Adverse effects of methylmercury on gut bacteria and accelerated accumulation of mercury in organs due to disruption of gut microbiota

While poorly-absorbed sugar alcohols such as sorbitol are widely used as sweeteners, they may induce diarrhea in some individuals. However, the factors which determine an individual’s susceptibility to sugar alcohol-induced diarrhea remain unknown. Here, we show that specific gut bacteria are involved in the suppression of sorbitol-induced diarrhea. Based on 16S rDNA analysis, the abundance of Enterobacteriaceae bacteria increased in response to sorbitol consumption. We found that Escherichia coli of the family Enterobacteriaceae degraded sorbitol and suppressed sorbitol-induced diarrhea. Finally, we showed that the metabolism of sorbitol by the E. coli sugar phosphotransferase system helped suppress sorbitol-induced diarrhea. Therefore, gut microbiota prevented sugar alcohol-induced diarrhea by degrading sorbitol in the gut. The identification of the gut bacteria which respond to and degrade sugar alcohols in the intestine has implications for microbiome science, processed food science, and public health.

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Gut Bacteria Shared by Children and Their Mothers Associate with Developmental Level and Social Deficits in Autism Spectrum Disorder

mSphere ◽

10.1128/msphere.01044-20 ◽

2020 ◽

Vol 5 (6) ◽

Author(s):

Yu Chen ◽

Hui Fang ◽

Chunyan Li ◽

Guojun Wu ◽

Ting Xu ◽

...

Keyword(s):

Autism Spectrum Disorder ◽

Gut Microbiota ◽

Autism Spectrum ◽

Gut Bacteria ◽

Spectrum Disorder ◽

Developmental Level ◽

Social Deficits ◽

Microbial Structure

Gut microbiota may contribute to the pathogenesis and development of autism spectrum disorder. The maternal gut microbiota influences offspring gut microbial structure and composition.

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Wild Apple-Associated Fungi and Bacteria Compete to Colonize the Larval Gut of an Invasive Wood-Borer Agrilus mali in Tianshan Forests

Frontiers in Microbiology ◽

10.3389/fmicb.2021.743831 ◽

2021 ◽

Vol 12 ◽

Author(s):

Tohir A. Bozorov ◽

Zokir O. Toshmatov ◽

Gulnaz Kahar ◽

Daoyuan Zhang ◽

Hua Shao ◽

...

Keyword(s):

Gut Microbiota ◽

Inhibitory Concentration ◽

Fungal Species ◽

Gut Bacteria ◽

Recent Analysis ◽

Fungal Colonization ◽

Antifungal Compound ◽

Concentration Method ◽

Malus Sieversii ◽

Wood Borer

The gut microflora of insects plays important roles throughout their lives. Different foods and geographic locations change gut bacterial communities. The invasive wood-borer Agrilus mali causes extensive mortality of wild apple, Malus sieversii, which is considered a progenitor of all cultivated apples, in Tianshan forests. Recent analysis showed that the gut microbiota of larvae collected from Tianshan forests showed rich bacterial diversity but the absence of fungal species. In this study, we explored the antagonistic ability of the gut bacteria to address this absence of fungi in the larval gut. The results demonstrated that the gut bacteria were able to selectively inhibit wild apple tree-associated fungi. Among them, Pseudomonas synxantha showed strong antagonistic ability, producing antifungal compounds. Using different analytical methods, such as column chromatography, mass spectrometry, HPLC, and NMR, an antifungal compound, phenazine-1-carboxylic acid (PCA), was identified. Activity of the compound was determined by the minimum inhibitory concentration method and electron microscopy. Moreover, our study showed that the gut bacteria could originate from noninfested apple microflora during infestation. Overall, the results showed that in newly invaded locations, A. mali larvae changed their gut microbiota and adopted new gut bacteria that prevented fungal colonization in the gut.

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The gut microbiota: a major player in the toxicity of environmental pollutants?

npj Biofilms and Microbiomes ◽

10.1038/npjbiofilms.2016.3 ◽

2016 ◽

Vol 2 (1) ◽

Cited By ~ 201

Author(s):

Sandrine P Claus ◽

Hervé Guillou ◽

Sandrine Ellero-Simatos

Keyword(s):

Gut Microbiota ◽

Environmental Contaminants ◽

Environmental Pollutants ◽

Gut Bacteria ◽

Environmental Chemicals ◽

Immune Functions ◽

Gastrointestinal Microbiota ◽

Major Player ◽

Gastrointestinal Bacteria ◽

Bidirectional Relationship

Abstract Exposure to environmental chemicals has been linked to various health disorders, including obesity, type 2 diabetes, cancer and dysregulation of the immune and reproductive systems, whereas the gastrointestinal microbiota critically contributes to a variety of host metabolic and immune functions. We aimed to evaluate the bidirectional relationship between gut bacteria and environmental pollutants and to assess the toxicological relevance of the bacteria–xenobiotic interplay for the host. We examined studies using isolated bacteria, faecal or caecal suspensions—germ-free or antibiotic-treated animals—as well as animals reassociated with a microbiota exposed to environmental chemicals. The literature indicates that gut microbes have an extensive capacity to metabolise environmental chemicals that can be classified in five core enzymatic families (azoreductases, nitroreductases, β-glucuronidases, sulfatases and β-lyases) unequivocally involved in the metabolism of >30 environmental contaminants. There is clear evidence that bacteria-dependent metabolism of pollutants modulates the toxicity for the host. Conversely, environmental contaminants from various chemical families have been shown to alter the composition and/or the metabolic activity of the gastrointestinal bacteria, which may be an important factor contributing to shape an individual’s microbiotype. The physiological consequences of these alterations have not been studied in details but pollutant-induced alterations of the gut bacteria are likely to contribute to their toxicity. In conclusion, there is a body of evidence suggesting that gut microbiota are a major, yet underestimated element that must be considered to fully evaluate the toxicity of environmental contaminants.

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Potential Role for the Gut Microbiota in Modulating Host Circadian Rhythms and Metabolic Health

Microorganisms ◽

10.3390/microorganisms7020041 ◽

2019 ◽

Vol 7 (2) ◽

pp. 41 ◽

Cited By ~ 50

Author(s):

Shanthi Parkar ◽

Andries Kalsbeek ◽

James Cheeseman

Keyword(s):

Circadian Rhythms ◽

Gut Microbiota ◽

Gut Bacteria ◽

Current Evidence ◽

Energy Regulation ◽

Eating Patterns ◽

Increased Risk ◽

Production Of Hydrogen ◽

Daily Rhythmicity ◽

Good Sleep

This article reviews the current evidence associating gut microbiota with factors that impact host circadian-metabolic axis, such as light/dark cycles, sleep/wake cycles, diet, and eating patterns. We examine how gut bacteria possess their own daily rhythmicity in terms of composition, their localization to intestinal niches, and functions. We review evidence that gut bacteria modulate host rhythms via microbial metabolites such as butyrate, polyphenolic derivatives, vitamins, and amines. Lifestyle stressors such as altered sleep and eating patterns that may disturb the host circadian system also influence the gut microbiome. The consequent disruptions to microbiota-mediated functions such as decreased conjugation of bile acids or increased production of hydrogen sulfide and the resultant decreased production of butyrate, in turn affect substrate oxidation and energy regulation in the host. Thus, disturbances in microbiome rhythms may at least partially contribute to an increased risk of obesity and metabolic syndrome associated with insufficient sleep and circadian misalignment. Good sleep and a healthy diet appear to be essential for maintaining gut microbial balance. Manipulating daily rhythms of gut microbial abundance and activity may therefore hold promise for a chrononutrition-based approach to consolidate host circadian rhythms and metabolic homeorhesis.

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Long-Term Exposure to Antibiotics Has Caused Accumulation of Resistance Determinants in the Gut Microbiota of Honeybees

mBio ◽

10.1128/mbio.00377-12 ◽

2012 ◽

Vol 3 (6) ◽

Cited By ~ 92

Author(s):

Baoyu Tian ◽

Nibal H. Fadhil ◽

J. Elijah Powell ◽

Waldan K. Kwong ◽

Nancy A. Moran

Keyword(s):

United States ◽

Gut Microbiota ◽

Resistance Genes ◽

Tetracycline Resistance ◽

The United States ◽

Term Treatment ◽

Gut Bacteria ◽

Human Pathogens ◽

Long Term Treatment

ABSTRACT Antibiotic treatment can impact nontarget microbes, enriching the pool of resistance genes available to pathogens and altering community profiles of microbes beneficial to hosts. The gut microbiota of adult honeybees, a distinctive community dominated by eight bacterial species, provides an opportunity to examine evolutionary responses to long-term treatment with a single antibiotic. For decades, American beekeepers have routinely treated colonies with oxytetracycline for control of larval pathogens. Using a functional metagenomic screen of bacteria from Maryland bees, we detected a high incidence of tetracycline/oxytetracycline resistance. This resistance is attributable to known resistance loci for which nucleotide sequences and flanking mobility genes were nearly identical to those from human pathogens and from bacteria associated with farm animals. Surveys using diagnostic PCR and sequencing revealed that gut bacteria of honeybees from diverse localities in the United States harbor eight tetracycline resistance loci, including efflux pump genes (tetB, tetC, tetD, tetH, tetL, and tetY) and ribosome protection genes (tetM and tetW), often at high frequencies. Isolates of gut bacteria from Connecticut bees display high levels of tetracycline resistance. Resistance genes were ubiquitous in American samples, though rare in colonies unexposed for 25 years. In contrast, only three resistance loci, at low frequencies, occurred in samples from countries not using antibiotics in beekeeping and samples from wild bumblebees. Thus, long-term antibiotic treatment has caused the bee gut microbiota to accumulate resistance genes, drawn from a widespread pool of highly mobile loci characterized from pathogens and agricultural sites. IMPORTANCE We found that 50 years of using antibiotics in beekeeping in the United States has resulted in extensive tetracycline resistance in the gut microbiota. These bacteria, which form a distinctive community present in healthy honeybees worldwide, may function in protecting bees from disease and in providing nutrition. In countries that do not use antibiotics in beekeeping, bee gut bacteria contained far fewer resistance genes. The tetracycline resistance that we observed in American samples reflects the capture of mobile resistance genes closely related to those known from human pathogens and agricultural sites. Thus, long-term treatment to control a specific pathogen resulted in the accumulation of a stockpile of resistance capabilities in the microbiota of a healthy gut. This stockpile can, in turn, provide a source of resistance genes for pathogens themselves. The use of novel antibiotics in beekeeping may disrupt bee health, adding to the threats faced by these pollinators.

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Predicted Metabolic Function of the Gut Microbiota of Drosophila melanogaster

mSystems ◽

10.1128/msystems.01369-20 ◽

2021 ◽

Vol 6 (3) ◽

Author(s):

Nana Y. D. Ankrah ◽

Brandon E. Barker ◽

Joan Song ◽

Cindy Wu ◽

John G. McMullen ◽

...

Keyword(s):

Gut Microbiota ◽

Community Composition ◽

Gut Microbiome ◽

Tca Cycle ◽

Gut Bacteria ◽

Growth Patterns ◽

Metabolic Function ◽

Ecological Interactions ◽

Metabolic Interactions ◽

Metabolic Models

ABSTRACT An important goal for many nutrition-based microbiome studies is to identify the metabolic function of microbes in complex microbial communities and their impact on host physiology. This research can be confounded by poorly understood effects of community composition and host diet on the metabolic traits of individual taxa. Here, we investigated these multiway interactions by constructing and analyzing metabolic models comprising every combination of five bacterial members of the Drosophila gut microbiome (from single taxa to the five-member community of Acetobacter and Lactobacillus species) under three nutrient regimes. We show that the metabolic function of Drosophila gut bacteria is dynamic, influenced by community composition, and responsive to dietary modulation. Furthermore, we show that ecological interactions such as competition and mutualism identified from the growth patterns of gut bacteria are underlain by a diversity of metabolic interactions, and show that the bacteria tend to compete for amino acids and B vitamins more frequently than for carbon sources. Our results reveal that, in addition to fermentation products such as acetate, intermediates of the tricarboxylic acid (TCA) cycle, including 2-oxoglutarate and succinate, are produced at high flux and cross-fed between bacterial taxa, suggesting important roles for TCA cycle intermediates in modulating Drosophila gut microbe interactions and the potential to influence host traits. These metabolic models provide specific predictions of the patterns of ecological and metabolic interactions among gut bacteria under different nutrient regimes, with potentially important consequences for overall community metabolic function and nutritional interactions with the host. IMPORTANCE Drosophila is an important model for microbiome research partly because of the low complexity of its mostly culturable gut microbiota. Our current understanding of how Drosophila interacts with its gut microbes and how these interactions influence host traits derives almost entirely from empirical studies that focus on individual microbial taxa or classes of metabolites. These studies have failed to capture fully the complexity of metabolic interactions that occur between host and microbe. To overcome this limitation, we reconstructed and analyzed 31 metabolic models for every combination of the five principal bacterial taxa in the gut microbiome of Drosophila. This revealed that metabolic interactions between Drosophila gut bacterial taxa are highly dynamic and influenced by cooccurring bacteria and nutrient availability. Our results generate testable hypotheses about among-microbe ecological interactions in the Drosophila gut and the diversity of metabolites available to influence host traits.

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Gut microbiota plays a pivotal role in opioid-induced adverse effects in gastrointestinal system

Critical Care ◽

10.1186/s13054-021-03867-0 ◽

2022 ◽

Vol 26 (1) ◽

Author(s):

Rongpeng Xu ◽

Liying Miao ◽

Chun Yang ◽

Bin Zhu

Keyword(s):

Adverse Effects ◽

Gut Microbiota ◽

Gastrointestinal System ◽

Pivotal Role

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Gut Bacteria and Neuropsychiatric Disorders

Microorganisms ◽

10.3390/microorganisms9122583 ◽

2021 ◽

Vol 9 (12) ◽

pp. 2583

Author(s):

Leon M. T. Dicks ◽

Diron Hurn ◽

Demi Hermanus

Keyword(s):

Gut Microbiota ◽

Gut Microbiome ◽

Structural Changes ◽

Neuropsychiatric Disorders ◽

Gut Bacteria ◽

Vast Number ◽

Irritable Bowel ◽

Endocrine Signaling ◽

Gastro Intestinal Tract ◽

External Stimuli

Bacteria in the gut microbiome plays an intrinsic part in immune activation, intestinal permeability, enteric reflex, and entero-endocrine signaling. Apart from physiological and structural changes brought about by gut bacteria on entero-epithelial cells and mucus layers, a vast number of signals generated in the gastro-intestinal tract (GIT) reaches the brain via the vagus nerve. Research on the gut–brain axis (GBA) has mostly been devoted to digestive functions and satiety. Less papers have been published on the role gut microbiota play in mood, cognitive behavior and neuropsychiatric disorders such as autism, depression and schizophrenia. Whether we will be able to fully decipher the connection between gut microbiota and mental health is debatable, especially since the gut microbiome is diverse, everchanging and highly responsive to external stimuli. Nevertheless, the more we discover about the gut microbiome and the more we learn about the GBA, the greater the chance of developing novel therapeutics, probiotics and psychobiotics to treat gastro-intestinal disorders such as inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS), but also improve cognitive functions and prevent or treat mental disorders. In this review we focus on the influence gut bacteria and their metabolites have on neuropsychiatric disorders.

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The Predicted Metabolic Function of the Gut Microbiota of Drosophila melanogaster

10.1101/2021.01.20.427455 ◽

2021 ◽

Author(s):

Nana Y.D. Ankrah ◽

Brandon E. Barker ◽

Joan Song ◽

Cindy Wu ◽

John G. McMullen ◽

...

Keyword(s):

Gut Microbiota ◽

Community Composition ◽

Gut Microbiome ◽

Tca Cycle ◽

Gut Bacteria ◽

Testable Hypothesis ◽

Metabolic Function ◽

Ecological Interactions ◽

Metabolic Interactions ◽

Metabolic Models

ABSTRACTAn important goal for many nutrition-based microbiome studies is to identify the metabolic function of microbes in complex microbial communities and its impact on host physiology. This research can be confounded by poorly-understood effects of community composition and host diet on the metabolic traits of individual taxa. Here, we investigated these multi-way interactions by constructing and analyzing metabolic models comprising every combination of five bacterial members of the Drosophila gut microbiome (from single taxa to the five-member community of Acetobacter and Lactobacillus species) under three nutrient regimes. We show that the metabolic function of Drosophila gut bacteria is dynamic, influenced by community composition and responsive to dietary modulation. Furthermore, we show that ecological interactions such as competition and mutualism identified from the growth patterns of gut bacteria are underlain by a diversity of metabolic interactions, and show that the bacteria tend to compete for amino acids and B vitamins more frequently than for carbon sources. Our results reveal that in addition to fermentation products such as acetate, intermediates of the tricarboxylic acid (TCA) cycle including 2-oxoglutarate and succinate are produced at high flux and cross-fed between bacterial taxa suggesting important roles for TCA cycle intermediates in modulating Drosophila gut microbe interactions and the potential to influence host traits. These metabolic models provide specific predictions of the patterns of ecological and metabolic interactions among gut bacteria under different nutrient regimes, with potentially important consequences for overall community metabolic function and nutritional interactions with the host.IMPORTANCEDrosophila is an important model for microbiome research partly because of the low complexity of its mostly culturable gut microbiota. Our current understanding of how Drosophila interacts with its gut microbes and how these interactions influence host traits derives almost entirely from empirical studies that focus on individual microbial taxa or classes of metabolites. These studies have failed to capture fully the complexity of metabolic interactions that occur between host and microbe. To overcome this limitation, we reconstructed and analyzed 31 metabolic models for every combination of the five principal bacterial taxa in the gut microbiome of Drosophila. This revealed that metabolic interactions between between Drosophila gut bacterial taxa are highly dynamic and influenced by co-occurring bacteria and nutrient availability. Our results generate testable hypothesis about among-microbe ecological interactions in the Drosophila gut and the diversity of metabolites available to influence host traits.

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