scholarly journals Minireview: Gut Microbiota: The Neglected Endocrine Organ

2014 ◽  
Vol 28 (8) ◽  
pp. 1221-1238 ◽  
Author(s):  
Gerard Clarke ◽  
Roman M. Stilling ◽  
Paul J. Kennedy ◽  
Catherine Stanton ◽  
John F. Cryan ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Metabolic Diseases ◽  
Peptide Yy ◽  
Body Weight Gain ◽  
Bacterial Species ◽  
Plasma Concentrations ◽  
Regulatory Control ◽  
Microbial Composition ◽  
Direct Role ◽  
Endocrine Organ

The concept that the gut microbiota serves as a virtual endocrine organ arises from a number of important observations. Evidence for a direct role arises from its metabolic capacity to produce and regulate multiple compounds that reach the circulation and act to influence the function of distal organs and systems. For example, metabolism of carbohydrates results in the production of short-chain fatty acids, such as butyrate and propionate, which provide an important source of nutrients as well as regulatory control of the host digestive system. This influence over host metabolism is also seen in the ability of the prebiotic inulin to influence production of relevant hormones such as glucagon-like peptide-1, peptide YY, ghrelin, and leptin. Moreover, the probiotic Lactobacillus rhamnosus PL60, which produces conjugated linoleic acid, has been shown to reduce body-weight gain and white adipose tissue without effects on food intake. Manipulating the microbial composition of the gastrointestinal tract modulates plasma concentrations of tryptophan, an essential amino acid and precursor to serotonin, a key neurotransmitter within both the enteric and central nervous systems. Indirectly and through as yet unknown mechanisms, the gut microbiota exerts control over the hypothalamic-pituitary-adrenal axis. This is clear from studies on animals raised in a germ-free environment, who show exaggerated responses to psychological stress, which normalizes after monocolonization by certain bacterial species including Bifidobacterium infantis. It is tempting to speculate that therapeutic targeting of the gut microbiota may be useful in treating stress-related disorders and metabolic diseases.

scholarly journals Dietary Proteins Relevant to Human Consumption Impact the Development of Obesity and Type 2 Diabetes in Association with Major Changes in the Gut Microbiota in a Mouse Model (OR27-03-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Noëmie Daniel ◽  
Béatrice Choi ◽  
Vanessa Houde ◽  
Thibault Varin ◽  
Cecile Vors ◽  
...  
Keyword(s):  
Animal Models ◽  
Gut Microbiota ◽  
Insulin Signaling ◽  
Body Weight Gain ◽  
Bacterial Species ◽  
Human Consumption ◽  
Oral Glucose ◽  
Rrna Gene ◽  
Dietary Proteins ◽  
The Impact

Abstract Objectives Animal models fed a high-fat high-sucrose (HFHS) diet are commonly used to study obesity and cardiometabolic diseases. While much attention is paid to the impact of fat and carbohydrates sources, very little consideration is given to the composition of dietary proteins. Indeed, casein is often the only source of protein in rodent's diet. This study aimed to evaluate the impact of a dietary protein mix that is more relevant to typical intakes of proteins in humans and its influences on body weight gain, metabolic health and gut microbiota. Methods Our new diet contained a mix of 10 protein sources based on NHANES data that were incorporated into low-fat low-sucrose (LFLS) and HFHS diets. C57BL/6J mice were fed these diets or control diets containing identical amounts of casein as the only source of protein for 12 weeks. Feces were collected for gut microbiota investigation, an oral glucose tolerance test was performed and tissues were harvested for analysis of insulin signaling and mTOR/S6K1 activation. Results 16S rRNA gene sequencing of fecal samples showed that both LFLS and HFHS mice fed the protein mix had increased gut microbiota diversity, and significant changes in the relative abundance of several bacterial species (higher Adlercreutzia or Tyzzerella, lower Bacteroides or Akkermansia) as compared to mice fed casein only. Importantly, inclusion of the protein mix amplified the effects of the HFHS diet on the development of obesity, glucose intolerance and hyperinsulinemia as compared to casein-fed animals, whereas no difference was observed in the context of LFLS feeding. Evaluation of insulin signaling in the liver also revealed that the protein mix potentiated the effect of HFHS feeding on the mTORC1/S6K1 pathway, increasing inhibitory phosphorylation of IRS-1 on Ser1101 and leading to further impairment of Akt activation by insulin. Conclusions Our results reveal that compared to pure casein, feeding a protein mixture causes major changes in the gut microbiota profile and greater impact on HFHS-induced obesity and associated metabolic impairments. This study illustrates the importance of considering a diverse source of dietary proteins when using laboratory animal models to more reliably reproduce the development of metabolic syndrome in humans, and to enhance the clinical relevance of nutritional and therapeutic interventions. Funding Sources N/A.

scholarly journals Gut microbiota and energy balance: role in obesity

2014 ◽  
Vol 74 (3) ◽  
pp. 227-234 ◽  
Author(s):  
Michael Blaut
Keyword(s):  
Energy Balance ◽  
Gut Microbiota ◽  
Dietary Fibre ◽  
Metabolic Diseases ◽  
De Novo ◽  
Peptide Yy ◽  
Intestinal Microbiome ◽  
Molar Ratio ◽  
Low Grade ◽  
Dietary Fibres

The microbial community populating the human digestive tract has been linked to the development of obesity, diabetes and liver diseases. Proposed mechanisms on how the gut microbiota could contribute to obesity and metabolic diseases include: (1) improved energy extraction from diet by the conversion of dietary fibre to SCFA; (2) increased intestinal permeability for bacterial lipopolysaccharides (LPS) in response to the consumption of high-fat diets resulting in an elevated systemic LPS level and low-grade inflammation. Animal studies indicate differences in the physiologic effects of fermentable and non-fermentable dietary fibres as well as differences in long- and short-term effects of fermentable dietary fibre. The human intestinal microbiome is enriched in genes involved in the degradation of indigestible polysaccharides. The extent to which dietary fibres are fermented and in which molar ratio SCFA are formed depends on their physicochemical properties and on the individual microbiome. Acetate and propionate play an important role in lipid and glucose metabolism. Acetate serves as a substrate for de novo lipogenesis in liver, whereas propionate can be utilised for gluconeogenesis. The conversion of fermentable dietary fibre to SCFA provides additional energy to the host which could promote obesity. However, epidemiologic studies indicate that diets rich in fibre rather prevent than promote obesity development. This may be due to the fact that SCFA are also ligands of free fatty acid receptors (FFAR). Activation of FFAR leads to an increased expression and secretion of enteroendocrine hormones such as glucagon-like-peptide 1 or peptide YY which cause satiety. In conclusion, the role of SCFA in host energy balance needs to be re-evaluated.

scholarly journals Elderly patients of mild cognitive impairment exhibit altered profiles of the gut microbiota

2020 ◽  
Author(s):  
Qiong Pan ◽  
Ya-Qian Li ◽  
Ke Guo ◽  
Min Xue ◽  
Yu Gan ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Gut Microbiota ◽  
Bacterial Species ◽  
Natural Aging ◽  
Microbial Composition ◽  
Principal Coordinates Analysis ◽  
Transitional State ◽  
Staphylococcus Intermedius ◽  
Principal Coordinates

Abstract Background As the transitional state between normal aging and Alzheimer’s disease (AD), mild cognitive impairment (MCI) is characterized by cognitive decline greater than natural aging. While the association between AD and gut microbiota has been reported in a number of studies, there is still very limited microbial research about MCI. Methods Here we enrolled 48 participants, including 22 MCI cases and 26 normal controls. Fecal samples were collected for 16S rRNA quantitative arrays and bioinformatics analysis. Results Both Principal Coordinates Analysis (PCoA) and Non-metric Multidimensional scaling (NMDS) demonstrated that the microbial composition of MCI individuals deviated from the cluster of healthy controls. Multiple bacterial species were significantly increased (e.g., Staphylococcus intermedius) or decreased (e.g., Bacteroides salyersiae) in the samples from MCI group. Conclusion Therefore, the composition of gut microbiota differed between control subjects and MCI cases. Our study is the first to identify a series of MCI signature species in the gut microbiota, thus providing a new direction for future development of early diagnosis and probiotics regimen.

scholarly journals Microsporidian Infection in Mosquitoes (Culicidae) Is Associated with Gut Microbiome Composition and Predicted Gut Microbiome Functional Content

2021 ◽  
Author(s):  
Artur Trzebny ◽  
Anna Slodkowicz-Kowalska ◽  
Johanna Björkroth ◽  
Miroslawa Dabert
Keyword(s):  
16S Rrna ◽  
Gut Microbiota ◽  
Gut Microbiome ◽  
Bacterial Communities ◽  
Bacterial Species ◽  
Rrna Gene ◽  
Microbial Composition ◽  
Microbiome Composition ◽  
Microsporidian Infection ◽  
Functional Content

AbstractThe animal gut microbiota consist of many different microorganisms, mainly bacteria, but archaea, fungi, protozoans, and viruses may also be present. This complex and dynamic community of microorganisms may change during parasitic infection. In the present study, we investigated the effect of the presence of microsporidians on the composition of the mosquito gut microbiota and linked some microbiome taxa and functionalities to infections caused by these parasites. We characterised bacterial communities of 188 mosquito females, of which 108 were positive for microsporidian DNA. To assess how bacterial communities change during microsporidian infection, microbiome structures were identified using 16S rRNA microbial profiling. In total, we identified 46 families and four higher taxa, of which Comamonadaceae, Enterobacteriaceae, Flavobacteriaceae and Pseudomonadaceae were the most abundant mosquito-associated bacterial families. Our data suggest that the mosquito gut microbial composition varies among host species. In addition, we found a correlation between the microbiome composition and the presence of microsporidians. The prediction of metagenome functional content from the 16S rRNA gene sequencing suggests that microsporidian infection is characterised by some bacterial species capable of specific metabolic functions, especially the biosynthesis of ansamycins and vancomycin antibiotics and the pentose phosphate pathway. Moreover, we detected a positive correlation between the presence of microsporidian DNA and bacteria belonging to Spiroplasmataceae and Leuconostocaceae, each represented by a single species, Spiroplasma sp. PL03 and Weissella cf. viridescens, respectively. Additionally, W. cf. viridescens was observed only in microsporidian-infected mosquitoes. More extensive research, including intensive and varied host sampling, as well as determination of metabolic activities based on quantitative methods, should be carried out to confirm our results.

Novel Interactions Between Circulating microRNAs and Gut Microbiota Composition in Human Obesity.

2020 ◽  
Author(s):  
Taís Silveira Assmann ◽  
Amanda Cuevas-Sierra ◽  
José Ignacio Riezu-Boj ◽  
Fermin Milagro ◽  
J Alfredo Martínez
Keyword(s):  
Gut Microbiota ◽  
Gut Microbiome ◽  
Target Genes ◽  
Metabolic Diseases ◽  
Bacterial Species ◽  
Microbiota Composition ◽  
Circulating Mirnas ◽  
Clinical Trial Registration ◽  
Body Adiposity ◽  
Gut Microbiota Composition

Abstract Background: Unbalances in microRNAs (miRNA) and gut microbiota patterns have been proposed as putative factors concerning onset and development of obesity and other metabolic diseases. However, the determinants that mediate the interactions between miRNAs and the gut microbiome impacting on obesity are scarcely understood. Thus, the aim of this article was to investigate possible interactions between circulating miRNAs and gut microbiota composition in obesity. Method: The analyzed sample comprised 78 subjects with obesity [cases, body mass index (BMI): 30 – 40 kg/m2] and 25 eutrophic individuals (controls, BMI £ 25 kg/m2). The expression of 96 miRNAs was investigated in plasma of all individuals using miRCURY LNA miRNA Custom PCR Panels (Exiqon). Bacterial DNA sequencing was performed following the Illumina 16S protocol. The FDR (Benjamini-Hochberg test, q-value) correction was used for multiple comparison analyses.Results: A total of 26 circulating miRNAs and 12 bacterial species were found differentially expressed between cases and controls. Interestingly, an interaction among three miRNAs (miR-130b-3p, miR-185-5p, and miR-21-5p) with Bacteroides eggerthi, and BMI levels was evidenced (r2= 0.148, P= 0.004). Those miRNAs that correlated with obesity-associated gut bacteria abundance are known to regulate target genes that participate in metabolism-related pathways, such as fatty acid degradation, carbohydrate digestion and absorption, insulin signaling, and glycerolipid metabolism. Conclusion: This study characterized an interaction between the abundance of 4 bacterial species and 14 circulating miRNAs in relation to body adiposity. Moreover, the current study also suggests that miRNAs may serve as a communication mechanism between the gut microbiome and human hosts. Clinical trial registration: clinicaltrials.gov (reg. no. NCT02737267).

scholarly journals Exercise Modifies the Gut Microbiota with Positive Health Effects

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Vincenzo Monda ◽  
Ines Villano ◽  
Antonietta Messina ◽  
Anna Valenzano ◽  
Teresa Esposito ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Commensal Bacteria ◽  
Physiological Changes ◽  
Human Gastrointestinal Tract ◽  
Positive Health ◽  
Microbial Composition ◽  
Endocrine Organ ◽  
Metabolic Functions ◽  
Epithelial Development ◽  
Health And Disease

The human gastrointestinal tract (GIT) is inhabited by a wide cluster of microorganisms that play protective, structural, and metabolic functions for the intestinal mucosa. Gut microbiota is involved in the barrier functions and in the maintenance of its homeostasis. It provides nutrients, participates in the signaling network, regulates the epithelial development, and affects the immune system. Considering the microbiota ability to respond to homeostatic and physiological changes, some researchers proposed that it can be seen as an endocrine organ. Evidence suggests that different factors can determine changes in the gut microbiota. These changes can be both quantitative and qualitative resulting in variations of the composition and metabolic activity of the gut microbiota which, in turn, can affect health and different disease processes. Recent studies suggest that exercise can enhance the number of beneficial microbial species, enrich the microflora diversity, and improve the development of commensal bacteria. All these effects are beneficial for the host, improving its health status. In this paper, we intend to shed some light over the recent knowledge of the role played by exercise as an environmental factor in determining changes in microbial composition and how these effects could provide benefits to health and disease prevention.

scholarly journals Shifts in microbiota species and fermentation products in a dietary model enriched in fat and sucrose

2015 ◽  
Vol 6 (1) ◽  
pp. 97-111 ◽  
Author(s):  
U. Etxeberria ◽  
N. Arias ◽  
N. Boqué ◽  
M.T. Macarulla ◽  
M.P. Portillo ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Bacterial Species ◽  
Intestinal Barrier ◽  
Short Chain Fatty Acids ◽  
Gas Chromatography Mass Spectrometry ◽  
Intestinal Barrier Function ◽  
Microbial Composition ◽  
Fermentation Products ◽  
Inflammatory Status ◽  
Male Wistar Rats

The gastrointestinal tract harbours a ‘superorganism’ called the gut microbiota, which is known to play a crucial role in the onset and development of diverse diseases. This internal ecosystem, far from being a static environment, can be manipulated by diet and dietary components. Feeding animals with high-fat sucrose (HFS) diets entails diet-induced obesity, a model which is usually used in research to mimic the obese phenotype of Western societies. The aim of the present study was to identify gut microbiota dysbiosis and associated metabolic changes produced in male Wistar rats fed a HFS diet for 6 weeks and compare it with the basal microbial composition. For this purpose, DNA extracted from faeces at baseline and after treatment was analysed by amplification of the V4-V6 region of the 16S ribosomal DNA (rDNA) gene using 454 pyrosequencing. Short-chain fatty acids, i.e. acetate, propionate and butyrate, were also evaluated by gas chromatography-mass spectrometry. At the end of the treatment, gut microbiota composition significantly differed at phylum level (Firmicutes, Bacteroidetes and Proteobacteria) and class level (Erisypelotrichi, Deltaproteobacteria, Bacteroidia and Bacilli). Interestingly, the class Clostridia showed a significant decrease after HFS diet treatment, which correlated with visceral adipose tissue, and is likely mediated by dietary carbohydrates. Of particular interest, Clostridium cluster XIVa species were significantly reduced and changes were identified in the relative abundance of other specific bacterial species (Mitsuokella jalaludinii, Eubacterium ventriosum, Clostridium sp. FCB90-3, Prevotella nanceiensis, Clostridium fusiformis, Clostridium sp. BNL1100 and Eubacterium cylindroides) that, in some cases, showed opposite trends to their relative families. These results highlight the relevance of characterising gut microbial population differences at species level and contribute to understand the plausible link between diet and specific gut bacterial species that are able to influence the inflammatory status, intestinal barrier function and obesity development.

scholarly journals Gut Microbiota Bacterial Species Associated with Mediterranean Diet-Related Food Groups in a Northern Spanish Population

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 636
Author(s):  
Carles Rosés ◽  
Amanda Cuevas-Sierra ◽  
Salvador Quintana ◽  
José I. Riezu-Boj ◽  
J. Alfredo Martínez ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Dietary Intake ◽  
Mediterranean Diet ◽  
Dietary Habits ◽  
Metabolic Diseases ◽  
Bacterial Species ◽  
Short Chain Fatty Acids ◽  
Normal Weight ◽  
Food Groups ◽  
Statistical Tool

The MD (Mediterranean diet) is recognized as one of the healthiest diets worldwide and is associated with the prevention of cardiovascular and metabolic diseases. Dietary habits are considered one of the strongest modulators of gut microbiota, which seem to play a significant role in health status of the host. The purpose of the present study was to evaluate interactive associations between gut microbiota composition and habitual dietary intake in 360 Spanish adults from the Obekit cohort (normal weight, overweight, and obese participants). Dietary intake and adherence to the MD tests were administered and fecal samples were collected from each participant. Fecal 16S rRNA (ribosomal Ribonucleic Acid) gene sequencing was performed and checked against the dietary habits. MetagenomeSeq was the statistical tool applied to analyze data at the species taxonomic level. Results from this study identified several beneficial bacteria that were more abundant in the individuals with higher adherence to the MD. Bifidobacterium animalis was the species with the strongest association with the MD. Some SCFA (Short Chain Fatty Acids) -producing bacteria were also associated with MD. In conclusion, this study showed that MD, fiber, legumes, vegetable, fruit, and nut intake are associated with an increase in butyrate-producing taxa such as Roseburia faecis, Ruminococcus bromii, and Oscillospira (Flavonifractor) plautii.

scholarly journals Elderly patients of mild cognitive impairment exhibit altered profiles of the gut microbiota

2020 ◽  
Author(s):  
Qiong Pan ◽  
Ya-Qian Li ◽  
Ke Guo ◽  
Min Xue ◽  
Yu Gan ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Gut Microbiota ◽  
Bacterial Species ◽  
Natural Aging ◽  
Microbial Composition ◽  
Principal Coordinates Analysis ◽  
Transitional State ◽  
Staphylococcus Intermedius ◽  
Principal Coordinates

Abstract Background As the transitional state between normal aging and Alzheimer’s disease (AD), mild cognitive impairment (MCI) is characterized by cognitive decline greater than natural aging. While the association between AD and gut microbiota has been reported in a number of studies, there is still very limited microbial research about MCI. Methods Here we enrolled 48 participants, including 22 MCI cases and 26 normal controls. Fecal samples were collected for 16S rRNA quantitative arrays and bioinformatics analysis. Results Both Principal Coordinates Analysis (PCoA) and Non-metric Multidimensional scaling (NMDS) demonstrated that the microbial composition of MCI individuals deviated from the cluster of healthy controls. Multiple bacterial species were significantly increased (e.g., Staphylococcus intermedius) or decreased (e.g., Bacteroides salyersiae) in the samples from MCI group. Conclusion Therefore, the composition of gut microbiota differed between control subjects and MCI cases. Our study is the first to identify a series of MCI signature species in the gut microbiota, thus providing a new direction for future development of early diagnosis and probiotics regimen.

scholarly journals Elderly Patients with Mild Cognitive Impairment Exhibit Altered Gut Microbiota Profiles

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Qiong Pan ◽  
Ya-Qian Li ◽  
Ke Guo ◽  
Min Xue ◽  
Yu Gan ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Gut Microbiota ◽  
Normal Control ◽  
Bacterial Species ◽  
Natural Aging ◽  
Microbial Composition ◽  
Principal Coordinates Analysis ◽  
Transitional State ◽  
Principal Coordinates

Background. As a transitional state between normal aging and Alzheimer’s disease (AD), mild cognitive impairment (MCI) is characterized by a worse cognitive decline than that of natural aging. The association between AD and gut microbiota has been reported in a number of studies; however, microbial research regarding MCI remains limited. Methods. This study examined 48 participants, of whom 22 were MCI cases and 26 were normal control cases. Fecal samples were collected for 16S ribosomal RNA (rRNA) quantitative arrays and bioinformatics analysis. Results. A principal coordinates analysis (PCoA) and nonmetric multidimensional scaling (NMDS) both demonstrated that the microbial composition of participants with MCI deviated from that of healthy control participants. Multiple bacterial species were significantly increased (e.g., Staphylococcus intermedius) or decreased (e.g., Bacteroides salyersiae) in samples from the MCI group. Conclusion. The composition of gut microbiota differed between normal control and MCI cases. This is the first study to identify a signature series of species in the gut microbiota of individuals with MCI. The results provide a new direction for the future development of an early diagnosis and probiotic regimen.

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