Gut Microbiome and Obesity: A Plausible Explanation for Obesity

Gut Microbiota Modulation Through Dietary Approaches Targeting Better Health During Metabolic Disorders

The impact of gut microbiota is known to play a significant role in an individual's metabolism and health. Many harmful food products or dietary imbalance adversely affect human health and changing lifestyle, environmental factors, and food habits may have their effect on gut microbiota. It has emerged that gut microbiota is regarded as an emerging metabolic organ, which is dependent on individual's diet and its composition. This review discusses the significance of lactic acid bacteria as a prominent inhabitant in the gut microbiota and the role of probiotics, prebiotics, and polyphenols to improve human health and metabolism. The role of fermented foods as an important source of probiotics and bioactive molecules is also discussed along with the role of gut microbiota in metabolic disorders like dyslipidemia, obesity, hypercholesterolemia, cancer, and hypertension. Finally, the review gives insights into the effective therapeutic prospects through gut microbiota alterations to tackle these metabolic disorders.

The Interplay Between Nutrition and Microbiota and the Role of Probiotics and Symbiotics in Pediatric Infectious Diseases

The interplay between nutrition and infectious diseases has been a central theme in health sciences for the last decades due to its great impact on the pediatric population, especially in immunocompromised patients and critically ill children. As conventional treatment and the development of antimicrobials for most infections standard treatment is either limited or not possible, alternative treatment options should be explored. Recent research shows that early enteral nutrition and nutritional supplements (such as probiotics and symbiotics) could have a pivotal role in promoting a healthy microbiome and subsequently preventing and improving outcomes for certain pediatric infectious diseases. However, understanding the specific mechanism of action and tailoring nutritional interventions remains a significant challenge. The optimal dose range for different probiotic strains and prebiotics and the most effective combination for each treatment indication needs further investigation and is yet to be defined. Additionally, in the era of personalized medicine, goal- and patient-directed treatment are key to optimizing and improving outcomes and minimizing potential complications and side effects, especially in complex and immunocompromised patients. The main objectives of this narrative review are 1. to explore the relationship and the complex interactions between microbiota and the human immune system; 2. to describe the influence of nutrition on infectious diseases; 3. to evaluate the impact of supplementation with probiotics and symbiotics in the prevention and treatment of the most relevant infections in children; and 4. to identify knowledge gaps and potential research priorities regarding the use of these supplements in pediatric patients.

Amelioration of metabolic syndrome in high-fat diet-fed mice by total sesquiterpene lactones of chicory via modulation of intestinal flora and bile acid excretion

Chicory (Cichorium intybus L.) is a commonly used vegetable in Europe and is also regarded as a plant for both medicinal and edible uses in China. Chicory exhibits a substantial abundance of sesquiterpene lactone compounds within its composition. The prevalence of metabolic syndrome (MetS) is increasing and has become a global public health issue threatening the well-being of the general population. Recent studies have identified plant secondary metabolites as potential substances for treating MetS. Sesquiterpene lactones, a type of secondary metabolite with diverse biological activities, have been reported to exhibit anti-inflammatory effects, reduce lipid accumulation, and normalize blood glucose levels. However, the therapeutic effects of chicory sesquiterpene lactones on MetS remain to be explored, and little is known about sesquiterpene lactones' effects on intestinal flora and bile acids (BAs). Therefore, the effects of total sesquiterpene lactones (TSLs) from chicory on metabolic disorders, intestinal flora, and BAs were investigated in this study. In this study, C57BL/6J mice were fed a high-fat diet (HFD) for 8 weeks, followed by administration of TSLs, total chicory extract (TCE), and pioglitazone (Pio) for another 8 weeks. TSL, TCE, and Pio interventions reduced body weight gain, hepatic lipid accumulation, and lipogenesis in HFD-fed mice and attenuated plasma biochemical parameters. Among them, TSLs exhibited more significant effects, prompting further analysis of their impact on intestinal flora and bile acid metabolism. TSL intervention influenced the composition and structure of intestinal flora and BAs. TSL intervention impacted the composition and structure of the intestinal flora, characterized by a decrease in the abundances of Allobaculum, unidentified_Coriobacteriaceae, and Odoribacter, while the abundances of Prevotella, unidentified_Erysipelotrichaceae and Akkermansia were increased. Additionally, the levels of BAs TCDCA, GDCA, UDCA, 12-ketoLCA, 7-ketoLCA, and 6,7-diketoLCA were reduced. The research results indicated that TSLs from chicory may serve as potential agents for regulating metabolic abnormalities associated with MetS, as their effects can influence intestinal flora and BAs. The conclusions of this study are expected to open new research trajectories in the field of food science and nutrition, providing a solid scientific basis and innovative intervention approaches for the development of strategies targeting MetS prevention and management.

Probiotic intervention and exercise mitigate inflammation and histopathological alterations in the liver of wistar rats on a high-fat diet

BACKGROUND

Controlling intestinal risk factors by consuming probiotics and modifying lifestyle with exercise modulates dietary damage. The aim of the present study was to investigate the effect of 6 weeks of aerobic exercise training and probiotic consumption on the expression of inflammatory genes and histopathological changes in the liver of rats with a high-fat diet model.

METHODS AND RESULTS

In this study, 40 male Wistar rats were divided into 5 groups: healthy control, high-fat diet (HFD), HFD with exercise (HFD + Exe), HFD with probiotic consumption (HFD + Prob), and HFD + Exe + Prob. Animals in the HFD group were first exposed to a special diet and after confirming liver tissue damage, they entered the main protocol. Animals in the exercise group performed aerobic exercise on a rodent treadmill for 6 weeks, 5 days a week. Animals in the probiotic group also received Lactobacillus bifidus by oral gavage after exercise. Finally, intestinal and liver tissue were removed and examined for histological and cellular examination. Based on the results, HFD caused tissue damage and fat infiltration in both intestinal and liver tissue. Also, inflammatory factors (IL-6 and IL-1β genes) in the liver tissue of this group increased significantly compared to the control group (p < 0.05). In contrast, probiotic intervention and aerobic exercise caused a significant decrease in IL-6 and IL-1β genes compared to the HFD group (p < 0.05).

CONCLUSION

The use of probiotic Lactobacillus bifidus along with exercise can neutralize inflammatory damage caused by a high-fat diet in liver tissue. However, further studies are needed in this field.

Effect of caloric restriction with probiotic supplementation on body composition, quality of life, and psychobiological factors of obese men: A randomized, double-blinded placebo-controlled clinical trial

BACKGROUND & AIMS

Obesity is a chronic disease characterized by an excess of fat mass. It is accompanied by a low-grade chronic systemic inflammation state that leads to numerous health disorders. To counteract this scenario, dietary-derived caloric restriction (CR) is the principal intervention for weight loss. Furthermore, probiotic supplementation has gained attention as a co-intervention to optimize weight loss and other health-related factors. As such, we aimed to verify the effect of CR with probiotic supplementation on the body composition, quality of life, sleep quality, anxiety, stress, and depression symptoms of adult men living with obesity.

METHODS

The study is called the Clinical Study of Obesity and Intestinal Microbiota (ECOMI). It is a randomized, double-blind, placebo-controlled clinical trial involving two parallel groups of stable-weight adult men living with obesity. The inclusion criteria were male individuals aged 25-44 years, with body mass index (BMI) ranging from 30.0 to 39.99 kg/m2, and stable body mass over the preceding three months. Participants were randomly assigned to two groups: Caloric Restriction with Probiotic (CRPRO) and Caloric Restriction with Placebo (CRPLA). The achieved CR was 30 % of the total daily energy expenditure. Macronutrients were distributed as 50 % carbohydrates, 30 % lipids, and 20 % proteins. Probiotic supplementation was carried out using two sachets/day of 1 g, containing 1 × 109 Colony Forming Units (CFU) of each strain: Lactobacillus acidophilus NCFM, Lactobacillus rhamnosus HN001, Lactobacillus paracasei Lpc-37 and Bifidobacterium lactis HN019, totaling 8 billion CFU/day. CR and probiotic (or placebo) supplementation intervention lasted 12 weeks. Body composition and psychobiological-related parameters (e.g., sleep, anxiety, stress, and depression) were assessed at baseline and following 12 weeks of intervention. Data are presented as mean and 95 % confidence interval (CI) and mean difference (MD).

RESULTS

The present study applied the per protocol analysis. Thirty-three subjects were evaluated and randomized, but only data from 25 (CRPLA n = 12 vs CRPRO n = 13) participants were included in the final analysis. We verified that CR resulted in weight loss (p < 0.001; η2ρ = 0.754) in both CRPLA (MD: -6.30 kg; p < 0.001) and CRPRO (MD: -5.97 kg; p < 0.001), without differences between groups (p = 0.823; η2ρ = 0.002). Moreover, both CRPLA (MD: -4.83 kg; p < 0.001) and CRPRO (MD: -5.20 kg; p < 0.001) decreased body fat without difference between groups (p = 0.712; η2ρ = 0.006). Regarding obesity-related problems, only the corporeality dimension (p < 0.001; η2ρ = 0.474) in both CRPLA (p = 0.028) and CRPRO (p = 0.039) improved. World Health Organization Quality of Life (WHOQoL)-related dimensions were improved for perception (p < 0.001; η2ρ = 0.630), satisfaction (p < 0.001; η2ρ = 0.778), and psychological domain (p < 0.001; η2ρ = 0.567), without differences between groups. Moreover, sleep quality (p < 0.001; η2ρ = 0.522) improved in both groups, without differences between groups. Finally, anxiety (p = 0.013; η2ρ = 0.250) and depression (p = 0.003; η2ρ = 0.345) scores assessed via the Depression, Anxiety and Stress Scale-21 (DASS-21) and the Beck Depression Inventory (BDI-II) (p < 0.001; η2ρ = 0.448) improved only in the CRPRO group.

CONCLUSIONS

Probiotic supplementation did not enhance the effects of caloric restriction on body composition, QoL-, or sleep-related parameters. However, anxiety and depressive symptoms improved only in the CRPRO group, despite no differences between groups after 12 weeks. Further studies are needed to confirm these findings.

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.

From Dysbiosis to Hepatic Inflammation: A Narrative Review on the Diet-Microbiota-Liver Axis in Steatotic Liver Disease

The gut microbiota has emerged as a critical player in metabolic and liver health, with its influence extending to the pathogenesis and progression of steatotic liver diseases. This review delves into the gut-liver axis, a dynamic communication network linking the gut microbiome and liver through metabolic, immunological, and inflammatory pathways. Dysbiosis, characterized by altered microbial composition, contributes significantly to the development of hepatic steatosis, inflammation, and fibrosis via mechanisms such as gut barrier dysfunction, microbial metabolite production, and systemic inflammation. Dietary patterns, including the Mediterranean diet, are highlighted for their role in modulating the gut microbiota, improving gut-liver axis integrity, and attenuating liver injury. Additionally, emerging microbiota-based interventions, such as fecal microbiota transplantation and bacteriophage therapy, show promise as therapeutic strategies for steatotic liver disease. However, challenges such as population heterogeneity, methodological variability, and knowledge gaps hinder the translational application of current findings. Addressing these barriers through standardized approaches and integrative research will pave the way for microbiota-targeted therapies to mitigate the global burden of steatotic liver disease.

The Oral Microbiome in Diabetes, Arterial Hypertension, and Obesity: A Scoping Review

BACKGROUND

Changes in the oral microbiome are expected in the presence of chronic conditions such as type 2 diabetes mellitus (T2D), arterial hypertension (AH), and obesity (OB).

OBJECTIVE

We aimed to map the literature regarding oral microbiome changes in people with T2D, AH, or OB compared to those without these conditions.

METHODS

This scoping review was guided by the JBI Manual for Evidence Synthesis and reported according to the PRISMA extension for scoping reviews (PRISMA-ScR). A search strategy was developed and adapted to five databases (Embase, LILACS, PubMed, Scopus, and Web of Science) and gray literature (Google Scholar and ProQuest Dissertation and Thesis). Two reviewers individually screened studies for inclusion. Data from the studies, including the molecular method to evaluate the microbiome and the type of sample, were extracted and analyzed. The focus was significant changes in phylum and genera.

RESULTS

A total of 1413 records were retrieved from databases, 86 from gray literature, and 7 from reference lists. After the screening process, 50 records were included, 28 on T2D, 8 on AH, and 12 on OB. Two studies addressed metabolic syndromes. Most studies identified the oral microbiome in saliva using 16S rRNA amplicon sequencing.

CONCLUSION

At the phylum level, Fusobacteria was enriched in ≥3 studies in people with T2D. Firmicutes enrichment was associated with T2D and OB. Genera enriched in T2D comprised Catonella, Leptotrichia, Prevotella, and Rothia. Aggregatibacter and Prevotella were enriched in OB. No phylum or genera were consistently enriched in AH.OSF protocol registration: DOI 10.17605/OSF.IO/XK72V (available at https://osf.io/z5fp4 ).

Fecal Microbiota Transplantation as an Alternative Method in the Treatment of Obesity

Fecal microbiota transplantation (FMT) has emerged as a promising therapeutic approach for various health conditions, particularly obesity and metabolic disorders. This review examines the mechanisms underlying FMT, including its role in restoring gut microbiota diversity and enhancing immunomodulatory functions, which are essential for maintaining overall health. Recent studies indicate that FMT can significantly improve body weight and metabolic parameters, suggesting its potential as an alternative or complementary treatment to current obesity therapies. However, the effectiveness of FMT depends on several factors, including the composition of the donor microbiota, recipient characteristics, and concomitant medications or dietary interventions. Despite its great promise, challenges such as standardized protocols, donor screening, and the need for a deeper understanding of gut microbiota dynamics remain key hurdles. Future research should focus on elucidating the specific microbial compositions necessary for optimal therapeutic outcomes and exploring personalized FMT approaches tailored to individual patient profiles. This evolving field presents exciting opportunities for innovative strategies in obesity treatment, warranting further investigation and clinical application.

The impact of host genetics on porcine gut microbiota composition excluding maternal and postnatal environmental influences

The gut microbiota of the pig is being increasingly studied due to its implications for host homeostasis and the importance of the pig as a meat source and biomedical model of human diseases. However, most studies comparing the microbiome between different breeds do not consider the influence of maternal environment during the colonization of the microbiota. The aim of the present study was to compare the gut microbiota during postnatal growth between two pig genotypes (purebred Iberian vs. crossbreds Iberian x Large White pigs), gestated in a single maternal environment (pure Iberian mothers) inseminated with heterospermic semen. Postnatally, piglets were maintained in the same environmental conditions, and their microbiota was studied at 60 and 210 days old. Results showed that age had the greatest influence on alpha and beta diversity, and genotype also affected beta diversity at both ages. There were differences in the microbiome profile between genotypes at the ASV and genus levels when jointly analyzing the total number of samples, which may help to explain phenotypical differences. When each time-point was analyzed individually, there were more differences at 210 days-old than 60 days-old. Fecal short-chain fatty acids (SCFA) were also affected by age, but not by genotype. These results may be a basis for further research on host genotype interactions with the gut microbiota.

Effects of traditional Chinese medicine polysaccharides on chronic diseases by modulating gut microbiota: A review

Intestinal tract is the largest immune system of human body. Gut microbiota (GM) can produce a large number of metabolites, such as short-chain fatty acids and bile acids, which regulate the physiological health of the host and affect the development of disease. In recent years, traditional Chinese medicine (TCM) polysaccharides have attracted extensive attention with multiple biological activities and low toxicity. TCM polysaccharides can promote the growth of intestinal beneficial bacteria and inhibit the growth of harmful bacteria by regulating the structure and function of GM, thus playing a crucial role in preventing or treating chronic diseases such as inflammatory bowel disease (IBD), obesity, type 2 diabetes mellitus (T2DM), liver diseases, cancer, etc. In this paper, the research progress of TCM polysaccharides in the treatment of chronic diseases such as inflammatory bowel disease, obesity, T2DM, liver diseases, cancer, etc. by modulating GM was reviewed. Meanwhile, this review makes an in-depth discussion on the shortcomings of the research of TCM polysaccharides on chronic diseases by modulating GM, and new valuable prospection for the future researches of TCM polysaccharides are proposed, which will provide new ideas for the further study of TCM polysaccharides.

Role of Microbiota-Derived Hydrogen Sulfide (H2S) in Modulating the Gut-Brain Axis: Implications for Alzheimer's and Parkinson's Disease Pathogenesis

Microbiota-derived hydrogen sulfide (H2S) plays a crucial role in modulating the gut-brain axis, with significant implications for neurodegenerative diseases such as Alzheimer's and Parkinson's. H2S is produced by sulfate-reducing bacteria in the gut and acts as a critical signaling molecule influencing brain health via various pathways, including regulating inflammation, oxidative stress, and immune responses. H2S maintains gut barrier integrity at physiological levels and prevents systemic inflammation, which could impact neuroinflammation. However, as H2S has a dual role or a Janus face, excessive H2S production, often resulting from gut dysbiosis, can compromise the intestinal barrier and exacerbate neurodegenerative processes by promoting neuroinflammation and glial cell dysfunction. This imbalance is linked to the early pathogenesis of Alzheimer's and Parkinson's diseases, where the overproduction of H2S exacerbates beta-amyloid deposition, tau hyperphosphorylation, and alpha-synuclein aggregation, driving neuroinflammatory responses and neuronal damage. Targeting gut microbiota to restore H2S homeostasis through dietary interventions, probiotics, prebiotics, and fecal microbiota transplantation presents a promising therapeutic approach. By rebalancing the microbiota-derived H2S, these strategies may mitigate neurodegeneration and offer novel treatments for Alzheimer's and Parkinson's diseases, underscoring the critical role of the gut-brain axis in maintaining central nervous system health.

Exploring the relationship between live microbe intake and obesity prevalence in adults

Obesity has become a global health problem. In recent years, the influence of dietary microbes in the obese population has attracted the attention of scholars. Our study aimed to investigate the link between live microbe intake and obesity in adults. Participants (aged over 20 years) for this study were from the 1999-2018 National Health and Nutrition Examination Survey (NHANES). Participants were categorised into low, medium and high dietary live microbe intake groups. Linear regression was used to analyse the link between live microbe intake and body mass index (BMI) and waist circumference (WC). Logistic regression was used to analyse the link between live microbe intake and obesity and abdominal obesity prevalence. Restricted cubic spline curves (RCS) were used to check whether there was a non-linear relationship between live microbe intake and obesity. A total of 42,749 participants were included in this study and the number of obese reached 15,463. We found that live microbe intake was negatively linked to BMI and WC. In models adjusted for all confounders, the high live microbe intake group had lower obesity (OR = 0.812, 95%CI: 0.754-0.873) and abdominal obesity prevalence (OR = 0.851, 95%CI: 0.785-0.923) than the lowest intake group. Upon further quantification of live microbe intake, we found similar results. RCS analyses showed that live microbe intake was nonlinearly negatively correlated with BMI, WC, obesity, and abdominal obesity prevalence (P for non-linearity < 0.05). This study preliminarily reveals a negative link between live microbe intake and obesity in adults.

Gut microbiota and childhood malnutrition: Understanding the link and exploring therapeutic interventions

Childhood malnutrition is a metabolic condition that affects the physical and mental well-being of children and leads to resultant disorders in maturity. The development of childhood malnutrition is influenced by a number of physiological and environmental factors including metabolic stress, infections, diet, genetic variables, and gut microbiota. The imbalanced gut microbiota is one of the main environmental risk factors that significantly influence host physiology and childhood malnutrition progression. In this review, we have evaluated the gut microbiota association with undernutrition and overnutrition in children, and then the quantitative and qualitative significance of gut dysbiosis in order to reveal the impact of gut microbiota modification using probiotics, prebiotics, synbiotics, postbiotics, fecal microbiota transplantation, and engineering biology methods as new therapeutic challenges in the management of disturbed energy homeostasis. Understanding the host-microbiota interaction and the remote regulation of other organs and pathways by gut microbiota can improve the effectiveness of new therapeutic approaches and mitigate the negative consequences of childhood malnutrition.

Association between gut microbiota at 3.5 years of age and body mass index at 5 years: results from two French nationwide birth cohorts

BACKGROUND/OBJECTIVES

The relationship between gut microbiota and changes in body mass index (BMI) or pediatric overweight in early life remains unclear, and information regarding the preterm population is scarce. This study aimed to investigate how the gut microbiota at 3.5 years of age is associated with (1) later BMI at 5 years, and (2) BMI z-score variations between 2 and 5 years in children from two French nationwide birth cohorts.

SUBJECTS/METHODS

Bacterial 16S rRNA gene sequencing was performed to profile the gut microbiota at 3.5 years of age in preterm children (n = 143, EPIPAGE 2 cohort) and late preterm/full-term children (n = 369, ELFE cohort). The predicted abundances of metabolic functions were computed using PICRUSt2. Anthropometric measurements were collected at 2 and 5 years of age during medical examinations or retrieved from children's health records. Statistical analyses included multivariable linear and logistic regressions, random forest variable selection, and MiRKAT.

RESULTS

The Firmicutes to Bacteroidetes (F/B) ratio at 3.5 years was positively associated with the BMI z-score at 5 years. Several genera were positively ([Eubacterium] hallii group, Fusicatenibacter, and [Eubacterium] ventriosum group) or negatively (Eggerthella, Colidextribacter, and Ruminococcaceae CAG-352) associated with the BMI z-scores at 5 years. Some genera were also associated with variations in the BMI z-scores between 2 and 5 years of age. Predicted metabolic functions, including steroid hormone biosynthesis, biotin metabolism, glycosaminoglycan degradation, and amino sugar and nucleotide sugar metabolism, were associated with lower BMI z-scores at 5 years. The unsaturated fatty acids biosynthesis pathway was associated with higher BMI z-scores.

CONCLUSIONS

These findings indicate that the gut microbiota at 3.5 years is associated with later BMI during childhood, independent of preterm or term birth, suggesting that changes in the gut microbiota that may predispose to adult obesity begin in early childhood.

Bariatric Surgery and New-Onset Substance Use Disorders: A Systematic review and Meta-analysis

Increasing evidence suggests that bariatric surgery (BS) patients are at risk for substance abuse disorders (SUD). The purpose of this systematic review and meta-analysis was to determine the relationship between BS and the development of new-onset substance abuse disorder (SUDNO) in bariatric patients. On October 31, 2023, we reviewed the scientific literature following PRISMA guidelines. A total of 3242 studies were analyzed, 7 met the inclusion criteria. The pooled incidence of SUDNO was 4.28%. Patients' characteristics associated with SUDNO included preoperative mental disorders, high pre-BS BMI, and public health insurance. Surgical factors associated with new SUDNOs included severe complications in the peri- or postoperative period. The occurrence of SUDNOs is a non-negligeable complication after BS. Predisposing factors may be identified and preventive actions undertaken.

Effect of Ketogenic Diet on Obesity and Other Metabolic Disorders: Narrative Review

Obesity is defined as an abnormal or excessive accumulation of fat that increases the burden of different chronic diseases in the population. It has reached epidemic proportions and is a major risk factor for a variety of diseases, including hypertension, cardiovascular disease, type 2 diabetes, dyslipidaemia, atherosclerosis, and some malignancies. Weight gain is a result of excessive energy intake compared to energy expenditure (energy loss from metabolism and physical exercise). A ketogenic diet has a more useful effect on obesity than other diets. A ketogenic diet is a low-carbohydrate, high-fat, moderate-protein diet that induces the production of ketone bodies by mimicking the breakdown of a fasting state. The mechanism behind the ketogenic diet is still unknown, although it obviously helps people with obesity lose weight. Several pathways for the ketogenic diet effect on weight loss have been hypothesized by researchers, including reduced appetite due to effects on appetite control hormones and a possible direct appetite suppressant action of ketone bodies; reduced lipogenesis and increased lipolysis; greater metabolic efficiency; and increased metabolic costs.

Preliminary characterization of gut mycobiome enterotypes reveals the correlation trends between host metabolic parameter and diet: a case study in the Thai Cohort

The association between the gut mycobiome and its potential influence on host metabolism in the Thai Cohort was assessed. Two distinct predominant enterotypes, Saccharomyces (Sa) and Aspergillus/Penicillium (Ap/Pe) showed differences in gut mycobiota diversity and composition. Notably, the Sa enterotype exhibited lower evenness and richness, likely due to the prevalence of Saccharomyces, while both enterotypes displayed unique metabolic behaviors related to nutrient metabolism and body composition. Fiber consumption was positively correlated with adverse body composition and fasting glucose levels in individuals with the Sa enterotype, whereas in the Ap/Pe enterotype it was positively correlated with fat and protein intake. The metabolic functional analysis revealed the Sa enterotype associated with carbohydrate metabolism, while the Ap/Pe enterotype involved in lipid metabolism. Very interestingly, the genes involved in the pentose and glucuronate interconversion pathway, such as polygalacturonase and L-arabinose-isomerase, were enriched in the Sa enterotype signifying a metabolic capacity for complex carbohydrate degradation and utilization of less common sugars as energy sources. These findings highlight the interplay between gut mycobiome composition, dietary habits, and metabolic outcomes within the Thai cohort studies.

Effect of Lifelong Exposure to Dietary Plant and Marine Sources of n-3 Polyunsaturated Fatty Acids on Morphologic and Gene Expression Biomarkers of Intestinal Health in Early Life

Altered intestinal health is also associated with the incidence and severity of many chronic inflammatory conditions, which could be attenuated via dietary n-3 PUFA interventions. However, little is known about the effect of lifelong exposure to n-3 PUFA from plant and marine sources (beginning in utero via the maternal diet) on early life biomarkers of intestinal health. Harems of C57Bl/6 mice were randomly assigned to one of three isocaloric AIN-93G modified diets differing in their fat sources consisting of the following: (i) 10% safflower oil (SO, enriched in n-6 PUFA), (ii) 3% flaxseed oil + 7% safflower oil (FX, plant-based n-3 PUFA-enriched diet), or (iii) 3% menhaden fish oil + 7% safflower oil (MO, marine-based n-3 PUFA-enriched diet). Mothers remained on these diets throughout pregnancy and offspring (n = 14/diet) continued on the same parental diet until termination at 3 weeks of age. In ileum, villi:crypt length ratios were increased in both the FX and MO dietary groups compared to SO (p < 0.05). Ileum mRNA expression of critical intestinal health biomarkers was increased by both n-3 PUFA-enriched diets including Relmβ and REG3γ compared to SO (p < 0.05), whereas only the FX diet increased mRNA expression of TFF3 and Muc2 (p < 0.05) and only the MO diet increased mRNA expression of ZO-1 (p < 0.05). In the proximal colon, both the FX and MO diets increased crypt lengths compared to SO (p < 0.05), whereas only the MO diet increased goblet cell numbers compared to SO (p < 0.05). Further, the MO diet increased proximal colon mRNA expression of Relmβ and REG3γ (p < 0.05) and both MO and FX increased mRNA expression of Muc2 compared to SO (p < 0.05). Collectively, these results demonstrate that lifelong exposure to dietary n-3 PUFA, beginning in utero, from both plant and marine sources, can support intestinal health development in early life. The differential effects between plant and marine sources warrants further investigation for optimizing health.

Long-Term Changes to the Microbiome, Blood Lipid Profiles and IL-6 in Female and Male Swedish Patients in Response to Bariatric Roux-en-Y Gastric Bypass

Lipid metabolism dysregulation is a critical factor contributing to obesity. To counteract obesity-associated disorders, bariatric surgery is implemented as a very effective method. However, surgery such as Roux-en-Y gastric bypass (RYGB) is irreversible, resulting in life-long changes to the digestive tract. The aim of the present study was to elucidate changes in the fecal microbiota before and after RYGB in relation to blood lipid profiles and proinflammatory IL-6. Here, we studied the long-term effects, up to six years after the RYGB procedure, on 15 patients' gut microbiomes and their post-surgery well-being, emphasizing the biological sex of the patients. The results showed improved health among the patients after surgery, which coincided with weight loss and improved lipid metabolism. Health changes were associated with decreased inflammation and significant alterations in the gut microbiome after surgery that differed between females and males. The Actinobacteriota phylum decreased in females and increased in males. Overall increases in the genera Prevotella, Paraprevotella, Gemella, Streptococcus, and Veillonella_A, and decreases in Bacteroides_H, Anaerostipes, Lachnoclostridium_B, Hydrogeniiclostridium, Lawsonibacter, Paludicola, and Rothia were observed. In conclusion, our findings indicate that there were long-term changes in the gut microbiota after RYGB, and shifts in the microbial taxa appeared to differ depending on sex, which should be investigated further in a larger cohort.

An Intestinal FXR Agonist Mitigates Dysbiosis, Intestinal Tight Junctions, and Inflammation in High-Fat Diet-Fed Mice

SCOPE

To analyze the effects of fexaramine (FEX), as an intestinal FXR agonist, on the modulation of the intestinal microbiota and ileum of mice fed a high-fat (HF) diet.

METHODS AND RESULTS

Three-month-old C57Bl/6 male mice are divided into two groups and received a control (C, 10% of energy from lipids) or HF (50% of energy from lipids) diet for 12 weeks. They are subdivided into the C, C + FEX, HF, and HF + FEX groups. FEX is administered (FEX-5 mg kg-1 ) via orogastric gavage for three weeks. Body mass (BM), glucose metabolism, qPCR 16S rRNA gene expression, and ileum gene expression, bile acids (BAs), tight junctions (TJs), and incretin are analyzed. FEX reduces BM and glucose intolerance, reduces plasma lipid concentrations and the Firmicutes/Bacteroidetes ratio, increases the Lactobacillus sp. and Prevotella sp. abundance, and reduces the Escherichia coli abundance. Consequently, the ileal gene expression of Fxr-Fgf15, Tgr5-Glp1, and Cldn-Ocldn-Zo1 is increased, and Tlr4-Il6-Il1beta is decreased.

CONCLUSION

FEX stimulates intestinal FXR and improves dysbiosis, intestinal TJs, and the release of incretins, mitigating glucose intolerance and BM increases induced by an HF diet. However, FEX results in glucose intolerance, insulin resistance, and reduces intestinal TJs in a control group, thus demonstrating limitations to this dietary model.

Bioactives and their roles in bone metabolism of osteoarthritis: evidence and mechanisms on gut-bone axis

Bioactives significantly modify and maintain human health. Available data suggest that Bioactives might play a beneficial role in chronic inflammatory diseases. Although promised, defining their mechanisms and opting to weigh their benefits and limitations is imperative. Detailed mechanisms by which critical Bioactives, including probiotics and prebiotics such as dietary lipids (DHA, EPA, alpha LA), vitamin D, polysaccharides (fructooligosaccharide), polyphenols (curcumin, resveratrol, and capsaicin) potentially modulate inflammation and bone metabolism is limited. Certain dietary bioactive significantly impact the gut microbiota, immune system, and pain response via the gut-immune-bone axis. This narrative review highlights a recent update on mechanistic evidence that bioactive is demonstrated demonstrated to reduce osteoarthritis pathophysiology.

Association between Gut Microbiota Compositions with MicrovascularComplications in Individuals with Diabetes: A Systematic Review

BACKGROUND

Diabetes is one of the chronic and very complex diseases that can lead to microvascular complications. Recent evidence demonstrates that dysbiosis of the microbiota composition might result in low-grade, local, and systemic inflammation, which contributes directly to the development of diabetes mellitus and its microvascular consequences.

OBJECTIVE

The aim of this systematic review was to investigate the association between diabetes microvascular complications, including retinopathy, neuropathy, nephropathy, and gut microbiota composition.

METHODS

A systematic search was carried out in PubMed, Scopus, and ISI Web of Science from database inception to March 2023. Screening, data extraction, and quality assessment were performed by two independent authors. The Newcastle-Ottawa Quality Assessment Scale was used for quality assessment.

RESULTS

About 19 articles were selected from 590 retrieved articles. Among the included studies, nephropathy has been studied more than other complications of diabetes, showing that the composition of the healthy microbiota is changed, and large quantities of uremic solutes that cause kidney injury are produced by gut microbes. Phyla, including Fusobacteria and Proteobacteria, accounted for the majority of the variation in gut microbiota between Type 2 diabetic patients with and without neuropathy. In cases with retinopathy, an increase in pathogenic and proinflammatory bacteria was observed.

CONCLUSION

Our results revealed that increases in Bacteroidetes, Proteobacteria and Fusobacteria may be associated with the pathogenesis of diabetic nephropathy, neuropathy, and retinopathy. In view of the detrimental role of intestinal dysbiosis in the development of diabetes-related complications, gut microbiota assessment may be used as a biomarker in the future and interventions that modulate the composition of microbiota in individuals with diabetes can be used to prevent and control these complications.

The Beneficial Effects of Dietary Interventions on Gut Microbiota-An Up-to-Date Critical Review and Future Perspectives

Different dietary interventions, especially intermittent fasting, are widely used and promoted by physicians; these regimens have been studied lately for their impact on the gut microbiota composition/function and, consequently, on the general physiopathological processes of the host. Studies are showing that dietary components modulate the microbiota, and, at the same time, the host metabolism is deeply influenced by the different products resulting from nutrient transformation in the microbiota compartment. This reciprocal relationship can potentially influence even drug metabolism for chronic drug regimens, significantly impacting human health/disease. Recently, the influence of various dietary restrictions on the gut microbiota and the differences between the effects were investigated. In this review, we explored the current knowledge of different dietary restrictions on animal and human gut microbiota and the impact of these changes on human health.

Linking Clinical Blood Metabogram and Gut Microbiota

Recently, a clinical blood metabogram was developed as a fast, low-cost and reproducible test that allows the implementation of metabolomics in clinical practice. The components of the metabogram are functionally related groups of blood metabolites associated with humoral regulation, the metabolism of lipids, carbohydrates and amines, lipid intake into the organism, and liver function, thereby providing clinically relevant information. It is known that the gut microbiota affects the blood metabolome, and the components of the blood metabolome may affect the composition of the gut microbiota. Therefore, before using the metabogram in the clinic, the link between the metabogram components and the level of gut microorganisms should be established. For this purpose, the metabogram and microbiota data were obtained in this work for the same individuals. Metabograms of blood plasma were obtained by direct mass spectrometry of blood plasma, and the gut microbiome was determined by a culture-based method and real-time polymerase chain reaction (PCR). This study involved healthy volunteers and individuals with varying degrees of deviation in body weight (n = 44). A correlation analysis determined which metabogram components are linked to which gut microorganisms and the strength of this link. Moreover, diagnostic parameters (sensitivity, specificity and accuracy) confirmed the capacity of metabogram components to be used for diagnosing gut microbiota alterations. Therefore, the obtained results allow the use of the metabogram in a clinical setting, taking into account its relationship with gut microbiota.

Comparison of the Gut Microbial Communities of Domestic and Wild Mallards (Anas platyrhynchos) Based on High-Throughput Sequencing Technology

Mallards (Anas platyrhynchos) are currently one of the most popular species in rare bird breeding in several southern provinces of China, but there have been no studies comparing the gut microbial communities of domestic and wild mallards. In this study, 16S rRNA gene high-throughput sequencing technology was used to compare the composition and diversity of gut microbial communities in domestic and wild mallards. Alpha diversity analysis showed significant differences in gut microbial communities between the two groups of mallards, and the diversity and richness of gut microbial communities were significantly higher in wild mallards than in domestic mallards. Beta diversity analysis showed that the two groups of stool samples were mostly separated on the principal coordinate analysis (PCoA) plot. In domestic mallards, Firmicutes (68.0% ± 26.5%) was the most abundant bacterial phylum, followed by Proteobacteria (24.5% ± 22.9%), Bacteroidetes (3.1% ± 3.2%), Fusobacteria (2.2% ± 5.9%), and Actinobacteria (1.1% ± 1.8%). The dominant bacterial phyla in wild mallards were Firmicutes (79.0% ± 10.2%), Proteobacteria (12.9% ± 9.5%), Fusobacteria (3.4% ± 2.5%), and Bacteroidetes (2.8% ± 2.4%). At the genus level, a total of 10 dominant genera (Streptococcus, Enterococcus, Clostridium, Lactobacillus, Soilbacillus, Bacillus, Acinetobacter, Comamonas, Shigella, and Cetobacterium) with an average relative abundance greater than 1% were detected in the fecal samples of both groups. The average relative abundance of five potential pathogenic genera (Streptococcus, Enterococcus, Acinetobacter, Comamonas, and Shigella) was higher in domestic mallards than in wild mallards. The enrichment of pathogenic bacteria in the intestinal tract of domestic mallards should be of sufficient concern.

Alteration of the fecal microbiome in patients with cholecystectomy: potential relationship with postcholecystectomy diarrhea - before and after study

BACKGROUND

Bile acid (BA) is a crucial determinant of the gut microbiome, and cholecystectomy can alter the physiology of BA. Physiological changes in BA resulting from cholecystectomy can also influence the gut microbiome. We aimed to identify the specific taxa associated with perioperative symptoms, including postcholecystectomy diarrhea (PCD), and to evaluate the effect of cholecystectomy on the microbiome by investigating the fecal microbiome of patients with gallstones.

METHODS

We analyzed the fecal samples of 39 patients with gallstones (GS group) and 26 healthy controls (HC group) to evaluate their gut microbiome. We also collected fecal samples from GS group 3 months postcholecystectomy. Symptoms of patients were evaluated before and after cholecystectomy. Further, 16S ribosomal RNA amplification and sequencing were performed to determine the metagenomic profile of fecal samples.

RESULTS

The microbiome composition of GS differed from that of HC; however, the alpha diversity was not different. No significant microbiome alterations were observed before and after cholecystectomy. Moreover, GS group showed a significantly lower Firmicutes to Bacteroidetes ratio before and after cholecystectomy than the HC group (6.2, P< 0.05). The inter-microbiome relationship was lower in GS than in HC and tended to recover 3 months after surgery. Furthermore, ~28.1% ( n =9) of patients developed PCD after surgery. The most prominent species among PCD (+) patients was Phocaeicola vulgatus. Compared with the preoperative state, Sutterellaceae , Phocaeicola , and Bacteroidals were the most dominant taxa among PCD (+) patients.

CONCLUSION

GS group showed a different microbiome from that of HC; however, their microbiomes were not different 3 months after cholecystectomy. Our data revealed taxa-associated PCD, highlighting the possibility of symptom relief by restoring the gut microbiome.

Enhancing Health Benefits through Chlorophylls and Chlorophyll-Rich Agro-Food: A Comprehensive Review

Chlorophylls play a crucial role in photosynthesis and are abundantly found in green fruits and vegetables that form an integral part of our diet. Although limited, existing studies suggest that these photosynthetic pigments and their derivatives possess therapeutic properties. These bioactive molecules exhibit a wide range of beneficial effects, including antioxidant, antimutagenic, antigenotoxic, anti-cancer, and anti-obesogenic activities. However, it is unfortunate that leafy materials and fruit peels often go to waste in the food supply chain, contributing to the prevailing issue of food waste in modern societies. Nevertheless, these overlooked materials contain valuable bioactive compounds, including chlorophylls, which offer significant health benefits. Consequently, exploring the potential of these discarded resources, such as utilizing them as functional food ingredients, aligns with the principles of a circular economy and presents exciting opportunities for exploitation.

Foundational Nutrition: Implications for Human Health

Human nutrition, and what can be considered "ideal" nutrition, is a complex, multi-faceted topic which many researchers and practitioners deliberate. While some attest that basic human nutrition is relatively understood, it is undeniable that a global nutritional problem persists. Many countries struggle with malnutrition or caloric deficits, while others encounter difficulties with caloric overconsumption and micronutrient deficiencies. A multitude of factors contribute to this global problem. Limitations to the current scope of the recommended daily allowances (RDAs) and dietary reference intakes (DRIs), changes in soil quality, and reductions in nutrient density are just a few of these factors. In this article, we propose a new, working approach towards human nutrition designated "Foundational Nutrition". This nutritional lens combines a whole food approach in conjunction with micronutrients and other nutrients critical for optimal human health with special consideration given to the human gut microbiome and overall gut health. Together, this a synergistic approach which addresses vital components in nutrition that enhances the bioavailability of nutrients and to potentiate a bioactive effect.

Effects of microbial-derived biotics (meta/pharma/post-biotics) on the modulation of gut microbiome and metabolome; general aspects and emerging trends

Potential effects of metabiotics (probiotics effector molecules or signaling factors), pharmabiotics (pro-functional metabolites produced by gut microbiota (GMB)) and postbiotics (multifunctional metabolites and structural compounds of food-grade microorganisms) on GMB have been rarely reviewed. These multifunctional components have several promising capabilities for prevention, alleviation and treatment of some diseases or disorders. Correlations between these essential biotics and GMB are also very interesting and important in human health and nutrition. Furthermore, these natural bioactives are involved in modulation of the immune function, control of metabolic dysbiosis and regulation of the signaling pathways. This review discusses the potential of meta/pharma/post-biotics as new classes of pharmaceutical agents and their effective mechanisms associated with GMB-host cell to cell communications with therapeutic benefits which are important in balance and the integrity of the host microbiome. In addition, cutting-edge findings about bioinformatics /metabolomics analyses related to GMB and these essential biotics are reviewed.

A Scoping Review of the Relationship between Intermittent Fasting and the Human Gut Microbiota: Current Knowledge and Future Directions

Intermittent fasting (IF) has been promoted as an alternative to dietary caloric restriction for the treatment of obesity. IF restricts the amount of food consumed and improves the metabolic balance by synchronizing it with the circadian rhythm. Dietary changes have a rapid effect on the gut microbiota, modulating the interaction between meal timing and host circadian rhythms. Our paper aims to review the relationships between IF and human gut microbiota. In this study, the primary area of focus was the effect of IF on the diversity and composition of gut microbiota and its relationship with weight loss and metabolomic alterations, which are particularly significant for metabolic syndrome characteristics. We discussed each of these findings according to the type of IF involved, i.e., time-restricted feeding, Ramadan fasting, alternate-day fasting, and the 5:2 diet. Favorable metabolic effects regarding the reciprocity between IF and gut microbiota changes have also been highlighted. In conclusion, IF may enhance metabolic health by modifying the gut microbiota. However additional research is required to draw definitive conclusions about this outcome because of the limited number and diverse designs of existing studies.

Implication of Obesity and Gut Microbiome Dysbiosis in the Etiology of Colorectal Cancer

The complexity and variety of gut microbiomes within and among individuals have been extensively studied in recent years in connection to human health and diseases. Our growing understanding of the bidirectional communication between metabolic diseases and the gut microbiome has also highlighted the significance of gut microbiome dysbiosis in the genesis and development of obesity-related cancers. Therefore, it is crucial to comprehend the possible role of the gut microbiota in the crosstalk between obesity and colorectal cancer (CRC). Through the induction of gut microbial dysbiosis, gut epithelial barrier impairment, metabolomic dysregulation, chronic inflammation, or dysregulation in energy harvesting, obesity may promote the development of colorectal tumors. It is well known that strategies for cancer prevention and treatment are most effective when combined with a healthy diet, physical activity, and active lifestyle choices. Recent studies also suggest that an improved understanding of the complex linkages between the gut microbiome and various cancers as well as metabolic diseases can potentially improve cancer treatments and overall outcomes. In this context, we herein review and summarize the clinical and experimental evidence supporting the functional role of the gut microbiome in the pathogenesis and progression of CRC concerning obesity and its metabolic correlates, which may pave the way for the development of novel prognostic tools for CRC prevention. Therapeutic approaches for restoring the microbiome homeostasis in conjunction with cancer treatments are also discussed herein.

Nutritional implications in the mechanistic link between the intestinal microbiome, renin-angiotensin system, and the development of obesity and metabolic syndrome

Obesity and metabolic disorders represent a significant global health problem and the gut microbiota plays an important role in modulating systemic homeostasis. Recent evidence shows that microbiota and its signaling pathways may affect the whole metabolism and the Renin-Angiotensin System (RAS), which in turn seems to modify microbiota. The present review aimed to investigate nutritional implications in the mechanistic link between the intestinal microbiome, renin-angiotensin system, and the development of obesity and metabolic syndrome components. A description of metabolic changes was obtained based on relevant scientific literature. The molecular and physiological mechanisms that impact the human microbiome were addressed, including the gut microbiota associated with obesity, diabetes, and hepatic steatosis. The RAS interaction signaling and modulation were analyzed. Strategies including the use of prebiotics, symbiotics, probiotics, and biotechnology may affect the gut microbiota and its impact on human health.

Resistant starch from black rice, Oryza sativa L. var. ameliorates renal inflammation, fibrosis and injury in insulin resistant rats

It has recently been reported that black rice (BR) extract has anti-obesity, anti-diabetic, and anti-osteoporosis effects. It has been shown to reduce obese-related kidney dysfunction in animal models. This study aimed to investigate the effect of resistant starch from BR (RS) on renal inflammation, oxidative stress, and apoptosis in obese insulin resistant rats. Male Wistar rats were divided into six groups: normal diet (ND), ND treated with 150 mg of RS (NDRS150), high-fat (HF) diet, HF treated with 100 and 150 mg of RS (HFRS100), (HFRS150), and HF treated with metformin as a positive control. Insulin resistance was shown in the HF rats by glucose intolerance, increased insulin, total area under the curve of glucose and homeostasis model assessment of insulin resistance and dyslipidemia. The resulting metabolic disturbance in the HF rats caused renal inflammation, fibrosis and apoptosis progressing to kidney injury and dysfunction. Prebiotic RS including anthocyanin from BR at doses of 100 and 150 mg ameliorated insulin resistance, dyslipidemia and liver injury. Treatment with RS reduced TGF-β fibrotic and apoptotic pathways by inhibition of NF-κB and inflammatory cytokines which potentially restore kidney damage and dysfunction. In conclusion, prebiotic RS from BR ameliorated obesity induced renal injury and dysfunction by attenuating inflammatory, fibrotic, and apoptotic pathways in insulin resistant rats induced by HF.

Mechanisms linking bariatric surgery to adipose tissue, glucose metabolism, fatty liver disease and gut microbiota

PURPOSE

In the last 20 years, bariatric surgery has achieved an important role in translational and clinical research because of obesity comorbidities. Initially, a tool to lose weight, bariatric surgery now has been shown to be involved in several metabolic pathways.

METHODS

We conducted a narrative review discussing the underlying mechanisms that could explain the impact of bariatric surgery and the relationship between obesity and adipose tissue, T2D, gut microbiota, and NAFLD.

RESULTS

Bariatric surgery has an impact in the relation between obesity and type 2 diabetes, but in addition  it induces the white-to-brown adipocyte trans-differentiation, by enhancing thermogenesis. Another issue is the connection of bariatric surgery with the gut microbiota and its role in the complex mechanism underlying weight gain.

CONCLUSION

Bariatric surgery modifies gut microbiota, and these modifications influence lipid metabolism, leading to improvement of non-alcoholic fatty liver disease.

Functional and Compositional Changes in the Fecal Microbiome of a Shorebird during Migratory Stopover

Shorebirds migrate long distances twice annually, which requires intense physiological and morphological adaptations, including the ability to rapidly gain weight via fat deposition at stopover locations. The role of the microbiome in weight gain in avian hosts is unresolved, but there is substantial evidence to support the hypothesis that the microbiome is involved with host weight from mammalian microbiome literature. Here, we collected 100 fecal samples of Ruddy Turnstones to investigate microbiome composition and function during stopover weight gain in Delaware Bay, USA. Using 16S rRNA sequencing on 90 of these samples and metatranscriptomic sequencing on 22, we show that taxonomic composition of the microbiome shifts during weight gain, as do functional aspects of the metatranscriptome. We identified 10 genes that are associated with weight class, and polyunsaturated fatty acid biosynthesis in the microbiota is significantly increasing as birds gain weight. Our results support that the microbiome is a dynamic feature of host biology that interacts with both the host and the environment and may be involved in the rapid weight gain of shorebirds. IMPORTANCE Many animals migrate long distances annually, and these journeys require intense physiological and morphological adaptations. One such adaptation in shorebirds is the ability to rapidly gain weight at stopover locations in the middle of their migrations. The role of the microbiome in weight gain in birds is unresolved but is likely to play a role. Here, we collected 100 fecal samples from Ruddy Turnstones to investigate microbiome composition (who is there) and function (what they are doing) during stopover weight gain in Delaware Bay, USA. Using multiple molecular methods, we show that both taxonomic composition and function of the microbiome shifts during weight gain. We identified 10 genes that are associated with weight class, and polyunsaturated fatty acid biosynthesis in the microbiota is significantly increasing as birds gain weight. Our results support that the microbiome is a dynamic feature of host biology that interacts with both the host and the environment and may be involved in the rapid weight gain of shorebirds.

Short-term exposure of HFD depresses intestinal cholinergic anti-inflammatory activity through hypothalamic inflammation in mice

High-fat diet (HFD) exposure has been proven to impair vagus nerve function. However, it is not yet known whether the HFD challenge impacts vagal efferent-based intestinal cholinergic anti-inflammation activity. This investigation aims to evaluate the effect of HFD on intestinal cholinergic anti-inflammatory activity in mice. Mice with or without intracerebroventricular treatment with an antibody against toll-like receptor 4 (TLR4) were fed with HFD or standard chow for 2 weeks. Vagus nerve-based anti-inflammatory activity was analyzed by heart rate variability. Acetylcholine (ACh) content, nicotinic acetylcholine receptor α7 subtype (α7nAChR), and pro-inflammatory cytokines were analyzed by biochemical kits or qRT-PCR. HFD feeding mice exhibit a significant increase in high frequency (HF) and a decrease in the ratio of low frequency/HF, which were accompanied by lower ACh levels and α7nAChR mRNA expression in the intestinal segments. However, anti-TLR4 antibody-treated HFD mice showed normal ACh levels and α7nAChR mRNA expression in the intestinal segments. Moreover, TNF-α production in small intestine was significantly reduced in HFD + antibody group compared with HFD + vehicle group. Collectively, our present results reveal that HFD challenge depresses intestinal cholinergic anti-inflammatory activity, which is mediated by hypothalamic inflammation. Impairment of intestinal cholinergic anti-inflammatory pathway is the cause of intestinal low-grade inflammation by HFD consumption.

Obesity and Its Multiple Clinical Implications between Inflammatory States and Gut Microbiotic Alterations

Obesity is a chronic multifactorial disease that has become a serious health problem and is currently widespread over the world. It is, in fact, strongly associated with many other conditions, including insulin resistance, type 2 diabetes, cardiovascular and neurodegenerative diseases, the onset of different types of malignant tumors and alterations in reproductive function. According to the literature, obesity is characterized by a state of low-grade chronic inflammation, with a substantial increase in immune cells, specifically macrophage infiltrates in the adipose tissue which, in turn, secrete a succession of pro-inflammatory mediators. Furthermore, recent studies on microbiota have postulated new possible mechanisms of interaction between obesity and unbalanced nutrition with inflammation. This intestinal "superorganism" complex seems to influence not only the metabolic balance of the host but also the immune response, favoring a state of systemic inflammation and insulin resistance. This review summarizes the major evidence on the interactions between the gut microbiota, energetic metabolism and host immune system, all leading to a convergence of the fields of immunology, nutrients physiology and microbiota in the context of obesity and its possible clinical complications. Finally, possible therapeutic approaches aiming to rebalance the intestinal microbial ecosystem are evaluated to improve the alteration of inflammatory and metabolic states in obesity and related diseases.

The Intake of Antioxidant Capacity of Children Depends on Their Health Status

The gastrointestinal digestion of food and further gut microbial activity render a myriad of different molecules that could be responsible for the biological activities that are classically assigned to their parent compounds. This has been previously shown for some phytochemicals whose antioxidant capacity was either increased or decreased after being metabolized by gut microbes. Whether a global antioxidant capacity that is extracted from food is determined by the gut microbial community structure is still not well described. In the present study, we in vitro digested and fermented 48 different foods that were submitted to different culinary treatments using the stools of lean children, obese children, celiac children and children with an allergy to cow’s milk proteins. Their antioxidant capacities were assessed with the DPPH and FRAP assays, and the percentage that each food contributed to their daily antioxidant intake as well as their antioxidant capacity by portion size was inferred. Overall, cereals, fruits and vegetables displayed a higher contribution to their daily antioxidant intake, while tubers, fish and meat exhibited a higher antioxidant capacity by serving size. The food that was fermented in the lean children’s and those children that were allergic to cow’s milk protein’s fecal material, showed a higher antioxidant capacity, which could imply that there is a larger role of the gut microbiota in this area.

Obesity and critical care nutrition: current practice gaps and directions for future research

Background

This review has been developed following a panel discussion with an international group of experts in the care of patients with obesity in the critical care setting and focuses on current best practices in malnutrition screening and assessment, estimation of energy needs for patients with obesity, the risks and management of sarcopenic obesity, the value of tailored nutrition recommendations, and the emerging role of immunonutrition. Patients admitted to the intensive care unit (ICU) increasingly present with overweight and obesity that require individualized nutrition considerations due to underlying comorbidities, immunological factors such as inflammation, and changes in energy expenditure and other aspects of metabolism. While research continues to accumulate, important knowledge gaps persist in recognizing and managing the complex nutritional needs in ICU patients with obesity. Available malnutrition screening and assessment tools are limited in patients with obesity due to a lack of validation and heterogeneous factors impacting nutrition status in this population. Estimations of energy and protein demands are also complex in patients with obesity and may include estimations based upon ideal, actual, or adjusted body weight. Evidence is still sparse on the role of immunonutrition in patients with obesity, but the presence of inflammation that impacts immune function may suggest a role for these nutrients in hemodynamically stable ICU patients. Educational efforts are needed for all clinicians who care for complex cases of critically ill patients with obesity, with a focus on strategies for optimal nutrition and the consideration of issues such as weight stigma and bias impacting the delivery of care.

Conclusions

Current nutritional strategies for these patients should be undertaken with a focus on individualized care that considers the whole person, including the possibility of preexisting comorbidities, altered metabolism, and chronic stigma, which may impact the provision of nutritional care. Additional research should focus on the applicability of current guidelines and evidence for nutrition therapy in populations with obesity, especially in the setting of critical illness.

Bone matrix quality in a developing high-fat diet mouse model is altered by RAGE deletion

Overweightness and obesity in adolescents are epidemics linked to chronic low-grade inflammation and elevated fracture risk. The increased fracture risk observed in overweight/obese adolescence contrasts the traditional concept that high body mass is protective against fracture, and thus highlights the need to determine why weight gain becomes detrimental to fracture during growth and maturity. The Receptor for Advanced Glycation End products (RAGE) is a central inflammatory regulator that can influence bone metabolism. It remains unknown how RAGE removal impacts skeletal fragility in overweightness/obesity, and whether increased fracture risk in adolescents could result from low-grade inflammation deteriorating bone quality. We characterized the multiscale structural, mechanical, and chemical properties of tibiae extracted from adolescent C57BL/6J (WT) and RAGE null (KO) mice fed either low-fat (LF) or high-fat (HF) diet for 12 weeks starting at 6 weeks of age using micro-computed tomography, strength, Raman spectroscopy, and nanoindentation. Overweight/obese WT HF mice possessed degraded mineral-crystal quality and increased matrix glycoxidation in the form of pentosidine and carboxymethyl-lysine, with HF diet in females only showing reduced cortical surface expansion and TMD independently of RAGE ablation. Furthermore, in contrast to males, HF diet in females led to more material damage and plastic deformation. RAGE KO mitigated glycoxidative matrix accumulation, preserved mineral quantity, and led to increased E/H ratio in females. Taken together, these results highlight the complex, multi-scale and sex-dependent relationships between bone quality and function under overweightness, and identifies RAGE-controlled glycoxidation as a target to potentially preserve matrix quality and mechanical integrity.

Nicotine Exposure during Rodent Pregnancy Alters the Composition of Maternal Gut Microbiota and Abundance of Maternal and Amniotic Short Chain Fatty Acids

Tobacco smoking is the leading cause of preventable death. Numerous reports link smoking in pregnancy with serious adverse outcomes, such as miscarriage, stillbirth, prematurity, low birth weight, perinatal morbidity, and infant mortality. Corollaries of consuming nicotine in pregnancy, separate from smoking, are less explored, and the mechanisms of nicotine action on maternal–fetal communication are poorly understood. This study examined alterations in the maternal gut microbiome in response to nicotine exposure during pregnancy. We report that changes in the maternal gut microbiota milieu are an important intermediary that may mediate the prenatal nicotine exposure effects, affect gene expression, and alter fetal exposure to circulating short-chain fatty acids (SCFAs) and leptin during in utero development.

Nutrition and the state of the intestinal microflora in the formation of the metabolic syndrome

The literature review presents the results of modern studies of the relationship between diet and intestinal microbiota in the regulation of metabolic disorders. Metabolic syndrome, which is a symptom complex that combines abdominal obesity, insulin resistance, hyperglycemia, dyslipidemia and arterial hypertension, remains an important problem, being a risk factor for cardiovascular, neurodegenerative, oncological diseases and the development of type 2 diabetes mellitus. Although the pathogenesis of the metabolic syndrome has not yet been fully elucidated, it is known that visceral obesity and its associated complications, such as dyslipidemia and increased levels of pro-inflammatory cytokines, play a central role. The article presents data on the impact of the consumption of certain food products, the inclusion of plant biologically active substances (flavonoids, polyphenols, etc.) in the diet, as well as the use of elimination diets with the exclusion of carbohydrates or fats from the diet, on reducing the risk of cardiovascular accidents, levels of fasting glucose, total cholesterol, LDL, triglycerides, C-reactive protein, leptin, insulin, reduction in body weight and waist circumference, reduction in the level of circulating endotoxins and changes in the activity of immunocompetent cells. Data are presented on the possible influence of the intestinal microbiota in maintaining inflammation and the formation of degenerative changes in the body. The role of changes in the ratio of the levels of pathogenic microflora, bifidobacteria and lactobacilli in the formation of a pathological condition is shown.

Implications of microbe-mediated crosstalk in the gut: Impact on metabolic diseases

Metabolic diseases continue to afflict most of the U.S. population. Advancements in gut microbiota research have led to the discovery of various functional roles of microorganisms that influence the development of obesity and co-morbidities including type 2 diabetes, non-alcoholic fatty liver disease and cardiovascular disease. Many mechanisms behind these host-microbe interactions stem from processes involving the intestinal epithelium including lipid metabolism. Thus, the purpose of this review is to discuss gut microbe-mediated changes in intestinal physiology and lipid metabolism that contribute to obesity, type 2 diabetes, non-alcoholic fatty liver disease and cardiovascular disease. Within each disease state, the causal role of bacteria in both driving disease development and protecting against metabolic disease will be discussed.

Relationship between gut microbiome characteristics and the effect of nutritional therapy on glycemic control in pregnant women with gestational diabetes mellitus

The purpose of this study was to explore the relationship between the characteristics of gut microbiome and the effect of medical nutrition therapy (MNT) on glycemic control in pregnant women with gestational diabetes mellitus (GDM). Seventy-four pregnant women newly diagnosed with GDM received MNT for one-week. The effect of glycemic control was evaluated by fasting and 2-hour postprandial blood glucose; and stool samples of pregnant women were collected to detect the gut microbiome before and after MNT. We used a nested case-control study design, with pregnant women with GDM who did not meet glycemic standards after MNT as the ineffective group and those with an age difference of ≤5 years, matched for pre-pregnancy body mass index (BMI) 1:1, and meeting glycemic control criteria as the effective group. Comparison of the gut microbiome characteristics before MNT showed that the ineffective group was enriched in Desulfovibrio, Aeromonadales, Leuconostocaceae, Weissella, Prevotella, Bacillales_Incertae Sedis XI, Gemella and Bacillales, while the effective group was enriched in Roseburia, Clostridium, Bifidobacterium, Bifidobacteriales, Bifidobacteriaceae, Holdemania and Proteus. After treatment, the effective group was enriched in Bifidobacterium and Actinomycete, while the ineffective group was enriched in Holdemania, Proteus, Carnobacteriaceae and Granulicatella. In conclusion, the decrease in the abundance of characteristic gut microbiome positively correlated with blood glucose may be a factor influencing the poor hypoglycemic effect of MNT in pregnant women with GDM. Abundance of more characteristic gut microbiome negatively correlated with blood glucose could help control blood glucose in pregnant women with GDM.

Gastrointestinal Autonomic Neuropathy Exacerbates Gut Microbiota Dysbiosis in Adult Patients With Type 2 Diabetes Mellitus

OBJECTIVE

The diabetic autonomic neuropathy is one of the most common complications in type 2 diabetes mellitus (T2DM), especially gastrointestinal autonomic neuropathy (GAN), which occurs in up to 75% of patients. The study aimed to investigate the gut microbiota composition, structure, and function in T2DM patients with GAN (T2DM_GAN) and set up a link between gut microbiota and clinical characteristics of patients.

METHODS

DNA was extracted from fecal samples of three groups using the kit method: healthy volunteers (n = 19), the patients with T2DM (n = 76), and T2DM_GAN (n = 27). Sequencing of 16S ribosomal DNA was performed using the MiSeq platform.

RESULTS

According to the clinical data, higher age, lower triglyceride, and lower body mass index were the main features of patients with T2DM_GAN. The gut microbiota analysis showed that Bacteroidetes, Firmicutes, and Proteobacteria constituted the three dominant phyla in healthy individuals. In addition, the gut microbiota structure and function of T2DM_GAN patients were clearly different from that of T2DM patients. T2DM patients were characterized by Fusobacteria, Fusobacteriia, Fusobacteriales, Fusobacteriaceae, Fusobacterium, Lachnoclostridium, and Fusobacterium_mortiferum. Those gut microbiota may be involved in carotenoid and flavonoid biosyntheses. Relatively, the Gammaproteobacteria, Enterobacteriales, Enterobacteriaceae, Escherichia-Shigella, Megasphaera, Escherichia_coli, and Megasphaera_elsdenii were characteristic in the T2DM_GAN patients. Those may be involved in bacterial invasion of epithelial cells and pathogenic Escherichia coli infection.

CONCLUSIONS

GAN exacerbated gut microbiota dysbiosis in adult patients with T2DM. The findings indicated that phyla Fusobacteria and class Gammaproteobacteria were closely related to the occurrence of T2DM. Especially the latter may promote T2DM_GAN.

n-3 polyunsaturated fatty acids in the regulation of adipose tissue browning and thermogenesis in obesity: Potential relationship with gut microbiota

BACKGROUND

Obesity is a worldwide public health problem characterized by fat tissue accumulation, favouring adipose tissue and metabolic alterations. Increasing energy expenditure (EE) through brown adipose tissue activation and white adipose tissue (WAT) browning has gained relevance as a therapeutic approach. Different bioactive compounds, such as n-3 polyunsaturated fatty acids (PUFA), have been shown to induce those thermogenic effects. This process is regulated by the gut microbiota as well. Nevertheless, obesity is characterized by gut microbiota dysbiosis, which can be restored by weight loss and n-3 PUFA intake, among other factors. Knowledge gap: However, the role of the gut microbiota on the n-3 PUFA effect in inducing thermogenesis in obesity has not been fully elucidated.

OBJECTIVE

This review aims to elucidate the potential implications of this interrelation on WAT browning adiposw sittue (BAT), BAT activity, and EE regulation in obesity models.

Association between severity of COVID-19 symptoms and habitual food intake in adult outpatients

Objective

To evaluate the association between habitual frequency of food intake of certain food groups during the COVID-19 pandemic and manifestations of COVID-19 symptoms in adult outpatients with suspected SARS-CoV-2 infection.

Design

We included 236 patients who attended an outpatient clinic for suspected COVID-19 evaluation. Severity of symptoms, habitual food intake frequency, demographics and Bristol chart scores were obtained before diagnostic confirmation with real-time reverse transcriptase PCR using nasopharyngeal swab.

Results

The results of the COVID-19 diagnostic tests were positive for 103 patients (44%) and negative for 133 patients (56%). In the SARS-CoV-2-positive group, symptom severity scores had significant negative correlations with habitual intake frequency of specific food groups. Multivariate binary logistic regression analysis adjusted for age, sex and occupation confirmed that SARS-CoV-2-positive patients showed a significant negative association between having higher symptom severity and the habitual intake frequency of ‘legumes’ and ‘grains, bread and cereals’.

Conclusions

Increase in habitual frequency of intake of ‘legumes’, and ‘grains, bread and cereals’ food groups decreased overall symptom severity in patients with COVID-19. This study provides a framework for designing a protective diet during the COVID-19 pandemic and also establishes a hypothesis of using a diet-based intervention in the management of SARS-CoV-2 infection, which may be explored in future studies.