Gut microbiome and its cofactors are linked to lipoprotein distribution profiles

Increasing evidence indicates that the gut microbiome (GM) plays an important role in the etiology of dyslipidemia. To date, however, no in depth characterization of the associations between GM and its metabolic attributes with deep profiling of lipoproteins distributions (LPD) among healthy individuals has been conducted. To determine associations and contributions of GM composition and its cofactors with distribution profiles of lipoprotein subfractions, we studied blood plasma LPD, fecal short-chain fatty acids (SCFA) and GM of 262 healthy Danish subjects aged 19-89 years. Stratification of LPD segregated subjects into three clusters of profiles that reflected differences in the lipoprotein subclasses, corresponded well with limits of recommended levels of main lipoprotein fractions and were largely explained by host characteristics such as age and body mass index. Higher levels of HDL, particularly driven by large subfractions (HDL2a and HDL2b), were associated with a higher relative abundance of Ruminococcaceae and Christensenellaceae. Increasing levels of total cholesterol and LDL, which were primarily associated with large 1 and 2 subclasses, were positively associated with Lachnospiraceae and Coriobacteriaceae, and negatively with Bacteroidaceae and Bifidobacteriaceae. Metagenome sequencing showed a higher abundance of genes involved in the biosynthesis of multiple B-vitamins and SCFA metabolism among subjects with healthier LPD profiles. Metagenomic assembled genomes (MAGs) affiliated mainly to Eggerthellaceae and Clostridiales were identified as the contributors of these genes and whose relative abundance correlated positively with larger subfractions of HDL. The results of this study demonstrate that remarkable differences in composition and metabolic traits of the GM are associated with variations in LPD among healthy subjects. Findings from this study provide evidence for GM considerations in future research aiming to shade light on mechanisms of the GM - dyslipidemia axis.

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Characterizing the Composition of the Pediatric Gut Microbiome: A Systematic Review

Nutrients ◽

10.3390/nu12010016 ◽

2019 ◽

Vol 12 (1) ◽

pp. 16 ◽

Cited By ~ 3

Author(s):

Kane E. Deering ◽

Amanda Devine ◽

Therese A. O’Sullivan ◽

Johnny Lo ◽

Mary C. Boyce ◽

...

Keyword(s):

Systematic Review ◽

16S Rrna ◽

Relative Abundance ◽

Gut Microbiome ◽

Geographical Location ◽

Short Chain Fatty Acids ◽

16S Rrna Sequencing ◽

Short Chain ◽

Α Diversity ◽

Rrna Sequencing

The consortium of trillions of microorganisms that live inside the human gut are integral to health. Little has been done to collate and characterize the microbiome of children. A systematic review was undertaken to address this gap (PROSPERO ID: CRD42018109599). MEDLINE and EMBASE were searched using the keywords: “healthy preadolescent children” and “gut microbiome” to 31 August 2018. Of the 815 journal articles, 42 met the inclusion criteria. The primary outcome was the relative abundance of bacteria at the phylum, family, and genus taxonomic ranks. α-diversity, short chain fatty acid concentrations, diet, 16S rRNA sequencing region, and geographical location were documented. The preadolescent gut microbiome is dominated at the phylum level by Firmicutes (weighted overall average relative abundance = 51.1%) and Bacteroidetes (36.0%); genus level by Bacteroides (16.0%), Prevotella (8.69%), Faecalibacterium (7.51%), and Bifidobacterium (5.47%). Geographic location and 16S rRNA sequencing region were independently associated with microbial proportions. There was limited consensus between studies that reported α-diversity and short chain fatty acids. Broadly speaking, participants from non-Western locations, who were less likely to follow a Westernized dietary pattern, had higher α-diversity and SCFA concentrations. Confirmatory studies will increase the understanding of the composition and functional capacity of the preadolescent gut microbiome.

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The Gut Microbiome in Hypertension

Circulation Research ◽

10.1161/circresaha.121.318065 ◽

2021 ◽

Vol 128 (7) ◽

pp. 934-950

Author(s):

Ellen G. Avery ◽

Hendrik Bartolomaeus ◽

Andras Maifeld ◽

Lajos Marko ◽

Helge Wiig ◽

...

Keyword(s):

Immune Cells ◽

Gut Microbiome ◽

Short Chain Fatty Acids ◽

The Body ◽

Model Systems ◽

Future Research ◽

Hypertensive Disease ◽

Preclinical Research ◽

Ongoing Research ◽

Diverse Range

The pathogenesis of hypertension is known to involve a diverse range of contributing factors including genetic, environmental, hormonal, hemodynamic and inflammatory forces, to name a few. There is mounting evidence to suggest that the gut microbiome plays an important role in the development and pathogenesis of hypertension. The gastrointestinal tract, which houses the largest compartment of immune cells in the body, represents the intersection of the environment and the host. Accordingly, lifestyle factors shape and are modulated by the microbiome, modifying the risk for hypertensive disease. One well-studied example is the consumption of dietary fibers, which leads to the production of short-chain fatty acids and can contribute to the expansion of anti-inflammatory immune cells, consequently protecting against the progression of hypertension. Dietary interventions such as fasting have also been shown to impact hypertension via the microbiome. Studying the microbiome in hypertensive disease presents a variety of unique challenges to the use of traditional model systems. Integrating microbiome considerations into preclinical research is crucial, and novel strategies to account for reciprocal host-microbiome interactions, such as the wildling mouse model, may provide new opportunities for translation. The intricacies of the role of the microbiome in hypertensive disease is a matter of ongoing research, and there are several technical considerations which should be accounted for moving forward. In this review we provide insights into the host-microbiome interaction and summarize the evidence of its importance in the regulation of blood pressure. Additionally, we provide recommendations for ongoing and future research, such that important insights from the microbiome field at large can be readily integrated in the context of hypertension.

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The Athlete and Gut Microbiome: Short-chain Fatty Acids as Potential Ergogenic Aids for Exercise and Training

International Journal of Sports Medicine ◽

10.1055/a-1524-2095 ◽

2021 ◽

Author(s):

Tindaro Bongiovanni ◽

Marilyn Ong Li Yin ◽

Liam Heaney

Keyword(s):

Fatty Acids ◽

Gut Microbiome ◽

Short Chain Fatty Acids ◽

Short Chain ◽

Future Research ◽

Immune Functions ◽

Additional Energy ◽

Chain Fatty Acids

AbstractShort-chain fatty acids (SCFAs) are metabolites produced in the gut via microbial fermentation of dietary fibers referred to as microbiota-accessible carbohydrates (MACs). Acetate, propionate, and butyrate have been observed to regulate host dietary nutrient metabolism, energy balance, and local and systemic immune functions. In vitro and in vivo experiments have shown links between the presence of bacteria-derived SCFAs and host health through the blunting of inflammatory processes, as well as purported protection from the development of illness associated with respiratory infections. This bank of evidence suggests that SCFAs could be beneficial to enhance the athlete’s immunity, as well as act to improve exercise recovery via anti-inflammatory activity and to provide additional energy substrates for exercise performance. However, the mechanistic basis and applied evidence for these relationships in humans have yet to be fully established. In this narrative review, we explore the existing knowledge of SCFA synthesis and the functional importance of the gut microbiome composition to induce SCFA production. Further, changes in gut microbiota associated with exercise and various dietary MACs are described. Finally, we provide suggestions for future research and practical applications, including how these metabolites could be manipulated through dietary fiber intake to optimize immunity and energy metabolism.

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Current Explorations of Nutrition and the Gut Microbiome: A Systematic Review (P20-032-19)

Current Developments in Nutrition ◽

10.1093/cdn/nzz040.p20-032-19 ◽

2019 ◽

Vol 3 (Supplement_1) ◽

Author(s):

Leigh Frame ◽

Elise Costa ◽

Scott Jackson

Keyword(s):

Systematic Review ◽

Gut Microbiome ◽

Food Additives ◽

Short Chain Fatty Acids ◽

Healthy Adults ◽

Future Research ◽

Intestinal Transit Time ◽

Food Components ◽

Health And Disease

Abstract Objectives The ability to measure and describe the microbiome has led to a surge in information about the gut microbiome and its role in health and disease. The relationship between nutrition and the gut microbiome is central, as the diet is a source of microbiota, a source of fuel for the microbiota, and an indicator of the composition of the gut microbiome. We aim to assess the current understanding of the interactions between nutrition and the gut microbiome in healthy adults. A solid understanding of the interactions between nutrition and a healthy gut microbiome will form the foundation for understanding the role in disease prevention and treatment. Methods PubMed and Google Scholar searches for review articles relating to nutrition and the gut microbiome in healthy adults led to the inclusion of 38 articles in this systematic review. Results Much of the research has focused on carbohydrates in the form of dietary fiber, which are fuel for the gut microbiota. The beneficial effects of fiber have centered on Short Chain Fatty Acids (SCFAs) that are required by colonocytes (barrier function), improve absorption (minerals, water), and reduce intestinal transit time (colon cancer). Contrastingly, a low fiber, high protein diet promotes microbial protein metabolism, leading to potentially dangerous by-products that can stagnate in the gut. The bidirectional relationship between micronutrition and the gut microbiome is emerging. The microbiota utilize and produce micronutrients, leading to confounding relationships between nutritional status and biologic micronutrient concentrations, chiefly the B and K vitamins. While promising, the study of non-nutritive food components (polyphenols) and the gut microbiome is in its infancy. The role of other food components (food additives, contaminants) warrant exploration and are a significant research gap to-date. Conclusions Diet and nutrition have profound effects on the gut microbiome composition. This, in turn, affects a wide array of metabolic, hormonal, and neurological processes that influence our health and disease. Currently, there is no consensus in the scientific community on what defines a “healthy” gut microbiome. Future research must consider individual responses to diet and the role of diet in the response of the gut microbiome to interventions. Funding Sources N/A. Supporting Tables, Images and/or Graphs

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Alcohol’s Impact on the Gut and Liver

Nutrients ◽

10.3390/nu13093170 ◽

2021 ◽

Vol 13 (9) ◽

pp. 3170

Author(s):

Keith Pohl ◽

Prebashan Moodley ◽

Ashwin D. Dhanda

Keyword(s):

Hepatocellular Carcinoma ◽

Liver Disease ◽

Gut Microbiome ◽

Digestive System ◽

Alcohol Misuse ◽

Short Chain Fatty Acids ◽

Future Research ◽

Micronutrient Deficiencies ◽

Excessive Alcohol

Alcohol is inextricably linked with the digestive system. It is absorbed through the gut and metabolised by hepatocytes within the liver. Excessive alcohol use results in alterations to the gut microbiome and gut epithelial integrity. It contributes to important micronutrient deficiencies including short-chain fatty acids and trace elements that can influence immune function and lead to liver damage. In some people, long-term alcohol misuse results in liver disease progressing from fatty liver to cirrhosis and hepatocellular carcinoma, and results in over half of all deaths from chronic liver disease, over half a million globally per year. In this review, we will describe the effect of alcohol on the gut, the gut microbiome and liver function and structure, with a specific focus on micronutrients and areas for future research.

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Current explorations of nutrition and the gut microbiome: a comprehensive evaluation of the review literature

Nutrition Reviews ◽

10.1093/nutrit/nuz106 ◽

2020 ◽

Vol 78 (10) ◽

pp. 798-812 ◽

Cited By ~ 5

Author(s):

Leigh A Frame ◽

Elise Costa ◽

Scott A Jackson

Keyword(s):

Gut Microbiome ◽

Comprehensive Evaluation ◽

Data Extraction ◽

Short Chain Fatty Acids ◽

Review Literature ◽

Healthy Adults ◽

Future Research ◽

Microbial Composition ◽

Intestinal Transit Time ◽

Neurological Processes

Abstract Context The ability to measure the gut microbiome led to a surge in understanding and knowledge of its role in health and disease. The diet is a source of fuel for and influencer of composition of the microbiome. Objective To assess the understanding of the interactions between nutrition and the gut microbiome in healthy adults. Data Sources PubMed and Google Scholar searches were conducted in March and August 2018 and were limited to the following: English, 2010–2018, healthy adults, and reviews. Data Extraction A total of 86 articles were independently screened for duplicates and relevance, based on preidentified inclusion criteria. Data Analysis Research has focused on dietary fiber – microbiota fuel. The benefits of fiber center on short-chain fatty acids, which are required by colonocytes, improve absorption, and reduce intestinal transit time. Contrastingly, protein promotes microbial protein metabolism and potentially harmful by-products that can stagnate in the gut. The microbiota utilize and produce micronutrients; the bidirectional relationship between micronutrition and the gut microbiome is emerging. Conclusions Nutrition has profound effects on microbial composition, in turn affecting wide-ranging metabolic, hormonal, and neurological processes. There is no consensus on what defines a “healthy” gut microbiome. Future research must consider individual responses to diet.

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Quantitative characterization of Clostridioides difficile population in the gut microbiome of patients with C. difficile infection and their association with clinical factors

Scientific Reports ◽

10.1038/s41598-020-74090-0 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Jieun Kim ◽

Youna Cho ◽

Mi-Ran Seo ◽

Mi Hyun Bae ◽

Bongyoung Kim ◽

...

Keyword(s):

Bacterial Diversity ◽

Relative Abundance ◽

Gut Microbiome ◽

Clinical Cure ◽

Clinical Characteristics ◽

Bacterial Composition ◽

Clostridioides Difficile ◽

End Of Treatment ◽

Metagenome Sequencing

Abstract Objective was to analyse bacterial composition and abundance of Clostridioides difficile in gut microbiome of patients with C. difficile infection (CDI) in association with clinical characteristics. Whole metagenome sequencing of gut microbiome of 26 CDI patients was performed, and the relative abundance of C. difficile and its toxin genes was measured. Clinical characteristics of the patients were obtained through medical records. A strong correlation between the abundance of C. difficile and tcdB genes in CDI patients was found. The relative abundance of C. difficile in the gut microbiome ranged from undetectable to 2.8% (median 0.089). Patients with fever exhibited low abundance of C. difficile in their gut, and patients with fewer C. difficile organisms required long-term anti-CDI treatment. Abundance of Bifidobacterium and Bacteroides negatively correlated with that of C. difficile at the genus level. CDI patients were clustered using the bacterial composition of the gut: one with high population of Enterococcus (cluster 1, n = 12) and another of Bacteroides or Lactobacillus (cluster 2, n = 14). Cluster1 showed significantly lower bacterial diversity and clinical cure at the end of treatment. Additionally, patients with CDI exhibited increased ARGs; notably, blaTEM, blaSHV and blaCTX-M were enriched. C. difficile existed in variable proportion of the gut microbiome in CDI patients. CDI patients with Enterococcus-rich microbiome in the gut had lower bacterial diversity and poorer clinical cure.

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Effects of oats on gastrointestinal health as assessed by in vitro, animal, and human studies

Nutrition Reviews ◽

10.1093/nutrit/nuz064 ◽

2019 ◽

Vol 78 (5) ◽

pp. 343-363

Author(s):

Renee Korczak ◽

Megan Kocher ◽

Kelly S Swanson

Keyword(s):

Gut Microbiome ◽

Animal Studies ◽

Short Chain Fatty Acids ◽

Human Studies ◽

In Vitro Studies ◽

Future Research ◽

Gastrointestinal Health ◽

Beneficial Effects ◽

Pubmed Database

Abstract Oats are uniquely nutritious, owing to their composition of bioactive compounds, lipids, and β-glucan. Scientific research has established that oats can improve diet quality, reduce cholesterol, regulate satiety, and protect against carcinogenesis in the colon; however, determining the effects of oats on gastrointestinal health and the gut microbiome is a newer, evolving area of research. To better understand the effects of oats on gastrointestinal health in humans, a literature review with predefined search criteria was conducted using the PubMed database and keywords for common gastrointestinal health outcomes. Moreover, to examine the gastrointestinal effects of oats across the scientific spectrum, a similar search strategy was executed to identify animal studies. In vitro studies were identified from the reference lists of human and animal studies. A total of 8 human studies, 19 animal studies, and 5 in vitro studies met the inclusion criteria for this review. The evidence in humans shows beneficial effects of oats on gastrointestinal health, with supportive evidence provided by in vitro and animal studies. The effective dose of oats varies by type, although an amount providing 2.5 to 2.9 g of β-glucan per day was shown to decrease fecal pH and alter fecal bacteria. For oat bran, 40 to 100 g/d was shown to increase fecal bacterial mass and short-chain fatty acids in humans. Differences in study design, methodology, and type of oats tested make valid comparisons difficult. The identification of best practices for the design of oat studies should be a priority in future research, as the findings will be useful for determining how oats influence specific indices of gastrointestinal health, including the composition of the human gut microbiome.

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Gut Microbial Associations to Plasma Metabolites Linked to Cardiovascular Phenotypes and Risk

Circulation Research ◽

10.1161/circresaha.118.314642 ◽

2019 ◽

Vol 124 (12) ◽

pp. 1808-1820 ◽

Cited By ~ 33

Author(s):

Alexander Kurilshikov ◽

Inge C.L. van den Munckhof ◽

Lianmin Chen ◽

Marc J. Bonder ◽

Kiki Schraa ◽

...

Keyword(s):

Gut Microbiome ◽

Bacterial Species ◽

Short Chain Fatty Acids ◽

Population Based ◽

Liver Fat ◽

Plasma Metabolites ◽

Cvd Risk ◽

Microbial Composition ◽

Lipoprotein Subclasses ◽

Microbial Associations

Rationale: Altered gut microbial composition has been linked to cardiovascular diseases (CVDs), but its functional links to host metabolism and immunity in relation to CVD development remain unclear. Objectives: To systematically assess functional links between the microbiome and the plasma metabolome, cardiometabolic phenotypes, and CVD risk and to identify diet-microbe-metabolism-immune interactions in well-documented cohorts. Methods and Results: We assessed metagenomics-based microbial associations between 231 plasma metabolites and microbial species and pathways in the population-based LLD (Lifelines DEEP) cohort (n=978) and a clinical obesity cohort (n=297). After correcting for age, sex, and body mass index, the gut microbiome could explain ≤11.1% and 16.4% of the variation in plasma metabolites in the population-based and obesity cohorts, respectively. Obese-specific microbial associations were found for lipid compositions in the VLDL, IDL, and LDL lipoprotein subclasses. Bacterial L-methionine biosynthesis and a Ruminococcus species were associated to cardiovascular phenotypes in obese individuals, namely atherosclerosis and liver fat content, respectively. Integration of microbiome-diet-inflammation analysis in relation to metabolic risk score of CVD in the population cohort revealed 48 microbial pathways associated to CVD risk that were largely independent of diet and inflammation. Our data also showed that plasma levels rather than fecal levels of short-chain fatty acids were relevant to inflammation and CVD risk. Conclusions: This study presents the largest metagenome-based association study on plasma metabolism and microbiome relevance to diet, inflammation, CVD risk, and cardiometabolic phenotypes in both population-based and clinical obesity cohorts. Our findings identified novel bacterial species and pathways that associated to specific lipoprotein subclasses and revealed functional links between the gut microbiome and host health that provide a basis for developing microbiome-targeted therapy for disease prevention and treatment.

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Parasite defense mechanisms in bees: behavior, immunity, antimicrobials, and symbionts

Emerging Topics in Life Sciences ◽

10.1042/etls20190069 ◽

2019 ◽

Vol 4 (1) ◽

pp. 59-76 ◽

Cited By ~ 2

Author(s):

Alison E. Fowler ◽

Rebecca E. Irwin ◽

Lynn S. Adler

Keyword(s):

Defense Mechanisms ◽

Poor Quality ◽

Future Research ◽

Immune Priming ◽

Social Bees ◽

Bee Health ◽

Landscape Scales ◽

And Function ◽

Solitary Species

Parasites are linked to the decline of some bee populations; thus, understanding defense mechanisms has important implications for bee health. Recent advances have improved our understanding of factors mediating bee health ranging from molecular to landscape scales, but often as disparate literatures. Here, we bring together these fields and summarize our current understanding of bee defense mechanisms including immunity, immunization, and transgenerational immune priming in social and solitary species. Additionally, the characterization of microbial diversity and function in some bee taxa has shed light on the importance of microbes for bee health, but we lack information that links microbial communities to parasite infection in most bee species. Studies are beginning to identify how bee defense mechanisms are affected by stressors such as poor-quality diets and pesticides, but further research on this topic is needed. We discuss how integrating research on host traits, microbial partners, and nutrition, as well as improving our knowledge base on wild and semi-social bees, will help inform future research, conservation efforts, and management.

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