Diet, Gut Microbiota, and Obesity: Links with Host Genetics and Epigenetics and Potential Applications

Beneficial effect of consuming milk containing only A2 beta-casein on gut microbiota: A single-center, randomized, double-blind, cross-over study

Cow milk contains essential nutrients, with β-casein existing in A1 and A2 forms. Studies suggest that A2 milk (containing only A2 β-casein) may offer gastrointestinal (GI) benefits compared to A1/A2 milk (containing both forms). This study investigated the effects of A2 milk consumption on the gut microbiota of South Korean cohort experiencing GI discomfort after consuming A1/A2 milk. Thirty-five participants with GI discomfort after milk consumption were included. Stool DNA was analyzed using 16S rRNA gene sequencing before and after consuming either A1/A2 or A2 milk. Beta diversity analysis using the generalized UniFrac distance method revealed a significant shift in gut microbiota composition after A2 milk consumption (p = 0.04), but no significant change after consuming A1/A2 milk. Significant differences in gut microbiota composition were found between A1/A2 and A2 milk drinkers after milk consumption (p = 0.031). Alpha diversity indices remained unchanged. Notable increases in beneficial microbes, including Bifidobacterium and Blautia, were observed after A2 milk intake. Linear discriminant analysis Effect Size (LEfSe) analysis identified significant enrichment of Actinobacteria, particularly Bifidobacterium longum and Blautia wexlerae, in the A2 group. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis highlighted enriched transport systems related to energy, peptides, sugars, and raffinose family oligosaccharides in the A2 group. Spearman correlation showed significant associations between Bifidobacterium, Blautia, and enhanced transport systems exclusively in the A2 group. Two weeks of A2 milk consumption led to significant alterations in gut microbiota, promoting beneficial microbes and related functions. A2 milk could be a suitable alternative for subjects who experience milk-intake-related GI discomfort.

Exhaustive Search of Dietary Intake Biomarkers as Objective Tools for Personalized Nutrimetabolomics and Precision Nutrition Implementation

OBJECTIVE

To conduct an exhaustive scoping search of existing literature, incorporating diverse bibliographic sources to elucidate the relationships between metabolite biomarkers in human fluids and dietary intake.

BACKGROUND

The search for biomarkers linked to specific dietary food intake holds immense significance for precision health and nutrition research. Using objective methods to track food consumption through metabolites offers a more accurate way to provide dietary advice and prescriptions on healthy dietary patterns by healthcare professionals. An extensive investigation was conducted on biomarkers associated with the consumption of several food groups and consumption patterns. Evidence is integrated from observational studies, systematic reviews, and meta-analyses to achieve precision nutrition and metabolism personalization.

METHODS

Tailored search strategies were applied across databases and gray literature, yielding 158 primary research articles that met strict inclusion criteria. The collected data underwent rigorous analysis using STATA and Python tools. Biomarker-food associations were categorized into 5 groups: cereals and grains, dairy products, protein-rich foods, plant-based foods, and a miscellaneous group. Specific cutoff points (≥3 or ≥4 bibliographic appearances) were established to identify reliable biomarkers indicative of dietary consumption.

RESULTS

Key metabolites in plasma, serum, and urine revealed intake from different food groups. For cereals and grains, 3-(3,5-dihydroxyphenyl) propanoic acid glucuronide and 3,5-dihydroxybenzoic acid were significant. Omega-3 fatty acids and specific amino acids showcased dairy and protein foods consumption. Nuts and seafood were linked to hypaphorine and trimethylamine N-oxide. The miscellaneous group featured compounds like theobromine, 7-methylxanthine, caffeine, quinic acid, paraxanthine, and theophylline associated with coffee intake.

CONCLUSIONS

Data collected from this research demonstrate potential for incorporating precision nutrition into clinical settings and nutritional advice based on accurate estimation of food intake. By customizing dietary recommendations based on individualized metabolic profiles, this approach could significantly improve personalized food consumption health prescriptions and support integrating multiple nutritional data.This article is part of a Nutrition Reviews special collection on Precision Nutrition.

Gut-on-a-chip platforms: Bridging in vitro and in vivo models for advanced gastrointestinal research

The gastrointestinal (GI) tract plays a critical role in nutrient absorption, immune responses, and overall health. Traditional models such as two-dimensional cell cultures have provided valuable insights but fail to replicate the dynamic and complex microenvironment of the human gut. Gut-on-a-chip platforms, which incorporate cells located in the gut into microfluidic devices that simulate peristaltic motion and fluid flow, represent a significant advancement in modeling GI physiology and diseases. This review discusses the evolution of gut-on-a-chip technology, from simple cellular mono-cultures models to more sophisticated systems incorporating bi-cultures and tri-cultures that enable studies of drug metabolism, disease modeling, and gut-microbiome interactions. Although challenges remain, including maintaining long-term cell viability and replicating immune responses, these platforms hold great potential for advancing personalized medicine and improving drug discovery efforts targeting gastrointestinal disorders.

Microbiota, mitochondria, and epigenetics in health and disease: converging pathways to solve the puzzle

Dysbiosis, which refers to an imbalance in the composition of the gut microbiome, has been associated with a range of metabolic disorders, including type 2 diabetes, obesity, and metabolic syndrome. Although the exact mechanisms connecting gut dysbiosis to these conditions are not fully understood, various lines of evidence strongly suggest a substantial role for the interaction between the gut microbiome, mitochondria, and epigenetics. Current studies suggest that the gut microbiome has the potential to affect mitochondrial function and biogenesis through the production of metabolites. A well-balanced microbiota plays a pivotal role in supporting normal mitochondrial and cellular functions by providing metabolites that are essential for mitochondrial bioenergetics and signaling pathways. Conversely, in the context of illnesses, an unbalanced microbiota can impact mitochondrial function, leading to increased aerobic glycolysis, reduced oxidative phosphorylation and fatty acid oxidation, alterations in mitochondrial membrane permeability, and heightened resistance to cellular apoptosis. Mitochondrial activity can also influence the composition and function of the gut microbiota. Because of the intricate interplay between nuclear and mitochondrial communication, the nuclear epigenome can regulate mitochondrial function, and conversely, mitochondria can produce metabolic signals that initiate epigenetic changes within the nucleus. Given the epigenetic modifications triggered by metabolic signals from mitochondria in response to stress or damage, targeting an imbalanced microbiota through interventions could offer a promising strategy to alleviate the epigenetic alterations arising from disrupted mitochondrial signaling.

Impact of bacteroides uniformis on fatty liver hemorrhagic syndrome in dawu golden phoenix laying hens: modulation of gut microbiota and arachidonic acid metabolism

This study explored the impact of Bacteroides uniformis (B. uniformis) on fatty liver hemorrhagic syndrome (FLHS) induced by a high-energy and low-protein (HELP) diet in laying hens, mainly focusing on hepatic lipid metabolism, gut microbiota, and arachidonic acid (AA) metabolism. A total of 120 Dawu Golden Phoenix laying hens (210-day-old) were randomly divided into four groups. The control group (CON) was fed a standard diet and received a daily gavage of PBS, while the other groups were fed with a HELP diet to induce FLHS and received a daily gavage of PBS (MOD), 1 × 109 CFU/ml B. uniformis (BUL), and 1 × 1011 CFU/ml B. uniformis (BUH) for 70 days. All hens were administered 1 ml daily by gavage. Each group had 6 replications with 5 hens per replication. The results showed that B. uniformis increased the egg production rate and feed conversion ratio and decreased body weight, liver index, and abdominal fat rate (p < 0.05). B. uniformis treatment reduced liver lipid accumulation by reducing the levels of Triglyceride (TG), Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), alanine transaminases (ALT), and aspartate transaminases (AST) in serum and significantly elevated high-density lipoprotein cholesterol (HDL-C) (p < 0.05). The results indicated that B. uniformis altered the gut microbiota. Specifically, the abundance of Bacteroides was higher, and the relative abundances of Treponema, Helicobacter, and Spirochaetota were lower than those of the MOD group (p < 0.05). Moreover, targeted metabolomic analysis showed that supplementation of B. uniformis significantly elevated 6-keto-PGF1α and AA levels, along with significantly reduced levels of thromboxane B2 (TXB2), leukotriene D4 (LTD4), 8-isoprostaglandin F2α (8-iso-PGF2α), 12S-hydroxyeicosatetraenoic acid (12S-HETE), 15S-hydroxyeicosatetraenoic acid (15S-HETE), 9-S-hydroxy-octadecadienoic acid (9S-HODE), and 13-S-hydroxy-octadecadienoic acid (13S-HODE) (p < 0.05). In conclusion, the oral intake of B. uniformis can improve liver function, gut microbiota, and AA metabolism, thereby helping to ameliorate FLHS in Dawu Golden Phoenix laying hens.

Gut microbiome links obesity to type 2 diabetes: insights from Mendelian randomization

BACKGROUND

Research has established links between the gut microbiome (GM) and both obesity and type 2 diabetes (T2D), which is much discussed, but underexplored. This study employed body mass index (BMI) as the measurement of obesity to delve deeper into the correlations from a genetic perspective.

METHODS

We performed the Mendelian randomization (MR) analysis to examine the causal effects of GM on T2D and BMI, and vice versa. Genome-wide association study (GWAS) summary datasets were utilized for the analysis, including T2D (N = 933,970), BMI (N = 806,834), and two GM datasets from the international consortium MiBioGen (211 taxa, N = 18,340) and the Dutch Microbiome Project (DMP) (207 taxa, N = 7,738). These datasets mainly cover European populations, with additional cohorts from Asia and other regions. To further explore the potential mediating role of GM in the connections between BMI and T2D, their interaction patterns were summarized into a network.

RESULTS

MR analysis identified 9 taxa that showed protective properties against T2D. Seven species were within the Firmicutes and Bacteroidales phyla in the DMP, and two were from the MiBioGen (Odds Ratio (OR): 0.94-0.95). Conversely, genetic components contributing to the abundance of 12 taxa were associated with increased risks of T2D (OR: 1.04-1.12). Furthermore, T2D may elevate the abundance of seven taxa (OR: 1.03-1.08) and reduce the abundance of six taxa (OR: 0.93-0.97). In the analysis of the influence of the genetic component of BMI on GM composition, BMI affected 52 bacterial taxa, with 28 decreasing (OR: 0.75-0.92) and 24 increasing (OR: 1.08-1.27). Besides, abundances of 25 taxa were negatively correlated with BMI (OR: 0.95-0.99), while positive correlations were detected for 14 taxa (OR: 1.01-1.05). Notably, we uncovered 11 taxa genetically associated with both BMI and T2D, which formed an interactive network.

CONCLUSIONS

Our findings provide evidence for the GM-mediated links between obesity and T2D. The identification of relevant GM taxa offers valuable insights into the potential role of the microbiome in these diseases.

Chronic inflammation in obesity and neurodegenerative diseases: exploring the link in disease onset and progression

Obesity, a worldwide health emergency, is defined by excessive fat accumulation and significantly impacts metabolic health. In addition to its recognized association with cardiovascular disease, diabetes, and other metabolic illnesses, recent studies have revealed the connection between obesity and neurodegeneration. The main reason for this link is inflammation caused by the growth of fat tissue, which activates harmful processes that affect how the brain works. Fat tissue, particularly the fat around the organs, produces various substances that cause inflammation, such as cytokines (TNF-α, IL-6), adipokines (leptin, resistin), and free fatty acids. These chemicals cause low-grade, persistent systemic inflammation, which is becoming more widely acknowledged as a major factor in peripheral metabolic dysfunction and pathology of the central nervous system (CNS). Inflammatory signals in the brain cause neuroinflammatory reactions that harm neuronal structures, change neuroplasticity, and disrupt synaptic function. When obesity-related inflammation is present, the brain's resident immune cells, known as microglia, become hyperactivated, which can lead to the production of neurotoxic chemicals, which can cause neuronal death. This neuroinflammation exacerbates the negative effects of obesity on brain health and is linked to cognitive decline, Alzheimer's disease, and other neurodegenerative disorders. Moreover, the blood-brain barrier (BBB) exhibits increased permeability during inflammatory states, facilitating the infiltration of peripheral immune cells and cytokines into the brain, hence exacerbating neurodegeneration. Adipose tissue is a source of chronic inflammatory mediators, which are examined in this review along with the molecular pathways that connect inflammation brought on by obesity to neurodegeneration. Additionally, it addresses various anti-inflammatory treatment approaches, including lifestyle modifications, anti-inflammatory medications, and gut microbiota modulation, to lessen the metabolic and neurological effects of obesity. Recognizing the link between obesity and inflammation opens up new opportunities for early intervention and the development of targeted treatments to prevent or alleviate neurodegenerative disorders.

Multidimensional-based exploration of gut microbial and metabolite differences in patients with recurrent stroke

This study aims to explore the differences in gut microbes and their metabolites between patients with original and recurrent stroke, providing insights and justification for the diagnosis and prevention of ischemic stroke progression from the perspective of the gut microbiota-metabolite-brain axis. In this study, fecal samples were collected from patients with Original stroke (Os) and patients with Recurrent stroke (Rs) to assess differences in gut microbiota and to screen for different metabolites that reveal the physiological changes related to the recurrent of ischemic stroke. The results found that there was no significant change in Alpha diversity between the two groups. Beta diversity analysis revealed slight changes in community composition between two groups (Bray-Curtis), although their overall microbial abundance may not have changed (UniFrac). Compared with Os patients, Prevotella, Lachnospiraceae_UCG-010, Holdemanella, and Coprococcus were significantly depleted in the Rs group. Correlation analysis showed that the risk of stroke recurrence was negatively correlated with Lachnospiraceae_UCG-010. In Rs group, metabolites such as carbohydrates and terpene lactones were up-regulated, while those of sesquiterpenoids, triterpenoids, and fatty acids and their couplings were down-regulated. These metabolites are significantly enriched in the pathways of arachidonic acid metabolism, betaine biosynthesis, and linoleic acid metabolism. Compared with the Os, Rs was mainly characterized by minor destruction of anaerobic bacteria and significant depletion of SCFAs-producing bacteria. In addition, the related compounds involved in arachidonic acid metabolism and linoleic acid metabolism pathway may be associated with the progression of ischemic stroke.

Epigenetic Mechanisms of Obesity: Insights from Transgenic Animal Models

Obesity is a chronic disease with prevalence rates that have risen dramatically over the past four decades. This increase is not due to changes in the human genome but rather to environmental factors that promote maladaptive physiological responses. Emerging evidence suggests that external influences, such as high-fat diets, modify the epigenome-the interface between genes and the environment-leading to persistent alterations in energy homeostasis. This review explores the role of epigenetic mechanisms in obesity, emphasizing insights from transgenic animal models and clinical studies. Additionally, we discuss the evolution of obesity research from homeostatic to allostatic frameworks, highlighting key neuroendocrine regulators of energy balance.

Association between excess body weight and disordered eating attitude among women living with systemic lupus erythematosus

The study aimed to: (i) characterize dietary intake and identify disorders eating attitudes in women with SLE, (ii) evaluate possible differences in both dietary intake and disorders eating attitudes in patients with SLE according to nutritional status, (iii) investigate possible associations between eating disorders attitudes, anthropometric characteristics and food consumption.

METHODS

This cross-sectional study included 46 premenopausal female patients (18-40 years), with inactive disease, using prednisone <10 mg/day and hydroxychloroquine at a stable dose. Patients were allocated into two groups according to their nutritional status by body mass index (BMI): normal weight (BMI between 18.5 and 24.9 kg/m2) and excess weight (BMI >25 kg/m2). Food consumption was assessed according to the processing level and energy and macronutrient content. The Disordered Eating Attitude Scale (DEAS) was applied.

RESULTS

Patients with excess weight had a higher DEAS score when compared to those with normal weight (34 ± 8.7 vs 25 ± 5.9, p = .001). A higher percentage of patients with excess weight demonstrated disturbance in their relationship with food and concerns about food and weight gain versus those with normal weight. DEAS score was positively associated with BMI, abdominal circumference, and fat mass percentage and negatively associated with lipid intake.

CONCLUSION

Disordered eating attitudes differ in SLE patients according to nutritional status, and those with excess weight show higher DEAS scores, which may be related to food and weight gain.

Puerarin affects adipose lipolysis and ameliorates obesity by gut microbiota

Background

Obesity has become a widespread metabolic disorder, marked by its escalating global prevalence. Puerarin, extracted from Pueraria lobata, one of the traditional homologies of medicine and food, demonstrates anti-obesity properties. Nonetheless, the mechanisms through which puerarin exerts its anti-obesity effects remain to be elucidated. This study seeks to highlight the potential application of puerarin in obesity management and to investigate the underlying mechanisms involving gut microbiota and lipid metabolism.

Method

Different doses of puerarin were administered to the high-fat diet mice model, and the structure and composition of gut microbiota were analyzed using 16S rRNA sequencing. Q-PCR evaluated the expression of genes related to lipid metabolism.

Result

Our findings demonstrate that puerarin treatment significantly reduces body weight and epithelial and beige fat mass. Furthermore, puerarin alters the structure and composition of gut microbiota, which is associated with metabolism. Additionally, puerarin treatment significantly upregulates gene expression, fatty acid transport protein 5 (FATP5) hormone-sensitive lipase (HSL), adipose triglyceride lipase (ATGL) in epithelial and beige adipose.

Conclusion

Puerarin demonstrates potential in ameliorating obesity by changing the structure and composition of gut microbiota, which enhances the transport of fatty acid and triglycerides hydrolysis within adipose tissue. This study provides a novel perspective on puerarin as a dietary supplement for obesity.

Microbiome alterations in primary Sjögren's syndrome: Regional dysbiosis and microbiome-targeted therapeutic strategies

Primary Sjögren's syndrome (pSS) is a complex autoimmune disease characterized by diverse clinical manifestations. While xerophthalmia and xerostomia are hallmark symptoms, the disease often involves multiple organ systems, including the kidneys, lungs, nervous system, and gastrointestinal tract, leading to systemic morbidity in severe cases. Despite extensive research, the precise pathogenesis of pSS remains unclear, likely involving infectious, hormonal, and genetic factors. Emerging evidence highlights the microbiome as a key contributor to autoimmune diseases, including pSS. Dysbiosis in the oral, ocular, gut, and genital microbiomes plays a critical role in disease onset, progression, and variability. This review summarizes current findings on microbiome alterations in pSS, emphasizing their role in pathogenesis and clinical features, and explores microbiome-targeted therapies. Understanding the role of the microbiome in pSS pathophysiology could advance disease management and inspire targeted therapeutic strategies.

The impact of gut microbiome modulation on anthropometric indices in metabolic syndrome: an umbrella review

Background

Metabolic syndrome (MetS) is a complex disorder characterized by a cluster of metabolic risk factors. Recent research highlights the gut microbiome's role in metabolic regulation, suggesting that modulation through probiotics, prebiotics, and synbiotics may provide a novel approach to managing MetS. This umbrella review aims to integrate insights from existing meta-analyses to explore how changes in gut microbiota influence key body measurement indicators in individuals with MetS.

Methods

A systematic search of PubMed, Scopus, and Web of Science databases identified meta-analyses that assessed the impact of probiotics, prebiotics, or synbiotics on anthropometric indices in MetS patients.

Results

The results indicated that microbial therapy leads to a significant reduction in body mass index (BMI) (SMD: -0.22; 95% CI: -0.35 to -0.09; P < 0.01) and waist circumference (WC) (SMD: -0.47; 95% CI: -0.80 to -0.15; P < 0.01). However, microbial therapy did not significantly affect body fat mass (SMD: -0.30; 95% CI: -0.64 to 0.02; P = 0.06), body fat percentage (SMD: -0.29; 95% CI: -0.62 to 0.03; P = 0.07), waist-to-hip ratio (SMD: -0.09; 95% CI: -0.46 to 0.28; P = 0.63), and weight (SMD: -0.06; 95% CI: -0.21 to 0.08; P = 0.37).

Conclusions

Gut microbial modulation, mainly through probiotics and synbiotics, shows promise in reducing BMI and WC in MetS patients. However, its effects on other anthropometric indices remain uncertain, warranting further high-quality research to fully understand microbial interventions' therapeutic potential.

Epigenomic mechanisms of dietary prescriptions for obesity therapy

Dietary modification is a cornerstone and a primary goal for weight loss, whose effects may be related to epigenetic phenomena. In this literature review, a comprehensive search without time restriction was performed in PubMed/Medline, Cochrane, SciELO, and Scopus databases to identify epigenetic signatures related to obesity outcomes upon dietary advice. In this context, experimental studies and clinical trials have identified certain DNA methylation marks, miRNA expression profiles and histone modifications putatively associated with adiposity outcomes after different nutritional interventions. These include traditional dietary patterns, diets with different macronutrient compositions, and supplementation with fatty acids, amino acids and derivatives, methyl donors, vitamins and minerals, probiotics and prebiotics, and bioactive food compounds. Some of these epigenetic signatures have been mapped to genes involved in food intake control, adipogenesis, lipolysis, fatty acid oxidation, body fat deposition, and gut microbiota modulation. However, additional studies are still required to address dosage and follow-up variability, validation of epigenetic marks, genome-wide approaches, and appropriate statistical settings. Although more investigation is required, these insights may contribute to the characterization of epigenetic biomarkers of body weight regulation toward the prescription of tailored dietary strategies targeting the epigenome for a more precise obesity management and control.

Probiotics Exert Gut Immunomodulatory Effects by Regulating the Expression of Host miRNAs

Probiotics exert a diverse range of immunomodulatory effects on the human gut immune system. These mechanisms encompass strengthening the intestinal mucosal barrier, inhibiting pathogen adhesion and colonization, stimulating immune modulation, and fostering the production of beneficial substances. As a result, probiotics hold significant potential in the prevention and treatment of various conditions, including inflammatory bowel disease and colorectal cancer. A pivotal mechanism by which probiotics achieve these effects is through modulating the expression of host miRNAs. miRNAs, non-coding RNA molecules, are vital regulators of fundamental biological processes like cell growth, differentiation, and apoptosis. By interacting with mRNAs, miRNAs can either promote their degradation or repress their translation, thereby regulating gene expression post-transcriptionally and modulating the immune system. This review provides a comprehensive overview of how probiotics modulate gut immune responses by altering miRNA expression levels, both upregulating and downregulating specific miRNAs. It further delves into how this modulation impacts the host's resistance to pathogens and susceptibility to diseases, offering a theoretical foundation and practical insights for the clinical utilization of probiotics in disease prevention and therapy.

DNA methylation dynamics in the small intestine of egg-selected laying hens along egg production stages

Decades of artificial selection have markedly enhanced egg production efficiency, yet the epigenetic underpinnings, notably DNA methylation dynamics in the gut, remain largely unexplored. Here, we investigate how breeds and developmental stages influence DNA methylation profiles in laying hens, and their potential relationship to laying performance and gut health. We compared two highly selected laying hen strains, Lohmann Brown-Classic (LB) and Lohmann Selected Leghorn-Classic (LSL), which exhibited similar egg production but divergent physiological, metabolic, and immunological characteristics. Our sampling encompassed key developmental stages: the pullet stage (10 and 16 wk old), peak production (24 and 30 wk old), and later stage (60 wk old) (n = 99; 10 per group), allowing us to elucidate the temporal dynamics of epigenetic regulation. Our findings highlight a crucial window of epigenetic modulation during the prelaying period, characterized by stage-specific methylation alterations and the involvement of predicted transcription factor motifs within methylated regions. This observation was consistent with the expression patterns of DNA methyltransferases (DNMTs), including DNMT1, DNMT3A, and DNMT3B. In addition, a higher methylation level was observed in specific loci or regions in the LSL compared with the LB strain. Notably, we uncover strain-specific differences in methylation levels, particularly pronounced in genomic regions associated with intestinal integrity, inflammation, and energy homeostasis. Our research contributes to the multidisciplinary framework of epigenetics and egg-laying performance, offering valuable implications for poultry production and welfare.NEW & NOTEWORTHY Our study reveals key methylation changes in the jejunum mucosa of laying hens across developmental stages and between strains, with implications for gut health, immune function, and egg production. These findings highlight a crucial role of epigenetic regulation in optimizing performance.

A comparative study of cognitive function and reaction time in obese and non-obese adults

OBJECTIVE

Obesity may negatively affect the physical health and cognitive functions of individuals and delay their reaction time to stimuli. However, the association among obesity, cognitive functions, and reaction times is yet to be fully elucidated. The aim of this study was to assess the effect of obesity on cognitive functions and visual and auditory reaction times in adults.

METHODS

Data of 100 participants (50 obese and 50 normal) were analyzed in the study. Anthropometric parameters and 24-h dietary recall data were recorded. The Montreal Cognitive Assessment (MoCA) was used to evaluate the cognitive functions, Simple Reaction Time Task (SRTT)-Visual and SRTT-Auditory were used to assess visual and auditory reaction times of the participants, respectively.

RESULTS

The mean MoCA score of the obese was significantly lower than normal (17.46 and 25.22, respectively; p < 0.001). In addition, the mean auditory (p < 0.001) and visual (p < 0.05) reaction times of obese were significantly longer than normal. Similarly, this condition was also observed for the fastest and lowest values of auditory and visual reaction times. Additionally, obesity caused a decrease in the MoCA score (β = -0.762; p < 0.001) and delayed visual (β = 0.423; p < 0.001) and auditory (β = 0.590; p < 0.001) reactions. The negative effect of obesity was maintained after controlling for potential factors (MoCA, β = -0.594; p < 0.001; SRTT-Auditory, β = 0.409; p < 0.01; SRTT-Visual, β = 0.330; p < 0.05).

CONCLUSION

Obese participants showed worse cognitive, auditory and visual performance. Additional research will be necessary in the future to shed light on the fundamental mechanisms involved.

Deciphering the coordinated roles of the host genome, duodenal mucosal genes, and microbiota in regulating complex traits in chickens

BACKGROUND

The complex interactions between host genetics and the gut microbiome are well documented. However, the specific impacts of gene expression patterns and microbial composition on each other remain to be further explored.

RESULTS

Here, we investigated this complex interplay in a sizable population of 705 hens, employing integrative analyses to examine the relationships among the host genome, mucosal gene expression, and gut microbiota. Specific microbial taxa, such as the cecal family Christensenellaceae, which showed a heritability of 0.365, were strongly correlated with host genomic variants. We proposed a novel concept of regulatability ( r b 2 ), which was derived from h2, to quantify the cumulative effects of gene expression on the given phenotypes. The duodenal mucosal transcriptome emerged as a potent influencer of duodenal microbial taxa, with much higher r b 2 values (0.17 ± 0.01, mean ± SE) than h2 values (0.02 ± 0.00). A comparative analysis of chickens and humans revealed similar average microbiability values of genes (0.18 vs. 0.20) and significant differences in average r b 2 values of microbes (0.17 vs. 0.04). Besides, cis ( h cis 2 ) and trans heritability ( h trans 2 ) were estimated to assess the effects of genetic variations inside and outside the cis window of the gene on its expression. Higher h trans 2 values than h cis 2 values and a greater prevalence of trans-regulated genes than cis-regulated genes underscored the significant role of loci outside the cis window in shaping gene expression levels. Furthermore, our exploration of the regulatory effects of duodenal mucosal genes and the microbiota on 18 complex traits enhanced our understanding of the regulatory mechanisms, in which the CHST14 gene and its regulatory relationships with Lactobacillus salivarius jointly facilitated the deposition of abdominal fat by modulating the concentration of bile salt hydrolase, and further triglycerides, total cholesterol, and free fatty acids absorption and metabolism.

CONCLUSIONS

Our findings highlighted a novel concept of r b 2 to quantify the phenotypic variance attributed to gene expression and emphasize the superior role of intestinal mucosal gene expressions over host genomic variations in elucidating host‒microbe interactions for complex traits. This understanding could assist in devising strategies to modulate host-microbe interactions, ultimately improving economic traits in chickens.

Roselle Extract Ameliorates Abnormal Glucolipid Metabolism and Gut Microbiota in Obese Mice Fed With High-Fat Diet

Roselle extract (RE) is rich in anthocyanins and chlorogenic acids. This study investigated the health-promoting effects of RE on lipid metabolism, oxidative stress, glycometabolism, and gut microbiota in obese mice fed a high-fat diet (HFD). The obesity model was induced by feeding mice a HFD, with RE supplementation added to their drinking water at concentrations of 2 and 4 mg/mL for 12 weeks. RE significantly reduced body weight gain and fat accumulation compared to the control group, alleviated hepatic steatosis, and improved insulin sensitivity. Additionally, RE restored antioxidative enzyme activities such as SOD and GSH-PX while reducing MDA levels. Transcriptomic analysis of the liver was performed to evaluate gene expression related to lipid metabolism, particularly in the PPAR signaling pathway. Gut microbiota analysis showed that RE increased beneficial bacteria and reduced the Firmicutes-to-Bacteroidetes ratio, suggesting an improvement in gut dysbiosis caused by the HFD. RE enhanced lipid metabolism, reduced oxidative stress, and improved insulin sensitivity in obese mice, potentially through modulation of the PPAR signaling pathway and gut microbiota, suggesting its potential as a therapeutic candidate for obesity-related metabolic disorders.

Participation of gut microbiota and bacterial translocation in chronic systemic inflammation in recently diagnosed rheumatoid arthritis patients

The objective of this study was to investigate the link between gut microbiota (GM) dysbiosis, gut inflammation, and bacterial translocation (BT) in recently diagnosed rheumatoid arthritis (RA). This case-control, observational study prospectively recruited recently diagnosed (<12 months) RA patients and age-matched healthy controls (HC) from two French hospitals between July 2014 to March 2018. The primary objective was to investigate GM composition in each group using 16S rRNA sequencing and metaproteomics approaches. Three plasmatic BT markers (sCD14, LPS-binding protein, and number of 16S rRNA gene copies) and one intestinal permeability marker (I-FABP) were quantified in blood samples. Twenty-five were included in each group, and 50 stools and blood samples were analyzed. 16S rRNA gene analysis showed an decrease in Coprococcus in RA patients after Body Mass Index and HLA status. Circulating bacterial DNA (number of copies of the 16S rRNA gene) and plasmatic I-FABP were higher in RA patients compared to HCs (p < 0.01), indicating increased BT and intestinal permeability in these patients. Metaproteomics from stool samples highlighted an increased host humoral immune response in RA, with elevated levels of inflammatory proteins (azurocidin, cathepsin G, neutrophil defensing 1). Gut inflammation may contribute to increased intestinal permeability, leading to BT into the systemic circulation and thus chronic inflammation.

In Vitro, In Vivo, and In Silico Investigation of Synbiotic-Mediated Activation of PPAR-α Curtails Nonalcoholic Steatohepatitis (NASH) in Wistar Rats by Inhibiting PNPLA3/SREBP1-c Lead Inflammatory Injury of Hepatic Cells

Nonalcoholic steatohepatitis (NASH) is an inflammation of the liver and a menace to human health. To treat NASH various pharmaceutical products have been used, but their prohibitive side effects limit their effectiveness. NASH, a multihit hypothesis involves high-fat diet and signals from the gut to the liver. Lactobacillus plantarum (probiotic) and aged garlic extract (AGE, a prebiotic) are antioxidative and anti-inflammatory and may be a latent combination therapy for NASH. The NASH model was developed using Wistar rats and treatments were administered to understand the mechanism. Initially, in the in vitro models, transepithelial electrical resistance (TEER) 2'-7'-dichlorodihydrofluorescein diacetate (DCFDA), 4-6-diamidino-2-phenylindole (DAPI) labeling and Oil Red O (ORO) conducted on HepG2 and Caco2 cells. Afterwards, in in vivo studies rat liver tissues were examined through confocal microscopy using the ORO staining and hematoxylin and eosin (H/E) stain, malondialdehyde (MDA), and biochemical indices were recorded. The levels of patatin-like phospholipase domain-containing protein 3 (PNPLA3) and sterol regulatory element binding protein-1c (SREBP-1c), peroxisome proliferators activated receptors (PPARs)-α, inflammatory, and apoptotic biomarkers were quantified by qRT-PCR. Synbiotic reduced the hepatic inflammation and apoptosis examined through the levels of PNPLA3, SREBP-1c, IL-6, TGF-β, Bcl-2, and caspase-3 in NASH models. In turn, the gram-negative species and bacterial translocation associated were reduced. Consequently, the Insilco analysis supports the theory that each (eight) bioactive compound of AGE targets PNPLA3 and enhances the PPAR-α activity. Additionally, PPAR-α inhibitors upregulated the PNPLA3 and SREBP-1C expression. As a result, the synbiotic may inhibit NASH progression by affecting PNPLA3/SREBP1-c through PPAR-α.

The Power of Environment: A Comprehensive Review of the Exposome's Role in Healthy Aging, Longevity, and Preventive Medicine-Lessons from Blue Zones and Cilento

Aging and longevity are shaped by the exposome, a dynamic network of environmental, social, and biological factors. Understanding how these exposures interact with biological mechanisms can inform strategies for healthier aging. Background/Objectives: This review explores the exposome as a dynamic system encompassing both protective and risk factors, with a specific focus on how beneficial environmental exposures, microbiome diversity, lifestyle behaviors, and resilience mechanisms contribute to successful aging. By analyzing high-longevity populations, such as the Blue Zones and Cilento, it aims to identify common determinants of successful aging. Methods: A mixed-method study was conducted, combining a systematic review of the English literature (2003-2024) with a comparative analysis of longevity regions. A structured search was performed in PubMed, Scopus, and Google Scholar using keywords such as "longevity", "Blue Zones", "Cilento", "microbiome", "environmental factors", and related terms. Additionally, qualitative and quantitative analysis were applied to assess key protective factors across different aging models. Results: This study identified key factors contributing to successful aging in longevity hotspots, including sustained exposure to biodiverse natural environments, adherence to Mediterranean or plant-based diet rich in polyphenols and probiotics, regular physical activity, strong social networks, and psychological resilience. A novel aspect of this review is the role of the gut microbiome as a mediator between environmental exposures and immune-metabolic health, influencing inflammation modulation and cellular aging. Despite geographic and cultural differences, case studies reveal a shared pattern of protective factors that collectively enhance lifespan and healthspan. Conclusions: The exposome is a critical determinant of aging trajectories, acting through complex interactions between environmental and biological mechanisms. By integrating insights from high-longevity populations, this mixed-method study proposes a comprehensive framework for optimizing microbiome health, enhancing resilience, and promoting protective environmental exposures. These findings provide a translational perspective to guide future interventions in aging research and global health initiatives.

Focus on Glucagon-like Peptide-1 Target: Drugs Approved or Designed to Treat Obesity

Obesity is closely related to metabolic diseases, which brings a heavy burden to the health care system. It is urgent to formulate and implement effective treatment strategies. Glucagon-like peptide-1 (GLP-1) is a protein with seven transmembrane domains connected by type B and G proteins, which is widely distributed and expressed in many organs and tissues. GLP-1 analogues can reduce weight, lower blood pressure, and improve blood lipids. Obesity, diabetes, cardiovascular diseases, and other diseases have caused scientists' research and development boom. Among them, GLP-1R agonist drugs have developed rapidly in weight-loss drugs. In this paper, based on the target of GLP-1, the mechanism of action of GLP-1 in obesity treatment was deeply studied, and the drugs approved and designed for obesity treatment based on GLP-1 target were elaborated in detail. Innovatively put forward and summarized the double and triple GLP-1 targeted drugs in the treatment of obesity with better effects and less toxic and side effects, and this can make full use of multi-target methods to treat other diseases in the future. Finally, it is pointed out that intestinal flora and microorganisms have many benefits in the treatment of obesity, and fecal bacteria transplantation may be a potential treatment for obesity with less harm to the body. This article provides some promising methods to treat obesity, which have strong practical value.

Therapeutic Strategies to Modulate Gut Microbial Health: Approaches for Chronic Metabolic Disorder Management

Numerous recent studies have suggested that the composition of the intestinal microbiota can trigger metabolic disorders, such as diabetes, prediabetes, obesity, metabolic syndrome, sarcopenia, dyslipidemia, hyperhomocysteinemia, and non-alcoholic fatty liver disease. Since then, considerable effort has been made to understand the link between the composition of intestinal microbiota and metabolic disorders, as well as the role of probiotics in the modulation of the intestinal microbiota. The aim of this review was to summarize the reviews and individual articles on the state of the art regarding ideal therapy with probiotics and prebiotics in order to obtain the reversion of dysbiosis (alteration in microbiota) to eubiosis during metabolic diseases, such as diabetes, prediabetes, obesity, hyperhomocysteinemia, dyslipidemia, sarcopenia, and non-alcoholic fatty liver diseases. This review includes 245 eligible studies. In conclusion, a condition of dysbiosis, or in general, alteration of the intestinal microbiota, could be implicated in the development of metabolic disorders through different mechanisms, mainly linked to the release of pro-inflammatory factors. Several studies have already demonstrated the potential of using probiotics and prebiotics in the treatment of this condition, detecting significant improvements in the specific symptoms of metabolic diseases. These findings reinforce the hypothesis that a condition of dysbiosis can lead to a generalized inflammatory picture with negative consequences on different organs and systems. Moreover, this review confirms that the beneficial effects of probiotics on metabolic diseases are promising, but more research is needed to determine the optimal probiotic strains, doses, and administration forms for specific metabolic conditions.

Life's Simple 7 and its impact on chronic bowel disorders: a study on constipation and diarrhea in the U.S. adult population

Background

Chronic gastrointestinal disorders, such as chronic constipation and diarrhea, pose significant public health challenges, affecting quality of life and healthcare costs. Life's Simple 7 (LS7), established by the American Heart Association, encompasses essential health behaviors that may influence bowel health.

Methods

We utilized data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2005 and 2010, focusing on adults aged 20 years and older. A total of 12,912 participants were included in the analysis. Bowel health was assessed through self-reported questionnaires, while LS7 was evaluated based on seven components: smoking status, physical activity, dietary quality, BMI, blood pressure, blood glucose, and blood cholesterol. Survey-weighted logistic regression models were employed to assess the associations between LS7 and chronic constipation and diarrhea, adjusting for various demographic and health-related covariates.

Results

Our findings revealed a significant inverse association between LS7 adherence and the prevalence of chronic constipation (OR: 0.914, 95% CI: 0.864-0.966, p = 0.003) and chronic diarrhea (OR: 0.883, 95% CI: 0.856-0.912, p < 0.0001). The protective effect of LS7 was more pronounced among males and individuals with a BMI under 30 kg/m2 for chronic constipation, and among younger adults and those without hypertension for chronic diarrhea. Restricted cubic spline analyses indicated a dose-response relationship, particularly for chronic diarrhea.

Conclusion

This study highlights the protective role of LS7 in promoting bowel health and preventing chronic constipation and diarrhea. Tailoring public health interventions based on demographic and health characteristics may enhance the effectiveness of strategies aimed at improving gastrointestinal health outcomes.

Nondigestible stachyose binds membranous HSP90β on small intestinal epithelium to regulate the exosomal miRNAs: A new function and mechanism

Oligosaccharides are conventionally recognized as "passersby" in the small intestine. However, our research has reframed this understanding by uncovering a new function of oligosaccharide stachyose, which binds hydrophobic residues of membranous HSP90β on small intestinal epithelial cells, thus reprograming the exosomal miRNA profile. CRISPR-Cas9-mediated HSP90β knockout abolished the accumulation of stachyose on cell membrane and its regulatory effects on these miRNAs. Notably, stachyose's regulation on these miRNAs is independent of its prebiotic role, as evidenced by the observation of stachyose-altered fecal miRNAs in pseudo-germ-free mice. These stachyose-altered miRNAs further shaped colonic microbiome, especially harboring Lactobacillus in mice. Thereinto, miR-30a-5p that was downregulated (Log2FC < -2) in both mice and human feces following stachyose treatment could specifically suppress the growth of Lactobacillus reuteri. These findings build a new regulatory axis of stachyose-intestinal miRNAs-gut microbiota and unveil a previously unknown mechanism underlying the direct "talk" of oligosaccharides to intestine epithelium via membranous HSP90β.

TRAF6 integrates innate immune signals to regulate glucose homeostasis via Parkin-dependent and -independent mitophagy

Activation of innate immune signaling occurs during the progression of immunometabolic diseases, including type 2 diabetes (T2D), yet the impact of innate immune signaling on glucose homeostasis is controversial. Here, we report that the E3 ubiquitin ligase TRAF6 integrates innate immune signals following diet-induced obesity to promote glucose homeostasis through the induction of mitophagy. Whereas TRAF6 was dispensable for glucose homeostasis and pancreatic β-cell function under basal conditions, TRAF6 was pivotal for insulin secretion, mitochondrial respiration, and increases in mitophagy following metabolic stress in both mouse and human islets. Indeed, TRAF6 was critical for the recruitment and function of machinery within both the ubiquitin-mediated (Parkin-dependent) and receptor-mediated (Parkin-independent) mitophagy pathways upon metabolic stress. Intriguingly, the effect of TRAF6 deficiency on glucose homeostasis and mitophagy was fully reversed by concomitant Parkin deficiency. Thus, our results implicate a role for TRAF6 in the cross-regulation of both ubiquitin- and receptor- mediated mitophagy through the restriction of Parkin. Together, we illustrate that β-cells engage innate immune signaling to adaptively respond to a diabetogenic environment.

Gut Microbiota: An Important Participant in Childhood Obesity

Increasing prevalence of childhood obesity has emerged as a critical global public health concern. Recent studies have challenged the previous belief that obesity was solely a result of excessive caloric intake. Alterations in early-life gut microbiota can contribute to childhood obesity through their influence on nutrient absorption and metabolism, initiation of inflammatory responses, and regulation of gut-brain communication. The gut microbiota is increasingly acknowledged to play a crucial role in human health, as certain beneficial bacteria have been scientifically proven to possess the capacity to reduce body fat content and enhance intestinal barrier function and their metabolic products to exhibit anti-inflammatory effect. Examples of such microbes include bifidobacteria, Akkermansia muciniphila, and Lactobacillus reuteri. In contrast, an increase in Enterobacteriaceae and propionate-producing bacteria (Prevotellaceae and Veillonellaceae) has been implicated in the induction of low-grade systemic inflammation and disturbances in lipid metabolism, which can predispose individuals to obesity. Studies have demonstrated that modulating the gut microbiota through diet, lifestyle changes, prebiotics, probiotics, or fecal microbiota transplantation may contribute to gut homeostasis and the management of obesity and its associated comorbidities. This review aimed to elucidate the impact of alterations in gut microbiota composition during early life on childhood obesity and explores the mechanisms by which gut microbiota contributes to the pathogenesis of obesity and specifically focused on recent advances in using short-chain fatty acids for regulating gut microbiota and ameliorating obesity. Additionally, it aimed to discuss the therapeutic strategies for childhood obesity from the perspective of gut microbiota, aiming to provide a theoretical foundation for interventions targeting pediatric obesity based on gut microbiota.

Reframing Diabetes Prevention: From Body Shaming to Metabolic Reprogramming

This review integrates new developments in psychology with updated physiological insight on the complex relationships among chronic psychological stress (arising from weight stigmatization and body shaming), food composition, physical activity and metabolic health for the example of diabetes. We address how visual measures of health, such as body mass index (BMI) and waist-to-hip ratio, do not adequately capture metabolic health and can instead contribute to weight stigmatization, chronic stress, and system-wide impairment of metabolic health. We also emphasize the importance of food composition over calorie counting. We summarize how chronic stress interacts with nutritional deficiencies and physical inactivity to disrupt the stress response, immune response, gut microbiome, and function of fat depots. We specifically address how interactions among lifestyle factors and the gut microbiome regulate whether fat stored around the waist has a negative or positive effect on metabolic health. We aim to provide a resource and updated framework for diabetes prevention and health promotion by (i) highlighting metabolic imbalances triggered by lifestyle changes during the transition to industrialized society and (ii) detailing the potential to support metabolic health through access to modest, but comprehensive lifestyle adjustments.

Parent-child microbiota relationships involved in childhood obesity: A CORALS ancillary study

OBJECTIVES

Childhood obesity continues to rise worldwide. Family gut microorganisms may be associated with childhood obesity. The aim of the study was to analyze bacterial similarities in fecal microbiota composition between parent-offspring pairs as linked to body weight.

METHODS

A total of 146 father/mother and offspring pairs were categorized into four groups according to the weight status of the parent-child pair as follows: group 1, parent and child with normal weight; group 2, parent and child with overweight/obesity; group 3, parent with normal weight and child with overweight/obesity; group 4, parent with overweight/obesity and child with normal weight. Anthropometric measurements and lifestyle assessments were performed in all participants. Microbiota characteristics were determined by 16S ribosomal RNA gene sequencing. Logistic regression models were performed to determine whether the abundance of any bacteria was able to predict childhood obesity. Moreover, receiver operating characteristic curves were fitted to define the relative diagnostic strength of bacterial taxa for the correct identification of childhood obesity.

RESULTS

The absence/abundance of Catenibacterium mitsuokai, Prevotella stercorea, Desulfovibrio piger, Massiliprevotella massiliensis, and Phascolarctobacterium succinatutens was involved in body weight family associations. A positive relationship between P. succinatutens richness from parents and M. massiliensis from children was observed with regard to body weight status (odds ratio, 1.14, P = 0.013).

CONCLUSIONS

This study describes five potential gut bacteria that may be putatively involved in family weight status relationships and appear to be useful for predicting obesity.

Sleep deprivation-induced shifts in gut microbiota: Implications for neurological disorders

Sleep deprivation is a prevalent issue in contemporary society, with significant ramifications for both physical and mental well-being. Emerging scientific evidence illuminates its intricate interplay with the gut-brain axis, a vital determinant of neurological function. Disruptions in sleep patterns disturb the delicate equilibrium of the gut microbiota, resulting in dysbiosis characterized by alterations in microbial composition and function. This dysbiosis contributes to the exacerbation of neurological disorders such as depression, anxiety, and cognitive decline through multifaceted mechanisms, including heightened neuroinflammation, disturbances in neurotransmitter signalling, and compromised integrity of the gut barrier. In response to these challenges, there is a burgeoning interest in therapeutic interventions aimed at restoring gut microbial balance and alleviating neurological symptoms precipitated by sleep deprivation. Probiotics, dietary modifications, and behavioural strategies represent promising avenues for modulating the gut microbiota and mitigating the adverse effects of sleep disturbances on neurological health. Moreover, the advent of personalized interventions guided by advanced omics technologies holds considerable potential for tailoring treatments to individualized needs and optimizing therapeutic outcomes. Interdisciplinary collaboration and concerted research efforts are imperative for elucidating the underlying mechanisms linking sleep, gut microbiota, and neurological function. Longitudinal studies, translational research endeavours, and advancements in technology are pivotal for unravelling the complex interplay between these intricate systems.

Hallmarks of Appetite: A Comprehensive Review of Hunger, Appetite, Satiation, and Satiety

PURPOSE OF REVIEW

The present review describes the available literature on the physiologic mechanisms that modulate hunger, appetite, satiation, and satiety with a particular focus on well-established and emerging factors involved in the classic satiety cascade model.

RECENT FINDING

Obesity is a significant risk factor for numerous chronic conditions like cancer, cardiovascular diseases, and diabetes. As excess energy intake is considered by some to be the primary driver of weight gain, tremendous collective effort should be directed toward reducing excessive feeding at the individual and population levels. From this perspective, detailed understanding of physiologic mechanisms that control appetite, and in turn, the design of effective interventions to manage appetite, may represent key strategies in controlling the obesity epidemic. With the obesity's prevalence on the rise worldwide, research on hunger, appetite, satiation and satiety is more relevant than ever. This research aims to provide practical insights for medical practitioners, nutrition professionals, and the broader scientific community in the fight against this global health challenge.

Effects of Supplementation With Different Specificities of Dietary Fiber on Health-Related Indicators in Adults With Overweight or Obesity: A Systematic Review and Meta-analysis of Randomized Controlled Trials

CONTEXT

Dietary fiber (DF) exhibits variations in its chemical and physical complexity, as well as in its utilization by the gut microbiota. However, the impact of these differences on the health status of adults with overweight or obesity remains unclear.

OBJECTIVE

This meta-analysis aimed to explore the varying effects of supplementing with different specificities of DF on the health of adults with overweight or obesity, providing guidance on selecting DF supplementation to improve health status.

DATA SOURCES

The literature search encompassed 4 electronic databases-PubMed, Cochrane Library, Web of Science, and EMBASE-and was conducted between January 1, 2012, and November 10, 2023. Randomized controlled trials comparing DF with placebo treatment, without energy restriction, were included.

DATA EXTRACTION

Two independent reviewers extracted data using a standardized form, resolving discrepancies through discussion. The data included study characteristics, participant demographics, DF specifications, and outcome measures.

DATA ANALYSIS

Random-effects models and the generic inverse variance method were used to analyze data, assuming varying outcomes based on DF specificity. Meta-regression assessed the impact of population, duration, and dosage. Publication bias was evaluated using funnel plots and Egger's and Begg's tests. The analysis included 34 trials (n = 1804) examining DF supplementation at 1.5 to 40 g/day for 3 to 16 weeks. DF supplementation significantly reduced glycated hemoglobin (HbA1c) by 0.13%, fasting insulin by 0.82 μIU/mL, and homeostatic model assessment of insulin resistance (HOMA-IR) by 0.33 in adults with overweight or obesity. Subgroup analyses based on DF specificity revealed differences in effects on HbA1c, fasting insulin, and systolic blood pressure. The low-specificity subgroup showed significant heterogeneity in body weight, body mass index, HbA1c, fasting insulin, and HOMA-IR, with a decrease in fasting insulin by 1.09 μIU/mL. The low-to-intermediate-specificity subgroup had reductions in HbA1c by 0.8%, fasting insulin by 2.08 μIU/mL, and HOMA-IR by 0.61. The intermediate-specificity subgroup experienced a 2.85-kg decrease in body weight and a 9.03-mg/dL increase in LDL cholesterol. The mixed subgroup showed an increase in systolic blood pressure by 3.85 mmHg.

CONCLUSION

Supplementing with different specificities of DF may have distinct effects on health-related indicators in adults with overweight or obesity. Considering individuals' gut microbiota composition and specific health goals is recommended when selecting DF supplementation for adults with overweight or obesity.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42023432920.

Population-specific differences in the human microbiome: Factors defining the diversity

Differences in microbial communities at different body habitats define the microbiome composition of the human body. The gut, oral, skin vaginal fluid and tissue microbiome, are pivotal for human development and immune response and cross talk between these microbiomes is evident. Population studies reveal that various factors, such as host genetics, diet, lifestyle, aging, and geographical location are strongly associated with population-specific microbiome differences. The present review discusses the factors that shape microbiome diversity in humans, and microbiome differences in African, Asian and Caucasian populations. Gut microbiome studies show that microbial species Bacteroides is commonly found in individuals living in Western countries (Caucasian populations), while Prevotella is prevalent in non-Western countries (African and Asian populations). This association is mainly due to the high carbohydrate, high fat diet in western countries in contrast to high fibre, low fat diets in African/ Asian regions. Majority of the microbiome studies focus on the bacteriome component; however, interesting findings reveal that increased bacteriophage richness, which makes up the virome component, correlates with decreased bacterial diversity, and causes microbiome dysbiosis. An increase of Caudovirales (bacteriophages) is associated with a decrease in enteric bacteria in inflammatory bowel diseases. Future microbiome studies should evaluate the interrelation between bacteriome and virome to fully understand their significance in the pathogenesis and progression of human diseases. With ethnic health disparities becoming increasingly apparent, studies need to emphasize on the association of population-specific microbiome differences and human diseases, to develop microbiome-based therapeutics. Additionally, targeted phage therapy is emerging as an attractive alternative to antibiotics for bacterial infections. With rapid rise in microbiome research, focus should be on standardizing protocols, advanced bioinformatics tools, and reducing sequencing platform related biases. Ultimately, integration of multi-omics data (genomics, transcriptomics, proteomics and metabolomics) will lead to precision models for personalized microbiome therapeutics advancement.

Dietary Influences on Gut Microbiota and Their Role in Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a major contributor to liver-related morbidity, cardiovascular disease, and metabolic complications. Lifestyle interventions, including diet and exercise, are first line in treating MASLD. Dietary approaches such as the low-glycemic-index Mediterranean diet, the ketogenic diet, intermittent fasting, and high fiber diets have demonstrated potential in addressing the metabolic dysfunction underlying this condition. The development and progression of MASLD are closely associated with taxonomic shifts in gut microbial communities, a relationship well-documented in the literature. Given the importance of diet as a primary treatment for MASLD, it is important to understand how gut microbiota and their metabolic byproducts mediate favorable outcomes induced by healthy dietary patterns. Conversely, microbiota changes conferred by unhealthy dietary patterns such as the Western diet may induce dysbiosis and influence steatotic liver disease through promoting hepatic inflammation, up-regulating lipogenesis, dysregulating bile acid metabolism, increasing insulin resistance, and causing oxidative damage in hepatocytes. Although emerging evidence has identified links between diet, microbiota, and development of MASLD, significant gaps remain in understanding specific microbial roles, metabolite pathways, host interactions, and causal relationships. Therefore, this review aims to provide mechanistic insights into the role of microbiota-mediated processes through the analysis of both healthy and unhealthy dietary patterns and their contribution to MASLD pathophysiology. By better elucidating the interplay between dietary nutrients, microbiota-mediated processes, and the onset and progression of steatotic liver disease, this work aims to identify new opportunities for targeted dietary interventions to treat MASLD efficiently.

Interplay between gut microbiome, host genetic and epigenetic modifications in MASLD and MASLD-related hepatocellular carcinoma

Metabolic dysfunction-associated steatotic liver disease (MASLD) encompasses a wide spectrum of liver injuries, ranging from hepatic steatosis, metabolic dysfunction-associated steatohepatitis (MASH), fibrosis, cirrhosis to MASLD-associated hepatocellular carcinoma (MASLD-HCC). Recent studies have highlighted the bidirectional impacts between host genetics/epigenetics and the gut microbial community. Host genetics influence the composition of gut microbiome, while the gut microbiota and their derived metabolites can induce host epigenetic modifications to affect the development of MASLD. The exploration of the intricate relationship between the gut microbiome and the genetic/epigenetic makeup of the host is anticipated to yield promising avenues for therapeutic interventions targeting MASLD and its associated conditions. In this review, we summarise the effects of gut microbiome, host genetics and epigenetic alterations in MASLD and MASLD-HCC. We further discuss research findings demonstrating the bidirectional impacts between gut microbiome and host genetics/epigenetics, emphasising the significance of this interconnection in MASLD prevention and treatment.

Postbiotics for the management of obesity, insulin resistance/type 2 diabetes and NAFLD. Beyond microbial viability

Highly prevalent comorbidities associated with metabolic syndrome, such as abdominal obesity, nonalcoholic fatty liver disease (NAFLD) and insulin-resistance/Type 2 diabetes (IR/T2D) share alterations in gut microbiota composition as a potential triggering factor. Recent studies put the attention in the potential usage of postbiotics (inactivated probiotics) on these metabolic alterations. This review summarizes the current evidence regarding the efficacy of postbiotic administration in both, preclinical and clinical studies, for the management of obesity, NAFLD and IR/T2D. Data from preclinical studies (rodents) suggest that postbiotic administration effectively prevents obesity, whereas clinical studies corroborate these benefits also in overweight/obese subjects receiving inactivated bacteria. As for NAFLD, although preclinical studies indicate that postbiotic administration improves different liver markers, no data obtained in humans have been published so far since all the studies are ongoing clinical trials. Finally, while the administration of inactivated bacteria demonstrated to be a promising approach for the management of IR/T2D in rodents, data from clinical trials indicates that in humans, this approach is more effective on IR than in T2D. In conclusion, the available scientific data indicate that postbiotic administration not only is safer, but also as effective as probiotic administration for the management of obesity associated prevalent metabolic alterations.

Bacterial cellulose is a desirable biological macromolecule that can prevent obesity via modulating lipid metabolism and gut microbiota

Obesity has attracted great concern because of its undesirable effects on our life quality. Bacterial cellulose (BC) is a biological macromolecule that can improve gut homeostasis and lipid metabolism. However, its potential role in preventing obesity and associated mechanisms is still poorly understood. Herein, a supplement of BC was used to fully evaluate how it prevents obesity based on physio-biochemical and gut microbial analyses. Results showed that BC consumption helped decrease body and liver weight, and fat accumulation in kidney and epididymis. Correspondingly, glucose concentrations, total triglycerides, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were reversed to the control levels. Consuming BC also improved liver fat metabolism and intestinal function, and alleviated ileum and epididymis inflammation. High-throughput sequencing suggested that a high-fat diet significantly decreased gut microbiota diversity, which could be reversed by consuming BC. A decreased Firmicutes and Proteobacteria and an increased Bacteroidetes following BC consumption were observed. The OTU-based analysis identified that Lachnospiraceae, Desulfovibrio, Lachnoclostridium, Blautia, Anaerotruncus, Bacteroides, Faecalibaculum, Bacteroidales S24-7 group, Prevotellaceae UCG-001 group, and Alloprevotella might be involved in obesity development or prevention. Our data suggest that BC is a good insoluble dietary fiber to prevent obesity via regulating lipid metabolism and gut microbiota.

Effects of different milk powders on the growth and intestinal flora in weaned rats: Comparison of special formula milk powder with ordinary milk powder

The objective of this investigation was to examine the effects of distinct dosages of infant formula and diverse formula constituents on the growth and development of weaned rats. Fifty specific pathogen-free (SPF) male Sprague-Dawley (SD) rats aged 3 weeks were divided into the basic diet group, 20% ordinary milk powder group, 20% special formula milk powder group, 30% ordinary milk powder group, and 30% special formula milk powder group randomly. After 28 days of feeding, compared with the basic diet group, the body mass and brain/body weight of rats in the 30% ordinary and special formula milk powder groups were decreased. At the Genus level, Bacteroides in the group supplemented with 20% special formula milk powder was significantly lower than that in the basic diet group, and Parabacteroides was significantly lower than that in the 20% ordinary milk powder group. Lactobacillus was significantly higher than those in the basic diet group and the 20% ordinary milk powder group, and Blautia was significantly higher than those in the basic diet group and the 20% and 30% ordinary milk powder groups, and UBA1819 was significantly higher than those in the other groups. The abundance of Parasutterella in the basic diet group was significantly higher than those in the groups supplemented with 20% ordinary milk powder, 20% special formula milk powder, and 30% ordinary milk powder. This study found that different doses and different formula components of infant milk powder could affect body mass and intestinal flora in Sprague-Dawley (SD) rats, and the addition of low-dose (20%) special formula infant milk powder can increase the beneficial bacteria in the intestinal flora of rats and may reduce the pathogenic bacteria.

Do poor psychosocial resources mediate health inequalities in type 2 diabetes mellitus? Findings from the Maastricht study

Low socioeconomic position (SEP) has been identified as a risk factor for type 2 diabetes mellitus (T2DM), and psychosocial resources might be on the pathway in this association. We examined two poor psychosocial resources, low control beliefs and inferiority beliefs, that might link low SEP with T2DM. 8292 participants aged 40-75 living in Southern Netherlands participated in The Maastricht Study starting from September 2010 to October 2020 and were followed up to 10 years with annual questionnaires. SEP (education, income, occupation), low control beliefs, inferiority beliefs, and (pre)diabetes by oral glucose tolerance test were measured at baseline. Incident T2DM was self-reported per annum. We analysed the mediating roles of poor psychosocial resources by using counterfactual mediation analysis. People with low SEP had more often prevalent and incident T2DM (e.g. low education: HR = 2.13, 95%CI: 1.53-2.97). Low control beliefs and high inferiority beliefs were more common among people with low SEP. Moreover, low control beliefs and high inferiority beliefs were risk factors for T2DM (e.g. low control beliefs: HR = 1.50, 95%CI: 1.08-2.09). The relationship between SEP and T2DM was partially mediated by control beliefs (8.0-13.6%) and inferiority beliefs (2.2-4.5%). We conclude that poor psychosocial resources are important in socioeconomic inequalities in diabetes. Researchers and practitioners should consider the psychosocial profile of people with lower SEP, as such a profile might interfere with the development, treatment, and prevention of T2DM. Further research should explore how poor psychosocial resources interact with chronic stress in relation to socioeconomic health inequalities.

Guidance and Position of RINN22 regarding Precision Nutrition and Nutriomics

BACKGROUND

Precision nutrition is based on the integration of individual's phenotypical and biological characteristics including genetic variants, epigenetic marks, gut microbiota profiles, and metabolite fingerprints as well as medical history, lifestyle practices, and environmental and cultural factors. Thus, nutriomics areas including nutrigenomics, nutrigenetics, nutriepigenetics, nutrimetabolomics, and nutrimetagenomics have emerged to comprehensively understand the complex interactions between nutrients, diet, and the human body's molecular processes through precision nutrition.

SUMMARY

This document from the Ibero-American Network of Nutriomics and Precision Nutrition (RINN22; https://rinn22.com/) provides a comprehensive overview of the concepts of precision nutrition approaches to guide their application in clinical and public health as well as establish the position of RINN22 regarding the current and future state of precision nutrition.

KEY MESSAGES

The progress and participation of nutriomics to precision nutrition is an essential pillar for addressing diet-related diseases and developing innovative managing strategies, which will be promoted by advances in bioinformatics, machine learning, and integrative software, as well as the description of specific novel biomarkers. In this context, synthesizing and critically evaluating the latest developments, potential applications, and future needs in the field of nutrition is necessary with a holistic perspective, incorporating progress in omics technologies aimed at precision nutrition interventions. This approach must address and confront healthy, social, food security, physically active lifestyle, sanitation, and sustainability challenges with preventive, participatory, and predictive strategies of personalized, population, and planetary nutrition for a precision tailored health.

Effect of Silibinin on Human Pancreatic Lipase Inhibition and Gut Microbiota in Healthy Volunteers: A Randomized Controlled Trial

Thistle (Onopordum acanthium) has been traditionally employed for liver protection. However, we recently identified silibinin, the main bioactive compound of thistle extract, as an in vitro pancreatic lipase inhibitor, which suggested a potential role as an anti-obesity agent. This study aimed to assess, in vivo, the efficacy, safety, and effects of silibinin on human lipase. As a secondary objective, we evaluated potential changes in gut microbiota after silibinin treatment. A randomized trial comparing 150 mg/silibinin, 300 mg/silibinin, and a thistle extract (equivalent to 150 mg/silibinin) with placebo and orlistat/120 mg was conducted. Fecal fat excretion, clinical parameters, and microbiota changes were analyzed. Orlistat showed the highest fecal fat excretion, although thistle extract had similar results (p = 0.582). The 150 mg/silibinin group reported the fewest adverse effects. Both silibinin and orlistat reduced plasma triglycerides (p = 0.016) and waist circumference (p = 0.001). Specific microbiota changes, such as increases in Mycobacteriaceae and Veillonellaceae, were associated with higher fat excretion. Although the present work was conducted in the short term and in people of normal weight, our results suggest that silibinin may be safe and effective for obesity, with minimal adverse effects and no significant changes in microbiota diversity. Further studies are needed to explore its microbiota-related benefits.

Summer-autumn tea promotes adipocyte browning and thermogenesis in association with gut microbiota regulation in high-fat diet-fed mice

This study revealed for the first time the anti-obesity effect of summer-autumn tea aqueous extract (SATE) and its underlying mechanism. High-fat diet (HFD)-fed C57BL/6J mice were treated with or without 400 mg kg-1 SATE for 12 weeks, and administration of SATE significantly ameliorated glucolipid metabolism disorder and induced beige-fat development and brown adipose tissue (BAT)-derived non-shivering thermogenesis via the AMPK-PGC-1α-UCP1 signal axis in HFD-fed mice. 16S rDNA-based microbiota and targeted metabolomics analyses indicated that SATE improved intestinal microbiota dysbiosis and microbial metabolism abnormality caused by HFD, reflected by a dramatic increase in the relative abundance of Muribaculaceae, Bifidobacterium and Odoribacter and production of short-chain fatty acids (SCFAs). Interestingly, SATE-induced thermogenesis was highly correlated with the reconstruction of the gut microbiome and the formation of SCFAs. These findings suggest that SATE has the potential to alleviate obesity by activating adipose browning and thermogenesis in association with the reconstruction of the gut microbiota and its metabolites, providing a theoretical foundation for summer-autumn tea as a functional tea to prevent obesity.

Review of the Relationships Between Human Gut Microbiome, Diet, and Obesity

Obesity is a complex disease that increases the risk of other pathologies. Its prevention and long-term weight loss maintenance are problematic. Gut microbiome is considered a potential obesity modulator. The objective of the present study was to summarize recent findings regarding the relationships between obesity, gut microbiota, and diet (vegetable/animal proteins, high-fat diets, restriction of carbohydrates), with an emphasis on dietary fiber and resistant starch. The composition of the human gut microbiome and the methods of its quantification are described. Products of the gut microbiome metabolism, such as short-chain fatty acids and secondary bile acids, and their effects on the gut microbiota, intestinal barrier function and immune homeostasis are discussed in the context of obesity. The importance of dietary fiber and resistant starch is emphasized as far as effects of the host diet on the composition and function of the gut microbiome are concerned. The complex relationships between human gut microbiome and obesity are finally summarized.

Integrative analysis of metabolites and microbial diversity revealed metabolic mechanism of coarse feeding tolerance in Songliao Black sows during gestation

Dietary fiber is a key nutritional regulatory factor that has been studied intensively for its role in improving reproduction in sows during gestation. However, the metabolic mechanism underlying the effect of interactions between metabolites and gut microbes on coarse feeding tolerance in indigenous sows remains to be elucidated. Therefore, the present study aimed to investigate the effects of dietary supplementation with alfalfa at different content ratios on the reproductive performance of pregnant Songliao Black sows. In total, 40 Songliao Black sows at 30 days of gestation were allocated to four treatments, which received the following diets: (1) a corn-soybean meal basal diet with no alfalfa meal (CON group), (2) a corn-soybean meal basal diet +10% alfalfa meal (Treatment 1 group), (3) a corn-soybean meal basal diet +20% alfalfa meal (Treatment 2 group), and (4) a corn-soybean meal basal diet +30% alfalfa meal (Treatment 3 group). Untargeted metabolomics, 16S rDNA sequencing, and enzyme-linked immunosorbent assay (ELISA) were performed to determine the possible effects of metabolites, the microbial communities in fecal samples and their functional potential, and the effects of dietary fiber on serum biochemical parameters, oxidative stress, and reproductive hormones in Songliao Black sows during gestation. The results revealed that the meals with 10 and 20% alfalfa had a beneficial effect on sows in terms of improving the reproductive performance of these sows. Bacterial 16S rDNA sequencing of the fecal samples revealed that the 10% alfalfa meal group had a higher α-diversity and higher abundance of probiotics. Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria were revealed as the most abundant groups at the phylum level and Lactobacillus, Prevotella, Ruminococcus, Streptococcus, and Clostridium were the most abundant at the genus level in the sows fed with diets containing higher fiber levels. A total of 239 differential metabolites were identified in the sows fed with alfalfa meals. These metabolites were enriched mainly in the cAMP signaling pathway, biosynthesis of amino acids, and steroid biosynthesis. Pearson correlation analysis revealed significant positive correlations between Blautia and Daizein, Fibrobacter and 5-alpha-Cholestanone, Sphaerochaeta, Sutterella, and Metaraminol. Negative correlations were revealed between Sphaerochaeta and Erucic acid, Prevotellaceae and Harmaline, and Streptococcus and 5-alpha-Cholestanone. Collectively, these findings provide novel insights into the application of dietary fiber in sow diets.

The Role of Gut Microbiota in the Onset and Progression of Obesity and Associated Comorbidities

Obesity, a global public health problem, is constantly increasing, so the concerns in preventing and combating it are increasingly focused on the intestinal microbiota. It was found that the microbiota is different in lean people compared to obese individuals, but the exact mechanisms by which energy homeostasis is influenced are still incompletely known. Numerous studies show the involvement of certain bacterial species in promoting obesity and associated diseases such as diabetes, hypertension, cancer, etc. Our aim is to summarize the main findings regarding the influence of several factors such as lifestyle changes, including diet and bariatric surgery, on the diversity of the gut microbiota in obese individuals. The second purpose of this paper is to investigate the potential effect of various microbiota modulation techniques on ameliorating obesity and its comorbidities. A literature search was conducted using the PubMed database, identifying articles published between 2019 and 2024. Most studies identified suggest that obesity is generally associated with alterations of the gut microbiome such as decreased microbial diversity, an increased Firmicutes-to-Bacteroidetes ratio, and increased SCFAs levels. Our findings also indicate that gut microbiota modulation techniques could represent a novel strategy in treating obesity and related metabolic diseases. Although some mechanisms (e.g., inflammation or hormonal regulation) are already considered a powerful connection between gut microbiota and obesity development, further research is needed to enhance the knowledge on this particular topic.

Functional yogurt: a comprehensive review of its nutritional composition and health benefits

Functional yogurt, renowned for its enhanced nutritional profile and potential health benefits, has emerged as a promising functional food. This review meticulously examines the nutritional composition of functional yogurt, highlighting its enriched content of probiotics, prebiotics, synbiotics, antioxidants, vitamins, minerals, proteins, and other bioactive compounds, which contribute to its health-promoting properties. Functional yogurt has positively affected digestive health, immune function, metabolic health, and mental well-being. It benefits digestive health by alleviating diarrhoeal symptoms, constipation, colon cancer, irritable bowel syndrome (IBS), Helicobacter pylori infection, and digestive-related allergies. Moreover, the immune-boosting properties of functional yogurt play a pivotal role in reducing the risk of infections and inflammation. In addition, functional yogurt has the potential to improve metabolic health, leading to decreased cholesterol levels and enhanced blood sugar regulation. Emerging research also suggests functional yogurt may positively influence mood, behavior, and cognitive function. Functional yogurt is a valuable addition to the human diet, holding significant implications for public health. In addition to its numerous health benefits, functional yogurt also faces limitations, such as the stability of functional compounds, sensory alterations, potential digestive discomfort, and inconsistent efficacy across populations, highlighting the need for further research and optimization.

Molecular mechanisms of obesity predisposes to atopic dermatitis

Obesity is a prevalent metabolic disease that reduces bacterial diversity, colonizes the epidermis with lipophilic bacteria, and increases intestinal pro-inflammatory species, all of which lead to impaired epithelial barriers. Adipose tissue secretes immunomodulatory molecules, such as adipokines, leptin, and adiponectin, which alters the morphology of adipocytes and macrophages as well as modulates T cell differentiation and peripheral Th2-dominated immune responses. Atopic dermatitis (AD) and obesity have similar pathological manifestations, including inflammation as well as insulin and leptin resistance. This review examines the major mechanisms between obesity and AD, which focus on the effect on skin and gut microbiota, immune responses mediated by the toll like receptor (TLR) signaling pathway, and changes in cytokine levels (TNF-a, IL-6, IL-4, and IL13). Moreover, we describe the potential effects of adipokines on AD and finally mechanisms by which PPAR-γ suppresses and regulates type 2 immunity.

Tea (Camellia sinensis L.) flower polysaccharide attenuates metabolic syndrome in high-fat diet induced mice in association with modulation of gut microbiota

There is a growing body of evidence suggesting that dietary polysaccharides play a crucial role in preventing metabolic syndrome (MetS) through their interaction with gut microbes. Tea (Camellia sinensis L.) flower polysacchride (TFPS) is a novel functional compound known for its diverse beneficial effects in both vivo and vitro. To further investigate the effects of TFPS on MetS and gut microbiota, and the possible association between gut microbiota and their activities, this study was carried out on mice that were fed a high-fat diet (HFD) and given oral TFPS at a dose of 400 and 800 mg/kg·body weight (BW)/d, respectively. TFPS treatment significantly mitigated HFD-induced MetS, evidenced by reductions in body weight, fat accumulation, plasma levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and pro-inflammatory cytokines tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and IL-1β, along with an increase in plasma IL-10 levels. Furthermore, TFPS induced alterations in the diversity and composition of HFD-induced gut microbiota. Specifically, TFPS influenced the relative abundance of 11 genera, including Lactobacillus and Lactococcus, which showed strong correlations with metabolic improvements and likely contributed to the amelioration of MetS. In conclusion, TFPS exhibits promising prebiotic properties in preventing MetS and regulating gut microbiota.