Contribution of diet to the composition of the human gut microbiota

Gut Microbiota Modulation: A Novel Strategy for Rheumatoid Arthritis Therapy

Rheumatoid arthritis (RA) is a chronic autoimmune disease that leads to joint inflammation, progressive tissue damage and significant disability, severely impacting patients' quality of life. While the exact mechanisms underlying RA remain elusive, growing evidence suggests a strong link between intestinal microbiota dysbiosis and the disease's development and progression. Differences in microbial composition between healthy individuals and RA patients point to the role of gut microbiota in modulating immune responses and promoting inflammation. Therapies targeting microbiota restoration have demonstrated promise in improving treatment efficacy, enhancing patient outcomes and slowing disease progression. However, the complex interplay between gut microbiota and autoimmune pathways in RA requires further investigation to establish causative relationships and mechanisms. Here, we review the current understanding of the gut microbiota's role in RA pathogenesis and its potential as a therapeutic target.

A Comparison of Digestive Strategies for Teratoscincus roborowskii With Different Diet Compositions: Digestive Enzyme Activities, Gut Microbiota, and Metabolites

Animal gut microbiota play important roles in host immunity, nutrient metabolism, and energy acquisition. The gut microbiota and its metabolic products interact with the host in many different ways, influencing gut homoeostasis and health. Teratoscincus roborowskii is an endemic species which displays special frugivorous behavior, and it has been observed consuming grapes. To explore the effects of grape intake on the gut microbiota and metabolites of T. roborowskii, 16S rRNA sequencing and liquid chromatography mass spectrometry metabolomics were applied to investigate the gut microbiota and metabolite profiles of T. roborowskii fed with mealworms (LC group) and a mixture of mealworms and grapes (FG group). Our results demonstrated that a notable shift in microbiota composition occurred, particularly in terms of an increase in the probiotic Lactococcus in the FG group. The metabolite analysis revealed a significant enrichment of the pathways related to glucose metabolism in the FG group. In addition, the digestive enzyme activity analysis showed that the α-amylase and cellulase activities in the FG group were significantly higher than those of the LC group, which was consistent with the food type. A strong correlation between diet, gut microbiota, and fecal metabolites was observed, which may imply that different diets promote the establishment of host intestinal adaptation strategies. Our study provides a theoretical basis for host health and the scientific captive breeding of the desert lizards T. roborowskii.

Dietary pattern and the corresponding gut microbiome in response to immunotherapy in Thai patients with advanced non-small cell lung cancer (NSCLC)

Gut microbiota is considered a key player modulating the response to immune checkpoint inhibitors (ICI) in cancer. The effects of dietary pattern on this interaction is not well-studied. A prospective multicenter cohort of 95 patients with advanced non-small cell lung cancer (NSCLC) undergoing ICI therapy were enrolled. Stool shotgun metagenomic sequencing was performed. Three-day dietary patterns before ICI were assessed. Patients were categorized as hyperprogressive disease (HPD) if they exhibited a time to treatment failure of less than 2 months. All others were categorized as non-hyperprogressive disease (non-HPD). The correlation between dietary patterns, gut microbiome, and response to ICI therapy was analyzed. In the multivariate analysis, a high abundance of Firmicutes unclassified and the Ruminococcaceae family correlated with a significantly diminished progression-free survival (PFS) with an HR of 2.40 [P = 0.006] and 4.30 [P = 0.005], respectively. More specifically, within the subset of NSCLC patients treated solely with ICI therapy, a high abundance of Intestinimonas and the Enterobacteriaceae family were associated with substantially reduced PFS with an HR of 2.61 [P = 0.02] and HR 3.34 [P = 0.005], respectively. In our comprehensive dietary pattern analysis, the HPD group showed increased consumption of cholesterol, sodium, and fats beyond recommended levels compared to the non-HPD group. This group also displayed a tendency towards higher food pattern scores characterized by a high intake of fat and dairy products. Our study revealed a distinct association between the gut microbiome composition and treatment outcomes. The overall composition of diet might be related to ICI therapeutic outcomes.

Gut dysbiosis mediates the association between antibiotic exposure and chronic disease

Antibiotics are safe, effective drugs and continue to save millions of lives and prevent long-term illness worldwide. A large body of epidemiological, interventional and experimental evidence shows that exposure to antibiotics has long-term negative effects on human health. We reviewed the literature data on the links between antibiotic exposure, gut dysbiosis, and chronic disease (notably with regard to the "developmental origins of health and disease" ("DOHaD") approach). Molecular biology studies show that the systemic administration of antibiotic to infants has a rapid onset but also often a long-lasting impact on the microbial composition of the gut. Along with other environmental factors (e.g., an unhealthy "Western" diet and sedentary behavior), antibiotics induce gut dysbiosis, which can be defined as the disruption of a previously stable, functionally complete microbiota. Gut dysbiosis many harmful long-term effects on health. Associations between early-life exposure to antibiotics have been reported for chronic diseases, including inflammatory bowel disease, celiac disease, some cancers, metabolic diseases (obesity and type 2 diabetes), allergic diseases, autoimmune disorders, atherosclerosis, arthritis, and neurodevelopmental, neurodegenerative and other neurological diseases. In mechanistic terms, gut dysbiosis influences chronic disease through direct effects on mucosal immune and inflammatory pathways, plus a wide array of direct or indirect effects of short-chain fatty acids, the enteric nervous system, peristaltic motility, the production of hormones and neurotransmitters, and the loss of intestinal barrier integrity (notably with leakage of the pro-inflammatory endotoxin lipopolysaccharide into the circulation). To mitigate dysbiosis, the administration of probiotics in patients with chronic disease is often (but not always) associated with positive effects on clinical markers (e.g., disease scores) and biomarkers of inflammation and immune activation. Meta-analyses are complicated by differences in probiotic composition, dose level, and treatment duration, and large, randomized, controlled clinical trials are lacking in many disease areas. In view of the critical importance of deciding whether or not to prescribe antibiotics (especially to children), we suggest that the DOHaD concept can be logically extended to "gastrointestinal origins of health and disease" ("GOHaD") or even "microbiotic origins of health and disease" ("MOHaD").

Impact of Dietary Fatty Acid Composition on the Intestinal Microbiota and Fecal Metabolism of Rats Fed a High-Fructose/High-Fat Diet

Background/Objectives: An inappropriate intake of dietary fats can disrupt the homeostasis of intestinal microbiota, affect the host's metabolic status, and increase the risk of chronic diseases. The impact of dietary fat types on the composition and metabolic functionality of the intestinal microbiota has become a research focus over recent years. The objective of this study was to explore the effects of regular peanut oil (PO) and high-oleic-acid peanut oil (HOPO) on the composition and metabolic function of the intestinal microbiota. Methods: A dietary intervention test was conducted on SD rats fed a high-fat/high-fructose (HFF) diet. The composition and metabolic functionality of the intestinal microbiota of the experimental rats were investigated by 16S rRNA gene sequencing and fecal metabolomics. Results: Compared with saturated fat, PO and HOPO enhanced the diversity of intestinal microbiota in HFF diet-fed rats. Compared with PO, HOPO significantly increased the relative abundance of Lachnospiraceae_NK4A136_group and Harryflintia (p < 0.05), which are able to generate butyrate and acetate. Compared with saturated fat, 318 and 271 fecal biomarkers were identified in PO and HOPO groups, respectively. In contrast, 68 fecal biomarkers were identified between the PO and HOPO groups. The inhibition of harmful proteolytic fermentation in the colon may represent the main regulatory mechanism. With regard to metabolic status, HOPO provided better control of body weight and insulin sensitivity than PO. Conclusions: Compared with saturated fat, peanut oils better regulated the composition and metabolic function of the intestinal microbiota. In addition, HOPO exhibited better regulatory effects than PO.

Rapid benefits in older age from transition to whole food diet regardless of protein source or fat to carbohydrate ratio: Arandomised control trial

Plant-based diets reduces the risk of chronic conditions. The interaction between protein source and other macronutrients-fat (F) and carbohydrate (C)-has yet to be investigated. The aim was to assess the main and interactive effects of protein-source (plant vs. animal) and F:C (high or low) and the transition from an Australian diet to a whole food diet on various health markers in older individuals. This single-blinded, parallel, randomised experimental trial used a 2 × 2 factorial design to compare pro-vegetarian (70:30 plant to animal) versus omnivorous (50:50 plant to animal) diets at 14% protein and varying fat-to-carbohydrate ratios (high fat ~40% vs. low fat ~30%) over 4 weeks. Study foods were provided, alcohol consumption was discouraged, and dietary intake was determined through food records. Analysis included both RCT and observational data. Changes in appetite, palatability of diets, and dietary intake were assessed. Body composition, muscle strength, function, gut microbiome, and cardiometabolic health parameters were measured. Data from 113 (of the 128 randomised) individuals aged 65-75 years were analysed. Pro-vegetarian diets reduced diastolic blood pressure, total cholesterol and glucose levels. Moreover, the overall sample exhibited increased short-chain fatty acids and FGF21 levels, as well as improvements in body composition, function, and cardio-metabolic parameters irrespective of dietary treatment. Transitioning to a diet rich in fruit, vegetables, fibre, and moderate protein was associated with improved health markers in older age, with added benefits from pro-vegetarian diets. Further research on long-term effects is needed.

Distinct Adjacent Substrate Binding Pocket Regulates the Activity of a Decameric Feruloyl Esterase from Bacteroides thetaiotaomicron

Understanding how the human gut microbiota contribute to the metabolism of dietary carbohydrates is of great interest, particularly those with ferulic acid (FA) decorations that have manifold health benefits. Here, we report the crystal structure of a decameric feruloyl esterase (BtFae) from Bacteroides thetaiotaomicron in complex with methyl ferulate (MFA), revealing that MFA is situated in a noncatalytic substrate binding pocket adjacent to the catalytic pocket. Molecular docking and mutagenesis studies further demonstrated that the adjacent pocket affects substrate binding in the active site and negatively regulates the BtFae activity on both synthetic and natural xylan substrates. Additionally, quantum mechanics (QM) calculations were employed to investigate the catalytic process of BtFae from substrate binding to product release, and identified TS_2 in the acylation step is rate-limiting. Collectively, this study unmasks a novel regulatory mechanism of FAE activity, which may contribute to further investigation of FA-conjugated polysaccharides metabolism in the human gut.

Exploring the population interaction of Przewalski's gazelle (Procapra przewalskii) based on the variations in gut microbiota across diverse geographic populations

The differences in gut microbiota among different populations, to a certain extent, reflect the degree of interaction between individuals within populations. To assess the interaction levels among several small populations of Przewalski's gazelle (Procapra przewalskii) (n = 105, from seven different regions) based on differences in gut microbiota, we used the closely related Tibetan gazelle (P. picticaudata) (n = 52, from seven different regions) as a control. We then compared the gut microbial communities between different populations of the two species using high-throughput sequencing of the 16S rRNA gene. The results showed that within a 100 km geographical distance, the intergroup differences in relative abundance of dominant bacteria, α-diversity, β-diversity, and functional metabolism abundance were higher or significantly higher in Przewalski's gazelle (narrowly distributed species) compared to the Tibetan gazelle (widely distributed species). Additionally, the proportion of shared OTUs between groups in Przewalski's gazelle was significantly lower than in Tibetan gazelle (p < 0.05). Additionally, neutral community model results also showed lower dispersal limitation in the Tibetan gazelle compared to Przewalski's gazelle. Therefore, based on the above results, we comprehensively speculate that the spatial interaction degree of Przewalski's gazelle in different habitat patches is relatively low. This study, starting from the perspective of gut microbiota, adopts a non-genetic perspective or method to assess whether there is, or to what extent there is, close interaction between species populations.

Food carbohydrates in the gut: structural diversity, microbial utilization, and analytical strategies

Carbohydrates, which are a vital dietary component, undergo digestion and gut fermentation through microbial enzymes to produce beneficial short-chain fatty acids. Certain carbohydrates selectively modulate the gut microbiota, impacting host health. Carbohydrate-active enzymes within the gut microbiota significantly contribute to carbohydrate utilization and microbial diversity. Despite their importance, the structural complexity of carbohydrates poses analytical challenges. However, recent advancements, notably, mass spectrometry, have allowed for their characterization and functional analysis. This review examines the intricate relationship between dietary carbohydrates and the gut microbiota, highlighting the crucial role of advanced analytical techniques in understanding their diversity and implications. These advancements provide valuable insights into carbohydrate bioactivity. Integrating high-throughput analysis with next-generation sequencing provides deeper insights into gut microbial interactions, potentially revealing which carbohydrate structures are beneficial for gut health.

Celiac disease and human gut microbiota - how can we study the composition of microorganisms?

Celiac disease is an autoimmune disorder induced by consumption of gluten protein present in foods such as wheat and rye. In recent years there has been increasing evidence that changes in composition of gut microbiota may play a significant role in the pathogenesis of celiac disease. Multiple methods of bacterial identification may be used to find microbiota changes characteristic for celiac disease, and the latest methods such as next generation sequencing offer new possibilities of detecting previously unknown bacterial groups that may play a role in the occurrence of celiac disease. This review focuses on multiple methods of identifying bacterial gut microbiome and presents results of recent studies exploring the link between gut microbiota composition and celiac disease.

Vegetable substrates as an alternative for the inclusion of lactic acid bacteria with probiotic potential in food matrices

Vegetable substrates are food matrices with micronutrients, antioxidants, and fiber content with a high potential for bioprocesses development. In addition, they have been recognized as essential sources of a wide range of phytochemicals that, individually or in combination, can act as bioactive compounds with potential benefits to health due to their antioxidant and antimicrobial activity and recently due to their status as prebiotics in the balance of the human intestinal microbiota. This systematic review explores the benefits of lactic fermentation of plant matrices such as fruits, vegetables, legumes, and cereals by bacteria with probiotic potential, guaranteeing cell viability (106-107 CFU/mL) and generating bioactive metabolic products for modulation of the gut microbiome.

Ascomycetes yeasts: The hidden part of human microbiome

The fungal component of the microbiota, the mycobiota, has been neglected for a long time due to its poor richness compared to bacteria. Limitations in fungal detection and taxonomic identification arise from using metagenomic approaches, often borrowed from bacteriome analyses. However, the relatively recent discoveries of the ability of fungi to modulate the host immune response and their involvement in human diseases have made mycobiota a fundamental component of the microbial communities inhabiting the human host, deserving some consideration in host-microbe interaction studies and in metagenomics. Here, we reviewed recent data on the identification of yeasts of the Ascomycota phylum across human body districts, focusing on the most representative genera, that is, Saccharomyces and Candida. Then, we explored the key factors involved in shaping the human mycobiota across the lifespan, ranging from host genetics to environment, diet, and lifestyle habits. Finally, we discussed the strengths and weaknesses of culture-dependent and independent methods for mycobiota characterization. Overall, there is still room for some improvements, especially regarding fungal-specific methodological approaches and bioinformatics challenges, which are still critical steps in mycobiota analysis, and to advance our knowledge on the role of the gut mycobiota in human health and disease. This article is categorized under: Immune System Diseases > Genetics/Genomics/Epigenetics Immune System Diseases > Environmental Factors Infectious Diseases > Environmental Factors.

Dietary Influences on Skin Health in Common Dermatological Disorders

The role of diet in the development of skin disorders is well-established, with nutritional deficiency often identified as a risk factor for skin diseases. Imbalances in the skin can be caused by nutritional deficiencies, excessive intake, insufficient nutrients, and hazardous ingredients. Patients frequently inquire about the impact of dietary patterns on skin health when consulting dermatologists in clinical settings. Simultaneously, the popularity of using nutritional supplements containing vitamins, minerals, and nutraceutical blends has been on the rise. It is crucial for dermatologists, primary care physicians, and other healthcare providers to be acquainted with evidence-based dietary interventions, distinguishing them from those that are more market-driven than truly efficacious. This review explores the modification of diet, encompassing both dietary exclusion and supplementation, as a therapeutic approach for conditions such as psoriasis, atopic dermatitis, bullous disease, vitiligo, and alopecia areata. A comprehensive literature search, utilizing the PubMed/Medline, Google Scholar, and Medscape databases, was conducted to investigate the relationship between each nutrient and various inflammatory skin diseases. The findings emphasize the significance of a well-balanced and thoughtfully planned diet in supplying adequate amounts of proteins, vitamins, and minerals to support optimal skin health. Additionally, this comprehensive review navigates through various dietary recommendations, offering insights into their multifaceted impacts on the immune system, gut microbiome, and skin health. The goal is to pave the way for informed and targeted dietary interventions for individuals dealing with food allergies and associated skin conditions.

New horizon to the world of gut microbiome: seeds germination

The second brain of humans has been known as the microbiome. The microbiome is a dynamic network composed of commensal bacteria, archaea, viruses, and fungi colonized in the human gastrointestinal tract. They play a vital role in human health by metabolizing components, maturation of the immune system, and taking part in the treatment of various diseases. Two important factors that can affect the gut microbiome's composition and/or function are the food matrix and methods of food processing. Based on scientific research, the consumption of whole grains can make positive changes in the gut microbiota. Seeds contain different microbiota-accessible substrates that can resist digestion in the upper gastrointestinal tract. Seed germination is one of the simplest and newest food processing approaches to improve seeds' bioavailability and overall nutritional value. During germination, the dormant hydrolytic seed's enzymes have been activated and then metabolize the macromolecules. The quality and quantity of bioactive compounds like prebiotics, fiber, phenolic compounds (PC), total free amino acids, and γ-aminobutyric acid (GABA) can increase even up to 4-10 folds in some cases. These components stimulate the survival and growth of healthful bacteria like probiotics and boost their activity. This effect depends on several parameters, e.g., germination environmental conditions. This review aims to provide up-to-date and latest research about promoting bioactive components during seed germination and investigating their impacts on gut microbiota to understand the possible direct and indirect effects of seed germination on the microbiome and human health.

Alterations in gut microbiota caused by major depressive disorder or a low FODMAP diet and where they overlap

Beneficial changes in microbiota observed in individuals with a major depressive disorder (MDD) may be initiated with a low fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) elimination diet. Academic Search Ultimate, APA PsychINFO, Cochrane Library, MEDLINE, Scopus and Web of Science were searched for original research documenting differences in microbiota in MDD or changes with a low FODMAP diet in adults (age 18 years +). Studies with fecal microbiota, 16 s RNA sequencing and QIIME pipelines were included. Studies using antibiotics, probiotics, and medications such as antidepressants were excluded. Additionally, studies based on a single gender were excluded as gender impacts microbiota changes in MDD. Four studies addressed differences in microbiota with MDD and another four assessed shifts occurring with a low FODMAP diet. The abundance of Bacteroidetes, Bacteroidaceae and Bacteroides were lower in individuals with MDD but increased with a low FODMAP diet. Abundance of Ruminoccaceae was lower and Bilophila was higher with both a low FODMAP diet and MDD. These results provide preliminary evidence that a low FODMAP diet might drive changes in microbiota that also benefit people with MDD. Further research to assess whether a low FODMAP diet can treat MDD through modification of targeted microbiota is warranted.

Shaping Microbiota During the First 1000 Days of Life

Given that the host-microbe interaction is shaped by the immune system response, it is important to understand the key immune system-microbiota relationship during the period from conception to the first years of life. The present work summarizes the available evidence concerning human reproductive microbiota, and also, the microbial colonization during early life, focusing on the potential impact on infant development and health outcomes. Furthermore, we conclude that some dietary strategies including specific probiotics and other-biotics could become potentially valuable tools to modulate the maternal-neonatal microbiota during this early critical window of opportunity for targeted health outcomes throughout the entire lifespan.

How Different Are the Influences of Mediterranean and Japanese Diets on the Gut Microbiome?

The gut microbiome is a complex ecosystem, mainly composed of bacteria, that performs essential functions for the host. Its composition is determined by many factors; however, diet has emerged as a key regulator. Both the Mediterranean (MD) and Japanese (JD) diets have been associated with significant health benefits and are therefore considered healthy dietary patterns. Both are plant-based diets and although they have much in common, they also have important differences mainly related to total calorie intake and the consumption of specific foods and beverages. Thus, it has been hypothesized that they exert their beneficial properties through different nutrients and bioactive compounds that interact with gut microbes and induce specific changes on gut metabolic pathways. In this review, we present current data on the effects of the MD and JD on the gut microbiome. Furthermore, we aim to examine whether there are differences or shared effects on the gut microbiome of people who adhere to these dietary patterns.

Effect of diet on the gut mycobiome and potential implications in inflammatory bowel disease

The gut microbiome is a complex, unique entity implicated in the prevention, pathogenesis, and progression of common gastrointestinal diseases. While largely dominated by bacterial populations, advanced sequencing techniques have identified co-inhabiting fungal communities, collectively referred to as the mycobiome. Early studies identified that gut inflammation is associated with altered microbial composition, known as gut dysbiosis. Altered microbial profiles are implicated in various pathological diseases, such as inflammatory bowel disease (IBD), though their role as a cause or consequence of systemic inflammation remains the subject of ongoing research. Diet plays a crucial role in the prevention and management of various diseases and is considered to be an essential regulator of systemic inflammation. This review compiles current literature on the impact of dietary modulation on the mycobiome, showing that dietary changes can alter the fungal architecture of the gut. Further research is required to understand the impact of diet on gut fungi, including the metabolic pathways and enzymes involved in fungal fermentation. Additionally, investigating whether dietary modulation of the gut mycobiome could be utilized as a therapy in IBD is essential.

Diet, Gut Microbes, and Cancer

Gut microbes are important and may play important role in spreading cancers specially the gastrointestinal malignancies preferably colorectal cancers. Gut microbes and diet can influence the tissues in gastrointestinal tract increasing the risk of cancer spread. Insufficient nutrient intake and imbalance diet can disturb the microbiome of gastrointestinal tract causing metabolism of xenobiotics which is beneficial as well as detrimental. Dietary imbalance may also weaken the immune system which is another reason for spreading and development of cancers. The triage of gut microbiome, host immune system, and dietary patterns may help the initiation of mechanism of carcinogenesis. In addition to its role in carcinogenesis and tumor development, there is still growing evidence as to how intestinal microflora influences the efficacy and toxicity of chemotherapy and immunotherapy by the gut microbiome. It can therefore be used as a biomarker to predict treatment response or poor response and can also be modified to improve cancer treatment.

A single dietary factor, daily consumption of a fermented beverage, can modulate the gut bacteria and fecal metabolites within the same ethnic community

IMPORTANCE

Our study investigated how a traditional drink called Apong, made from fermented rice, affects the gut and health of the Mishing community in India. We compared two groups of people who drink Apong to a group of people who do not drink it. To accomplish this, we studied the gut bacteria, fecal metabolites, and blood samples of the participants. It was found that the people who drank Apong had higher blood pressure but lower blood sugar and protein levels than people who did not drink it. We also found that the gut microbiome composition of people who drank Apong was different from those who did not drink it. Moreover, people who drank Apong had lower levels of isovaleric acid in their feces. Overall, this study shows that a traditional drink like Apong can affect the gut bacteria of a community.

Probiotics and prebiotics: potential prevention and therapeutic target for nutritional management of COVID-19?

Scientists are working to identify prevention/treatment methods and clinical outcomes of coronavirus disease 2019 (COVID-19). Nutritional status and diet have a major impact on the COVID-19 disease process, mainly because of the bidirectional interaction between gut microbiota and lung, that is, the gut-lung axis. Individuals with inadequate nutritional status have a pre-existing imbalance in the gut microbiota and immunity as seen in obesity, diabetes, hypertension and other chronic diseases. Communication between the gut microbiota and lungs or other organs and systems may trigger worse clinical outcomes in viral respiratory infections. Thus, this review addresses new insights into the use of probiotics and prebiotics as a preventive nutritional strategy in managing respiratory infections such as COVID-19 and highlighting their anti-inflammatory effects against the main signs and symptoms associated with COVID-19. Literature search was performed through PubMed, Cochrane Library, Scopus and Web of Science databases; relevant clinical articles were included. Significant randomised clinical trials suggest that specific probiotics and/or prebiotics reduce diarrhoea, abdominal pain, vomiting, headache, cough, sore throat, fever, and viral infection complications such as acute respiratory distress syndrome. These beneficial effects are linked with modulation of the microbiota, products of microbial metabolism with antiviral activity, and immune-regulatory properties of specific probiotics and prebiotics through Treg cell production and function. There is a need to conduct clinical and pre-clinical trials to assess the combined effect of consuming these components and undergoing current therapies for COVID-19.

Mechanistic Insights into Immune-Microbiota Interactions and Preventive Role of Probiotics Against Autoimmune Diabetes Mellitus

Recent studies on genetically susceptible individuals and animal models revealed the potential role of the intestinal microbiota in the pathogenesis of type 1 diabetes (T1D) through complex interactions with the immune system. T1D incidence has been increasing exponentially with modern lifestyle altering normal microbiota composition, causing dysbiosis characterized by an imbalance in the gut microbial community. Dysbiosis has been suggested to be a potential contributing factor in T1D. Moreover, several studies have shown the potential role of probiotics in regulating T1D through various mechanisms. Current T1D therapies target curative measures; however, preventive therapeutics are yet to be proven. This review highlights immune microbiota interaction and the immense role of probiotics and postbiotics as important immunological interventions for reducing the risk of T1D.

Schizophrenia and obesity: May the gut microbiota serve as a link for the pathogenesis?

Schizophrenia (SZ) places a tremendous burden on public health as one of the leading causes of disability and death. SZ patients are more prone to developing obesity than the general population from the clinical practice. The development of obesity frequently causes poor psychiatric outcomes in SZ patients. In turn, maternal obesity during pregnancy has been associated with an increased risk of SZ in offspring, suggesting that these two disorders may have shared neuropathological mechanisms. The gut microbiota is well known to serve as a major regulator of bidirectional interactions between the central nervous system and the gastrointestinal tract. It also plays a critical role in maintaining physical and mental health in humans. Recent studies have shown that the dysbiosis of gut microbiota is intimately associated with the onset of SZ and obesity through shared pathophysiological mechanisms, particularly the stimulation of immune inflammation. Therefore, gut microbiota may serve as a common biological basis for the etiology in both SZ and obesity, and the perturbed gut-brain axis may therefore account for the high prevalence of obesity in patients with SZ. On the basis of these findings, this review provides updated perspectives and intervention approaches on the etiology, prevention, and management of obesity in SZ patients by summarizing the recent findings on the role of gut microbiota in the pathogenesis of SZ and obesity, highlighting the role of gut-derived inflammation.

Effects of dragon fruit oligosaccharides on immunity, gut microbiome, and their metabolites in healthy adults – a randomized double-blind placebo controlled study

Healthy food has wide popularity and relates positively to health. Our previous studies have shown that dragon fruit oligosaccharides (DFO) have prebiotic activities, balancing the gut microbiota in a simulated human colon system, and are safe and stimulate the immune system in rats. The effects of DFO on immune stimulation gut microbe modulation and the correlation of gut microbiota and nutrients were investigated in a human trial. This clinical study was a randomized, double-blinded, placebo-controlled trial. The participants were 107 healthy adults, divided into 3 groups that received DFO in drinking waterdoses of 4 and 8 g/day, compared to the placebo group for 4 consecutive weeks. DFO consumption at 4 g/day increased IgA level (11.31 mg/dL or 10.95% from baseline) and 8 g/day outstandingly promoted the growth of Bifidobacterium spp. (8.41%) and Faecalibacterium (1.99%) and decreased harmful bacteria, especially, Escherichia coli (8.44%). The relationship between gut microbes and nutrient intake was explored and significant (p < 0.05) correlations between specific microbial groups and intakes of specific macro- and micronutrients were observed. The potential dose of DFO for healthy adults was established as 4 g/day for improving IgA level and 8 g/day for promoting beneficial gut microbiota.

Role of Bifidobacterium spp. intake in improving depressive mood and well-being and its link to kynurenine blood level: an interventional study

OBJECTIVES

Evidence for the contribution of the brain-gut-microbiota axis to the depression pathophysiology is increasing nowadays. Disturbed gut microbiota equilibrium along with bad dietary habits both lead to kynurenine pathway abnormalities contributing to the depression pathophysiology. In this respect, many studies are found but the interventional clinical trials are limited. The present interventional study aims to evaluate the impact of Bifidobacterium spp. supplementation together with improving dietary intake on depressive mood and well-being and their correlation with kynurenine blood level in adult Egyptian healthy volunteers.

METHODS

A number of 98 healthy female volunteers with a mean age of 46.96 ± 1.82 years were selected and enrolled in this study. They were given yogurt enriched with Bifidobacterium spp. daily for eight weeks. Clinical examination as well as questionnaires for the evaluation of psychological well-being and depression were done at base line and after eight weeks of intervention. Fasting blood samples and stool samples were collected from all subjects at baseline and eight weeks after the intervention for the investigation of serum kynurenine concentration, blood hemoglobin, serum transaminases (ALT & AST) serum urea and creatinine as well as fecal Bifidobacterium count.

RESULTS

Data revealed that both depression and well-being showed highly significant improvement combined with significant drop in kynurenine blood level after intervention. Also, a significant rise in fecal Bifidobacterium count and a significant improvement in hemoglobin level and activity of liver enzymes were recorded. After intervention, a significant negative correlation was recorded between depression and fecal Bifidobacterium count as well as between serum kynurenine level, and well-being.

CONCLUSION

Bifidobacterium spp. supplementation combined with improvement in dietary intake resulted in improvement of depressive mood and well-being and reduced kynurenine blood level.

Cross-sectional evaluation of gut microbial-host cometabolites in patients with chronic pancreatitis

OBJECTIVES

Gut bacteria facilitate nutrient metabolism and generate small molecules that form part of the broader "metabolome". It is unclear whether these metabolites are disturbed in chronic pancreatitis (CP). This study aimed to evaluate the gut microbial-host cometabolites and their relationship in patients with CP.

METHODS

Fecal samples were collected from 40 patients with CP and 38 healthy family members. Each sample was examined with 16S rRNA gene profiling and gas chromatography time-of-flight mass spectrometry to estimate the relative abundances of specific bacterial taxa between the two groups and to profile any changes in the metabolome, respectively. Correlation analysis was used to evaluate the differences in metabolites and gut microbiota between the two groups.

RESULTS

The abundance of Actinobacteria was lower at the phylum level, and that of Bifidobacterium was lower at the genus level in the CP group. Eighteen metabolites had significantly different abundances and the concentrations of 13 metabolites were significantly different between the two groups. Oxoadipic acid and citric acid levels were positively correlated with Bifidobacterium abundance (r = 0.306 and 0.330, respectively, both P < 0.05), while the 3-methylindole concentration was negatively correlated with Bifidobacterium abundance (r = -0.252, P = 0.026) in CP.

CONCLUSIONS

Gut microbiome and host microbiome metabolic products might be altered in patients with CP. Evaluating gastrointestinal metabolite levels may further enhance our understanding of the pathogenesis and/or progression of CP.

Differences in dietary patterns related to metabolic health by gut microbial enterotypes of Korean adults

Diet has a profound impact on the progression of metabolic syndrome (MetS) into various diseases. The gut microbiota could modulate the effect of diet on metabolic health. We examined whether dietary patterns related to MetS differed according to gut microbial enterotypes among 348 Korean adults aged 18-60 years recruited between 2018∼2021 in a cross-sectional study. The enterotype of each participant was identified based on 16S rRNA gut microbiota data. The main dietary pattern predicting MetS (MetS-DP) of each enterotype was derived using reduced-rank regression (RRR) models. In the RRR models, 27 food group intakes assessed by a semi-quantitative food frequency questionnaire and MetS prediction markers including triglyceride to high-density lipoprotein cholesterol (TG/HDL) ratio and homeostatic model assessment for insulin resistance (HOMA-IR) were used as predictor and response variables, respectively. The MetS-DP extracted in Bacteroides enterotype (B-type) was characterized by high consumption of refined white rice and low consumption of eggs, vegetables, and mushrooms. The MetS-DP derived among Prevotella enterotype (P-type) was characterized by a high intake of sugary food and low intakes of bread, fermented legumes, and fermented vegetables. The MetS-DP of B-type was positively associated with metabolic unhealthy status (OR T3 vs. T1 = 3.5; 95% CI = 1.5-8.2), comparing the highest tertile to the lowest tertile. Although it was not significantly associated with overall metabolic unhealthy status, the MetS-DP of P-type was positively associated with hyperglycemia risk (OR T3 vs. T1 = 6.2; 95% CI = 1.6-24.3). These results suggest that MetS-DP may differ according to the gut microbial enterotype of each individual. If such associations are found to be causal, personalized nutrition guidelines based on the enterotypes could be recommended to prevent MetS.

Deducing the Interplay Between Gut Flora and Respiratory Diseases: A New Therapeutic Strategy?

The gastrointestinal system, also referred to as the gut, is a universe that colonizes trillions of microbes. In addition to its digestive functions, the gut represents a biosystem that determines all the health vectors. It is now recognized as one of the body's defense systems, and good gut health regulates the body's immune responses. Disturbance of this barrier can trigger many diseases, including respiratory tract infections, as there is a close correlation between the gut microbiome and the chances of triggering illness. This review investigates the various factors affecting the gut microbiome, the diseases that can result from the dysregulation of the same, and their molecular mechanisms. The most basic solution to tackle this problem is to maintain the gut microbiome at the desired level. Timely diagnosis and interventions are needed for the proper management of the ensuing conditions. It is important to address the effects of factors on the gut microbiome and thereby regulate this level. The study also found that dysregulation in the system can lead to various diseases such as asthma, COPD, lung cancer following their respective pathways. In short, this paper reinforces the importance of the gut microbiome, the need to maintain its average level, and the need for proper interventions to treat the consequences. The manuscript posit that medications, diet as well and good physiological conditions of the human body can alter the microbiome and can ward off respiratory infections.

Isomaltooligosaccharides Sustain the Growth of Prevotella Both In Vitro and in Animal Models

The human digestive tract is colonized by trillions of bacterial cells that play important roles in human health and diseases. It is well known that dietary habits are associated with human microbiota enterotypes. However, the factors that determine the enterotype still remain elusive. In this study, it was first examined, via in vitro batch fermentation, how different carbohydrates affect the Bacteroides and Prevotella enterotypes. Among the 11 substrates (fructo-, galacto-, xylo-, manno-, and isomalto-oligosaccharides [IMO] and lactulose, raffinose, starch, inulin [INU], mannitol, and xylitol) tested, IMO, INU, and starch were found to sustain the growth of Prevotella through batch fermentation. The development of the Prevotella and Bacteroides enterotypes was further simulated in chemostats using fecal samples. IMO coupled with faster dilution rates and lower pH were required to sustain the growth of Prevotella copri in the chemostat based on 16S rRNA gene and metagenomic sequencing. Meanwhile, starch with relatively lower dilution rates and higher pH was required to support the development of the Bacteroides enterotype. Amylo-α-1,6-glucosidase, pectin, and xylan lyases were the carbohydrate-active enzymes associated with the Prevotella enterotype. The Bacteroides enterotype was associated with more diversified carbohydrate-active enzymes. Consistently, since honey contains high isomaltose content, mice fed IMO and honey displayed an increased relative abundance of Prevotella in the colon. In conclusion, both in vitro systems and a mouse model were used to demonstrate that IMO maintains the Prevotella enterotype. This result provides insight into the nutritional requirements underlying gut enterotype formation. IMPORTANCE The Prevotella enterotype type is a human traditional enterotype with high dietary fiber intake, which is related to healthy ageing and Parkinson's disease development. Manipulations of the dwelled gut microbes by dietary isomalto-oligosaccharides efficiently sustained Prevotella type enterotypes, indicating that it can be used in the improvement of elderly health by increasing the gut transit time.

Characteristics of gut microbiota and fecal metabolomes in patients with celiac disease in Northwest China

Celiac disease (CD) is an autoimmune small bowel disease. The pattern of gut microbiota is closely related to dietary habits, genetic background, and geographical factors. There is a lack of research on CD-related gut microbiota in China. This study aimed to use 16S rDNA sequencing and metabolomics to analyze the fecal microbial composition and metabolome characteristics in patients diagnosed with CD in Northwest China, and to screen potential biomarkers that could be used for its diagnosis. A significant difference in the gut microbiota composition was observed between the CD and healthy controls groups. At the genus level, the abundance of Streptococcus, Lactobacillus, Veillonella, and Allisonella communities in the CD group were increased (Q < 0.05). Furthermore, the abundance of Ruminococcus, Faecalibacterium, Blautia, Gemmiger, and Anaerostipes community in this group were decreased (Q < 0.05). A total of 222 different fecal metabolites were identified in the two groups, suggesting that CD patients have a one-carbon metabolism defect. Four species of bacteria and six metabolites were selected as potential biomarkers using a random forest model. Correlation analysis showed that changes in the gut microbiota were significantly correlated with changes in fecal metabolite levels. In conclusion, the patterns of distribution of gut microbiota and metabolomics in patients with CD in Northwest China were found to be unique to these individuals. This has opened up a new way to explore potential beneficial effects of supplementing specific nutrients and potential diagnostic and therapeutic targets in the future.

Impact of Daily Consumption of Whole-Grain Quinoa-Enriched Bread on Gut Microbiome in Males

Diets rich in whole grains are associated with improved health and a lower risk of non-communicable diseases, but the mechanisms through which these health benefits are conveyed are uncertain. One mechanism may be improvements in the gut environment by the delivery of fermentable substrates and associated phytochemicals to the lower gut and modification of the gut microbiome. Quinoa is included in the whole-grain category because of its structural similarities to cereals but the effects of its consumption on the gut microbiome have not been investigated to date. Our aim was to examine the impact of daily quinoa consumption on the gut microbiome in a 4-week randomised cross-over intervention separated by a 4-week wash-out period involving 28 adult males. Participants consumed either a quinoa-enriched wheat-bread roll providing 20 g quinoa flour each day, or a control wheat-only bread roll. Stool samples were collected in sterile collection tubes immediately before and at the end of each intervention period. DNA was then extracted, and the 16S rRNA V4 region of extracted DNA was amplified and sequenced. For both the control and quinoa bread periods, there were no changes at the phyla or genus level between baseline and week 4 (all p > 0.05). Diversity in the microbiome profile was not different from baseline after either intervention arms. The results show that small changes in the type of cereal consumed—substituting 20 g of refined wheat flour with whole-grain quinoa flour—was not able to significantly modulate the gut microbiome. Further studies with higher levels of quinoa or longer exposure periods are needed to ascertain if there is a dose−response effect of quinoa, and if these effects are able to translate into clinical outcomes.

Effects of Fermented Bamboo Powder Supplementation on Serum Biochemical Parameters, Immune Indices, and Fecal Microbial Composition in Growing-Finishing Pigs

This experiment aimed to investigate the effects of fermented bamboo powder (FBP) on the growth performance, serum biochemical parameters, immunoglobulins and inflammatory cytokines, and fecal microbial composition of growing−finishing pigs. A total of 108 barrows (initial body weight, 56.30 ± 0.55 kg) were randomly allocated to three dietary treatments in a 75 d trial, including a control (CON) diet and two FBP supplementation diets. The CON diet was formulated to three-phase diets according to the body weight of pigs, and the FBP diets were formulated used 5.00% (FBP1) or 10.00% (FBP2) FBP to replace the wheat bran in the CON diet, respectively. The results showed that there were no influences on growth performances between the CON diet and FBP addition diets, whereas the 5% FBP addition decreased the feed:gain of pigs compared to the pigs fed the FBP2 diet from d 0−75 (p < 0.05). Meanwhile, the FBP addition increased the high-density lipoprotein cholesterol (HDLC) and immunoglobulin A (IgA) content in serum (linear, p < 0.05), and pigs fed the FBP1 diet had greater HDLC and IgA contents in serum than those in the pigs fed the CON diet (p < 0.05). Microbial analysis showed that the FBP addition diets decreased the abundance of Spirochaetes, and the FBP2 diet increased the abundance of Firmicutes more than the CON diet (p < 0.05). In addition, the pigs fed the FBP2 diet increased the abundance of uncultured_bacterium_f_Lachnospiraceae, Ruminococcaceae_UCG-005, Prevotellaceae_UCG-003, Lachnospiraceae_XPB1014_group, and Lactobacillus more than the CON group (p < 0.05). In conclusion, the FBP supplementation to the diet had no negative effects on the growth performance and exerted beneficial effects on promoting serum biochemical and immune indices, as well as modulating the fecal microbiota of pigs. Therefore, these results showed that the fermented bamboo powder could be one potential fiber-rich ingredient for growing−finishing pigs, and that the recommended addition proportion in the growing−finishing pigs’ diet is 5%.

Gut microbial response to host metabolic phenotypes

A large number of studies have proved that biological metabolic phenotypes exist objectively and are gradually recognized by humans. Gut microbes affect the host's metabolic phenotype. They directly or indirectly participate in host metabolism, physiology and immunity through changes in population structure, metabolite differences, signal transduction and gene expression. Obtaining comprehensive information and specific identification factors associated with gut microbiota and host metabolic phenotypes has become the focus of research in the field of gut microbes, and it has become possible to find new and effective ways to prevent or treat host metabolic diseases. In the future, precise treatment of gut microbes will become one of the new therapeutic strategies. This article reviews the content of gut microbes and carbohydrate, amino acid, lipid and nucleic acid metabolic phenotypes, including metabolic intermediates, mechanisms of action, latest research findings and treatment strategies, which will help to understand the relationship between gut microbes and host metabolic phenotypes and the current research status.

Assessment of Energy and Nutrient Intake and the Intestinal Microbiome (ErNst study): Protocol and Methods of a Cross-sectional Human Observational Study (Preprint)

BACKGROUND

On the national level, nutritional monitoring requires the assessment of reliable representative dietary intake data. To achieve this, standardized tools need to be developed, validated, and kept up-to-date with recent developments in food products and the nutritional behavior of the population. Recently, the human intestinal microbiome has been identified as an essential mediator between nutrition and host health. Despite growing interest in this connection, only a few associations between the microbiome, nutrition, and health have been clearly established. Available studies paint an inconsistent picture, partly due to a lack of standardization.

OBJECTIVE

First, we aim to verify if food consumption, as well as energy and nutrient intake of the German population, can be recorded validly by means of the dietary recall software GloboDiet, which will be applied in the German National Nutrition Monitoring. Second, we aim to obtain high-quality data using standard methods on the microbiome, combined with dietary intake data and additional fecal sample material, and to also assess the functional activity of the microbiome by measuring microbial metabolites.

METHODS

Healthy female and male participants aged between 18 and 79 years were recruited. Anthropometric measurements included body height and weight, BMI, and bioelectrical impedance analysis. For validation of the GloboDiet software, current food consumption was assessed with a 24-hour recall. Nitrogen and potassium concentrations were measured from 24-hour urine collections to enable comparison with the intake of protein and potassium estimated by the GloboDiet software. Physical activity was measured over at least 24 hours using a wearable accelerometer to validate the estimated energy intake. Stool samples were collected in duplicate for a single time point and used for DNA isolation and subsequent amplification and sequencing of the 16S rRNA gene to determine microbiome composition. For the identification of associations between nutrition and the microbiome, the habitual diet was determined using a food frequency questionnaire covering 30 days.

RESULTS

In total, 117 participants met the inclusion criteria. The study population was equally distributed between the sexes and 3 age groups (18-39, 40-59, and 60-79 years). Stool samples accompanying habitual diet data (30-day food frequency questionnaire) are available for 106 participants. Current diet data and 24-hour urine samples for the validation of GloboDiet are available for 109 participants, of which 82 cases also include physical activity data.

CONCLUSIONS

We completed the recruitment and sample collection of the ErNst study with a high degree of standardization. Samples and data will be used to validate the GloboDiet software for the German National Nutrition Monitoring and to compare microbiome composition and nutritional patterns.

TRIAL REGISTRATION

German Register of Clinical Studies DRKS00015216; https://drks.de/search/de/trial/DRKS00015216.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/42529.

Sirtfoods: New Concept Foods, Functions, and Mechanisms

Sirtfood is a new concept food that compounds diets that can target sirtuins (SIRTs). SIRTs are nicotinamide adenine dinucleotide (NAD⁺)-dependent deacylases and ADP-ribosyltransferases (enzymes). SIRTs are mediators of calorie restriction (CR) and their activation can achieve some effects similar to CR. SIRTs play essential roles in ameliorating obesity and age-related metabolic diseases. Food ingredients such as resveratrol, piceatannol, anthocyanidin, and quinine are potential modulators of SIRTs. SIRT modulators are involved in autophagy, apoptosis, aging, inflammation, and energy homeostasis. Sirtfood proponents believe that natural Sirtfood recipes exert significant health effects.

Diet, microbiota, and the mucus layer: The guardians of our health

The intestinal tract is an ecosystem in which the resident microbiota lives in symbiosis with its host. This symbiotic relationship is key to maintaining overall health, with dietary habits of the host representing one of the main external factors shaping the microbiome-host relationship. Diets high in fiber and low in fat and sugars, as opposed to Western and high-fat diets, have been shown to have a beneficial effect on intestinal health by promoting the growth of beneficial bacteria, improve mucus barrier function and immune tolerance, while inhibiting pro-inflammatory responses and their downstream effects. On the contrary, diets low in fiber and high in fat and sugars have been associated with alterations in microbiota composition/functionality and the subsequent development of chronic diseases such as food allergies, inflammatory bowel disease, and metabolic disease. In this review, we provided an updated overview of the current understanding of the connection between diet, microbiota, and health, with a special focus on the role of Western and high-fat diets in shaping intestinal homeostasis by modulating the gut microbiota.

Knowledge of fermentation and health benefits among general population in North-eastern Slovenia

Background

Fermented foods are staples of the human diet and fermentation process has been used by humans for thousands of years. The preparation of fermented foods was performed in the past without knowledge of the role of microorganisms involved. Nowadays, fermented foods, due to their proclaimed health benefits for consumers, are becoming increasingly popular. Our study was constructed to provide data on awareness and use of fermented foods among people in North-eastern Slovenia.

Methods

The cross-sectional study included 349 individuals (16–89 years of age). An online survey was designed to assess the participants' knowledge of fermentation, fermented foods, the consumption of fermented foods and awareness of the health benefits. Data were collected from March to June 2021 and analyzed using IBM SPSS 27.0.

Results

Compared with the youngest participants (< 21 years) knowledge of fermentation was higher in older individuals (p < 0.001). More than a half of the participants recognized the role of lactic acid bacteria and yeasts in fermentation process, however, only 18.3% of participants were aware of the role of the molds. Only 25.9% of the participants have become acquainted with fermented foods at home and 62.2% of them were aware of health benefits of fermented foods, but mostly on gastrointestinal health and the immune system.

Conclusions

As people today live predominantly in urban areas and incline towards westernized foods, they often lack the knowledge of fermentation and awareness regarding the nutritional value of fermented foods and their preparation. Steps should be taken to educate younger generations regarding the health benefits of fermented foods especially considering that most of them expressed their interest in learning more about the process.

Stability and volatility shape the gut bacteriome and Kazachstania slooffiae dynamics in preweaning, nursery and adult pigs

The gut microbiome plays important roles in the maintenance of health and pathogenesis of diseases in the growing host. In order to fully comprehend the interplay of the gut microbiome and host, a foundational understanding of longitudinal microbiome, including bacteria and fungi, development is necessary. In this study, we evaluated enteric microbiome and host dynamics throughout the lifetime of commercial swine. We collected a total of 234 fecal samples from ten pigs across 31 time points in three developmental stages (5 preweaning, 15 nursery, and 11 growth adult). We then performed 16S rRNA gene amplicon sequencing for bacterial profiles and qPCR for the fungus Kazachstania slooffiae. We identified distinct bacteriome clustering according to the host developmental stage, with the preweaning stage exhibiting low bacterial diversity and high volatility amongst samples. We further identified clusters of bacteria that were considered core, increasing, decreasing or stage-associated throughout the host lifetime. Kazachstania slooffiae was absent in the preweaning stage but peaked during the nursery stage of the host. We determined that all host growth stages contained negative correlations between K. slooffiae and bacterial genera, with only the growth adult stage containing positive correlates. Our stage-associated bacteriome results suggested the neonate contained a volatile gut microbiome. Upon weaning, the microbiome became relatively established with comparatively fewer perturbations in microbiome composition. Differential analysis indicated bacteria might play distinct stage-associated roles in metabolism and pathogenesis. The lack of positive correlates and shared K. slooffiae-bacteria interactions between stages warranted future research into the interactions amongst these kingdoms for host health. This research is foundational for understanding how bacteria and fungi develop singularly, as well as within a complex ecosystem in the host's gut environment.

Digestive Tract Morphology and Gut Microbiota Jointly Determine an Efficient Digestive Strategy in Subterranean Rodents: Plateau Zokor

Simple Summary

Investigation of mechanistic insights of digestive strategies in rodents can be difficult, but it is important to understand how rodents adapt to different environments. Applying physiological analyses to compare the differences between digestive tracts in plateau zokor and laboratory rats, we found that the length and weight of the digestive tract of the plateau zokor was significantly greater than the laboratory rat. Particularly, the weight and length of the large intestine and cecum in plateau zokor is three times that of the laboratory rat. Our gut microbiota analysis results showed that bacteria associated with cellulose degradation were significantly enriched in laboratory rats, when compared to plateau zokor. However, both plateau zokor and laboratory rats were predicted to share the same functions in carbohydrate metabolism and energy metabolism. Our findings suggest that both the morphology of the digestive tract and gut microbiota are vital to the digestion in wild rodents.

Abstract

Rodents’ lifestyles vary in different environments, and to adapt to various lifestyles specific digestion strategies have been developed. Among these strategies, the morphology of the digestive tracts and the gut microbiota are considered to play the most important roles in such adaptations. However, how subterranean rodents adapt to extreme environments through regulating gut microbial diversity and morphology of the digestive tract has yet to be fully studied. Here, we conducted the comparisons of the gastrointestinal morphology, food intake, food assimilation, food digestibility and gut microbiota of plateau zokor Eospalax baileyi in Qinghai-Tibet Plateau and laboratory rats Rattus norvegicus to further understand the survival strategy in a typical subterranean rodent species endemic to the Qinghai-Tibet Plateau. Our results revealed that plateau zokor evolved an efficient foraging strategy with low food intake, high food digestibility, and ultimately achieved a similar amount of food assimilation to laboratory rats. The length and weight of the digestive tract of the plateau zokor was significantly higher than the laboratory rat. Particularly, the weight and length of the large intestine and cecum in plateau zokor is three times greater than that of the laboratory rat. Microbiome analysis showed that genus (i.e., Prevotella, Oscillospira, CF231, Ruminococcus and Bacteroides), which are usually associated with cellulose degradation, were significantly enriched in laboratory rats, compared to plateau zokor. However, prediction of metagenomic function revealed that both plateau zokor and laboratory rats shared the same functions in carbohydrate metabolism and energy metabolism. The higher digestibility of crude fiber in plateau zokor was mainly driven by the sizes of cecum and cecum tract, as well as those gut microbiota which associated with cellulose degradation. Altogether, our results highlight that both gut microbiota and the morphology of the digestive tract are vital to the digestion in wild rodents.

Effect of a reduced fat and sugar maternal dietary intervention during lactation on the infant gut microbiome

Objective

A growing body of literature has shown that maternal diet during pregnancy is associated with infant gut bacterial composition. However, whether maternal diet during lactation affects the exclusively breastfed infant gut microbiome remains understudied. This study sets out to determine whether a two-week of a reduced fat and sugar maternal dietary intervention during lactation is associated with changes in the infant gut microbiome composition and function.

Design

Stool samples were collected from four female and six male (n = 10) infants immediately before and after the intervention. Maternal baseline diet from healthy mothers aged 22–37 was assessed using 24-h dietary recall. During the 2-week dietary intervention, mothers were provided with meals and their dietary intake was calculated using FoodWorks 10 Software. Shotgun metagenomic sequencing was used to characterize the infant gut microbiome composition and function.

Results

In all but one participant, maternal fat and sugar intake during the intervention were significantly lower than at baseline. The functional capacity of the infant gut microbiome was significantly altered by the intervention, with increased levels of genes associated with 28 bacterial metabolic pathways involved in biosynthesis of vitamins (p = 0.003), amino acids (p = 0.005), carbohydrates (p = 0.01), and fatty acids and lipids (p = 0.01). Although the dietary intervention did not affect the bacterial composition of the infant gut microbiome, relative difference in maternal fiber intake was positively associated with increased abundance of genes involved in biosynthesis of storage compounds (p = 0.016), such as cyanophycin. Relative difference in maternal protein intake was negatively associated with Veillonella parvula (p = 0.006), while positively associated with Klebsiella michiganensis (p = 0.047). Relative difference in maternal sugar intake was positively associated with Lactobacillus paracasei (p = 0.022). Relative difference in maternal fat intake was positively associated with genes involved in the biosynthesis of storage compounds (p = 0.015), fatty acid and lipid (p = 0.039), and metabolic regulator (p = 0.038) metabolic pathways.

Conclusion

This pilot study demonstrates that a short-term maternal dietary intervention during lactation can significantly alter the functional potential, but not bacterial taxonomy, of the breastfed infant gut microbiome. While the overall diet itself was not able to change the composition of the infant gut microbiome, changes in intakes of maternal protein and sugar during lactation were correlated with changes in the relative abundances of certain bacterial species.

Clinical trial registration: Australian New Zealand Clinical Trials Registry (ACTRN12619000606189).

Food for healthier aging: power on your plate

Inflammageing is a persistent low-level inflammatory burden that accompanies age-related dysregulation of the immune system during normative aging and within the diseasome of aging. A healthy diet containing a balanced amount of macronutrients, vitamins and minerals, adequate in calories and rich in poly(phenols), has an essential role in mitigating the effects of inflammageing and extending healthspan through modulation of the activity of a range of factors. These include transcription factors, such as nuclear factor erythroid-derived 2 related factor 2 (Nrf2) and nuclear factor-κB (NF-kB), the inflammasome and the activities of the gut microbiota. The aim of this narrative review is to discuss the potential of food to ameliorate the effects of the diseasome of aging.

Effects of Resveratrol Administration in Liver Injury Prevention as Induced by an Obesogenic Diet: Role of Ruminococcaceae

Gut microbiota dysbiosis has been described in several metabolic disruptions, such as non-alcoholic fatty liver disease (NAFLD). Administration of resveratrol has been claimed to elicit benefits against NAFLD along with modulating gut microbiota composition. This investigation aims to study the putative mediating role of gut microbiota in the potential hepato-protective effects of resveratrol in a diet-induced NAFLD rat model. The involvement of bacteria from the Ruminococcaceae family in such effects was also addressed. Resveratrol administration resulted in lowered liver weight and serum total and non-HDL cholesterol concentrations, as well as in increased serum HDL cholesterol levels. The administration of this polyphenol also prevented obesogenic diet-induced serum transaminase increases. In addition, histopathological analysis revealed that resveratrol administration ameliorated the dietary-induced liver steatosis and hepatic inflammation. Gut microbiota sequencing showed an inverse relationship between some bacteria from the Ruminococcaceae family and the screened hepatic markers, whereas in other cases the opposite relationship was also found. Interestingly, an interaction was found between UBA-1819 abundance and resveratrol induced liver weight decrease, suggesting that for this marker resveratrol induced effects were greater when the abundance of this bacteria was high, while no actions were found when UBA-1819 abundance was low.

Altered Gut Microbiota in Patients With Peutz-Jeghers Syndrome

BACKGROUND

Peutz-Jeghers syndrome (PJS) is a rare genetic disorder characterized by the development of pigmented spots and gastrointestinal polyps and increased susceptibility to cancers. It remains unknown whether gut microbiota dysbiosis is linked to PJS.

AIM

This study aimed to assess the structure and composition of the gut microbiota, including both bacteria and fungi, in patients with PJS and investigate the relationship between gut microbiota dysbiosis and PJS pathogenesis.

METHODS

The bacterial and fungal composition of the fecal microbiota was analyzed in 23 patients with PJS (cases), 17 first-degree asymptomatic relatives (ARs), and 24 healthy controls (HCs) using 16S (MiSeq) and ITS2 (pyrosequencing) sequencing for bacteria and fungi, respectively. Differential analyses of the intestinal flora were performed from the phylum to species level.

RESULTS

Alpha-diversity distributions of bacteria and fungi indicated that the abundance of both taxa differed between PJS cases and controls. However, while the diversity and composition of fecal bacteria in PJS cases were significantly different from those in ARs and HCs, fungal flora was more stable. High-throughput sequencing confirmed the special characteristics and biodiversity of the fecal bacterial and fungal microflora in patients with PJS. They had lower bacterial biodiversity than controls, with a higher frequency of the Proteobacteria phylum, Enterobacteriaceae family, and Escherichia-Shigella genus, and a lower frequency of the Firmicutes phylum and the Lachnospiraceae and Ruminococcaceae families. Of fungi, Candida was significantly higher in PJS cases than in controls.

CONCLUSION

The findings reported here confirm gut microbiota dysbiosis in patients with PJS. This is the first report on the bacterial and fungal microbiota profile of subjects with PJS, which may be meaningful to provide a structural basis for further research on intestinal microecology in PJS.

The Tissue-Associated Microbiota in Colorectal Cancer: A Systematic Review

Simple Summary

Growing evidence shows a close relationship between the microbiome and colorectal cancer, but most studies analyze fecal samples. However, solid information on the microbial community that is present locally in the intestinal tumor tissues is lacking. Therefore, the aim of this systematic review was to compile evidence on the relationship between tissue-associated microbiota and colorectal cancer. Among 5080 screened publications, 39 were eligible and included in the analysis. Despite the heterogeneity in methodologies and reporting between studies, 12 groups of bacteria with strong positive and 18 groups of bacteria with strong negative associations with colorectal cancer were identified. Such knowledge may ultimately be used in novel strategies that aim to prevent, detect, and treat colorectal cancer in the upcoming years.

Abstract

The intestinal microbiome is associated with colorectal cancer. Although the mucosal microbiota better represents an individual’s local microbiome, studies on the colorectal cancer microbiota mainly reflect knowledge obtained from fecal samples. This systematic review aimed to summarize the current evidence on the relationship between the mucosal-associated bacterial microbiota and colorectal cancer. Searches were conducted in PubMed and Web of Science databases for publications comparing the mucosal microbiome of colorectal cancer patients with that of healthy controls, or with that of non-cancerous mucosal tissues. The primary outcomes were differences in microbial diversity and taxonomy. The Newcastle-Ottawa Scale was used to assess the quality of the included studies. Of the 5080 studies identified, 39 were eligible and included in the systematic review. No consistent results were identified for the α- and β-diversity, due to high heterogeneity in reporting and to differences in metrics and statistical approaches, limiting study comparability. Qualitative synthesis of microbial taxonomy identified 12 taxa with strong positive and 18 taxa with strong negative associations with colorectal cancer. Fusobacterium, Campylobacter, Parvimonas, Peptostreptococcus, Streptococcus, and Granulicatella were defined as enriched in colorectal cancer. Despite the methodological limitations of the studies, consistent evidence on bacterial taxa associated with colorectal cancer was identified. Prospective studies in large and well-characterized patient populations will be crucial to validate these findings.

Comparative Analysis of Gut Microbial Composition and Functions in Przewalski's Gazelle (Procapra przewalskii) From Various Habitats

Gut microbiota of mammals participates in host nutrient metabolism and plays an important role in host adaptation to the environment. Herein, to understand the relationship between environment differences and the composition and abundance of the gut microbiota of Przewalski's gazelle (Procapra przewalskii) in almost all its habitats, high throughput sequencing of the 16S rRNA gene was used to compared the characteristics of the gut microbiota based on total 120 fecal samples. The results showed that Przewalski's gazelle exhibited different characteristics of microbiota diversity in different habitats. The Jiangxigou Rescue Station (JX), Nongchang (NC), and Ganzihe and Haergai townships (GH) groups had a relatively high microbiota diversity, while the Niaodao scenic area (ND) group had the lowest diversity. This finding seemed to follow a similar pattern of change in the population of Przewalski's gazelle. Bacteroidetes and Actinobacteria were the phyla with significant differences, especially between the Wayu township (WY) and the other groups. The difference in the microbiota mainly included the Ruminococcaceae UCG-005, Christensenellaceae R-7 group, and Bacteroidaceae and was enriched in the ND, WY, and other regions. We speculated that the difference in the gut microbiota was due to a difference in environmental characteristics, particularly the food resources that the host can obtain. We speculated that a similar microbiome has important functions for species survival and represents the evolutionary commonality of Przewalski's gazelle, while a different microbiome plays an important role in the adaptation of Przewalski's gazelle to a different environment. The results of this study illustrate how the same species adapts to different environments from the perspective of gut microbiota plasticity and therefore are of great significance for the protection and restoration of the population of this species.

An Infancy-Onset 20-Year Dietary Counselling Intervention and Gut Microbiota Composition in Adulthood

The randomized controlled Special Turku Coronary Risk Factor Intervention Project (STRIP) has completed a 20-year infancy-onset dietary counselling intervention to reduce exposure to atherosclerotic cardiovascular disease risk factors via promotion of a heart-healthy diet. The counselling on, e.g., low intake of saturated fat and cholesterol and promotion of fruit, vegetable, and whole-grain consumption has affected the dietary characteristics of the intervention participants. By leveraging this unique cohort, we further investigated whether this long-term dietary intervention affected the gut microbiota bacterial profile six years after the intervention ceased. Our sub-study comprised 357 individuals aged 26 years (intervention n = 174, control n = 183), whose gut microbiota were profiled using 16S rRNA amplicon sequencing. We observed no differences in microbiota profiles between the intervention and control groups. However, out of the 77 detected microbial genera, the Veillonella genus was more abundant in the intervention group compared to the controls (log2 fold-change 1.58, p < 0.001) after adjusting for multiple comparison. In addition, an association between the study group and overall gut microbiota profile was found only in males. The subtle differences in gut microbiota abundances observed in this unique intervention setting suggest that long-term dietary counselling reflecting dietary guidelines may be associated with alterations in gut microbiota.

Gut microbiota is associated with dietary intake and metabolic markers in healthy individuals

Background

Metabolic diseases have been related to gut microbiota, and new knowledge indicates that diet impacts host metabolism through the gut microbiota. Identifying specific gut bacteria associated with both diet and metabolic risk markers may be a potential strategy for future dietary disease prevention. However, studies investigating the association between the gut microbiota, diet, and metabolic markers in healthy individuals are scarce.

Objective

We explored the relationship between a panel of gut bacteria, dietary intake, and metabolic and anthropometric markers in healthy adults.

Design

Forty-nine volunteers were included in this cross-sectional study. Measures of glucose, serum triglyceride, total cholesterol, hemoglobin A1c (HbA1c), blood pressure (BP), and body mass index (BMI) were collected after an overnight fast, in addition to fecal samples for gut microbiota analyzes using a targeted approach with a panel of 48 bacterial DNA probes and assessment of dietary intake by a Food Frequency Questionnaire (FFQ). Correlations between gut bacteria, dietary intake, and metabolic and anthropometric markers were assessed by Pearson’s correlation. Gut bacteria varying according to dietary intake and metabolic markers were assessed by a linear regression model and adjusted for age, sex, and BMI.

Results

Of the 48 gut bacteria measured, 24 and 16 bacteria correlated significantly with dietary intake and metabolic and/or anthropometric markers, respectively. Gut bacteria including Alistipes, Lactobacillus spp., and Bacteroides stercoris differed according to the intake of the food components, fiber, sodium, saturated fatty acids, and dietary indices, and metabolic markers (BP and total cholesterol) after adjustments. Notably, Bacteroides stercoris correlated positively with the intake of fiber, grain products, and vegetables, and higher Bacteroides stercoris abundance was associated with higher adherence to Healthy Nordic Food Index (HNFI) and lower diastolic BP after adjustment.

Conclusion

Our findings highlight the relationship between the gut microbiota, diet, and metabolic markers in healthy individuals. Further investigations are needed to address whether these findings are causally linked and whether targeting these gut bacteria can prevent metabolic diseases.

Supplementation of Dietary Crude Lentinan Improves the Intestinal Microbiota and Immune Barrier in Rainbow Trout (Oncorhynchus mykiss) Infected by Infectious Hematopoietic Necrosis Virus

The effects of crude lentinan (CLNT) on the intestinal microbiota and the immune barrier were evaluated in rainbow trout (Oncorhynchus mykiss) infected by infectious hematopoietic necrosis virus (IHNV). The results showed that supplementary CLNT declined the rainbow trout mortality caused by IHNV, which suggested that CLNT has preventive effects on IHNV infection. IHNV destroyed intestinal integrity, as well as caused the intestinal oxidative and damage in rainbow trout. Supplementary CLNT significantly strengthened the intestinal immune barrier by declining intestinal permeability, as well as enhancing intestinal antioxidant and anti-inflammatory abilities in IHNV-infected rainbow trout (P<0.05). In addition, CLNT modified the aberrant changes of intestinal microbiota induced by IHNV, mainly represented by promoting the growths of Carnobacterium and Deefgea and inhibiting Mycobacterium and Nannocystis. Especially, supplementing with CLNT significantly promoted the growth of short-chain fatty acid–producing bacteria (P<0.05) and consequently increased the production of acetic acid, butanoic acid, and hexanoic acid in the intestine of IHNV-infected rainbow trout. Furthermore, it was speculated that CLNT could regulate the self-serving metabolic pathways of intestinal microbiota induced by IHNV, such as fatty acid metabolism and amino acid metabolism. Together, CLNT played the antiviral effects on IHNV infection through strengthening the intestinal immune barrier, as well as regulating intestinal microbiota and SCFA metabolism in rainbow trout. The present data revealed that CLNT exerted a promising prebiotic role in preventing the rainbow trout from IHNV infection.

How Diet and Physical Activity Modulate Gut Microbiota: Evidence, and Perspectives

Gut microbiota plays a significant role in the maintenance of physiological homeostasis, contributing to human health. Nevertheless, some factors (sex, age, lifestyle, physical activity, drug-based therapies, diet, etc.) affect its composition and functionality, linked to pathologies and immunological diseases. Concerning diet, it interacts with microorganisms, leading to beneficial or detrimental outcomes for the health of host. On the other hand, physical activity is known to be useful for preventing and, sometimes, treating several diseases of cardiovascular, neuroendocrine, respiratory, and muscular systems. This paper focuses on diet and physical activity presenting the current knowledge about how different diets (Western, ketogenic, vegan, gluten free, Mediterranean) as well as different types of exercise (intensive, endurance, aerobic) could shape gut microbiota.