Search results for "Biota"
showing 10 items of 679 documents
Polyamines and microbiota in bicuspid and tricuspid aortic valve aortopathy
2019
Polyamines are small aliphatic cationic molecules synthesized via a highly regulated pathway and involved in general molecular and cellular phenomena. Both mammalian cells and microorganisms synthesize polyamines, and both sources may contribute to the presence of polyamines in the circulation. The dominant location for microorganisms within the body is the gut. Accordingly, the gut microbiota probably synthesizes most of the polyamines in the circulation in addition to those produced by the mammalian host cells. Polyamines are mandatory for cellular growth and proliferation. Established evidence suggests that the polyamine spermidine prolongs lifespan and improves cardiovascular health in …
Composition of Human Breast Milk Microbiota and Its Role in Children's Health
2021
: Human milk contains a number of nutritional and bioactive molecules including microorganisms that constitute the so-called "Human Milk Microbiota (HMM)". Recent studies have shown that not only bacterial but also viral, fungal, and archaeal components are present in the HMM. Previous research has established, a "core" microbiome, consisting of Firmicutes (i.e., Streptococcus, Staphylococcus), Proteobacteria (i.e., Serratia, Pseudomonas, Ralstonia, Sphingomonas, Bradyrhizobium), and Actinobacteria (i.e., Propionibacterium, Corynebacterium). This review aims to summarize the main characteristics of HMM and the role it plays in shaping a child's health. We reviewed the most recent literature…
The intestinal 3M (microbiota, metabolism, metabolome) zeitgeist – from fundamentals to future challenges
2021
The role of the intestine in human health and disease has historically been neglected and was mostly attributed to digestive and absorptive functions. In the past two decades, however, discoveries related to human nutrition and intestinal host-microbe reciprocal interaction have established the essential role of intestinal health in the pathogenesis of chronic diseases and the overall wellbeing. That transfer of gut microbiota could be a means of disease phenotype transfer has revolutionized our understanding of chronic disease pathogenesis. This narrative review highlights the major concepts related to intestinal microbiota, metabolism, and metabolome (3M) that have facilitated our fundame…
Experimental investigation on dispersion mechanisms in rigid and flexible vegetated beds
2018
Vegetation in channels strongly affects flow structure and turbulence, with consequences on the hydrological storage of nutrients and chemical tracers, the shelter of stream biota as well as the trapping or transport of sediments. At the same time, all these phenomena are inevitably subjected to alteration of hydrological conditions in fluvial systems due to climate change. The present study intends to provide a thorough investigation into the processes of transport and dispersion induced by flow turbulence within the vegetation structure. Specifically, velocity measurements in vegetated channels were intensively conducted and analyzed in the case of both flexible submerged and rigid emerge…
Impact of probiotics on risk factors for cardiovascular diseases. A review.
2014
International audience; Probiotic microorganisms have historically been used to rebalance disturbed intestinal microbiota and to diminish gastrointestinal disorders, such as diarrhea or inflammatory bowel diseases (e.g., Crohn's disease and ulcerative colitis). Recent studies explore the potential for expanded uses of probiotics on medical disorders that increase the risk of developing cardiovascular diseases and diabetes, such as obesity, hypercholesterolemia, arterial hypertension, and metabolic disturbances such as hyperhomocysteinemia and oxidative stress. This review aims at summarizing the proposed molecular and cellular mechanisms involved in probiotic-host interactions and to identi…
Coping with cyclic oxygen availability: evolutionary aspects
2007
Both the gradual rise in atmospheric oxygen over the Proterozoic Eon as well as episodic fluctuations in oxygen over several million-year time spans during the Phanerozoic Era, have arguably exerted strong selective forces on cellular and organismic respiratory specialization and evolution. The rise in atmospheric oxygen, some 2 billion years after the origin of life, dramatically altered cell biology and set the stage for the appearance of multicelluar life forms in the Vendian (Ediacaran) Period of the Neoproterozoic Era. Over much of the Paleozoic, the level of oxygen in the atmosphere was near the present atmospheric level (21%). In the Late Paleozoic, however, there were extended times…
HEAT SHOCK PROTEINS AND AUTOIMMUNE SYSTEM ACTIVATION IN IBD: ARTICULAR MANIFESTATIONS AND THE EPIDEMIOLOGICAL FREQUENCY IN ORTHPEDICS
2013
clinical evidence suggest that arthritis is one of the complications of inflammatori bowel disease (IBD) of which the etiological causes are still not completely understood. Among the possible explanations the most probable theory is poor regulation of the intestinal immune system, which causes a cross-like immune reactivity against the resident micro flora. Arthritis is these subjects involves different joints and is asymmetric, with greater involvement of the large joints of the lower limbs. Joints may also be involved with the spinal forms of sacroileitis and ankilosing spondylitis. This clinical evidence explains the existence of Lesnioski-Crohn's disease, a variant of IBD in which pati…
Food-mediated modulation of immunity in a phytophagous insect: An effect of nutrition rather than parasitic contamination.
2015
7 pages; International audience; Inherent to the cost of immunity, the immune system itself can exhibit tradeoffs between its arms. Phytophagous insects face a wide range of microbial and eukaryotic parasites, each activating different immune pathways that could compromise the activity of the others. Feeding larvae are primarily exposed to microbes, which growth is controlled by antibiotic secondary metabolites produced by the host plant. The resulting variation in abundance of microbes on plants is expected to differentially stimulate the insect antimicrobial immune defenses. Under the above tradeoff hypothesis, stimulation of the insect antimicrobial defenses is expected to compromise imm…
Microbial symbionts of parasitoids
2020
Parasitoids depend on other insects for the development of their offspring. Their eggs are laid in or on a host insect that is consumed during juvenile development. Parasitoids harbor a diversity of microbial symbionts including viruses, bacteria, and fungi. In contrast to symbionts of herbivorous and hematophagous insects, parasitoid symbionts do not provide nutrients. Instead, they are involved in parasitoid reproduction, suppression of host immune responses, and manipulation of the behavior of herbivorous hosts. Moreover, recent research has shown that parasitoid symbionts such as polydnaviruses may also influence plant-mediated interactions among members of plant-associated communities…
Microbiome Changes in Connective Tissue Diseases and Vasculitis: Focus on Metabolism and Inflammation
2022
The microbial community acts as an active player in maintaining homeostasis and immune functions through a continuous and changeable cross-talk with the host immune system. Emerging evidence suggests that altered microbial composition, known as dysbiosis, might perturb the delicate balance between the microbiota and the immune system, triggering inflammation and potentially contributing to the pathogenesis and development of chronic inflammatory diseases. This review will summarize the current evidence about the microbiome-immunity cross-talk, especially focusing on the microbiota alterations described in patients with rheumatic diseases and on the recent findings concerning the interaction…