDC1 deletion reduced pro-inflammatory and pro-fibrotic gene expression, while gut microbiome analysis indicated a shift toward MASH-protective bacteria. These findings suggest that HKDC1 may exacerbate MASH progression through its role in metabolic and inflammatory pathways, making it a potential therapeutic target.

Reduced enrichment of short-chain fatty acid (SCFA)-producing pathways in the gut microbiome (GM) and SCFA levels are associated with increased risk of type 1 diabetes (T1D). Free fatty acid receptor 2 (FFA2), an SCFA receptor on pancreatic β-cells, mediates GM and β-cell crosstalk. Here, we examine its T1D-specific role in male mice, using a novel tamoxifen-inducible adult-onset β-cell FFA2 knockout (FFA2 βKO) mouse model and its controls (cre and flox), treated with multiple low-dose streptozotocin (MLDS). FFA2 βKO mice show significantly lower diabetes incidence compared to control mice (57% vs 100%). Early in the MLDS insult (7th day), FFA2 βKO mice show significantly lower β-cell apoptosis and higher β-cell mass, persisting up to 43 days. Mechanistically, we observed higher SOCS1/3 expression and reduced T1-IFN signaling in FFA2 βKO islets. Our data suggest that β-cell FFA2 modulates early islet apoptosis, likely via the T1-IFN-SOCS1/3 pathway and may be a pharmacological target for slowing T1D progression.

Introduction and Objective: The Gut Microbiome (GM) is a large player in maintaining whole body health, while dysregulation is linked to pathologies including obesity and Type 2 Diabetes. Microbes influence host function by producing metabolites, such as short chain fatty acids (SCFAs), produced when the GM ferments soluble fibers. Fiber intake is known to increase gut microbiome diversity, leading to protection against obesity, type 2 diabetes, and other metabolic dysfunctions. While SCFAs have been implicated in this process, the overall mechanism is still unclear. Globally expressed GPCRs, free fatty acid receptors 2 and 3 (FFA2 and FFA3) sense SCFAs and can modulate subsequent effects. For this reason, complete understanding of their function is necessary as the receptors may have significant therapeutic value in the treatment of the obesity epidemic and diabetes. Methods: We seek to understand the whole-body impact of the microbiome-fiber-SCFA-FFA2/3 axis in metabolic syndrome by characterizing novel global Ffar2/Ffar3 double KO mice, and matched WT controls, fed a high-fat high-sugar western diet (WD) supplemented with or without fermentable fiber. Metabolic analyses were conducted, including body weight and insulin resistance tracking, measuring food intake and energy expenditure via indirect calorimetry, and RNA seq of intestinal mucosa. Results: Wild type mice fed the WD diet supplemented with fiber were protected from increased body weights and insulin resistance seen in both DKO and WT mice on the same diet. DKO mice fed a WD supplemented with fiber were not protected. There were no differences in food intake observed. RNA seq of jejunal tissue shows DKO mice fed fiber-supplemented diets have increased anti-microbial peptide production. Conclusion: This confirms that the action of fiber-produced SCFAs occurs at least partially through FFA2 and FFA3 signaling pathways. No relevant differences in food intake and energy expenditure were observed, suggesting that FFA2/FFA3 activity in intestinal absorption and health impact whole body physiology. N. Pandya: None. M. Priyadarshini: None. B.T. Layden: None. VA -1I01BX003382 NIH NIDDK (R01DK104927) UICCOM

PURPOSE OF REVIEW:This review evaluates the current knowledge of gut microbiome alterations in acute pancreatitis, including those that can increase acute pancreatitis risk or worsen disease severity, and the mechanisms of gut microbiome driven injury in acute pancreatitis. RECENT FINDINGS:Recent observational studies in humans showed the association of gut microbiome changes (decreased gut microbiome diversity, alterations in relative abundances of certain species, and association of unique species with functional pathways) with acute pancreatitis risk and severity. Furthermore, in-vivo studies highlighted the role of gut microbiome in the development and severity of acute pancreatitis using FMT models. The gut barrier integrity, immune cell homeostasis, and microbial metabolites appear to play key roles in acute pancreatitis risk and severity. SUMMARY:Large human cohort studies that assess gut microbiome profile, its metabolites and impact on acute pancreatitis risk and severity will be crucial for development of innovative prediction, prevention and treatment strategies.

Background: Studies suggest that short chain fatty acids (SCFAs), which are primarily produced from fermentation of fiber, regulate insulin secretion through free fatty acid receptors 2 and 3 (FFA2 and FFA3). As these are G-protein coupled receptors (GPCRs), they have potential therapeutic value as targets for treating type 2 diabetes (T2D). The exact mechanism by which these receptors regulate insulin secretion and other aspects of pancreatic beta cell function is unclear. It has been reported that glucose-dependent release of acetate from pancreatic beta cells negatively regulates glucose stimulated insulin secretion. While these data raise the possibility of acetate's potential autocrine action on these receptors, these findings have not been independently confirmed, and multiple concerns exist with this observation, particularly the lack of specificity and precision of the acetate detection methodology used. Methods: Using Min6 cells and mouse islets, we assessed acetate and pyruvate production and secretion in response to different glucose concentrations, via liquid chromatography mass spectrometry. Results: Using Min6 cells and mouse islets, we showed that both intracellular pyruvate and acetate increased with high glucose conditions; however, intracellular acetate level increased only slightly and exclusively in Min6 cells but not in the islets. Further, extracellular acetate levels were not affected by the concentration of glucose in the incubation medium of either Min6 cells or islets. Conclusions: Our findings do not substantiate the glucose-dependent release of acetate from pancreatic beta cells, and therefore, invalidate the possibility of an autocrine inhibitory effect on glucose stimulated insulin secretion.

Short-chain fatty acids (SCFAs) are key nutrients that play a diverse set of roles in physiological function, including regulating metabolic homeostasis. Generated through the fermentation of dietary fibers in the distal colon by the gut microbiome, SCFAs and their effects are partially mediated by their cognate receptors, including free fatty acid receptor 2 (FFA2). FFA2 is highly expressed in the intestinal epithelial cells, where its putative functions are controversial, with numerous in vivo studies relying on global knockout mouse models to characterize intestine-specific roles of the receptor. Here, we used the Villin-Cre mouse line to generate a novel, intestine-specific knockout mouse model for FFA2 (Vil-FFA2) to investigate receptor function within the intestine. Because dietary changes are known to affect the composition of the gut microbiome, and can thereby alter SCFA production, we performed an obesogenic challenge on male Vil-FFA2 mice and their littermate controls (FFA2-floxed, FFA2fl/fl) to identify physiological changes on a high-fat, high-sugar 'Western diet' (WD) compared to a low-fat control diet (CD). We found that the WD-fed Vil-FFA2 mice were transiently protected from the obesogenic effects of the WD and had lower fat mass and improved glucose homeostasis compared to the WD-fed FFA2fl/fl control group during the first half of the study. Additionally, major differences in respiratory exchange ratio and energy expenditure were observed in the WD-fed Vil-FFA2 mice, and food intake was found to be significantly reduced at multiple points in the study. Taken together, this study uncovers a novel role of intestinal FFA2 in mediating the development of obesity.

Obesity is linked to 30-53% of new diabetes cases in the U.S. yearly. This project investigates how supplementation with fructo-oligosaccharides (FOS), a widely used dietary fiber, protects against diet induced obesity (DIO) by decreasing bodyweight (BW) and fat accumulation. The beneficial effects of FOS are largely attributed to the production of Short-Chain Fatty Acids (SCFA) through gut microbiota-mediated fermentation. Our findings indicate that supplementing a Western diet (WD) with 10% FOS for 8 weeks increases SCFA levels in the bloodstream, prevents weight gain in mice, and reduces markers of hypothalamic inflammation and microglial activation. Building on these findings, we further investigated the short-term effects of 7-day FOS supplementation. We found that adding 10% FOS to the WD completely prevented body weight gain and fat mass accumulation, while also lowering fasting blood glucose levels. Notably, mice treated with FOS maintained circadian oscillation of fuel utilization, as observed through the respiratory exchange ratio (RER), in contrast to WD-treated mice whose RER oscillation was disrupted within the first day of the diet. These protective effects were accompanied by reduced expression of hypothalamic interleukin-6 and iNOS after just 1 day of diet treatment. Taken together, our results suggest that early suppression of hypothalamic inflammation may be responsible for the beneficial effects of FOS supplementation. Understanding the mechanisms underlying the protective effects of FOS is a crucial step in developing new dietary strategies and therapeutic targets to address the obesity epidemic and its associated comorbidities. Disclosure M.D. Munoz: None. X. Yang: None. P. Luo: None. V.C. Torres Irizarry: None. L. Carrillo-Sáenz: None. M. Priyadarshini: None. B.T. Layden: None. P. Xu: None. Funding National Institutes of Health (R01DK123098)

Abstract Disclosure: N.S. Pandya: None. M. Priyadarshini: None. B.T. Layden: None. The Gut Microbiome (GM) is a key player in whole body metabolism. Microbial dysregulation and dysbiosis have been linked to multiple pathologies including obesity and type 2 diabetes. Microbes influence host function by releasing various metabolites when interacting with ingested materials. Key metabolites include short chain fatty acids (SCFAs) produced through microbial fermentation of fiber. Fiber intake is known to increase GM diversity; this process has been suggested to protect against obesity and type 2 diabetes. While SCFAs have been implicated in this process, the overall mechanism is still unclear. Free fatty acid receptors 2 and 3 (FFA2 and FFA3) occupy a unique position through which the GM can exert an effect on host metabolism. These G-protein coupled receptors are known to sense SCFAs and can modulate the subsequent secretion of incretin and insulin hormones thus regulating host appetite and blood-glucose control. FFA2 and FFA3 are expressed in many tissues, including adipocytes, neurons, and most importantly, intestinal enteroendocrine L cells and pancreatic β cells. For this reason, complete understanding of their function is necessary, and elucidating their signaling mechanisms may have significant therapeutic value in the treatment of the obesity epidemic and diabetes. Here, we seek to understand the whole-body impact of the gut microbiota-SCFA-FFA2/3 axis in the metabolically protective role of fiber. We used here a novel whole-body FFA2/FFA3 double knockout (F2,3-dKO) mouse model to obtain a holistic understanding of SCFA sensing mechanisms when mice are fed obesogenic diets supplemented with or without fermentable fiber. Double knockout mice, alongside matched wild-type controls were challenged with either a high fat western diet (WD), or WD supplemented with 20% fructooligosaccharides (FOS), a fermentable fiber (WD + 20% FOS). Preliminary data showed a significant rise in body weight, fat mass, and insulin resistance in WD fed F2,3-dKO mice alongside matched wild-type controls. Wild-type mice, when challenged with WD supplemented with fiber, were protected from this effect with only a mild increase in body weight and insulin resistance. Interestingly, F2,3-dKO mice, fed WD + 20% FOS were insensitive to fiber induced metabolic benefits. This suggests that FFA2 and FFA3 are essential for fermentable fiber mediated metabolic benefits against WD induced obesity. Further studies are now aimed to understand the mechanism behind this protective effect. Presentation: Friday, June 16, 2023

Replacement of β cells is only a curative approach for type 1 diabetes (T1D) patients to avoid the threat of iatrogenic hypoglycemia. In this pursuit, islet allotransplantation under Edmonton's protocol emerged as a medical miracle to attain hypoglycemia-free insulin independence in T1D. Shortage of allo-islet donors and post-transplantation (post-tx) islet loss are still unmet hurdles for the widespread application of this therapeutic regimen. The long-term survival and effective insulin independence in preclinical studies have strongly suggested pig islets to cure overt hyperglycemia. Importantly, CRISPR-Cas9 technology is pursuing to develop "humanized" pig islets that could overcome the lifelong immunosuppression drug regimen. Lately, induced pluripotent stem cell (iPSC)-derived β cell approaches are also gaining momentum and may hold promise to yield a significant supply of insulin-producing cells. Theoretically, personalized β cells derived from a patient's iPSCs is one exciting approach, but β cell-specific immunity in T1D recipients would still be a challenge. In this context, encapsulation studies on both pig islet as well as iPSC-β cells were found promising and rendered long-term survival in mice. Oxygen tension and blood vessel growth within the capsules are a few of the hurdles that need to be addressed. In conclusion, challenges associated with both procedures, xenotransplantation (of pig-derived islets) and stem cell transplantation, are required to be cautiously resolved before their clinical application.