scholarly journals Mutually Beneficial Symbiosis Between Human and Gut-Dominant Bacteroides Species Through Bacterial Assimilation of Host Mucosubstances

2020 ◽  
Author(s):  
Masahiro Sato ◽  
Kanta Kajikawa ◽  
Tomoya Kumon ◽  
Daisuke Watanabe ◽  
Ryuichi Takase ◽  
...  
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Health Promotion ◽  
Gut Microbiota ◽  
Human Health ◽  
Short Chain Fatty Acids ◽  
Essential Amino Acids ◽  
Fasting State ◽  
Human Gut ◽  
Human Host

AbstractThe composition of gut microbiota is influenced by the quantity and type of nutrients in host. Even with some Bacteroides species being categorized as pathogens, Bacteroides is one of the most dominant gut bacteria. Here we indicate the physiological determinants of the species of Bacteroides for being dominant in human gut microbiota. Each of the host extracellular mucosubstances including glycosaminoglycans (GAGs) and mucin has grown human gut microbiota. In spite of the differences among initial microbiota profiles, Bacteroides species dominated the community when GAG (e.g., chondroitin sulfate or hyaluronan) was used as a sole carbon source. In fact, GAGs and the Bacteroides genes which are vital for the degradation of GAGs were commonly detected in human feces. Mucin has encouraged the growth of Bacteroides and several other genera. A comprehensive analysis on the degradation and assimilation of mucosubstances by the genus Bacteroides using around 30 species has shown that most species degrade and assimilate GAGs and mucin, showing that Bacteroides species can survive even in the undernutrition condition including the fasting state. In the assimilation of GAG or mucin, Bacteroides species significantly secreted essential amino acids, γ-amino butyrate (GABA), and/or short-chain fatty acids which are needed for human health. This is the first report as regards mutually beneficial interaction between human and Bacteroides species via bacterial assimilation of host mucosubstances and secretion of metabolites for host health promotion.SignificanceThe genus Bacteroides is one of the most dominant gut bacteria, although its beneficial effects on human health have not been well understood. Here, we show modes of action in human-Bacteroides interrelationship. Mucosubstances including GAGs and mucin secreted by human host are abundant in gut for microbiota to grow well. Bacteroides species are dominant in the community in the presence of GAGs, and provide human host with a considerable amount of essential amino acids, γ-amino butyrate, and short-chain fatty acids produced from mucosubstances. These results postulate mutually beneficial symbiosis system between human and Bacteroides through bacterial assimilation of host mucosubstances and secretion of metabolites for human body and mental health promotion even in the undernutrition condition including the fasting state.

Gastrointestinal Interaction between Dietary Amino Acids and Gut Microbiota: With Special Emphasis on Host Nutrition

2020 ◽  
Vol 21 (8) ◽  
pp. 785-798 ◽  
Author(s):  
Abedin Abdallah ◽  
Evera Elemba ◽  
Qingzhen Zhong ◽  
Zewei Sun
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Immune System ◽  
Gut Microbiota ◽  
Short Chain Fatty Acids ◽  
Nutrition And Health ◽  
Nitrogenous Compounds ◽  
Dietary Amino Acids ◽  
Host Nutrition ◽  
Chain Fatty Acids

The gastrointestinal tract (GIT) of humans and animals is host to a complex community of different microorganisms whose activities significantly influence host nutrition and health through enhanced metabolic capabilities, protection against pathogens, and regulation of the gastrointestinal development and immune system. New molecular technologies and concepts have revealed distinct interactions between the gut microbiota and dietary amino acids (AAs) especially in relation to AA metabolism and utilization in resident bacteria in the digestive tract, and these interactions may play significant roles in host nutrition and health as well as the efficiency of dietary AA supplementation. After the protein is digested and AAs and peptides are absorbed in the small intestine, significant levels of endogenous and exogenous nitrogenous compounds enter the large intestine through the ileocaecal junction. Once they move in the colonic lumen, these compounds are not markedly absorbed by the large intestinal mucosa, but undergo intense proteolysis by colonic microbiota leading to the release of peptides and AAs and result in the production of numerous bacterial metabolites such as ammonia, amines, short-chain fatty acids (SCFAs), branched-chain fatty acids (BCFAs), hydrogen sulfide, organic acids, and phenols. These metabolites influence various signaling pathways in epithelial cells, regulate the mucosal immune system in the host, and modulate gene expression of bacteria which results in the synthesis of enzymes associated with AA metabolism. This review aims to summarize the current literature relating to how the interactions between dietary amino acids and gut microbiota may promote host nutrition and health.

scholarly journals Microbiota-Associated Metabolites and Related Immunoregulation in Colorectal Cancer

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 4054
Author(s):  
Yan Chen ◽  
Ying-Xuan Chen
Keyword(s):  
Colorectal Cancer ◽  
Fatty Acids ◽  
Gut Microbiota ◽  
Immune Responses ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Indole Derivatives ◽  
Human Gut ◽  
Growing Body ◽  
Specific Influence

A growing body of research has found close links between the human gut microbiota and colorectal cancer (CRC), associated with the direct actions of specific bacteria and the activities of microbiota-derived metabolites, which are implicated in complex immune responses, thus influencing carcinogenesis. Diet has a significant impact on the structure of the microbiota and also undergoes microbial metabolism. Some metabolites, such as short-chain fatty acids (SCFAs) and indole derivatives, act as protectors against cancer by regulating immune responses, while others may promote cancer. However, the specific influence of these metabolites on the host is conditional. We reviewed the recent insights on the relationships among diet, microbiota-derived metabolites, and CRC, focusing on their intricate immunomodulatory responses, which might influence the progression of colorectal cancer.

scholarly journals Dietary Fatty Acids Sustain the Growth of the Human Gut Microbiota

2018 ◽  
Vol 84 (21) ◽  
Author(s):  
Richard Agans ◽  
Alex Gordon ◽  
Denise Lynette Kramer ◽  
Sergio Perez-Burillo ◽  
José A. Rufián-Henares ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Small Intestine ◽  
Fatty Acid ◽  
Gut Microbiota ◽  
Short Chain Fatty Acids ◽  
Dietary Fatty Acids ◽  
Dietary Fats ◽  
High Fat ◽  
Human Gut ◽  
Content Type

ABSTRACTWhile a substantial amount of dietary fats escape absorption in the human small intestine and reach the colon, the ability of resident microbiota to utilize these dietary fats for growth has not been investigated in detail. In this study, we used anin vitromultivessel simulator system of the human colon to reveal that the human gut microbiota is able to utilize typically consumed dietary fatty acids to sustain growth. Gut microbiota adapted quickly to a macronutrient switch from a balanced Western diet-type medium to its variant lacking carbohydrates and proteins. We defined specific genera that increased in their abundances on the fats-only medium, includingAlistipes,Bilophila, and several genera of the classGammaproteobacteria. In contrast, the abundances of well-known glycan and protein degraders, includingBacteroides,Clostridium, andRoseburiaspp., were reduced under such conditions. The predicted prevalences of microbial genes coding for fatty acid degradation enzymes and anaerobic respiratory reductases were significantly increased in the fats-only environment, whereas the abundance of glycan degradation genes was diminished. These changes also resulted in lower microbial production of short-chain fatty acids and antioxidants. Our findings provide justification for the previously observed alterations in gut microbiota observed in human and animal studies of high-fat diets.IMPORTANCEIncreased intake of fats in many developed countries has raised awareness of potentially harmful and beneficial effects of high fat consumption on human health. Some dietary fats escape digestion in the small intestine and reach the colon where they can be metabolized by gut microbiota. We show that human gut microbes are able to maintain a complex community when supplied with dietary fatty acids as the only nutrient and carbon sources. Such fatty acid-based growth leads to lower production of short-chain fatty acids and antioxidants by community members, which potentially have negative health consequences on the host.

scholarly journals Prebiotics and Community Composition Influence Gas Production of the Human Gut Microbiota

mBio ◽  
2020 ◽  
Vol 11 (5) ◽  
Author(s):  
Xiaoqian Yu ◽  
Thomas Gurry ◽  
Le Thanh Tu Nguyen ◽  
Hunter S. Richardson ◽  
Eric J. Alm
Keyword(s):  
Fatty Acids ◽  
Chemical Composition ◽  
Gut Microbiota ◽  
Community Composition ◽  
Human Body ◽  
Ex Vivo ◽  
Short Chain Fatty Acids ◽  
Gas Production ◽  
Human Gut ◽  
Human Gut Microbiota

ABSTRACT Prebiotics confer benefits to human health, often by promoting the growth of gut bacteria that produce metabolites valuable to the human body, such as short-chain fatty acids (SCFAs). While prebiotic selection has strongly focused on maximizing the production of SCFAs, less attention has been paid to gases, a by-product of SCFA production that also has physiological effects on the human body. Here, we investigate how the content and volume of gas production by human gut microbiota are affected by the chemical composition of the prebiotic and the community composition of the microbiota. We first constructed a linear system model based on mass and electron balance and compared the theoretical product ranges of two prebiotics, inulin and pectin. Modeling shows that pectin is more restricted in product space, with less potential for H2 but more potential for CO2 production. An ex vivo experimental system showed pectin degradation produced significantly less H2 than inulin, but CO2 production fell outside the theoretical product range, suggesting fermentation of fecal debris. Microbial community composition also impacted results: methane production was dependent on the presence of Methanobacteria, while interindividual differences in H2 production during inulin degradation were driven by a Lachnospiraceae taxon. Overall, these results suggest that both the chemistry of the prebiotic and the composition of the microbiota are relevant to gas production. Metabolic processes that are relatively prevalent in the microbiome, such as H2 production, will depend more on substrate, while rare metabolisms such as methanogenesis depend more strongly on microbiome composition. IMPORTANCE Prebiotic fermentation in the gut often leads to the coproduction of short-chain fatty acids (SCFAs) and gases. While excess gas production can be a potential problem for those with functional gut disorders, gas production is rarely considered during prebiotic design. In this study, we combined the use of theoretical models and an ex vivo experimental platform to illustrate that both the chemical composition of the prebiotic and the community composition of the human gut microbiota can affect the volume and content of gas production during prebiotic fermentation. Specifically, more prevalent metabolic processes such as hydrogen production were strongly affected by the oxidation state of the probiotic, while rare metabolisms such as methane production were less affected by the chemical nature of the substrate and entirely dependent on the presence of Methanobacteria in the microbiota.

scholarly journals Dietary Components, Microbial Metabolites and Human Health: Reading between the Lines

Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1045
Author(s):  
Yao Guo ◽  
Xiaohan Bian ◽  
Jiali Liu ◽  
Ming Zhu ◽  
Lin Li ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Gut Microbiota ◽  
Human Health ◽  
Kynurenic Acid ◽  
Molecular Mechanisms ◽  
Eating Habits ◽  
Short Chain Fatty Acids ◽  
Human Gut ◽  
Dietary Components ◽  
Host Metabolism

Trillions of bacteria reside in the human gut and they metabolize dietary substances to obtain nutrients and energy while producing metabolites. Therefore, different dietary components could affect human health in various ways through microbial metabolism. Many such metabolites have been shown to affect human physiological activities, including short-chain fatty acids metabolized from carbohydrates; indole, kynurenic acid and para-cresol, metabolized from amino acids; conjugated linoleic acid and linoleic acid, metabolized from lipids. Here, we review the features of these metabolites and summarize the possible molecular mechanisms of their metabolisms by gut microbiota. We discuss the potential roles of these metabolites in health and diseases, and the interactions between host metabolism and the gut microbiota. We also show some of the major dietary patterns around the world and hope this review can provide insights into our eating habits and improve consumers’ health conditions.

scholarly journals Gut Microbiota-Derived Metabolites in Irritable Bowel Syndrome

2021 ◽  
Vol 11 ◽  
Author(s):  
Lin Xiao ◽  
Qin Liu ◽  
Mei Luo ◽  
Lishou Xiong
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Irritable Bowel Syndrome ◽  
Gut Microbiota ◽  
Short Chain Fatty Acids ◽  
Functional Bowel Disorder ◽  
Irritable Bowel ◽  
The Brain ◽  
Bowel Disorder

Irritable bowel syndrome (IBS) is the most common functional bowel disorder worldwide and is associated with visceral hypersensitivity, gut motility, immunomodulation, gut microbiota alterations, and dysfunction of the brain-gut axis; however, its pathophysiology remains poorly understood. Gut microbiota and its metabolites are proposed as possible etiological factors of IBS. The aim of our study was to investigate specific types of microbiota-derived metabolites, especially bile acids, short-chain fatty acids, vitamins, amino acids, serotonin and hypoxanthine, which are all implicated in the pathogenesis of IBS. Metabolites-focused research has identified multiple microbial targets relevant to IBS patients, important roles of microbiota-derived metabolites in the development of IBS symptoms have been established. Thus, we provide an overview of gut microbiota and their metabolites on the different subtypes of IBS (constipation-predominant IBS-C, diarrhea-predominant IBS-D) and present controversial views regarding the role of microbiota in IBS.

scholarly journals Antibiotic Exposure Has Sex-Dependent Effects on the Gut Microbiota and Metabolism of Short-Chain Fatty Acids and Amino Acids in Mice

mSystems ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Hongchang Gao ◽  
Qi Shu ◽  
Jiuxia Chen ◽  
Kai Fan ◽  
Pengtao Xu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Gut Microbiota ◽  
Gut Microbiome ◽  
Short Chain Fatty Acids ◽  
Antibiotic Exposure ◽  
Male Mice ◽  
Female Mice ◽  
Structural Composition ◽  
Host Metabolism

ABSTRACT The gut microbiota has the capability to regulate homeostasis of the host metabolism. Since antibiotic exposure can adversely affect the microbiome, we hypothesized that antibiotic effects on the gut microbiota and host metabolism are sex dependent. In this study, we examined the effects of antibiotic treatments, including vancomycin (Vanc) and ciprofloxacin-metronidazole (CiMe), on the gut microbiome and metabolome in colonic contents and tissues in both male and female mice. We found that the relative abundances and structural composition of Firmicutes were significantly reduced in female mice after both Vanc and CiMe treatments but in male mice only after treatment with Vanc. However, Vanc exposure considerably altered the relative abundances and structural composition of representatives of the Proteobacteria especially in male mice. The levels of short-chain fatty acids (SCFAs; acetate, butyrate, and propionate) in colonic contents and tissues were significantly decreased in female mice after both antibiotic treatments, while these reductions were detected in male mice only after Vanc treatment. However, another SCFA, formate, exhibited the opposite tendency in colonic tissues. Both antibiotic exposures significantly decreased the levels of alanine, branched-chain amino acids (BCAAs; leucine, isoleucine, and valine) and aromatic amino acids (AAAs; phenylalanine and tyrosine) in colonic contents of female mice but not in male mice. Additionally, female mice had much greater correlations between microbe and metabolite than male mice. These findings suggest that sex-dependent effects should be considered for antibiotic-induced modifications of the gut microbiota and host metabolism. IMPORTANCE Accumulating evidence shows that the gut microbiota regulates host metabolism by producing a series of metabolites, such as amino acids, bile acids, fatty acids, and others. These metabolites have a positive or negative effect on host health. Antibiotic exposure can disrupt the gut microbiota and thereby affect host metabolism and physiology. However, there are a limited number of studies addressing whether antibiotic effects on the gut microbiota and host metabolism are sex dependent. In this study, we uncovered a sex-dependent difference in antibiotic effects on the gut microbiota and metabolome in colonic contents and tissues in mice. These findings reveal that sex-dependent effects need to be considered for antibiotic use in scientific research or clinical practice. Moreover, this study will also give an important direction for future use of antibiotics to modify the gut microbiome and host metabolism in a sex-specific manner.

scholarly journals The Controversial Role of Human Gut Lachnospiraceae

2020 ◽  
Vol 8 (4) ◽  
pp. 573 ◽  
Author(s):  
Mirco Vacca ◽  
Giuseppe Celano ◽  
Francesco Maria Calabrese ◽  
Piero Portincasa ◽  
Marco Gobbetti ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Gut Microbiota ◽  
Short Chain Fatty Acids ◽  
Intestinal Lumen ◽  
Human Gut ◽  
The Core ◽  
Host Diet ◽  
Health And Disease ◽  
Host Physiology

The complex polymicrobial composition of human gut microbiota plays a key role in health and disease. Lachnospiraceae belong to the core of gut microbiota, colonizing the intestinal lumen from birth and increasing, in terms of species richness and their relative abundances during the host’s life. Although, members of Lachnospiraceae are among the main producers of short-chain fatty acids, different taxa of Lachnospiraceae are also associated with different intra- and extraintestinal diseases. Their impact on the host physiology is often inconsistent across different studies. Here, we discuss changes in Lachnospiraceae abundances according to health and disease. With the aim of harnessing Lachnospiraceae to promote human health, we also analyze how nutrients from the host diet can influence their growth and how their metabolites can, in turn, influence host physiology.

scholarly journals Prebiotics and community composition influence gas production of the human gut microbiota

2020 ◽  
Author(s):  
Xiaoqian Yu ◽  
Thomas Gurry ◽  
Le Thanh Tu Nguyen ◽  
Hunter S. Richardson ◽  
Eric J. Alm
Keyword(s):  
Fatty Acids ◽  
Chemical Composition ◽  
Gut Microbiota ◽  
Community Composition ◽  
Human Body ◽  
Ex Vivo ◽  
Short Chain Fatty Acids ◽  
Gas Production ◽  
Human Gut ◽  
Human Gut Microbiota

AbstractPrebiotics confer benefits to human health often by promoting the growth of gut bacteria that produce metabolites valuable to the human body, such as short chain fatty acids (SCFAs). While prebiotic selection has strongly focused on maximizing the production of SCFAs, less attention has been paid to gases, a byproduct of SCFA production that also has physiological effects on the human body. Here, we investigate how the content and volume of gas production by human gut microbiota is affected by the chemical composition of the prebiotic and by the composition of the microbiota. We first constructed a linear systems model based on mass and electron balance and compared the theoretical product range of two prebiotics, inulin and pectin. Modeling shows that pectin is more restricted in product space, with less potential for H2 but more potential for CO2 production. An ex vivo experimental system showed pectin degradation produced significantly less H2 than inulin, but CO2 production fell outside the theoretical product range, suggesting fermentation of fecal debris. Microbial community composition also impacted results: methane production was dependent on the presence of Methanobacteria, while inter-individual differences in H2 production during inulin degradation was driven by a Lachnospiraceae taxon. Overall, these results suggest that both the chemistry of the prebiotic and the composition of the microbiota are relevant to gas production. Metabolic processes that are relatively prevalent in the microbiome, such as H2 production will depend more on substrate, while rare metabolisms like methanogenesis depend more strongly on microbiome composition.ImportancePrebiotic fermentation in the gut often leads to the co-production of short chain fatty acids (SCFAs) and gases. While excess gas production can be a potential problem for those with functional gut disorders, gas production is rarely taken into account during prebiotic design. In this study, we combined the use of theoretical models and an ex vivo experimental platform to illustrate that both the chemical composition of the prebiotic and the community composition of the human gut microbiota can affect the volume and content of gas production during prebiotic fermentation. Specifically, more prevalent metabolic processes such as hydrogen production was strongly affected by the oxidation state of the probiotic, while rare metabolisms such as methane production was less affected by the chemical nature of the substrate and entirely dependent on the presence of Methanobacteria in the microbiota.

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