Diet-Related Changes of Short-Chain Fatty Acids in Blood and Feces in Obesity and Metabolic Syndrome

The Influence of an AI-Driven Personalized Nutrition Program on the Human Gut Microbiome and Its Health Implications

Background/Objectives: Personalized nutrition programs enhanced with artificial intelligence (AI)-based tools hold promising potential for the development of healthy and sustainable diets and for disease prevention. This study aimed to explore the impact of an AI-based personalized nutrition program on the gut microbiome of healthy individuals. Methods: An intervention using an AI-based mobile application for personalized nutrition was applied for six weeks. Fecal and blood samples from 29 healthy participants (females 52%, mean age 35 years) were collected at baseline and at six weeks. Gut microbiome through 16s ribosomal RNA (rRNA) amplicon sequencing, anthropometric and biochemical data were analyzed at both timepoints. Dietary assessment was performed using food frequency questionnaires. Results: A significant increase in richness (Chao1, 220.4 ± 58.5 vs. 241.5 ± 60.2, p = 0.024) and diversity (Faith's phylogenetic diversity, 15.5 ± 3.3 vs. 17.3 ± 2.8, p = 0.0001) was found from pre- to post-intervention. Following the intervention, the relative abundance of genera associated with the reduction in cholesterol and heart disease risk (e.g., Eubacterium coprostanoligenes group and Oscillobacter) was significantly increased, while the abundance of inflammation-associated genera (e.g., Eubacterium ruminantium group and Gastranaerophilales) was decreased. Alterations in the abundance of several butyrate-producing genera were also found (e.g., increase in Faecalibacterium, decrease in Bifidobacterium). Further, a decrease in carbohydrate (272.2 ± 97.7 vs. 222.9 ± 80.5, p = 0.003) and protein (113.6 ± 38.8 vs. 98.6 ± 32.4, p = 0.011) intake, as well as a reduction in waist circumference (78.4 ± 12.1 vs. 77.2 ± 11.2, p = 0.023), was also seen. Changes in the abundance of Oscillospiraceae_UCG_002 and Lachnospiraceae_UCG_004 were positively associated with changes in olive oil intake (Rho = 0.57, p = 0.001) and levels of triglycerides (Rho = 0.56, p = 0.001). Conclusions: This study highlights the potential for an AI-based personalized nutrition program to influence the gut microbiome. More research is now needed to establish the use of gut microbiome-informed strategies for personalized nutrition.

Fecal microbiota transplantation fails to impart the benefits of circadian-dependent intermittent fasting following ischemic stroke

Intermittent fasting (IF) is known to induce significant ischemic tolerance. Diet is a major proponent of gut microbiota, and gut microbial dysbiosis plays a role in post-stroke brain damage. Hence, we currently evaluated whether IF-mediated ischemic tolerance is mediated by gut microbiota. Additionally, circadian cycle is known to modulate post-ischemic outcomes, and thus we further evaluated if gut microbiota would be influenced by prophylactic IF during the inactive phase (fasting during daytime; IIF) or active phase (fasting during nighttime; AIF). The AIF, but not IIF, cohort showed a significantly decreased fecal Firmicutes/Bacteroidetes ratio compared with the ad libitum (AL) cohort. Moreover, the levels of gut microbiota-derived metabolites butyrate and propionate decreased in AL cohort following focal ischemia, whereas they increased in AIF cohort. However, fecal microbiota transplantation (FMT) from IIF or AIF cohort had no significant effects on post-ischemic motor and cognitive function recovery, anxiety-, and depression-like behaviors compared with FMT from AL cohort. Furthermore, FMT from IIF or AIF cohort did not influence the post-ischemic infarct volume, atrophy volume or white matter damage. Overall, the current findings indicate that the beneficial effects of IF after focal ischemia are not mediated by the gut microbiota.

Comparative analysis of gut microbiome-derived short-chain fatty acids in patients with severe mental disorder: Insights from schizophrenia and bipolar disorder

Both schizophrenia (SZ) and bipolar disorder (BD) are associated with disruptions in the gut microbiome. Short-chain fatty acids (SCFAs), such as acetate, propionate and butyrate, are key metabolites produced by gut bacteria that influence brain function, immune responses and behaviour. We conducted a cross-sectional observational study with 123 patients (86 with SZ and 37 with BD). We analysed faecal samples for SCFA and examined associations with clinical (psychopathology and cognition), metabolic and lifestyle factors. We performed analysis of covariance to find differences in SCFA levels between diagnostic groups, adjusting for covariates. Faecal SCFA levels were numerically higher in the SZ group than in the BD group. However, after adjusting for covariates, a significant sex-by-diagnosis interaction was observed only for acetate levels. Body mass index emerged as a key predictor of SCFA levels but we observed no significant associations with other metabolic or lifestyle variables, including diet, physical activity and blood inflammatory biomarkers. Additionally, SCFA levels showed no correlation with symptom severity or cognitive performance in either group. This study is the first to compare SCFA profiles between SZ and BD, highlighting potential differences in gut microbiota-derived metabolites between these disorders. These findings suggest greater disruption of the gut-brain axis in SZ, potentially reflecting distinct pathophysiological mechanisms involving metabolic and sex-related factors. Further research, including blood SCFA measurements, could better explain the role of SCFAs and explore microbiota-targeted therapeutic strategies for SZ and BD.

Fermented Lignan-Enriched Soy Beverage Ameliorates the Metabolic Effects of a High-Fat Diet on Female Mice

Fermented vegetable beverages have potential beneficial effects on the health associated with the production of bioactive flavonoids and lignans by selected bacterial strains. Here, we studied the effects of a soy beverage and a soy beverage fermented by Bifidobacterium pseudocatenulatum INIA P815, both supplemented with lignan extracts, in a female mouse model on a high-fat diet followed for 16 weeks. The high-fat diet induced an increase in adipose tissue and plasma cholesterol as well as modified the fecal microbiota. Mice groups receiving any of the beverages showed a reduction in the mean area of ovarian fat tissue adipocytes and exhibited bioactive flavonoids and lignans in plasma and tissues, accompanied by a higher antioxidant activity in plasma. The group of mice subjected to the fermented beverage also demonstrated a lower increase in plasma cholesterol levels, an increase in short-chain fatty acid production, and higher levels of daidzein, genistein, enterolignans, and herbacetin in the plasma and organs. Moreover, the fertility of the mice that received the fermented beverage was also enhanced, resulting in a higher percentage of blastocysts per female mouse. Therefore, the consumption of the beverage fermented by B. pseudocatenulatum INIA P815 could be favoring the health of mice by ameliorating, to some extent, the effects of a high-fat diet.

Microbial effects of cold-pressed Sacha inchi oil supplementation in rats

Oil supplements have various benefits for metabolism, particularly Sacha inchi oil (SI), which is rich in polyunsaturated fatty acids (PUFAs) such as ω-3 and fat-soluble vitamins. However, the impacts of oil supplements on gut health remain unclear. The aim of this study was to compare the effects of an SI supplement with those of lard oil (LO), known for its high saturated fatty acid content, and a normal diet on gut health in male Sprague Dawley rats for 12 consecutive weeks. Fecal DNA was used to assess gut microbiota diversity and species abundance, diversity, and function prediction. Colon tissue from each rat was examined for colon crypt depth and histology. Rats administered the LO supplement exhibited higher dysbiosis than those administered the SI supplement, with the LO supplement influencing the relative abundance of various bacteria at the genus level. A KEGG analysis was conducted to examine the effects on metabolic pathways, revealing that the SI supplement promoted carbohydrate metabolism while reducing immune system activity. In contrast, the LO supplement increased replication, repair, and translation activities. A histological analysis of the colon tissues showed no significant alterations in crypt depth or lesions in all groups, indicating that neither supplement induced adverse structural changes in the gut. The results of this study suggest that SI supplementation modulates the gut microbiota, thereby enhancing gut health and metabolic function.

Investigating the impact of microbiome-changing interventions on food decision-making: MIFOOD study protocol

BACKGROUND

Obesity is a multifactorial disease reaching pandemic proportions with increasing healthcare costs, advocating the development of better prevention and treatment strategies. Previous research indicates that the gut microbiome plays an important role in metabolic, hormonal, and neuronal cross-talk underlying eating behavior. We therefore aim to examine the effects of prebiotic and neurocognitive behavioral interventions on food decision-making and to assay the underlying mechanisms in a Randomized Controlled Trial (RCT).

METHOD

This study uses a parallel arm RCT design with a 26-week intervention period. We plan to enroll 90 participants (male/diverse/female) living with overweight or obesity, defined as either a Waist-to-Hip Ratio (WHR) ≥ 0.9 (male)/0.85 (diverse, female) or a Body Mass Index (BMI) ≥ 25 kg/m2. Key inclusion criteria are 18-60 years of age and exclusion criteria are type 2 diabetes, psychiatric disease, and Magnetic Resonance Imaging (MRI) contraindications. The interventions comprise either a daily supplementary intake of 30 g soluble fiber (inulin), or weekly neurocognitive behavioral group sessions, compared to placebo (equicaloric maltodextrin). At baseline and follow-up, food decision-making is assessed utilizing task-based MRI. Secondary outcome measures include structural MRI, eating habits, lifestyle factors, personality traits, and mood. Further, we obtain fecal and blood samples to investigate gut microbiome composition and related metabolites.

DISCUSSION

This study relies on expanding research suggesting that dietary prebiotics could improve gut microbiome composition, leading to beneficial effects on gut-brain signaling and higher-order cognitive functions. In parallel, neurocognitive behavioral interventions have been proposed to improve unhealthy eating habits and metabolic status. However, causal evidence on how these "bottom-up" and "top-down" processes affect food decision-making and neuronal correlates in humans is still scarce. In addition, microbiome, and gut-brain-axis-related mediating mechanisms remain unclear. The present study proposes a comprehensive approach to assess the effects of these gut-brain-related processes influencing food decision-making in overweight and obesity.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05353504. Retrospectively registered on 29 April 2022.

Association between gut microbiota and short-chain fatty acids in children with obesity

The gut microbiome and its metabolites may be important role in regulating the pathogenesis of obesity. This study aimed to characterize the gut microbiome and short-chain fatty acid (SCFA) metabolome in obese children. This case-control study recruited children aged 7‒14 years and divided them into a normal group (NG) and an obese group (OG) based on their body mass index. Whole-genome shotgun metagenomic analysis was performed on fecal samples from the OG and NG groups to characterize the signatures and functional potential of the gut microbiota. Serum metabolite profiles were analyzed using high-performance liquid chromatography/mass spectrometry (LC/MS). The Statistical Package for the Social Sciences (SPSS, version 26) and R software were used for data analysis. A total of 99 children were recruited, with 49 in the OG and 50 in the NG. At the phylum level, Proteobacteria were significantly more abundant in children in the OG than those in the NG. At the genus level, Oscillibacter and Alistipes were significantly lower in children in the OG than those in the NG. Caproate levels significantly increased, whereas butyrate and isobutyrate levels decreased in children in the OG than those in the NG. Kyoto encyclopedia of genes and genomes (KEGG) functional analysis revealed 28 enriched KEGG pathways, of which/with the phosphotransferase system (PTS) and enhanced biofilm formation by Escherichia coli were particularly significant in the OG. Spearman's correlation analysis indicated that the genus Oscillibacter and species Clostridium_sp._CAG:302 connect serum metabolites and the gut microbiota in childhood obesity. Childhood obesity is correlated with the symbiotic status of the gut microbiota. The microbiota influences human metabolism via specific pathways, particularly butyrate, caproate, and the genus Oscillibacter, all closely associated with obesity.

Complexation of starch and konjac glucomannan during screw extrusion exhibits obesity-reducing effects by modulating the intestinal microbiome and its metabolites

Dietary interventions have been shown to improve gut health by altering the gut flora, preventing obesity, and mitigating inflammatory disorders. This study investigated the benefits of a rice starch-konjac glucomannan (ERS-KGM) complex, produced via screw extrusion, for gut health and obesity prevention. Analyzed through in vitro starch digestion, scanning electron microscopy, and structural analysis, the ERS-KGM complex exhibited a notable increase in resistant starch content due to its well-ordered structure. When administered to mice on a high-fat diet for 8 weeks, the ERS-KGM complex significantly reduced body weight, white adipose tissue mass, adipocyte size, and food intake while increasing water consumption. It also improved glucose metabolism, insulin sensitivity, and lipid profiles by lowering serum triglycerides and total glycerol content. Enhanced metabolic biomarkers and enzyme activities were observed, specifically involving glycerophospholipid metabolism. It decreased the activities of aldehyde dehydrogenase, lactate dehydrogenase, and amino acid transaminase while increasing antioxidant enzymes like glutathione peroxidase and superoxide dismutase. Additionally, it elevated glycogen and positively altered gut microbiota by enriching Firmicutes, Desulfobacterota, and Bifidobacterium. This change enhanced the ability to degrade specific compounds and elevated the concentrations of short-chain fatty acids in feces. These findings suggest that the ERS-KGM complex could serve as a dietary supplement for obesity prevention.

Urinary Metabolite Profiles of Participants with Overweight and Obesity Prescribed a Weight Loss High Fruit and Vegetable Diet: A Single Arm Intervention Study

BACKGROUND/OBJECTIVES

Thus far, no studies have examined the relationship between fruit and vegetable (F and V) intake, urinary metabolite quantities, and weight change. Therefore, the aim of the current study was to explore changes in urinary metabolomic profiles during and after a 10-week weight loss intervention where participants were prescribed a high F and V diet (7 servings daily).

METHODS

Adults with overweight and obesity (n = 34) received medical nutrition therapy counselling to increase their F and V intakes to national targets (7 servings a day). Data collection included weight, dietary intake, and urine samples at baseline at week 2 and week 10. Urinary metabolite profiles were quantified using 1H NMR spectroscopy. Machine learning statistical approaches were employed to identify novel urine-based metabolite biomarkers associated with high F and V diet patterns at weeks 2 and 10. Metabolic changes appearing in urine in response to diet were quantified using Metabolite Set Enrichment Analysis (MSEA).

RESULTS

Energy intake was significantly lower (p = 0.02) at week 10 compared with baseline. Total F and V intake was significantly higher at week 2 and week 10 (p < 0.05). In total, 123 urinary metabolites were quantified. At week 10, 21 metabolites showed significant changes relative to baseline. Of these, 11 metabolites also significantly changed at week 2. These overlapping metabolites were acetic acid, dimethylamine, choline, fumaric acid, glutamic acid, L-tyrosine, histidine, succinic acid, uracil, histamine, and 2-hydroxyglutarate. Ridge Classifier and Linear Discriminant Analysis provided best prediction accuracy values of 0.96 when metabolite level of baseline was compared to week 10.

CONCLUSIONS

Urinary metabolites quantified represent potential candidate biomarkers of high F and V intake, associated with a reduction in energy intake. Further studies are needed to validate these findings in larger population studies.

Phytoactives for Obesity Management: Integrating Nanomedicine for Its Effective Delivery

Obesity is a global health concern that requires urgent investigation and management. While synthetic anti-obesity medications are available, they come with a high risk of side-effects and variability in their efficacy. Therefore, natural compounds are increasingly being used to treat obesity worldwide. The proposition that naturally occurring compounds, mainly polyphenols, can be effective and safer for obesity management through food and nutrient fortification is strongly supported by extensive experimental research. This review focuses on the pathogenesis of obesity while reviewing the efficacy of an array of phytoactives used for obesity treatment. It details mechanisms such as enzyme inhibition, energy expenditure, appetite suppression, adipocyte differentiation, lipid metabolism, and modulation of gut microbiota. Comprehensive in vitro, in vivo, and preclinical studies underscore the promise of phytoactives in combating obesity, which have been thoroughly reviewed. However, challenges, such as poor bioavailability and metabolism, limit their potential. Advances in nanomedicines may overcome these constraints, offering a new avenue for enhancing the efficacy of phytoactives. Nonetheless, rigorous and targeted clinical trials are essential before applying phytoactives as a primary treatment for obesity.

The Impact of Yoyo Dieting and Resistant Starch on Weight Loss and Gut Microbiome in C57Bl/6 Mice

Cyclic weight loss and subsequent regain after dieting and non-dieting periods, a phenomenon termed yoyo dieting, places individuals at greater risk of metabolic complications and alters gut microbiome composition. Resistant starch (RS) improves gut health and systemic metabolism. This study aimed to investigate the effect of yoyo dieting and RS on the metabolism and gut microbiome. C57BL/6 mice were assigned to 6 diets for 20 weeks, including control, high fat (HF), yoyo (alternating HF and control diets every 5 weeks), control with RS, HF with RS, and yoyo with RS. Metabolic outcomes and microbiota profiling using 16S rRNA sequencing were examined. Yoyo dieting resulted in short-term weight loss, which led to improved liver health and insulin tolerance but also a greater rate of weight gain compared to continuous HF feeding, as well as a different microbiota profile that was in an intermediate configuration between the control and HF states. Mice fed HF and yoyo diets supplemented with RS gained less weight than those fed without RS. RS supplementation in yoyo mice appeared to shift the gut microbiota composition closer to the control state. In conclusion, yoyo dieting leads to obesity relapse, and increased RS intake reduces weight gain and might help prevent rapid weight regain via gut microbiome restoration.

The short-chain fatty acid acetate modulates orexin/hypocretin neurons: A novel mechanism in gut-brain axis regulation of energy homeostasis and feeding

The short-chain fatty acids (SCFAs) acetate, propionate and butyrate, the major products of intestinal microbial fermentation of dietary fibres, are involved in fine-tuning brain functions via the gut-brain axis. However, the effects of SCFAs in the hypothalamic neuronal network regulating several autonomic-brain functions are still unknown. Using NMR spectroscopy, we detected a reduction in brain acetate concentrations in the hypothalamus of obese leptin knockout ob/ob mice compared to lean wild-type littermates. Therefore, we investigated the effect of acetate on orexin/hypocretin neurons (hereafter referred as OX or OX-A neurons), a subset of hypothalamic neurons regulating energy homeostasis, which we have characterized in previous studies to be over-activated by the lack of leptin and enhancement of endocannabinoid tone in the hypothalamus of ob/ob mice. We found that acetate reduces food-intake in concomitance with a reduction of orexin neuronal activity in ob/ob mice. This was demonstrated by evaluating food-intake behaviour and orexin-A/c-FOS immunoreactivity coupled with patch-clamp recordings in Hcrt-eGFP neurons, quantification of prepro-orexin mRNA, and immunolabeling of GPR-43, the main acetate receptor. Our data provide new insights into the mechanisms of the effects of chronic dietary supplementation with acetate, or complex carbohydrates, on energy intake and body weight, which may be partly mediated by inhibition of orexinergic neuron activity.

Dietary Polycan, a β-glucan originating from Aureobasidium pullulansSM-2001, attenuates high-fat-diet-induced intestinal barrier damage in obese mice by modulating gut microbiota dysbiosis

Various metabolic diseases caused by a high-fat diet (HFD) are closely related to gut microbiota dysbiosis and epithelial barrier dysfunction. Polycan, a type of β-glucan, is effective in treating anti-obesity and metabolic diseases caused by HFD. However, the effect of Polycan on dysbiosis and epithelial barrier damage is still unknown. In this study, the effects of Polycan on dysbiosis and intestinal barrier damage were investigated using HFD-induced obese model mice. C57BL/6 mice were fed a HFD for 12 weeks and treated with two different doses of Polycan (250 and 500 mg/kg) orally administered during weeks 9 to 12. Polycan supplementation increased the expression of tight junction genes (zonula occludens-1, occludin, and claudin-3) and short-chain fatty acid (SCFA) content while reducing toxic substances (phenol, p-cresol, and skatole). Most significantly, Polycan enriched SCFA-producing bacteria (i.e., Phocaeicola, Bacteroides, Faecalibaculum, Oscillibacter, Lachnospiraceae, and Muribaculaceae), and decreased the Firmicutes/Bacteroidetes ratio and toxic substances-producing bacteria (i.e., Olsenella, Clostridium XVIII, and Schaedlerella). Furthermore, microbial functional capacity prediction of the gut microbiota revealed that Polycan enriched many SCFA-related KEGG enzymes while toxic substance-related KEGG enzymes were depleted. These findings indicated that Polycan has the potential to alleviate HFD-induced intestinal barrier damage by modulating the function and composition of the gut microbiota.

Effect of Lacticaseibacillus casei LC2W Supplementation on Glucose Metabolism and Gut Microbiota in Subjects at High Risk of Metabolic Syndrome: A Randomized, Double-blinded, Placebo-controlled Clinical Trial

Metabolic syndrome (MetS) is a global epidemic complex and will cause serious metabolic comorbidities without treatment. A prevention strategy for MetS development has been proposed to modulate gut microbiota by probiotic administration to improve intestinal dysbiosis and benefit the host. Lacticaseibacillus casei LC2W has exhibited positive effects in preventing colitis and anti-hypertension in vivo. However, the effect of L. casei LC2W on subjects at high risk of MetS is unknown. Here, a randomized, double-blinded, placebo-controlled study was conducted on 60 subjects with high risk of MetS, and the hypoglycemic and hypolipidemic activity and possible pathways of L. casei LC2W were inferred from the correlation analysis with gut microbiome composition, function, and clinical phenotypic indicators. The results showed that oral administration of L. casei LC2W could exert significant benefits on weight control, glucose and lipid metabolism, inflammatory and oxidative stress parameters, and SCFA production, as well as modulate the composition of gut microbiota. The relative abundance of Lacticaseibacillus, Bifidobacterium, Dorea, and Blautia was enriched, and their interaction with other gut microbes was strengthened by oral administration of L. casei LC2W, which was beneficial in ameliorating gut inflammation, promoting glucose and lipids degradation pathways, thus alleviated MetS. The present study confirmed the prevention effects of L. casei LC2W towards MetS from aspects of clinical outcomes and microflora modulation, providing an alternative strategy for people at high risk of MetS.Trial registration: The study was proactively registered in ClinicalTrial.gov with the registration number of ChiCTR2000031833 on April 09, 2020.

Obesity-associated inflammation countered by a Mediterranean diet: the role of gut-derived metabolites

The prevalence of obesity has increased dramatically worldwide and has become a critical public health priority. Obesity is associated with many co-morbid conditions, including hypertension, diabetes, and cardiovascular disease. Although the physiology of obesity is complex, a healthy diet and sufficient exercise are two elements known to be critical to combating this condition. Years of research on the Mediterranean diet, which is high in fresh fruits and vegetables, nuts, fish, and olive oil, have demonstrated a reduction in numerous non-communicable chronic diseases associated with this diet. There is strong evidence to support an anti-inflammatory effect of the diet, and inflammation is a key driver of obesity. Changes in diet alter the gut microbiota which are intricately intertwined with human physiology, as gut microbiota-derived metabolites play a key role in biological pathways throughout the body. This review will summarize recent published studies that examine the potential role of gut metabolites, including short-chain fatty acids, bile acids, trimethylamine-N-oxide, and lipopolysaccharide, in modulating inflammation after consumption of a Mediterranean-like diet. These metabolites modulate pathways of inflammation through the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, toll-like receptor 4 signaling, and macrophage driven effects in adipocytes, among other mechanisms.

Research Progress on the Correlation Between Hypertension and Gut Microbiota

Among cardiovascular diseases, hypertension is the most important risk factor for morbidity and mortality worldwide, and its pathogenesis is complex, involving genetic, dietary and environmental factors. The characteristics of the gut microbiota can vary in response to increased blood pressure (BP) and influence the development and progression of hypertension. This paper describes five aspects of the relationship between hypertension and the gut microbiota, namely, the different types of gut microbiota, metabolites of the gut microbiota, sympathetic activation, gut-brain interactions, the effects of exercise and dietary patterns and the treatment of the gut microbiota through probiotics, faecal microbiota transplantation (FMT) and herbal remedies, providing new clues for the future prevention of hypertension. Diet, exercise and traditional Chinese medicine may contribute to long-term improvements in hypertension, although the effects of probiotics and FMT still need to be validated in large populations.

Metabolic control of puberty: 60 years in the footsteps of Kennedy and Mitra's seminal work

An individual's nutritional status has a powerful effect on sexual maturation. Puberty onset is delayed in response to chronic energy insufficiency and is advanced under energy abundance. The consequences of altered pubertal timing for human health are profound. Late puberty increases the chances of cardiometabolic, musculoskeletal and neurocognitive disorders, whereas early puberty is associated with increased risks of adult obesity, type 2 diabetes mellitus, cardiovascular diseases and various cancers, such as breast, endometrial and prostate cancer. Kennedy and Mitra's trailblazing studies, published in 1963 and using experimental models, were the first to demonstrate that nutrition is a key factor in puberty onset. Building on this work, the field has advanced substantially in the past decade, which is largely due to the impressive development of molecular tools for experimentation and population genetics. In this Review, we discuss the latest advances in basic and translational sciences underlying the nutritional and metabolic control of pubertal development, with a focus on perspectives and future directions.

Nutraceuticals and biotics in pediatric gastrointestinal disorders

In recent years there has been growing interest in the use of nutraceuticals and biotics in both pediatric and adult clinical practice. The overlapping and often ambiguous symptoms of both functional and organic gastrointestinal disorders have led to a search for alternative therapeutic approaches that avoid the use of synthetic or chemical treatments. However, while nutraceuticals and natural supplements are widely used, their health benefits are often not supported by adequate scientific evidence, and an unregulated use of nutraceuticals can be potentially harmful. The correct use of nutraceuticals, prebiotics, and probiotics can optimize the results of drug therapy in some cases and reduce the risk of side effects. This review aims to provide clinicians with guidance on the use of complementary therapies for pediatric gastrointestinal symptoms and disorders, highlighting the scarcity of studies on the kinetics and dynamics of nutraceuticals and biotics. While it is generally difficult to associate their intakes with adverse events due to the often-coexisting pharmacological treatments, it is essential to avoid the abandonment of traditional drugs with proven efficacy in the treatment of single diseases. Overall, the use of nutraceuticals, prebiotics, and probiotics in pediatric gastroenterological practice requires caution and medical supervision. Further research is needed to determine the effects of alternative therapies on pediatric gastrointestinal symptoms and disorders, and to ensure their safe and effective use in the clinical practice.

A polyphenol-rich plant extract prevents hypercholesterolemia and modulates gut microbiota in western diet-fed mice

Introduction

Totum-070 is a combination of five plant extracts enriched in polyphenols to target hypercholesterolemia, one of the main risk factors for cardiovascular diseases. The aim of this study was to investigate the effects of Totum-070 on cholesterol levels in an animal model of diet-induced hypercholesterolemia.

Methods

C57BL/6JOlaHsd male mice were fed a Western diet and received Totum-070, or not, by daily gavage (1g/kg and 3g/kg body weight) for 6 weeks.

Results

The Western diet induced obesity, fat accumulation, hepatic steatosis and increased plasma cholesterol compared with the control group. All these metabolic perturbations were alleviated by Totum-070 supplementation in a dose-dependent manner. Lipid excretion in feces was higher in mice supplemented with Totum-070, suggesting inhibition of intestinal lipid absorption. Totum-070 also increased the fecal concentration of short chain fatty acids, demonstrating a direct effect on intestinal microbiota.

Discussion

The characterization of fecal microbiota by 16S amplicon sequencing showed that Totum-070 supplementation modulated the dysbiosis associated with metabolic disorders. Specifically, Totum-070 increased the relative abundance of Muribaculum (a beneficial bacterium) and reduced that of Lactococcus (a genus positively correlated with increased plasma cholesterol level). Together, these findings indicate that the cholesterol-lowering effect of Totum-070 bioactive molecules could be mediated through multiple actions on the intestine and gut microbiota.

Metabolic Syndrome: A Narrative Review from the Oxidative Stress to the Management of Related Diseases

Metabolic syndrome (MS) is a growing disorder affecting thousands of people worldwide, especially in industrialised countries, increasing mortality. Oxidative stress, hyperglycaemia, insulin resistance, inflammation, dysbiosis, abdominal obesity, atherogenic dyslipidaemia and hypertension are important factors linked to MS clusters of different pathologies, such as diabesity, cardiovascular diseases and neurological disorders. All biochemical changes observed in MS, such as dysregulation in the glucose and lipid metabolism, immune response, endothelial cell function and intestinal microbiota, promote pathological bridges between metabolic syndrome, diabesity and cardiovascular and neurodegenerative disorders. This review aims to summarise metabolic syndrome's involvement in diabesity and highlight the link between MS and cardiovascular and neurological diseases. A better understanding of MS could promote a novel strategic approach to reduce MS comorbidities.

Dietary Patterns Are Associated with the Gut Microbiome and Metabolic Syndrome in Mexican Postmenopausal Women

Postmenopausal women are at an increased risk of developing metabolic syndrome (MetS) due to hormonal changes and lifestyle factors. Gut microbiota (GM) have been linked to the development of MetS, and they are influenced by dietary habits. However, the interactions between dietary patterns (DP) and the GM of postmenopausal women, as well as their influence on MetS, still need to be understood. The present study evaluated the DP and microbiota composition of postmenopausal Mexican women with MetS and those in a control group. Diet was assessed using a food frequency questionnaire, and the GM were profiled using 16S rRNA gene sequencing. Greater adherence to a "healthy" DP was significantly associated with lower values of MetS risk factors. GM diversity was diminished in women with MetS, and it was negatively influenced by an "unhealthy" DP. Moreover, a higher intake of fats and proteins, as well as lower amounts of carbohydrates, showed a reduction in some of the short-chain fatty acid-producing genera in women with MetS, as well as increases in some harmful bacteria. Furthermore, Roseburia abundance was positively associated with dietary fat and waist circumference, which may explain 7.5% of the relationship between this macronutrient and MetS risk factors. These findings suggest that GM and diet interactions are important in the development of MetS in postmenopausal Mexican women.

Low Short-Chain-Fatty-Acid-Producing Activity of the Gut Microbiota Is Associated with Hypercholesterolemia and Liver Fibrosis in Patients with Metabolic-Associated (Non-Alcoholic) Fatty Liver Disease

The aim of this study was to investigate the short-chain fatty acid (SCFA) activity of the gut microbiota of patients with metabolic-associated fatty liver disease (MAFLD). The level and spectrum of short-chain fatty acids (SCFAs) were determined via gas–liquid chromatography. Liver fibrosis was assessed using the FIB-4 index and elastography. Among 42 non-cirrhotic MAFLD patients, 24 had high fecal SCFA levels (group H) and 18 had low fecal SCFA levels (group L). Patients in group H had lower serum uric acid, total cholesterol, and LDL cholesterol levels but a higher BMI than those in group L. All patients in group L and only 37.9% of those in group H were found to have hypercholesterolemia. In patients with hypercholesterolemia, the level of SCFAs was lower than that in patients without hypercholesterolemia. Patients in group H had less liver fibrosis than patients in group L. A total of 50.0% of the patients in group H and 92.3% of those in group L had significant liver fibrosis (≥F2). Patients with significant liver fibrosis had lower levels of fecal SCFAs—particularly acetate and butyrate. The fecal SCFA levels were positively correlated with gamma-glutamyl transferase, total bilirubin levels, BMI, and platelet count and were negatively correlated with FIB-4, liver stiffness, serum total, and LDL cholesterol levels.

Multispecies probiotic affects fecal short-chain fatty acids in postmenopausal women with obesity: A post hoc analysis of a randomized, double-blind, placebo-controlled study

OBJECTIVES

Probiotics are known to regulate host metabolism. The aim of this study was to assess whether interventions with a multi-strain probiotic formula affect fecal short-chain fatty acids (SCFAs).

METHODS

The analysis was carried out in 56 obese, postmenopausal women randomized to three groups: probiotic dose 2.5 × 109 CFU/d (n = 18; lower probiotic dose [LPD]), 1 × 1010 CFU/d (n = 18; higher probiotic dose [HPD]), or placebo (n = 20).

RESULTS

An increase in three SCFA fecal concentrations in the HPD group was observed: acetic acid (C2; effect [E] = 1.72, SE = 0.73; 95% confidence interval [CI], 0.28-3.16; P = 0.019), butyric acid (C4; E = 0.98, SE = 0.46; 95% CI, 0.08-1.88; P = 0.033), and valeric acid (C5; E = 0.68, SE = 0.23; 95% CI, 0.23-1.12; P = 0.003). The mediation analysis showed that the decrease in uric acid under HPD may be transmitted through the elevation of C5 content. Multi-strain probiotic increases the SCFA content in the stool in a dose-dependent manner, which may diminish some cardiovascular risk factors because of a reduction in blood uric acid levels.

CONCLUSION

Assessing long-term health benefits requires further research, including assessment of blood SCFA concentrations and multiomic and mechanistic approaches.

Macronutrient quality and the incidence of metabolically unhealthy phenotypes in adults with normal weight and overweight/obesity

OBJECTIVE

We aimed to investigate the associations of macronutrient quality indices with the incident metabolically unhealthy normal weight (MUNW) and metabolically unhealthy overweight/obesity (MUO) phenotypes.

METHODS

This prospective study included 512 metabolically healthy normal weight and 787 metabolically healthy overweight/obese adults from the third study examination of the Tehran Lipid and Glucose Study. The participants were followed through the sixth study examination. Diet was measured with a food frequency questionnaire. The macronutrient quality index (MQI), carbohydrate quality index (CQI), fat quality index (FQI), and healthy plate quality index (HPPQI) were calculated. Hazard ratio (HR) and 95 % confidence interval (95 % CI) were estimated for incident unhealthy phenotypes using Cox regression.

RESULTS

After controlling all possible confounding factors, a one-point higher HPPQI was linked to a 28 % lower risk of MUNW (HR = 0.72; 95 % CI = 0.59, 0.87). Compared to the lowest quartile, the incident MUNW was also lower in the two last quartiles of the HPPQI. A one-unit increase in MQI was associated with a 5 % lower incident MUO (HR = 0.95; 95 % CI = 0.92, 0.99). The incident MUO was also higher for the highest compared to the lowest MQI quartile. In quartiles 2-4 of the HPPQI, incident MUO was lower with respective HRs (95 % CI) of 0.71 (0.54, 0.93), 0.60 (0.45, 0.80), and 0.66 (0.50, 0.86) in the fully-adjusted model.

CONCLUSIONS

A higher overall macronutrient quality was independently associated with a lower incident MUO. A higher dietary protein quality was related to a lower risk for MUNW and MUO.

Metabolism of free fatty acids in patients with gastrointestinal diseases depending on the body mass index

Background. The purpose of the study is to analyze the content of free fatty acids (FFA) in the blood serum of overweight and underweight patients with gastrointestinal diseases. Mate­rials and methods. Thirty-one patients with gastrointestinal diseases were examined, 19 (61.3 %) men and 12 (38.7 %) women with a median age of 39 (27; 48) years. Depending on the results of the body composition study with the multifunctional monitor TANITA MC-780MA (Japan), they were divided into the following groups: overweight patients (body mass index (BMI) more than 25.0 kg/m2) and underweight persons (BMI below 18.5 kg/m2). Determination of the FFA spectrum in the blood serum was carried out using a gas chromatograph with a flame ionization detector Chromatek-Crystal 5000. The control group consisted of 16 practically healthy people. Statistical processing of the results was carried out using the Statistica 6.1 application program package. Results. Patients with a change in body weight reported a statistically significant decrease in the median total content of short-chain saturated FFA (C4:0) mainly due to a decrease in the butyric acid content by 67 times (p = 0.001) with increased BMI and by 114 times (p = 0.002) with decreased BMI compared to controls. At the same time, the analysis of the serum spectrum of saturated FFA with an average carbon chain length showed a probable increase in the content of capric acid by 14 times (p < 0.01), undecyl acid by 19 times (p < 0.01), and lauric acid by 25 times (p < 0.001) in patients with changes in body weight. The content of caproic acid increased in the group with excessive body weight by 3.9 times (p = 0.046) compared to controls and by 2.6 times (p > 0.05) compared to underweight patients. The total content of monounsaturated FFA in the blood serum of patients with increased and decreased BMI increased significantly by 32 times (p < 0.001) and 19 times (p = 0.001), respectively, compared to controls. The total content of polyunsaturated FFA in the blood serum of patients of both groups was found in a trace amount. Overweight patients had a 38-fold (p < 0.01) increase in the trans-FFA elaidic acid (C18:1(trans-9)) compared to controls, while underweight patients had a decrease in linoelaidic acid (C18:2(trans-9,12)) by 11.7 times (p < 0.05). Correlation analysis revealed a positive relationship between BMI and increased serum content of saturated caproic acid (r = 0.39; p = 0.019); monounsaturated acids — palmitoleic (r = 0.33; р = 0.045) and heptadecenoic (r = 0.35; р = 0.034); trans-configuration fatty acids — elaidic (r = 0.43; p = 0.009) and linoelaidic (r = 0.43; p = 0.007). Conclusions. Patients with gastrointestinal diseases had an imbalance in the fatty acid spectrum of the blood serum. Against the background of the tendency to decrease the total content of short-chain saturated FFA, a significant increase in the content of monounsaturated FFA and trans-FFA was noted, especially with increased BMI. In all patients, the trace amount of polyunsaturated FFA fractions was found. The obtained results can be used to improve the differential treatment of metabolic disorders in patients with gastrointestinal tract pathology.

First Comparative Evaluation of Short-Chain Fatty Acids and Vitamin-K-Dependent Proteins Levels in Mother-Newborn Pairs at Birth

BACKGROUND

The interplay between vitamin K (vitK) (as carboxylation cofactor, partially produced by the gut microbiota) and short-chain fatty acids (SCFAs), the end-product of fiber fermentation in the gut, has never been assessed in mother-newborn pairs, although newborns are considered vitK deficient and with sterile gut.

METHODS

We collected venous blood from 45 healthy mothers with uncomplicated term pregnancies and umbilical cord blood from their newborns at birth. The concentrations of total SCFAs and hepatic/extra-hepatic vitK-dependent proteins (VKDPs), as proxies of vitK status were assayed: undercarboxylated and total matrix Gla protein (ucMGP and tMGP), undercarboxylated osteocalcin (ucOC), undercarboxylated Gla-rich protein (ucGRP), and protein induced by vitK absence II (PIVKA-II).

RESULTS

We found significantly higher ucOC (18.6-fold), ucMGP (9.2-fold), and PIVKA-II (5.6-fold) levels in newborns, while tMGP (5.1-fold) and SCFAs (2.4-fold) were higher in mothers, and ucGRP was insignificantly modified. In mother-newborn pairs, only ucGRP (r = 0.746, p < 0.01) and SCFAs (r = 0.428, p = 0.01) levels were correlated. Conclusions: We report for the first time the presence of SCFAs in humans at birth, probably transferred through the placenta to the fetus. The increased circulating undercarboxylated VKDPSs in newborns revealed a higher vitamin K deficiency at the extrahepatic level compared to liver VKDPs.

Proanthocyanidins: Impact on Gut Microbiota and Intestinal Action Mechanisms in the Prevention and Treatment of Metabolic Syndrome

The metabolic syndrome (MS) is a cluster of risk factors, such as central obesity, hyperglycemia, dyslipidemia, and arterial hypertension, which increase the probability of causing premature mortality. The consumption of high-fat diets (HFD) is a major driver of the rising incidence of MS. In fact, the altered interplay between HFD, microbiome, and the intestinal barrier is being considered as a possible origin of MS. Consumption of proanthocyanidins (PAs) has a beneficial effect against the metabolic disturbances in MS. However, there are no conclusive results in the literature about the efficacy of PAs in improving MS. This review allows a comprehensive validation of the diverse effects of the PAs on the intestinal dysfunction in HFD-induced MS, differentiating between preventive and therapeutic actions. Special emphasis is placed on the impact of PAs on the gut microbiota, providing a system to facilitate comparison between the studies. PAs can modulate the microbiome toward a healthy profile and strength barrier integrity. Nevertheless, to date, published clinical trials to verify preclinical findings are scarce. Finally, the preventive consumption of PAs in MS-associated dysbiosis and intestinal dysfunction induced by HFD seems more successful than the treatment strategy.