The Influence of Dietary Factors on the Gut Microbiota

The effects of Lactobacillus plantarum PS128 in patients with major depressive disorder: an eight-week double-blind, placebo-controlled study

Major depressive disorder (MDD) is a complex mental disorder, potentially linked to the gut-microbiota-brain axis. Probiotics like Lactobacillus plantarum PS128 (PS128) may improve depressive symptoms by modulating the gut microbiota based on our previous open trial. We conducted an 8-week double-blind, placebo-controlled trial to investigate the impact of PS128 on depression severity, markers of inflammation and gut permeability, and the gut microbiota composition in 32 patients with MDD with stable antidepressant treatment but moderate symptom severity. Following the 8-week intervention, both the Hamilton Depression Rating Scale-17 score (HAMD), and Depression and Somatic Symptoms Scale (DSSS) showed a significant decrease in both groups (p<0.001). However, there was no significant difference in the change of depression severity between groups (p=0.203). Moreover, alterations in serum levels of high sensitivity C-reactive protein, interleukin-6, tumor necrosis factor-α, and intestinal fatty acid binding protein, as well as changes in the gut microbiota composition, did not exhibit significant differences before and after intervention or between the groups. In comparison to the placebo group, our study did not find significant effects of PS128 on depressive symptoms, biomarkers of inflammation and gut permeability, and the overall gut microbiota composition. Nonetheless, we observed a potential impact of PS128 on the symbiosis of specific taxa. To comprehensively understand the psychophysiological effects of PS128 in patients with MDD, further research with a larger sample size is imperative.

Insights into the modulatory effects of host-gut microbial xanthine co-metabolism on high-fat diet-fed mice

Gut microbiota-mediated endobiotic and xenobiotic metabolism play crucial roles in disease progression, and drug therapy/toxicity. Our recent study suggested that gut microbiota-mediated xanthine metabolism is correlated with resistance to high-fat diet (HFD)-induced obesity. Here, we explored the role of host-gut microbial xanthine co-metabolism in the prevention and treatment of HFD-induced obesity by orally administration of Bifidobacterium longum, xanthine, and a xanthine oxidase inhibitor (topiroxostat). The findings indicate that xanthine exhibits a significantly protective effect against HFD-induced obesity. While B. longum, xanthine, and topiroxostat did not alleviate the dysbiosis of the weight and glucose metabolism of HFD-induced obesity (DIO) and obesity resistance (DIR) mice. 16S rRNA sequencing analyses revealed that treatments with B. longum significantly altered gut microbiota composition in HFD-fed and DIO mice. Microbial interaction network analysis revealed several Bacteroidetes species, such as Amulumruptor caecigallinarius and Muribaculum intestinale, as keystone taxa that were notably enriched by B. longum. Untargeted metabolomics analysis implied that xanthine might serve as a crucial molecule in regulating body weight, exerting a preventive effect on HFD-induced obesity. This study offers new perspectives on the influence of host-gut microbial xanthine co-metabolism on HFD-fed mice and emphasizes the promising role of xanthine in promoting weight loss.

The dynamic crosslinking between gut microbiota and inflammation during aging: reviewing the nutritional and hormetic approaches against dysbiosis and inflammaging

The early-life gut microbiota (GM) is increasingly recognized for its contributions to human health and disease over time. Microbiota composition, influenced by factors like race, geography, lifestyle, and individual differences, is subject to change. The GM serves dual roles, defending against pathogens and shaping the host immune system. Disruptions in microbial composition can lead to immune dysregulation, impacting defense mechanisms. Additionally, GM aids digestion, releasing nutrients and influencing physiological systems like the liver, brain, and endocrine system through microbial metabolites. Dysbiosis disrupts intestinal homeostasis, contributing to age-related diseases. Recent studies are elucidating the bacterial species that characterize a healthy microbiota, defining what constitutes a 'healthy' colonic microbiota. The present review article focuses on the importance of microbiome composition for the development of homeostasis and the roles of GM during aging and the age-related diseases caused by the alteration in gut microbial communities. This article might also help the readers to find treatments targeting GM for the prevention of various diseases linked to it effectively.

Barley β-glucan consumption improves glucose tolerance by increasing intestinal succinate concentrations

Barley is rich in β-glucan, which can alter gut microbiota and metabolome profiles, potentially affecting host metabolism. However, the microbiota and metabolites increased by barley β-glucan remain unclear. In this study, we focused on the gut-microbiota-derived metabolite succinate and investigated the microbiome and metabolome profiles altered by barley β-glucan intake. C57BL/6 J mice were fed a standard or middle-fat diet containing barley flour rich in β-glucan or barley flour without β-glucan, and their gut microbiota and metabolome profiles were analyzed. The results showed increased Bacteroides, Parasutterella, and succinate due to barley β-glucan intake independent of diet differences. Next, we used mice lacking slc13a2, a gene that is involved in the cellular uptake of succinate. Wild-type mice showed improved glucose tolerance after the intake of barley β-glucan, but this effect was attenuated in the slc13a2-deficient mice. These results suggest that barley β-glucan intake increases succinate and succinate-producing bacteria and affects glucose metabolism.

A New Strategy for Dietary Nutrition to Improve Intestinal Homeostasis in Diarrheal Irritable Bowel Syndrome: A Perspective on Intestinal Flora and Intestinal Epithelial Interaction

BACKGROUND AND OBJECTIVES

Although a reasonable diet is essential for promoting human health, precise nutritional regulation presents a challenge for different physiological conditions. Irritable Bowel Syndrome (IBS) is characterized by recurrent abdominal pain and abnormal bowel habits, and diarrheal IBS (IBS-D) is the most common, seriously affecting patients' quality of life. Therefore, the implementation of precise nutritional interventions for IBS-D has become an urgent challenge in the fields of nutrition and food science. IBS-D intestinal homeostatic imbalance involves intestinal flora disorganization and impaired intestinal epithelial barrier function. A familiar interaction is evident between intestinal flora and intestinal epithelial cells (IECs), which together maintain intestinal homeostasis and health. Dietary patterns, such as the Mediterranean diet, have been shown to regulate gut flora, which in turn improves the body's health by influencing the immune system, the hormonal system, and other metabolic pathways.

METHODS

This review summarized the relationship between intestinal flora, IECs, and IBS-D. It analyzed the mechanism behind IBS-D intestinal homeostatic imbalance by examining the interactions between intestinal flora and IECs, and proposed a precise dietary nutrient intervention strategy.

RESULTS AND CONCLUSION

This increases the understanding of the IBS-D-targeted regulation pathways and provides guidance for designing related nutritional intervention strategies.

Protecting Endangered Animal Species

Currently, global biodiversity loss is a growing problem, and more species are endangered and at risk of extinction [...].

Geographic and environmental impacts on gut microbiome in Himalayan langurs (Semnopithecus schistaceus) and Xizang macaques (Macaca mulatta vestita)

Introduction

Gut microbiome plays a crucial role in the health of wild animals. Their structural and functional properties not only reflect the host's dietary habits and habitat conditions but also provide essential support for ecological adaptation in various environments.

Methods

This study investigated the gut microbiome of Himalayan langurs (Semnopithecus schistaceus) and Xizang macaques (Macaca mulatta vestita) across different geographic regions using 16S rRNA gene and metagenomic sequencing.

Results

Results showed distinct clustering patterns in gut microbiota based on geographic location. Soil had an insignificant impact on host gut microbiome. Himalayan langurs from mid-altitude regions exhibited higher levels of antibiotic resistance genes associated with multidrug resistance, while Xizang macaques from high-altitude regions showed a broader range of resistance genes. Variations in carbohydrate-active enzymes and KEGG pathways indicated unique metabolic adaptations to different environments.

Discussion

These findings provide valuable insights into the health and conservation of these primates and the broader implications of microbial ecology and functional adaptations in extreme conditions.

Gut microbiota modulatory capacity of fermented ketchup in a validated in vitro model of the colon

This study aimed to evaluate the effects of fermented beetroot ketchup enriched with Lactobacillus johnsonii K4 and non-fermented beetroot ketchup on pooled fecal microbiota from healthy adults in in vitro colon model. The research focused on how these products influenced the composition and functionality of the gut microbiota, as well as metabolite production, using the validated dynamic in vitro colon model, TNO Intestinal Model (TIM-2). After an initial starvation phase, a single 60 g dose of predigested and freeze-dried ketchup was introduced into the model. The potential probiotic strain Lactobacillus johnsonii K4 was added over three days. A carbohydrate mixture of standard ileal effluent medium (SIEM) served as the control. Our analysis identified 21 bacterial taxa that were significantly modulated (q-value < 0.2) when comparing ketchup samples to control samples. Notably, the ketchup samples led to an increase in butyrate-producing taxa, including Faecalibacterium, Blautia, Ruminococcaceae, Ruminiclostridium 6, and Anaerostipes. Conversely, there was a reduction in potentially pathogenic genera Desulfovibrio and Escherichia-Shigella. Distinct profiles of short-chain fatty acids (SCFA) were observed among the fermented ketchup, non-fermented ketchup, and control samples. Non-fermented ketchup resulted in higher proportions of acetate, propionate, and butyrate compared to the other interventions. This may be related to the fermentation with lactic acid bacteria in fermented samples with lower levels of substrate for SCFAs production. However, fermented ketchup sample has higher relative abundance of beneficial bacteria like Lactobacillus, Weissella and Dorea in gut microbiota. These findings suggest that beetroot ketchup, can positively influence gut microbiota composition and function, highlighting its potential benefits for human health.

Nutrition Intervention and Microbiome Modulation in the Management of Breast Cancer

Breast cancer (BC) is one of the most common cancers worldwide and a leading cause of cancer-related deaths among women. The escalating incidence of BC underscores the necessity of multi-level treatment. BC is a complex and heterogeneous disease involving many genetic, lifestyle, and environmental factors. Growing evidence suggests that nutrition intervention is an evolving effective prevention and treatment strategy for BC. In addition, the human microbiota, particularly the gut microbiota, is now widely recognized as a significant player contributing to health or disease status. It is also associated with the risk and development of BC. This review will focus on nutrition intervention in BC, including dietary patterns, bioactive compounds, and nutrients that affect BC prevention and therapeutic responses in both animal and human studies. Additionally, this paper examines the impacts of these nutrition interventions on modulating the composition and functionality of the gut microbiome, highlighting the microbiome-mediated mechanisms in BC. The combination treatment of nutrition factors and microbes is also discussed. Insights from this review paper emphasize the necessity of comprehensive BC management that focuses on the nutrition-microbiome axis.

Time-restricted eating, the clock ticking behind the scenes

Introduction

Maintaining metabolic balance relies on accumulating nutrients during feeding periods and their subsequent release during fasting. In obesity and metabolic disorders, strategies aimed at reducing food intake while simulating fasting have garnered significant attention for weight loss. Caloric restriction (CR) diets and intermittent fasting (IF) interventions have emerged as effective approaches to improving cardiometabolic health. Although the comparative metabolic benefits of CR versus IF remain inconclusive, this review focuses on various forms of IF, particularly time-restricted eating (TRE).

Methods

This study employs a narrative review methodology, systematically collecting, synthesizing, and interpreting the existing literature on TRE and its metabolic effects. A comprehensive and unbiased search of relevant databases was conducted to identify pertinent studies, including pre-clinical animal studies and clinical trials in humans. Keywords such as "Obesity," "Intermittent Fasting," "Time-restricted eating," "Chronotype," and "Circadian rhythms" guided the search. The selected studies were critically appraised based on predefined inclusion and exclusion criteria, allowing for a thorough exploration and synthesis of current knowledge.

Results

This article synthesizes pre-clinical and clinical studies on TRE and its metabolic effects, providing a comprehensive overview of the current knowledge and identifying gaps for future research. It explores the metabolic outcomes of recent clinical trials employing different TRE protocols in individuals with overweight, obesity, or type II diabetes, emphasizing the significance of individual chronotype, which is often overlooked in practice. In contrast to human studies, animal models underscore the role of the circadian clock in mitigating metabolic disturbances induced by obesity through time-restricted feeding (TRF) interventions. Consequently, we examine pre-clinical evidence supporting the interplay between the circadian clock and TRF interventions. Additionally, we provide insights into the role of the microbiota, which TRE can modulate and its influence on circadian rhythms.

Pembrolizumab in combination with trastuzumab for treatment of HER2-positive advanced gastric or gastro-esophageal junction cancer

Introduction

Gastric cancer remains a challenging malignancy with a high global mortality rate. Recent advances in targeted therapy and immunotherapy have shown promise in improving patient outcomes. This paper reviews the impact of incorporating targeted agents such as trastuzumab and immunotherapeutic agents like pembrolizumab into standard chemotherapy regimens for gastric cancer treatment.

Methods

A comprehensive analysis was conducted on pivotal clinical trials, including KEYNOTE-590, KEYNOTE-811, and ToGA, focusing on their methodologies, patient populations, treatment regimens, and outcome measures. The review also explored emerging research avenues in precision medicine, particularly genomic sequencing and biomarker identification.

Aim

To assess the efficacy and survival benefits of adding trastuzumab and pembrolizumab to standard chemotherapy in the treatment of gastric cancer and to outline future directions in gastric cancer research.

Results

Including trastuzumab and pembrolizumab in treatment regimens for human epidermal growth factor receptor 2 (HER2)-positive and PD-L1-expressing gastric cancers significantly improved progression-free and overall survival rates compared to chemotherapy alone. These findings highlight the potential of personalized therapy in enhancing treatment outcomes. Furthermore, ongoing research into the gastric cancer microenvironment and the role of the microbiome suggests novel targets for future therapeutic interventions.

Conclusion

The integration of targeted and immunotherapeutic agents with traditional chemotherapy represents a pivotal shift in gastric cancer treatment, moving towards more personalized and effective regimens.

Interactions between Dietary Antioxidants, Dietary Fiber and the Gut Microbiome: Their Putative Role in Inflammation and Cancer

The intricate relationship between the gastrointestinal (GI) microbiome and the progression of chronic non-communicable diseases underscores the significance of developing strategies to modulate the GI microbiota for promoting human health. The administration of probiotics and prebiotics represents a good strategy that enhances the population of beneficial bacteria in the intestinal lumen post-consumption, which has a positive impact on human health. In addition, dietary fibers serve as a significant energy source for bacteria inhabiting the cecum and colon. Research articles and reviews sourced from various global databases were systematically analyzed using specific phrases and keywords to investigate these relationships. There is a clear association between dietary fiber intake and improved colon function, gut motility, and reduced colorectal cancer (CRC) risk. Moreover, the state of health is reflected in the reciprocal and bidirectional relationships among food, dietary antioxidants, inflammation, and body composition. They are known for their antioxidant properties and their ability to inhibit angiogenesis, metastasis, and cell proliferation. Additionally, they promote cell survival, modulate immune and inflammatory responses, and inactivate pro-carcinogens. These actions collectively contribute to their role in cancer prevention. In different investigations, antioxidant supplements containing vitamins have been shown to lower the risk of specific cancer types. In contrast, some evidence suggests that taking antioxidant supplements can increase the risk of developing cancer. Ultimately, collaborative efforts among immunologists, clinicians, nutritionists, and dietitians are imperative for designing well-structured nutritional trials to corroborate the clinical efficacy of dietary therapy in managing inflammation and preventing carcinogenesis. This review seeks to explore the interrelationships among dietary antioxidants, dietary fiber, and the gut microbiome, with a particular focus on their potential implications in inflammation and cancer.

Role of Nutrition in the Management of Patients with Chronic Musculoskeletal Pain

Chronic musculoskeletal pain (CMP), defined as persistent discomfort in musculoskeletal tissues persisting for over 3 months, afflicts an estimated 1.71 billion people globally, leading to significant functional impairments and psychological distress, thereby detrimentally affecting individuals' quality of life. The objective of this narrative review is to elucidate the complex relationship among dietary habits, sarcopenia, and gut microbiota composition, with an eye toward enhancing patient management and outcomes. Given the burgeoning interest in the influence of diet on CMP, a detailed examination of the current literature is warranted. Nutritional intake is a critical determinant of the gut microbiota profile, which, in turn, is linked to musculature integrity and performance, potentially leading to sarcopenia. The development of sarcopenia can aggravate CMP owing to diminished muscular strength and functionality. Additionally, disruptions in the gut microbiota may directly modulate nociception, intensifying CMP manifestations. Thus, nutritional optimization emerges as a viable approach to CMP management. Emphasizing a diet conducive to a healthy gut microbiome could forestall or mitigate sarcopenia, thereby attenuating CMP intensity. Nevertheless, the domain calls for further empirical exploration to unravel the nuances of these interactions and to forge efficacious dietary strategies for individuals with CMP. Beyond mere analgesia, comprehensive patient care for CMP requires acknowledgment of the complex and multifactorial nature of pain and its foundational elements. Embracing an integrative treatment model allows healthcare practitioners to promise better patient prognoses, enriched life quality, and a decrease in the sustained healthcare costs associated with CMP.

Hindrance to sustainable development: Global inequities, non-progressive education and inadequate science-policy dialogue

Social habits and economies driven by profit are opposing efforts to reach a path of sustainable development. In addition, many communities worldwide have diverged away from nature through consumerism and technology. In the context of the escalating risks and consequences related to global challenges such as the climate crisis and ecosystem degradation, education for sustainable development and science-driven decision-making offer tremendous opportunities for improvement.

Gut-liver axis: Potential mechanisms of action of food-derived extracellular vesicles

Food-derived extracellular vesicles (FEVs) are nanoscale membrane vesicles obtained from dietary materials such as breast milk, plants and probiotics. Distinct from other EVs, FEVs can survive the harsh degrading conditions in the gastrointestinal tract and reach the intestines. This unique feature allows FEVs to be promising prebiotics in health and oral nanomedicine for gut disorders, such as inflammatory bowel disease. Interestingly, therapeutic effects of FEVs have recently also been observed in non-gastrointestinal diseases. However, the mechanisms remain unclear or even mysterious. It is speculated that orally administered FEVs could enter the bloodstream, reach remote organs, and thus exert therapeutic effects therein. However, emerging evidence suggests that the amount of FEVs reaching organs beyond the gastrointestinal tract is marginal and may be insufficient to account for the significant therapeutic effects achieved regarding diseases involving remote organs such as the liver. Thus, we herein propose that FEVs primarily act locally in the intestine by modulating intestinal microenvironments such as barrier integrity and microbiota, thereby eliciting therapeutic impact remotely on the liver in non-gastrointestinal diseases via the gut-liver axis. Likewise, drugs delivered to the gastrointestinal system through FEVs may act via the gut-liver axis. As the liver is the main metabolic hub, the intestinal microenvironment may be implicated in other metabolic diseases. In fact, many patients with non-alcoholic fatty liver disease, obesity, diabetes and cardiovascular disease suffer from a leaky gut and dysbiosis. In this review, we provide an overview of the recent progress in FEVs and discuss their biomedical applications as therapeutic agents and drug delivery systems, highlighting the pivotal role of the gut-liver axis in the mechanisms of action of FEVs for the treatment of gut disorders and metabolic diseases.

A novel combinatorial approach using sulforaphane- and withaferin A-rich extracts for prevention of estrogen receptor-negative breast cancer through epigenetic and gut microbial mechanisms

Estrogen receptor-negative [ER(-)] mammary cancer is the most aggressive type of breast cancer (BC) with higher rate of metastasis and recurrence. In recent years, dietary prevention of BC with epigenetically active phytochemicals has received increased attention due to its feasibility, effectiveness, and ease of implementation. In this regard, combinatorial phytochemical intervention enables more efficacious BC inhibition by simultaneously targeting multiple tumorigenic pathways. We, therefore, focused on investigation of the effect of sulforaphane (SFN)-rich broccoli sprouts (BSp) and withaferin A (WA)-rich Ashwagandha (Ash) combination on BC prevention in estrogen receptor-negative [ER(-)] mammary cancer using transgenic mice. Our results indicated that combinatorial BSp + Ash treatment significantly reduced tumor incidence and tumor growth (~ 75%) as well as delayed (~ 21%) tumor latency when compared to the control treatment and combinatorial BSp + Ash treatment was statistically more effective in suppressing BC compared to single BSp or Ash intervention. At the molecular level, the BSp and Ash combination upregulated tumor suppressors (p53, p57) along with apoptosis associated proteins (BAX, PUMA) and BAX:BCL-2 ratio. Furthermore, our result indicated an expressional decline of epigenetic machinery HDAC1 and DNMT3A in mammary tumor tissue because of combinatorial treatment. Interestingly, we have reported multiple synergistic interactions between BSp and Ash that have impacted both tumor phenotype and molecular expression due to combinatorial BSp and Ash treatment. Our RNA-seq analysis results also demonstrated a transcriptome-wide expressional reshuffling of genes associated with multiple cell-signaling pathways, transcription factor activity and epigenetic regulations due to combined BSp and Ash administration. In addition, we discovered an alteration of gut microbial composition change because of combinatorial treatment. Overall, combinatorial BSp and Ash supplementation can prevent ER(-) BC through enhanced tumor suppression, apoptosis induction and transcriptome-wide reshuffling of gene expression possibly influencing multiple cell signaling pathways, epigenetic regulation and reshaping gut microbiota.

Unraveling the Microbiome-Human Body Axis: A Comprehensive Examination of Therapeutic Strategies, Interactions and Implications

This review scrutinizes the intricate interplay between the microbiome and the human body, exploring its multifaceted dimensions and far-reaching implications. The human microbiome, comprising diverse microbial communities inhabiting various anatomical niches, is increasingly recognized as a critical determinant of human health and disease. Through an extensive examination of current research, this review elucidates the dynamic interactions between the microbiome and host physiology across multiple organ systems. Key topics include the establishment and maintenance of microbiota diversity, the influence of host factors on microbial composition, and the bidirectional communication pathways between microbiota and host cells. Furthermore, we delve into the functional implications of microbiome dysbiosis in disease states, emphasizing its role in shaping immune responses, metabolic processes, and neurological functions. Additionally, this review discusses emerging therapeutic strategies aimed at modulating the microbiome to restore host-microbe homeostasis and promote health. Microbiota fecal transplantation represents a groundbreaking therapeutic approach in the management of dysbiosis-related diseases, offering a promising avenue for restoring microbial balance within the gut ecosystem. This innovative therapy involves the transfer of fecal microbiota from a healthy donor to an individual suffering from dysbiosis, aiming to replenish beneficial microbial populations and mitigate pathological imbalances. By synthesizing findings from diverse fields, this review offers valuable insights into the complex relationship between the microbiome and the human body, highlighting avenues for future research and clinical interventions.

Impact of high-salt diet in health and diseases and its role in pursuit of cancer immunotherapy by modulating gut microbiome

Cancer chemotherapy remains an area of concern, as many of the therapies are uncomfortable involving side effects and unpleasant experiences. These factors could further reduce patient's quality of life, and even endanger their life. Many therapeutic strategies have been tried to reduce the unpleasant side effects and increase the treatment effectiveness; however, none have shown to have promising effects. One of the main hindrances to cancer therapy is the escape strategies by tumor cells to the immune attack. Promoting inflammation in the tumor microenvironment is the cornerstone and key therapeutic target in cancer chemotherapy. High-salt diet (HSD) intake, though it has deleterious effects on human health by promoting chronic inflammation, is found to be advantageous in the tumor microenvironment. Studies identified HSD favors an increased abundance of Bifidobacterium species in the tumor environment due to gut barrier alteration, which, in turn, promotes inflammation and favors improved response to cancer chemotherapy. A review of the literature was carried out to find out the effects of an HSD on health and diseases, with special mention of its effect on cancer chemotherapy. Studies emphasized HSD would block the myeloid-derived suppressor cells which will enhance the tumor immunity. Exploration of the precise mechanism of simple HSD regime/ingestion of specific bacterial species as probiotics will be effective and essential to formulate the game-changing cancer chemotherapy. With the modern era of healthcare moving toward precision medicine where the physician can choose the treatment option suitable for the individual, HSD regime/ingestion of specific bacterial species can be considered.

In Vitro Fermentation Shows Polyphenol and Fiber Blends Have an Additive Beneficial Effect on Gut Microbiota States

Polyphenols and fermentable fibers have shown favorable effects on gut microbiota composition and metabolic function. However, few studies have investigated whether combining multiple fermentable fibers or polyphenols may have additive beneficial effects on gut microbial states. Here, an in vitro fermentation model, seeded with human stool combined from 30 healthy volunteers, was supplemented with blends of polyphenols (PP), dietary fibers (FB), or their combination (PPFB) to determine influence on gut bacteria growth dynamics and select metabolite changes. PP and FB blends independently led to significant increases in the absolute abundance of select beneficial taxa, namely Ruminococcus bromii, Bifidobacterium spp., Lactobacillus spp., and Dorea spp. Total short-chain fatty acid concentrations, relative to non-supplemented control (F), increased significantly with PPFB and FB supplementation but not PP. Indole and ammonia concentrations decreased with FB and PPFB supplementation but not PP alone while increased antioxidant capacity was only evident with both PP and PPFB supplementation. These findings demonstrated that, while the independent blends displayed selective positive impacts on gut states, the combination of both blends provided an additive effect. The work outlines the potential of mixed substrate blends to elicit a broader positive influence on gut microbial composition and function to build resiliency toward dysbiosis.

A Perspective Review on Diet Quality, Excess Adiposity, and Chronic Psychosocial Stress and Implications for Early-Onset Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer worldwide. Although the overall incidence of CRC has been decreasing over the past 40 y, early-onset colorectal cancer (EOCRC), which is defined as a CRC diagnosis in patients aged >50 y has increased. In this Perspective, we highlight and summarize the association between diet quality and excess adiposity, and EOCRC. We also explore chronic psychosocial stress (CPS), a less investigated modifiable risk factor, and EOCRC. We were able to show that a poor-quality diet, characterized by a high intake of sugary beverages and a Western diet pattern (high intake of red and processed meats, refined grains, and foods with added sugars) can promote risk factors associated with EOCRC development, such as an imbalance in the composition and function of the gut microbiome, presence of chronic inflammation, and insulin resistance. Excess adiposity, particularly obesity onset in early adulthood, is a likely contributor of EOCRC. Although the research is sparse examining CPS and CRC/EOCRC, we describe likely pathways linking CPS to tumorigenesis. Although additional research is needed to understand what factors are driving the uptick in EOCRC, managing body weight, improving diet quality, and mitigating psychosocial stress, may play an important role in reducing an individual's risk of EOCRC.

Gut microbiota profiling in obese children from Southeastern China

Childhood obesity not only has a negative impact on a child's health but is also a significant risk factor for adult obesity and related metabolic disorders, making it a major global public health concern. Recent studies have revealed the crucial role of gut microbiota in the occurrence and development of obesity, in addition to genetic and lifestyle factors. In this study, we recruited 19 normal-weight children and 47 children with varying degrees of obesity. A questionnaire survey was conducted to inquire about the family background, lifestyle habits and dietary composition of the 66 children. Findings indicate that fathers of obese children tend to be obese themselves, while children with highly educated mothers are more likely to maintain a normal weight. Furthermore, overweight children tend to spend more time on electronic devices and less time on physical activities compared to their normal-weight counterparts. Obese children exhibit significant differences in breakfast and dinner dietary composition when compared to children with normal weight. Additionally, the gut microbiota of these 66 children was analyzed using 16S rRNA sequencing. Analysis of gut microbiota composition showed similar compositions among children with varying degrees of obesity, but significant differences were observed in comparison to normal-weight children. Obese children exhibited a reduced proportion of Bacteroidota and an increased proportion of Firmicutes, resulting in an elevated Firmicutes/Bacteroidota ratio. Moreover, Actinobacteriota were found to be increased in the gut microbiota of children with varying degrees of obesity. PICRUSt analysis indicated significant metabolic differences in the microbiota functions between obese and normal-weight children, suggesting the composition of gut microbiota could be a crucial factor contributing to obesity. These findings provide valuable insights for the treatment of childhood obesity.

The Role of the Gut Microbiome and Microbial Dysbiosis in Common Skin Diseases

Dermatoses are an increasingly common problem, particularly in developed countries. The causes of this phenomenon include genetic factors and environmental elements. More and more scientific reports suggest that the gut microbiome, more specifically its dysbiosis, also plays an important role in the induction and progression of diseases, including dermatological diseases. The gut microbiome is recognised as the largest endocrine organ, and has a key function in maintaining human homeostasis. In this review, the authors will take a close look at the link between the gut-skin axis and the pathogenesis of dermatoses such as atopic dermatitis, psoriasis, alopecia areata, and acne. The authors will also focus on the role of probiotics in remodelling the microbiome and the alleviation of dermatoses.

Integrated microbiome, metabolome and transcriptome profiling reveals the beneficial effects of fish oil and Bacillus subtilis jzxj-7 on mouse gut ecosystem

The effects of fish oil (FO) and Bacillus subtilis jzxj-7 (JZXJ-7) on the colonic physiology, bacteria, metabolites, and gene expressions were studied in C57BL/6J mice. Co-administration of FO and JZXJ-7 was more beneficial than individual supplementation, as evidenced by improved growth performance, enhanced colon crypt depth and goblet cell numbers. FO + JZXJ-7 inhibited colonic fibrosis by downregulating fibrosis marker protein expression and upregulating occludin, claudin-2 and claudin-4 gene expressions. FO + JZXJ-7 ameliorated oxidative stress and inflammation by increasing catalase, superoxide dismutase, total anti-oxidation capacity, and reducing colon tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 levels. Mechanistically, FO + JZXJ-7 modulated the colon micro-ecological environment by enriching Roseburia, Lachnospiraceae NK4B4, Faecalibaculum and Lactococcus and its derived short-chain fatty acids, and activating Ppara and Car1 mediated peroxisome proliferators-activated receptor (PPAR) and phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) signaling. Overall, FO + JZXJ-7 may serve as a promising nutraceutical to improve health by boosting the growth of colonic beneficial bacteria, altering metabolic phenotype, and regulating gene expression.

Targeting the Gut Microbiome to Improve Immunotherapy Outcomes: A Review

The following narrative review embarks on a comprehensive exploration of the role played by the gut microbiome within the Diet-Microbiota-Immunity (DMI) tripartite, aiming to enhance anti-cancer immunotherapy efficacy. While revolutionizing cancer treatment, resistance to immunotherapy and immune-related adverse events (irAEs) remain challenges. The tumor microenvironment (TME), shaped by cancer cells, influences immunotherapy resistance. The gut microbiome, influenced by genetics, environment, diet, and interventions, emerges as a critical player in TME reshaping, thereby modulating immune responses and treatment outcomes. Dietary patterns like the Mediterranean diet, caloric restriction modifications, and specific nutritional components show promise in influencing the tumor microenvironment and gut microbiome for better treatment outcomes. Antibiotics, disrupting gut microbiota diversity, may compromise immunotherapy efficacy. This review emphasizes the need for tailored nutritional strategies to manipulate microbial communities, enhance immune regulation, and improve immunotherapy accessibility while minimizing side effects. Ongoing studies investigate the impact of dietary interventions on cancer immunotherapy, pointing toward promising developments in personalized cancer care. This narrative review synthesizes existing knowledge and charts a course for future investigations, presenting a holistic perspective on the dynamic interplay between dietary interventions, the gut microbiome, and cancer immunotherapy within the DMI tripartite.

Triangulating nutrigenomics, metabolomics and microbiomics toward personalized nutrition and healthy living

The unique physiological and genetic characteristics of individuals influence their reactions to different dietary constituents and nutrients. This notion is the foundation of personalized nutrition. The field of nutrigenetics has witnessed significant progress in understanding the impact of genetic variants on macronutrient and micronutrient levels and the individual's responsiveness to dietary intake. These variants hold significant value in facilitating the development of personalized nutritional interventions, thereby enabling the effective translation from conventional dietary guidelines to genome-guided nutrition. Nevertheless, certain obstacles could impede the extensive implementation of individualized nutrition, which is still in its infancy, such as the polygenic nature of nutrition-related pathologies. Consequently, many disorders are susceptible to the collective influence of multiple genes and environmental interplay, wherein each gene exerts a moderate to modest effect. Furthermore, it is widely accepted that diseases emerge because of the intricate interplay between genetic predisposition and external environmental influences. In the context of this specific paradigm, the utilization of advanced "omic" technologies, including epigenomics, transcriptomics, proteomics, metabolomics, and microbiome analysis, in conjunction with comprehensive phenotyping, has the potential to unveil hitherto undisclosed hereditary elements and interactions between genes and the environment. This review aims to provide up-to-date information regarding the fundamentals of personalized nutrition, specifically emphasizing the complex triangulation interplay among microbiota, dietary metabolites, and genes. Furthermore, it highlights the intestinal microbiota's unique makeup, its influence on nutrigenomics, and the tailoring of dietary suggestions. Finally, this article provides an overview of genotyping versus microbiomics, focusing on investigating the potential applications of this knowledge in the context of tailored dietary plans that aim to improve human well-being and overall health.

Beyond Diet and Exercise: The Impact of Gut Microbiota on Control of Obesity

Obesity, a widespread health concern characterized by the excessive accumulation of body fat, is a complex condition influenced by genetics, environment, and social determinants. Recent research has increasingly focused on the role of gut microbiota in obesity, highlighting its pivotal involvement in various metabolic processes. The gut microbiota, a diverse community of microorganisms residing in the gastrointestinal tract, interacts with the host in a myriad of ways, impacting energy metabolism, appetite regulation, inflammation, and the gut-brain axis. Dietary choices significantly shape the gut microbiota, with diets high in fat and carbohydrates promoting the growth of harmful bacteria while reducing beneficial microbes. Lifestyle factors, like physical activity and smoking, also influence gut microbiota composition. Antibiotics and medications can disrupt microbial diversity, potentially contributing to obesity. Early-life experiences, including maternal obesity during pregnancy, play a vital role in the developmental origins of obesity. Therapeutic interventions targeting the gut microbiota, including prebiotics, probiotics, fecal microbiota transplantation, bacterial consortium therapy, and precision nutrition, offer promising avenues for reshaping the gut microbiota and positively influencing weight regulation and metabolic health. Clinical applications of microbiota-based therapies are on the horizon, with potential implications for personalized treatments and condition-based interventions. Emerging technologies, such as next-generation sequencing and advanced bioinformatics, empower researchers to identify specific target species for microbiota-based therapeutics, opening new possibilities in healthcare. Despite the promising outlook, microbiota-based therapies face challenges related to microbial selection, safety, and regulatory issues. However, with ongoing research and advances in the field, these challenges can be addressed to unlock the full potential of microbiota-based interventions.

The Maternal Microbiome and Gestational Diabetes Mellitus: Cause and Effect

Gestational diabetes mellitus (GDM) is a growing public health concern that affects many pregnancies globally. The condition is associated with adverse maternal and neonatal outcomes including gestational hypertension, preeclampsia, placental abruption, preterm birth, stillbirth, and fetal growth restriction. In the long-term, mothers and children have an increased risk of developing metabolic diseases such as type 2 diabetes and cardiovascular disease. Accumulating evidence suggest that alterations in the maternal microbiome may play a role in the pathogenesis of GDM and adverse pregnancy outcomes. This review describes changes in the maternal microbiome during the physiological adaptations of pregnancy, GDM and adverse maternal and neonatal outcomes. Findings from this review highlight the importance of understanding the link between the maternal microbiome and GDM. Furthermore, new therapeutic approaches to prevent or better manage GDM are discussed. Further research and clinical trials are necessary to fully realize the therapeutic potential of the maternal microbiome and translate these findings into clinical practice.

Decoding the Microbiome's Influence on Rheumatoid Arthritis

The aim is better to understand and critically explore and present the available data from observational studies on the pathogenetic role of the microbiome in the development of rheumatoid arthritis (RA). The electronic databases PubMed, Scopus, and Web of Science were screened for the relevant literature published in the last ten years. The primary outcomes investigated included the influence of the gut microbiome on the pathogenesis and development of rheumatoid arthritis, exploring the changes in microbiota diversity and relative abundance of microbial taxa in individuals with RA and healthy controls (HCs). The risk of bias in the included literature was assessed using the GRADE criteria. Ten observational studies were identified and included in the qualitative assessment. A total of 647 individuals with RA were represented in the literature, in addition to 16 individuals with psoriatic arthritis (PsA) and 247 HCs. The biospecimens comprised fecal samples across all the included literature, with 16S rDNA sequencing representing the primary method of biological analyses. Significant differences were observed in the RA microbiome compared to that of HCs: a decrease in Faecalibacterium, Fusicatenibacter, Enterococcus, and Megamonas and increases in Eggerthellales, Collinsella, Prevotella copri, Klebsiella, Escherichia, Eisenbergiella, and Flavobacterium. There are significant alterations in the microbiome of individuals with RA compared to HCs. This includes an increase in Prevotella copri and Lactobacillus and reductions in Collinsella. Collectively, these alterations are proposed to induce inflammatory responses and degrade the integrity of the intestinal barrier; however, further studies are needed to confirm this relationship.

Uncovering changes in microbiome profiles across commercial and backyard poultry farming systems

The microbiome profiles of poultry production systems significantly impact bird health, welfare, and the environment. This study investigated the influence of broiler-rearing systems on the microbiome composition of commercial and backyard chicken farms and their environment over time. Understanding these effects is vital for optimizing animal growth, enhancing welfare, and addressing human and environmental health implications. We collected and analyzed various samples from commercial and backyard farms, revealing significant differences in microbial diversity measurements between the two systems. Backyard farms exhibited higher alpha diversity measurements in soil and water samples, while commercial farms showed higher values for litter and feeder samples. The differences in microbial diversity were also reflected in the relative abundance of various microbial taxa. In backyard farms, Proteobacteria levels increased over time, while Firmicutes levels decreased. Campilobacterota, including the major poultry foodborne pathogen Campylobacter, increased over time in commercial farm environments. Furthermore, Bacteroides, associated with improved growth performance in chickens, were more abundant in backyard farms. Conversely, pathogenic Acinetobacter was significantly higher in backyard chicken fecal and feeder swab samples. The presence of Brevibacterium and Brachybacterium, associated with low-performing broiler flocks, was significantly higher in commercial farm samples. The observed differences in microbial composition and diversity suggest that farm management practices and environmental conditions significantly affect poultry health and welfare and have potential implications for human and environmental health. Understanding these relationships can inform targeted interventions to optimize poultry production, improve animal welfare, and mitigate foodborne pathogens and antimicrobial resistance risks. IMPORTANCE The microbiome of poultry production systems has garnered significant attention due to its implications on bird health, welfare, and overall performance. The present study investigates the impact of different broiler-rearing systems, namely, commercial (conventional) and backyard (non-conventional), on the microbiome profiles of chickens and their environment over time. Understanding the influence of these systems on microbiome composition is a critical aspect of the One-Health concept, which emphasizes the interconnectedness of animal, human, and environmental health. Our findings demonstrate that the type of broiler production system significantly affects both the birds and their environment, with distinct microbial communities associated with each system. This study reveals the presence of specific microbial taxa that differ in abundance between commercial and backyard poultry farms, providing valuable insights into the management practices that may alter the microbiome in these settings. Furthermore, the dynamic changes in microbial composition over time observed in our study highlight the complex interplay between the poultry gut microbiome, environmental factors, and production systems. By identifying the key microbial players and their fluctuations in commercial and backyard broiler production systems, this research offers a foundation for developing targeted strategies to optimize bird health and welfare while minimizing the potential risks to human and environmental health. The results contribute to a growing body of knowledge in the field of poultry microbiome research and have the potential to guide future improvements in poultry production practices that promote a sustainable and healthy balance between the birds, their environment, and the microbial communities they host.

Insight into the Potential Mechanisms of Endocrine Disruption by Dietary Phytoestrogens in the Context of the Etiopathogenesis of Endometriosis

Phytoestrogens (PEs) are estrogen-like nonsteroidal compounds derived from plants (e.g., nuts, seeds, fruits, and vegetables) and fungi that are structurally similar to 17β-estradiol. PEs bind to all types of estrogen receptors, including ERα and ERβ receptors, nuclear receptors, and a membrane-bound estrogen receptor known as the G protein-coupled estrogen receptor (GPER). As endocrine-disrupting chemicals (EDCs) with pro- or antiestrogenic properties, PEs can potentially disrupt the hormonal regulation of homeostasis, resulting in developmental and reproductive abnormalities. However, a lack of PEs in the diet does not result in the development of deficiency symptoms. To properly assess the benefits and risks associated with the use of a PE-rich diet, it is necessary to distinguish between endocrine disruption (endocrine-mediated adverse effects) and nonspecific effects on the endocrine system. Endometriosis is an estrogen-dependent disease of unknown etiopathogenesis, in which tissue similar to the lining of the uterus (the endometrium) grows outside of the uterus with subsequent complications being manifested as a result of local inflammatory reactions. Endometriosis affects 10-15% of women of reproductive age and is associated with chronic pelvic pain, dysmenorrhea, dyspareunia, and infertility. In this review, the endocrine-disruptive actions of PEs are reviewed in the context of endometriosis to determine whether a PE-rich diet has a positive or negative effect on the risk and course of endometriosis.

Dietary Supplementation with Popped Amaranth Modulates the Gut Microbiota in Low Height-for-Age Children: A Nonrandomized Pilot Trial

Amaranth has been recognized as a nutraceutical food because it contains high-quality proteins due to its adequate amino acid composition that covers the recommended requirements for children and adults. Since pre-Hispanic times, amaranth has been consumed as popped grain; the popping process improves its nutritive quality and improves its digestibility. Popped amaranth consumption has been associated with the recovery of malnourished children. However, there is no information on the impact that popped amaranth consumption has on gut microbiota composition. A non-randomized pilot trial was conducted to evaluate the changes in composition, structure, and function of the gut microbiota of stunted children who received four grams of popped amaranth daily for three months. Stool and serum were collected at the beginning and at the end of the trial. Short-chain fatty acids (SCFA) were quantified, and gut bacterial composition was analyzed by 16S rRNA gene sequencing. Biometry and hematology results showed that children had no pathology other than low height-for-age. A decrease in the relative abundance of Alistipes putredinis, Bacteroides coprocola, and Bacteroides stercoris bacteria related to inflammation and colitis, and an increase in the relative abundance of Akkermansia muciniphila and Streptococcus thermophiles bacteria associated with health and longevity, was observed. The results demonstrate that popped amaranth is a nutritious food that helps to combat childhood malnutrition through gut microbiota modulation.

Microbiome-Gut-Mucosal-Immune-Brain Axis and Autism Spectrum Disorder (ASD): A Novel Proposal of the Role of the Gut Microbiome in ASD Aetiology

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder characterised by deficits in social interaction and communication, as well as restricted and stereotyped interests. Due of the high prevalence of gastrointestinal disorders in individuals with ASD, researchers have investigated the gut microbiota as a potential contributor to its aetiology. The relationship between the microbiome, gut, and brain (microbiome-gut-brain axis) has been acknowledged as a key factor in modulating brain function and social behaviour, but its connection to the aetiology of ASD is not well understood. Recently, there has been increasing attention on the relationship between the immune system, gastrointestinal disorders and neurological issues in ASD, particularly in relation to the loss of specific species or a decrease in microbial diversity. It focuses on how gut microbiota dysbiosis can affect gut permeability, immune function and microbiota metabolites in ASD. However, a very complete study suggests that dysbiosis is a consequence of the disease and that it has practically no effect on autistic manifestations. This is a review of the relationship between the immune system, microbial diversity and the microbiome-gut-brain axis in the development of autistic symptoms severity and a proposal of a novel role of gut microbiome in ASD, where dysbiosis is a consequence of ASD-related behaviour and where dysbiosis in turn accentuates the autistic manifestations of the patients via the microbiome-gut-brain axis in a feedback circuit.

The Role of Gut Microbiota in the Clinical Outcome of Septic Patients: State of the Art and Future Perspectives

Sepsis is a life-threatening multiple-organ dysfunction caused by a dysregulated host response to infection, with high mortality worldwide; 11 million deaths per year are attributable to sepsis in high-income countries. Several research groups have reported that septic patients display a dysbiotic gut microbiota, often related to high mortality. Based on current knowledge, in this narrative review, we revised original articles, clinical trials, and pilot studies to evaluate the beneficial effect of gut microbiota manipulation in clinical practice, starting from an early diagnosis of sepsis and an in-depth analysis of gut microbiota.

Structural Characteristics and Immunomodulatory Effects of Melanoidins from Black Garlic

Melanoidins are considered to have several biological activities. In this study, black garlic melanoidins (MLDs) were collected using ethanol solution extraction; 0%, 20%, and 40% ethanol solutions were used for chromatography. Three kinds of melanoidins were produced by macroporous resin, named MLD-0, MLD-20, and MLD-40. The molecular weight was determined, and the infrared and microscopic structures were studied. In addition, Balb/c mice were induced with cyclophosphamide (CTX) to establish an immune deficiency model to evaluate the immune efficacy of black garlic melanoidins (MLDs). The results showed that MLDs restored the proliferation and phagocytosis ability of macrophages, and the proliferation activity of B lymphocytes in the MD group was 63.32% (♀) and 58.11% (♂) higher than that in the CTX group, respectively. In addition, MLDs alleviated the abnormal expression of serum factors such as IFN-γ, IL-10, and TNF-α. 16SrDNA sequencing of intestinal fecal samples of mice showed that MLDs changed the structure and quantity of intestinal flora, and especially that the relative abundance of Bacteroidaceae was significantly increased. The relative abundance of Staphylococcaceae was significantly reduced. These results showed that MLDs improved the diversity of intestinal flora in mice, and improved the adverse state of immune organs and immune cells. The experiments confirm that black garlic melanoidins have potential value in immune activity, which provides an important basis for the development and utilization of melioidosis.

Gut Microbiome in the Progression of NAFLD, NASH and Cirrhosis, and Its Connection with Biotics: A Bibliometric Study Using Dimensions Scientific Research Database

There is growing evidence that gut microbiota dysbiosis is linked to the etiopathogenesis of nonalcoholic fatty liver disease (NAFLD), from the initial stage of disease until the progressive stage of nonalcoholic steatohepatitis (NASH) and the final stage of cirrhosis. Conversely, probiotics, prebiotics, and synbiotics have shown promise in restoring dysbiosis and lowering clinical indicators of disease in a number of both preclinical and clinical studies. Additionally, postbiotics and parabiotics have recently garnered some attention. The purpose of this bibliometric analysis is to assess recent publishing trends concerning the role of the gut microbiome in the progression of NAFLD, NASH and cirrhosis and its connection with biotics. The free access version of the Dimensions scientific research database was used to find publications in this field from 2002 to 2022. VOSviewer and Dimensions' integrated tools were used to analyze current research trends. Research into the following topics is expected to emerge in this field: (1) evaluation of risk factors which are correlated with the progression of NAFLD, such as obesity and metabolic syndrome; (2) pathogenic mechanisms, such as liver inflammation through toll-like receptors activation, or alteration of short-chain fatty acids metabolisms, which contribute to NAFLD development and its progression in more severe forms, such as cirrhosis; (3) therapy for cirrhosis through dysbiosis reduction, and research on hepatic encephalopathy a common consequence of cirrhosis; (4) evaluation of diversity, and composition of gut microbiome under NAFLD, and as it varies under NASH and cirrhosis by rRNA gene sequencing, a tool which can also be used for the development of new probiotics and explore into the impact of biotics on the gut microbiome; (5) treatments to reduce dysbiosis with new probiotics, such as Akkermansia, or with fecal microbiome transplantation.

Exploring body weight-influencing gut microbiota by elucidating the association with diet and host gene expression

We aimed to identify gut microbiota that influences body weight by elucidating the association with diets and host genes. Germ-free (GF) mice with and without fecal microbiota transplant (FMT) were fed a normal, high-carbohydrate, or high-fat diet. FMT mice exhibited greater total body weight; adipose tissue and liver weights; blood glucose, insulin, and total cholesterol levels; and oil droplet size than the GF mice, regardless of diet. However, the extent of weight gain and metabolic parameter levels associated with gut microbiota depended on the nutrients ingested. For example, a disaccharide- or polysaccharide-rich diet caused more weight gain than a monosaccharide-rich diet. An unsaturated fatty acid-rich diet had a greater microbial insulin-increasing effect than a saturated fatty acid-rich diet. Perhaps the difference in microbial metabolites produced from substances taken up by the host created metabolic differences. Therefore, we analyzed such dietary influences on gut microbiota, differentially expressed genes between GF and FMT mice, and metabolic factors, including body weight. The results revealed a correlation between increased weight gain, a fat-rich diet, increased Ruminococcaceae abundance, and decreased claudin 22 gene expression. These findings suggest that weight regulation might be possible through the manipulation of the gut microbiota metabolism using the host's diet.

Undernutrition Disrupts Cecal Microbiota and Epithelium Interactions, Epithelial Metabolism, and Immune Responses in a Pregnant Sheep Model

Undernutrition may change cecal microbiota-epithelium interactions to influence cecal feed fermentation, nutrient absorption and metabolism, and immune function. Sixteen late-gestation Hu-sheep were randomly divided into control (normal feeding) and treatment (feed restriction) groups to establish an undernourished sheep model. Cecal digesta and epithelium were collected to analyze microbiota-host interactions based on 16S rRNA gene and transcriptome sequencing. Results showed that cecal weight and pH were decreased, volatile fatty acids and microbial proteins concentrations were increased, and epithelial morphology was changed upon undernutrition. Undernutrition reduced the diversity, richness, and evenness of cecal microbiota. The relative abundances of cecal genera involved in acetate production (Rikenellaceae dgA-11 gut group, Rikenellaceae RC9 gut group, and Ruminococcus) and negatively correlated with butyrate proportion (Clostridia vadinBB60 group_norank) were decreased, while genera related to butyrate (Oscillospiraceae_uncultured and Peptococcaceae_uncultured) and valerate (Peptococcaceae_uncultured) production were increased in undernourished ewes. These findings were consistent with the decreased molar proportion of acetate and the increased molar proportions of butyrate and valerate. Undernutrition changed the overall transcriptional profile and substance transport and metabolism in cecal epithelium. Undernutrition suppressed extracellular matrix-receptor interaction and intracellular phosphatidyl inositol 3-kinase (PI3K) signaling pathway then disrupted biological processes in cecal epithelium. Moreover, undernutrition repressed phagosome antigen processing and presentation, cytokine-cytokine receptor interaction, and intestinal immune network. In conclusion, undernutrition affected cecal microbial diversity and composition and fermentation parameters, inhibited extracellular matrix-receptor interaction and the PI3K signaling pathway, and then disrupted epithelial proliferation and renewal and intestinal immune functions. Our findings exposed cecal microbiota-host interactions upon undernutrition and contribute to their further exploration. IMPORTANCE Undernutrition is commonly encountered in ruminant production, especially during pregnancy and lactation in females. Undernutrition not only induces metabolic diseases and threatens pregnant mothers' health, but also inhibits fetal growth and development, leading to weakness or even death of fetuses. Cecum works importantly in hindgut fermentation, providing volatile fatty acids and microbial proteins to the organism. Intestinal epithelial tissue plays a role in nutrient absorption and transport, barrier function, and immune function. However, little is known about cecal microbiota and epithelium interactions upon undernutrition. Our findings showed that undernutrition affected bacterial structures and functions, which changed fermentation parameters and energy regimens, and therefore affected the substance transport and metabolism in cecal epithelium. Extracellular matrix-receptor interactions were inhibited, which repressed cecal epithelial morphology and cecal weight via the PI3K signaling pathway and lowered immune response function upon undernutrition. These findings will help in further exploring microbe-host interactions.

Gut microbiota in relation to frailty and clinical outcomes

PURPOSE OF REVIEW

The gut microbiota is involved in several aspects of host health and disease, but its role is far from fully understood. This review aims to unveil the role of our microbial community in relation to frailty and clinical outcomes.

RECENT FINDINGS

Ageing, that is the continuous process of physiological changes that begin in early adulthood, is mainly driven by interactions between biotic and environmental factors, also involving the gut microbiota. Indeed, our gut microbial counterpart undergoes considerable compositional and functional changes across the lifespan, and ageing-related processes may be responsible for - and due to - its alterations during elderhood. In particular, a dysbiotic gut microbiota in the elderly population has been associated with the development and progression of several age-related disorders.

SUMMARY

Here, we first provide an overview of the lifespan trajectory of the gut microbiota in both health and disease. Then, we specifically focus on the relationship between gut microbiota and frailty syndrome, that is one of the major age-related burdens. Finally, examples of microbiome-based precision interventions, mainly dietary, prebiotic and probiotic ones, are discussed as tools to ameliorate the symptoms of frailty and its overlapping conditions (e.g. sarcopenia), with the ultimate goal of actually contributing to healthy ageing and hopefully promoting longevity.

The Interplay of Dietary Fibers and Intestinal Microbiota Affects Type 2 Diabetes by Generating Short-Chain Fatty Acids

Foods contain dietary fibers which can be classified into soluble and insoluble forms. The nutritional composition of fast foods is considered unhealthy because it negatively affects the production of short-chain fatty acids (SCFAs). Dietary fiber is resistant to digestive enzymes in the gut, which modulates the anaerobic intestinal microbiota (AIM) and fabricates SCFAs. Acetate, butyrate, and propionate are dominant in the gut and are generated via Wood-Ljungdahl and acrylate pathways. In pancreatic dysfunction, the release of insulin/glucagon is impaired, leading to hyperglycemia. SCFAs enhance insulin sensitivity or secretion, beta-cell function, leptin release, mitochondrial function, and intestinal gluconeogenesis in human organs, which positively affects type 2 diabetes (T2D). Research models have shown that SCFAs either enhance the release of peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) from L-cells (entero-endocrine), or promotes the release of leptin hormone in adipose tissues through G-protein receptors GPR-41 and GPR-43. Dietary fiber is a component that influences the production of SCFAs by AIM, which may have beneficial effects on T2D. This review focuses on the effectiveness of dietary fiber in producing SCFAs in the colon by the AIM as well as the health-promoting effects on T2D.

Chrono-Nutrition: Circadian Rhythm and Personalized Nutrition

The human circadian system has a period of approximately 24 h and studies on the consequences of "chornodisruption" have greatly expanded. Lifestyle and environmental factors of modern societies (i.e., artificial lighting, jetlag, shift work, and around-the-clock access to energy-dense food) can induce disruptions of the circadian system and thereby adversely affect individual health. Growing evidence demonstrates a complex reciprocal relationship between metabolism and the circadian system, in which perturbations in one system affect the other one. From a nutritional genomics perspective, genetic variants in clock genes can both influence metabolic health and modify the individual response to diet. Moreover, an interplay between the circadian rhythm, gut microbiome, and epigenome has been demonstrated, with the diet in turn able to modulate this complex link suggesting a remarkable plasticity of the underlying mechanisms. In this view, the study of the impact of the timing of eating by matching elements from nutritional research with chrono-biology, that is, chrono-nutrition, could have significant implications for personalized nutrition in terms of reducing the prevalence and burden of chronic diseases. This review provides an overview of the current evidence on the interactions between the circadian system and nutrition, highlighting how this link could in turn influence the epigenome and microbiome. In addition, possible nutritional strategies to manage circadian-aligned feeding are suggested.

Short Chain Fatty Acid Metabolism in Relation to Gut Microbiota and Genetic Variability

It is widely accepted that the gut microbiota plays a significant role in modulating inflammatory and immune responses of their host. In recent years, the host-microbiota interface has gained relevance in understanding the development of many non-communicable chronic conditions, including cardiovascular disease, cancer, autoimmunity and neurodegeneration. Importantly, dietary fibre (DF) and associated compounds digested by the microbiota and their resulting metabolites, especially short-chain fatty acids (SCFA), were significantly associated with health beneficial effects, such as via proposed anti-inflammatory mechanisms. However, SCFA metabolic pathways are not fully understood. Major steps include production of SCFA by microbiota, uptake in the colonic epithelium, first-pass effects at the liver, followed by biodistribution and metabolism at the host's cellular level. As dietary patterns do not affect all individuals equally, the host genetic makeup may play a role in the metabolic fate of these metabolites, in addition to other factors that might influence the microbiota, such as age, birth through caesarean, medication intake, alcohol and tobacco consumption, pathogen exposure and physical activity. In this article, we review the metabolic pathways of DF, from intake to the intracellular metabolism of fibre-derived products, and identify possible sources of inter-individual variability related to genetic variation. Such variability may be indicative of the phenotypic flexibility in response to diet, and may be predictive of long-term adaptations to dietary factors, including maladaptation and tissue damage, which may develop into disease in individuals with specific predispositions, thus allowing for a better prediction of potential health effects following personalized intervention with DF.

A Proinflammatory Diet Is Associated with Higher Risk of Peripheral Artery Disease

Peripheral arterial disease (PAD) has a strong relationship with inflammation. However, it is unclear whether the dietary inflammatory potential is associated with PAD. We aimed to address this knowledge gap. The dietary inflammatory index (DII) was obtained using a 24-h dietary recall interview for each individual. Logistic regression models and restricted cubic spline were performed to assess the relationship of DII with the prevalence of PAD. In addition, Spearman correlation analysis and subgroup analysis were also undertaken. In total, 5840 individuals from the 1999–2004 National Health and Nutrition Examination Survey (NHANES) were enrolled in our study. Participants in higher DII quartile tended to have higher rates of PAD. The increase in DII scores showed a positive association with PAD after fully multivariate adjustment (OR (odds ratios) = 1.094, 95% confidence interval (CI): 1.022–1.171). The multivariable-adjusted OR and 95% CI of the highest DII index quartile compared with the lowest quartile was 1.543 (95% CI: 1.116–2.133). Subgroup analysis demonstrated that the positive association between DII and PAD was persistent across population subgroups. In conclusion, we report that a proinflammatory dietary pattern is related to a higher risk of developing PAD among US adults.