Microbiota intestinal en la salud humana / Gut microbiota in human health

Introducción: La microbiota describe a un grupo de microorganismos en una región o período de tiempo que incluye: bacterias, arqueas, protistas, hongos y virus. Objetivos: Explicar la función de la microbiota intestinal en la salud humana. Métodos: Se realizó una búsqueda en diferentes de bases de datos como NHI, Ebsco y PubMed en idioma español e inglés, se revisó un total de 17 artículos de los cuales el mayor por ciento es de menos de 5 años. Resultados: Las microbiota intestinal en su mayoría se compone de Gram negativa, con una pared celular rica en lipopolisacáridos (LPS) que potencia a la inmunidad innata por interacción de receptor Toll-like (TLR) ligando, desencadena la producción de citoquinas proinflamatorias, entre otros. Conclusiones: La microbiota intestinal funciona como un señalizador antiinflamatorio y regulador de la permeabilidad epitelial intestinal(AU)

Introduction: Microbiota describes a group of microorganisms in a region or period of time that includes bacteria, archaea, protists, fungi, and viruses. Objectives: To explain the role of the intestinal microbiota in human health. Methods: A search was carried out in different databases such as NHI, Ebsco and PubMed in Spanish and English, a total of 17 articles were reviewed, most of them are less than 5 years. Results: Intestinal microbiota is mostly composed of Gram negative, with a cell wall rich in lipopolysaccharides (LPS) that enhances innate immunity by Toll-like receptor (TLR) ligand interaction, triggers the production of proinflammatory cytokines, among others. Conclusions: Intestinal microbiota functions as an anti-inflammatory signaling agent and regulator of intestinal epithelial permeability(AU)

Helicobacter pylori may participate in the development of inflammatory bowel disease by modulating the intestinal microbiota / 中华医学杂志(英文版)

Inflammatory bowel disease (IBD) is a non-specific inflammatory disease of the gastrointestinal (GI) tract that is generally accepted to be closely related to intestinal dysbiosis in the host. GI infections contribute a key role in the pathogenesis of IBD; however, although the results of recent clinical studies have revealed an inverse correlation between Helicobacter pylori (H. pylori) infection and IBD, the exact mechanism underlying the development of IBD remains unclear. H. pylori, as a star microorganism, has been a focus for decades, and recent preclinical and real-world studies have demonstrated that H. pylori not only affects the changes in the gastric microbiota and microenvironment but also influences the intestinal microbiota, indicating a potential correlation with IBD. Detailed analysis revealed that H. pylori infection increased the diversity of the intestinal microbiota, reduced the abundance of Bacteroidetes, augmented the abundance of Firmicutes, and produced short-chain fatty acid-producing bacteria such as Akkermansia. All these factors may decrease vulnerability to IBD. Further studies investigating the H. pylori-intestinal microbiota metabolite axis should be performed to understand the mechanism underlying the development of IBD.

Characterization of metal(loid)s and antibiotic resistance in bacteria of human gut microbiota from chronic kidney disease subjects

BACKGROUND: Human Gut Microbiota (HGM) is composed of more than one thousand species, playing an important role in the health status of individuals. Dysbiosis (an HGM imbalance) is augmented as chronic kidney disease (CKD) progresses, as loss of kidney function accelerates. Increased antibiotic use in CKD subjects and consumption of nephrotoxic heavy metals and metalloids such as lead, cadmium, arsenic, and mercury in tap water increases the dysbiosis state. Studies in people with stage 3 CKD are complex to carry out, mainly because patients are self-reliant who rarely consult a specialist. The current work focused on this type of patient. RESULTS: Lead and arsenic-resistant bacteria were obtained from self-reliant (that stands on its own) stage 3 CKD subjects. Pathogen-related Firmicutes and Proteobacteria genus bacteria were observed. Resistance and potentiation of antibiotic effects in the presence of metal(loid)s in vitro were found. Furthermore, the presence of the following genes markers for antibiotic and metal(loid) resistance were identified by qPCR: oxa10, qnrB1, mphB, ermB, mefE1, arr2, sulll, tetA, floR, strB, dhfr1, acrB, cadA2k, cadA3k, arsC, pbrA. We observed a decrease in the number of metal resistance markers. CONCLUSIONS: The presence of cadA and arsC genetic markers of antibiotics and metal(loid)s resistance were detected in samples from stage 3 CKD subjects. Lower gene amplification in advanced stages of CKD were also observed, possibly associated with a decrease in resident HGM during kidney disease progression.

Facilitating the gut brain axis by probiotic bacteria to modulate neuroimmune response on lead exposed zebra fish models

Unravelling the efficacy of gut biome has a major impact on health. An unbalanced microbiome composition is linked to many common illnesses such as gut dysbiosis, mental deformities and immunological imbalance. An optimistic influence on the gut biome can be made by consumingprobiotics. This would stimulate neuroprotection and immunomodulation intended by heavy metals pollution. Lead is a major source of neurotoxin that can induce neural deformities. Lactobacillusspecies isolated from curd were characterized to confirm its specificity. Zebra fish was reared at standard conditions and preclinical assessment on the intensity of induced neurotoxin lead was performed. The embryo toxic assay, immunomodulation effects and animal behavioural models endorsed the consequence of neurotoxicity. Different concentrations of bacterial isolate with standard antidepressant was considered for analysing the vigour of toxicity and its influence on cognitive behaviour by novel tank diving method. The restrain in the animal behaviour was also conferred by all the test samples with a decreased bottom dwelling time which was authenticated with haematology and histopathological studies. The alterations in morphology of the lymphocytes were balanced by the treated test samples. This study paves a twofold potential of probiotic as neuroprotectant and immune modulator against heavy metal toxicity.

Gut microbiota in Mexican patients with common variable immunodeficiency

Introduction: Common variable immunodeficiency (CVID) is the main symptomatic primary immunodeficiency and is associated with complex immune disorders. Gut microbiota interacts closely with the immune system, and intestinal dysbiosis is related to multiple diseases. Objective: To describe for the first time the composition of gut microbiota in Mexican patients with CVID. Methods: Fecal samples from five patients with CVID were collected and massive sequencing of the V3-V4 region of 16S rRNA gene was carried out using illumina technology. Results: Bacterial relative abundance was observed at all taxonomic levels. Firmicutes, Actinobacteria and Verrucomicrobia were the predominant phyla. The Clostridia class and the Clostridial order were the most common in their respective taxon; the Ruminococcaceae family predominated. A total of 166 genera were reported, with the most abundant being Faecalibacterium. Five species were identified, but only Bifidobacterium longum was present in all patients. Conclusions: Unlike healthy subjects' gut microbiota, where Firmicutes and Bacteroidetes predominate, the microbiota of the patients with CVID considered in this study was abundant in Firmicutes, Actinobacteria and Verrucomicrobia. The low presence of Bacteroidetes and high abundance of Firmicutes might indicate the existence of intestinal dysbiosis in these patients.

Disruption of the Gut Ecosystem by Antibiotics

The intestinal microbiota is a complex ecosystem consisting of various microorganisms that expands human genetic repertoire and therefore affects human health and disease. The metabolic processes and signal transduction pathways of the host and intestinal microorganisms are intimately linked, and abnormal progression of each process leads to changes in the intestinal environment. Alterations in microbial communities lead to changes in functional structures based on the metabolites produced in the gut, and these environmental changes result in various bacterial infections and chronic enteric inflammatory diseases. Here, we illustrate how antibiotics are associated with an increased risk of antibiotic-associated diseases by driving intestinal environment changes that favor the proliferation and virulence of pathogens. Understanding the pathogenesis caused by antibiotics would be a crucial key to the treatment of antibiotic-associated diseases by mitigating changes in the intestinal environment and restoring it to its original state.

Fecal transplantation: passing fashion or here to stay?

Several trillions of bacteria, distributed among more than 1,000 species, are natural inhabitants of the human intestinal tract and constitute what is now known as the gut microbiota. Although its composition varies within and between individuals with age, diet, and health status, it is becoming increasingly recognized that imbalances in the bacterial microbiota (dysbiosis) are linked to a number of conditions such as antibiotic-associated diarrhea, inflammatory bowel disease, and obesity, among others. Fecal transplantation where a preparation of stool from a microbiologically screened donor is administered into the colon of an affected recipient has been shown to be highly effective for the treatment of recurrent Clostridium difficile infection. Several trials of this therapy are now underway for gut dysbiosis in a number of patient disease groups raising concerns on the risk of transmission of infectious agents from donor to recipient, possible long-term adverse consequences of treatment, and effective regulation of the stool material used for the procedure. A worrying aspect is the emergence of private stool banks providing samples to the general public for self-administration.