scholarly journals Bacteriocins and Bacteriophages: Therapeutic Weapons for Gastrointestinal Diseases?

2019 ◽  
Vol 20 (1) ◽  
pp. 183 ◽  
Author(s):  
Loris Riccardo Lopetuso ◽  
Maria Ernestina Giorgio ◽  
Angela Saviano ◽  
Franco Scaldaferri ◽  
Antonio Gasbarrini ◽  
...  
Keyword(s):  
Gastrointestinal Diseases ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Gut Health ◽  
Complex Environment ◽  
Therapeutic Application ◽  
Human Gut ◽  
Viral Components ◽  
Diverse Groups

Bacteriocins are bactericidal peptides, ribosomally synthesized, with an inhibitory activity against diverse groups of undesirable microorganisms. Bacteriocins are produced by both gram-positive and gram-negative bacteria, and to a lesser extent by some archaea. Bacteriophages are viruses that are able to infect bacterial cells and force them to produce viral components, using a lytic or lysogenic cycle. They constitute a large community in the human gut called the phageome, the most abundant part of the gut virome. Bacteriocins and bacteriophages may have an influence on both human health and diseases, thanks to their ability to modulate the gut microbiota and regulate the competitive relationship among the different microorganisms, strains and cells living in the human intestine. In this review, we explore the role of bacteriocins and bacteriophages in the most frequent gastrointestinal diseases by dissecting their interaction with the complex environment of the human gut, analyzing a possible link with extra-intestinal diseases, and speculating on their possible therapeutic application with the end goal of promoting gut health.

scholarly journals Gut Microbiome and Social Determinants of Health (SDOH)

2020 ◽  
Vol 4 (2) ◽  
pp. 01-05
Author(s):  
Suneeta Kumari
Keyword(s):  
Gut Microbiota ◽  
Gut Microbiome ◽  
Bacterial Cells ◽  
Medical Field ◽  
Human Gut ◽  
Environmental Implications ◽  
Human Microbiota ◽  
The Social ◽  
Tremendous Amount

With technological advancements in the medical field, new discoveries have been unfolded about the human microbiota. A tremendous amount of work has been studied within the last two decades. Some of the human microbiota sites include nonsterile areas such as mouth, skin, gut, nose, and vagina. Additionally, there are bacterial cells in areas that were considered sterile such as lungs and placenta before delivery. Out of all the sites, the gut houses the most with an amount of 100 trillion bacteria (Guinane, 2013). Environmental implications have been known to impact these new areas of medicine. There has been a growing interest by the social epidemiologists on how health inequalities impact the role of human gut microbiota.

scholarly journals The Effects of Mediterranean Diet on the Human Gut Microbiota; a Brief Discussion of Evidence in Humans

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Anita H Kelleher ◽  
Angelos K Sikalidis ◽  
Keyword(s):  
Gut Microbiota ◽  
Mediterranean Diet ◽  
Metabolic Diseases ◽  
Short Chain Fatty Acids ◽  
Gut Health ◽  
Omega 3 ◽  
Bioactive Components ◽  
Human Gut ◽  
The Mediterranean

The Mediterranean diet (MD) is considered one of the healthiest dietary patterns due to its rich provision of phytochemicals, antioxidants, vitamins, fiber, polyunsaturated, omega-3, and short-chain fatty acids through a variety of foods. The supply of such nutrients and bioactive components can support gut health and reduce systemic inflammation, with accumulating evidence from several human studies demonstrating the utility of the Mediterranean diet in the prevention of chronic and metabolic diseases. Further studies are needed to explore the role of the Mediterranean diet protecting against such diseases and the related mechanisms, including the interplay between components of the MD and gut microbiota. This brief systematic review specifically explores the recent evidence in humans investigating the link between MD and the human microbiota. Herein, over 50 articles were revised and referenced, after a careful vetting process, to produce this manuscript. Articles were ultimately selected based upon the detail and novelty of their content and contribution to the field.

RND efflux pumps in Gram-negative bacteria; regulation, structure and role in antibiotic resistance

2020 ◽  
Vol 15 (2) ◽  
pp. 143-157 ◽  
Author(s):  
Abigail L Colclough ◽  
Ilyas Alav ◽  
Emily E Whittle ◽  
Hannah L Pugh ◽  
Elizabeth M Darby ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Efflux Pumps ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Intrinsic Resistance ◽  
Gram Negative ◽  
New Information ◽  
Rnd Efflux Pumps ◽  
Gram Negative Organisms

Rresistance-nodulation-division (RND) efflux pumps in Gram-negative bacteria remove multiple, structurally distinct classes of antimicrobials from inside bacterial cells therefore directly contributing to multidrug resistance. There is also emerging evidence that many other mechanisms of antibiotic resistance rely on the intrinsic resistance conferred by RND efflux. In addition to their role in antibiotic resistance, new information has become available about the natural role of RND pumps including their established role in virulence of many Gram-negative organisms. This review also discusses the recent advances in understanding the regulation and structure of RND efflux pumps.

scholarly journals Exopolysaccharide protectsVibrio choleraefrom exogenous attacks by the type 6 secretion system

2018 ◽  
Vol 115 (31) ◽  
pp. 7997-8002 ◽  
Author(s):  
Jonida Toska ◽  
Brian T. Ho ◽  
John J. Mekalanos
Keyword(s):  
Biofilm Formation ◽  
Potential Role ◽  
Secretion System ◽  
Effector Proteins ◽  
Solid Surfaces ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Macromolecular Protein ◽  
Insight Into

The type 6 secretion system (T6SS) is a nanomachine used by many Gram-negative bacteria, includingVibrio cholerae, to deliver toxic effector proteins into adjacent eukaryotic and bacterial cells. Because the activity of the T6SS is dependent on direct contact between cells, its activity is limited to bacteria growing on solid surfaces or in biofilms.V. choleraecan produce an exopolysaccharide (EPS) matrix that plays a role in adhesion and biofilm formation. In this work, we investigated the effect of EPS production on T6SS activity between cells. We found that EPS produced byV. choleraecells functions as a unidirectional protective armor that blocks exogenous T6SS attacks without interfering with its own T6SS functionality. This EPS armor is effective against both same-species and heterologous attackers. Mutations modulating the level of EPS biosynthesis gene expression result in corresponding modulation inV. choleraeresistance to exogenous T6SS attack. These results provide insight into the potential role of extracellular biopolymers, including polysaccharides, capsules, and S-layers in protecting bacterial cells from attacks involving cell-associated macromolecular protein machines that cannot readily diffuse through these mechanical defenses.

The role of mucosal barriers in human gut health

2021 ◽  
Vol 44 (4) ◽  
pp. 325-341
Author(s):  
Kangseok Seo ◽  
Jeongmi Seo ◽  
Jiyoun Yeun ◽  
Haebin Choi ◽  
Young-In Kim ◽  
...  
Keyword(s):  
Gut Health ◽  
Human Gut

scholarly journals Microbial associations with Microscopic Colitis

2021 ◽  
Author(s):  
Shan Sun ◽  
Ivory Blakley ◽  
Anthony A Fodor ◽  
Temitope O Keku ◽  
John T Woosley ◽  
...  
Keyword(s):  
Chronic Diarrhea ◽  
Alpha Diversity ◽  
Microscopic Colitis ◽  
Gut Health ◽  
Human Gut ◽  
Complex Models ◽  
Microbial Associations ◽  
Descending Colon ◽  
Highly Correlated

BACKGROUND AND OBJECTIVE: Microscopic colitis is a relatively common cause of chronic diarrhea and may be linked to luminal factors. Given the essential role of the microbiome in human gut health, analysis of microbiome changes associated with microscopic colitis could provide insights into the development of the disease. METHODS: We enrolled patients who underwent colonoscopy for diarrhea. An experienced pathologist classified patients as having microscopic colitis (n=52) or controls (n=153). Research biopsies were taken from the ascending and descending colon, and the microbiome was characterized with Illumina sequencing. We analyzed the associations between microscopic colitis and microbiome with a series of increasingly complex models adjusted for a range of demographic and health factors. RESULTS: We found that alpha-diversity was significantly lower in microscopic colitis cases compared to controls in the descending colon microbiome. In the descending colon, a series of models that adjusted for an increasing number of co-variates found taxa significantly associated with microscopic colitis, including Proteobacteria that was enriched in cases and Collinsella enriched in controls. While the alpha-diversity and taxa were not significantly associated with microscopic colitis in the ascending colon microbiome, the inference p-values based on ascending and descending microbiomes were highly correlated. CONCLUSION: Our study demonstrates an altered microbiome in microscopic colitis cases compared to controls. Because both the cases and controls had diarrhea, we have identified candidate taxa that could be mechanistically responsible for the development of microscopic colitis independent of changes to the microbial community caused by diarrhea.

scholarly journals UG/Abi: a highly diverse family of prokaryotic reverse transcriptases associated with defense functions

2021 ◽  
Author(s):  
Mario Rodríguez Mestre ◽  
Linyi Gao ◽  
Shiraz A. Shah ◽  
Adrián López-Beltrán ◽  
Alejandro González-Delgado ◽  
...  
Keyword(s):  
Mobile Genetic Elements ◽  
Abortive Infection ◽  
Human Gut ◽  
Systematic Analysis ◽  
Biotechnological Potential ◽  
Genetic Elements ◽  
Reverse Transcriptases ◽  
Diverse Groups

AbstractReverse transcriptases (RTs) are enzymes capable of synthesizing DNA using RNA as a template. Within the last few years, a burst of research has led to the discovery of novel prokaryotic RTs with diverse antiviral properties, such as DRTs (Defense-associated RTs), which belong to the so-called group of unknown RTs (UG) and are closely related to the Abortive Infection system (Abi) RTs. In this work, we performed a systematic analysis of UG and Abi RTs, increasing the number of UG/Abi members up to 42 highly diverse groups, most of which are predicted to be functionally associated with other gene(s) or domain(s). Based on this information, we classified these systems into three major classes. In addition, we reveal that most of these groups are associated with defense functions and/or mobile genetic elements, and demonstrate the antiphage role of four novel groups. Besides, we highlight the presence of one of these systems in novel families of human gut viruses infecting members of the Bacteroidetes and Firmicutes phyla. This work lays the foundation for a comprehensive and unified understanding of these highly diverse RTs with enormous biotechnological potential.

scholarly journals Assessing the impact of heat treatment on antimicrobial resistant (AMR) genes and their potential uptake by other ‘live’ bacteria

2021 ◽  
Author(s):  
Christian James ◽  
Ronald Dixon ◽  
Luke Talbot ◽  
Stephen James ◽  
Nicola Williams ◽  
...  
Keyword(s):  
Action Plan ◽  
Food Poisoning ◽  
Bacterial Cells ◽  
Human Gut ◽  
The Public ◽  
Live Bacteria ◽  
Exposure Risks ◽  
The Uk ◽  
The Impact

Addressing the public health threat posed by AMR is a national strategic priority for the UK, which has led to both a 20-year vision of AMR and a 5-year (2019 to 2024) AMR National Action Plan (NAP). The latter sets out actions to slow the development and spread of AMR with a focus on antimicrobials. The NAP used an integrated ‘One-Health’ approach which spanned people, animals, agriculture and the environment, and calls for activities to “identify and assess the sources, pathways, and exposure risks” of AMR. The FSA continues to contribute to delivery of the NAP in a number of ways, including through furthering our understanding of the role of the food chain and AMR.Thorough cooking of food kills vegetative bacterial cells including pathogens and is therefore a crucial step in reducing the risk of most forms of food poisoning. Currently, there is uncertainty around whether cooking food is sufficient to denature AMR genes and mobile genetic elements from these ‘dead’ bacteria to prevent uptake by ‘live’ bacteria in the human gut and other food environments - therefore potentially contributing to the overall transmission of AMR to humans. This work was carried out to assess these evidence gaps.

scholarly journals Critical role of the periplasm in copper homeostasis in Gram-negative bacteria

2020 ◽  
Author(s):  
Jun-ichi Ishihara ◽  
Tomohiro Mekubo ◽  
Chikako Kusaka ◽  
Suguru Kondo ◽  
Hirofumi Aiba ◽  
...  
Keyword(s):  
Critical Role ◽  
Copper Homeostasis ◽  
Efflux Pumps ◽  
Ecological Niches ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Gram Negative ◽  
Wide Range ◽  
Periplasmic Proteins

AbstractCopper is essential for life, but is toxic in excess; that is, cells must keep an optimal internal copper concentration. Under aerobic conditions, less toxic Cu(II) taken up by bacterial cells is reduced to more toxic Cu(I) in the cytoplasm. Copper homeostasis is achieved in the cytoplasm and the periplasm as a unique feature of Gram-negative bacteria. The copper efflux pumps, CopA and CusCBA export Cu(I) from the cytoplasm or the periplasm to outside of the cells in Escherichia coli. In addition, the periplasmic proteins, such as a multi-copper oxidase CueO, play a role in the periplasmic detoxification. While the efflux pumps are highly conserved in Gram-negative bacteria, the periplasmic proteins are diversified, indicating that copper homeostasis in the periplasm could contribute to adaptation to various living environments. However, the role of the periplasm and periplasmic proteins in regard to whole-cell copper homeostasis remains unknown. In this study, we addressed the role of the periplasm and periplasmic proteins in copper homeostasis to adapt to various ecological niches. We have used a systems approach, alternating rounds of experiments and models, to further elucidate the dynamics of copper efflux system. We measured the response to copper of the main specific copper export systems in the wild type E. coli strain, and a series of deletion mutant strains. We interpreted these data using a detailed mathematical model and Bayesian model fitting routines, and verified copper homeostasis. Compared with the simulation and the growth in response to copper, we found that the growth was associated with copper abundance in the periplasm. In particular, CueO unique to Gram-negative bacteria contributes both to protection against Cu(I) toxicity and to incorporating copper into the periplasmic components/proteins, resulting in maximizing the growth. These results suggest that Gram-negative bacteria have evolved to utilize the periplasm as a sensor and store for copper, in order to enable Gram-negative bacteria to adapt to a wide range of environmental copper concentrations.

scholarly journals Gut health: predictive biomarkers for preventive medicine and development of functional foods

2010 ◽  
Vol 103 (10) ◽  
pp. 1539-1544 ◽  
Author(s):  
Raish Oozeer ◽  
Maria Rescigno ◽  
R. Paul Ross ◽  
Jan Knol ◽  
Michael Blaut ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Predictive Biomarkers ◽  
Gut Health ◽  
Human Gut ◽  
Observation Study ◽  
Industry Collaboration ◽  
Health And Disease ◽  
Micro Organisms ◽  
First Time

There is an urgent need to develop and validate a series of biomarkers, which accurately measure and inform on how the human gut microbiota can affect human health. The human gut hosts a complex community of micro-organisms, with unique features in each individual. The functional role of this gut microbiota in health and disease is increasingly evident, but poorly understood. Comprehension of this ecosystem implies a significant challenge in the elucidation of interactions between all of its components, but promises a paradigm shift in preventive nutrition and medicine. ‘Omics’ technologies for the first time offer tools of sufficient subtlety to tackle this challenge. However, these techniques must be allied with traditional skills of the microbial physiologist, which are in danger of being lost. Targeting these efforts at the identification of biomarkers associated with gut health will require access to a ‘biobank’ from a pan-European or worldwide observation study, which would include samples taken with appropriate frequency from healthy individuals of different ages. This offers a pragmatic opportunity for a unique food and pharmaceutical industry collaboration.

Sign in / Sign up

Export Citation Format

Share Document