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Frontiers in Microbiology 2022The intestinal tract of a healthy body is home to a large variety and number of microorganisms that will affect every aspect of the host's life. In recent years,... (Review)
Review
The intestinal tract of a healthy body is home to a large variety and number of microorganisms that will affect every aspect of the host's life. In recent years, polysaccharides have been found to be an important factor affecting intestinal flora. Polysaccharides are widely found in nature and play a key role in the life activities of living organisms. In the intestinal tract of living organisms, polysaccharides have many important functions, such as preventing the imbalance of intestinal flora and maintaining the integrity of the intestinal barrier. Moreover, recent studies suggest that gut microbes can influence brain health through the brain-gut axis. Therefore, maintaining brain health through polysaccharide modulation of gut flora deserves further study. In this review, we outline the mechanisms by which polysaccharides maintain normal intestinal flora structure, as well as improving cognitive function in the brain the brain-gut axis by virtue of the intestinal flora. We also highlight the important role that gut microbes play in the pathogenesis of depression and the potential for treating depression through the use of polysaccharides to modulate the intestinal flora.
PubMed: 35369451
DOI: 10.3389/fmicb.2022.807076 -
Frontiers in Cellular and Infection... 2020Yeasts of the genus, , formerly known as , are lipophilic yeasts, which are a part of the normal skin flora (microbiome). colonize the human skin after birth and must... (Review)
Review
Yeasts of the genus, , formerly known as , are lipophilic yeasts, which are a part of the normal skin flora (microbiome). colonize the human skin after birth and must therefore, as commensals, be normally tolerated by the human immune system. The yeasts also have a pathogenic potential where they can, under appropriate conditions, invade the stratum corneum and interact with the host immune system, both directly but also through chemical mediators. The species distribution on the skin and the pathogenetic potential of the yeast varies between different related diseases such as head and neck dermatitis, seborrheic dermatitis, pityriasis versicolor, and folliculitis. The diagnostic methods used to confirm the presence of yeasts include direct microcopy, culture based methods (often a combination of morphological features of the isolate combined with biochemical test), molecular based methods such as Polymerase Chain Reaction techniques, and Matrix Assisted Laser Desorption/Ionization-Time Of Flight mass spectrometry and the chemical imprint method Raman spectroscopy. Skin diseases caused by are usually treated with antifungal therapy and if there are associated inflammatory skin mechanisms this is often supplemented by anti-inflammatory therapy. The aim of this paper is to provide an overview of related skin disease, diagnostic methods and treatment options.
Topics: Dermatitis, Seborrheic; Folliculitis; Humans; Malassezia; Skin; Tinea Versicolor
PubMed: 32266163
DOI: 10.3389/fcimb.2020.00112 -
Indian Journal of Medical Microbiology 2013Bacterial translocation is the invasion of indigenous intestinal bacteria through the gut mucosa to normally sterile tissues and the internal organs. Sometimes instead... (Review)
Review
Bacterial translocation is the invasion of indigenous intestinal bacteria through the gut mucosa to normally sterile tissues and the internal organs. Sometimes instead of bacteria, inflammatory compounds are responsible for clinical symptoms as in systemic inflammatory response syndrome (SIRS). The difference between sepsis and SIRS is that pathogenic bacteria are isolated from patients with sepsis but not with those of SIRS. Bacterial translocation occurs more frequently in patients with intestinal obstruction and in immunocompromised patients and is the cause of subsequent sepsis. Factors that can trigger bacterial translocation from the gut are host immune deficiencies and immunosuppression, disturbances in normal ecological balance of gut, mucosal barrier permeability, obstructive jaundice, stress, etc. Bacterial translocation occurs through the transcellular and the paracellular pathways and can be measured both directly by culture of mesenteric lymph nodes and indirectly by using labeled bacteria, peripheral blood culture, detection of microbial DNA or endotoxin and urinary excretion of non-metabolisable sugars. Bacterial translocation may be a normal phenomenon occurring on frequent basis in healthy individuals without any deleterious consequences. But when the immune system is challenged extensively, it breaks down and results in septic complications at different sites away from the main focus. The factors released from the gut and carried in the mesenteric lymphatics but not in the portal blood are enough to cause multi-organ failure. Thus, bacterial translocation may be a promoter of sepsis but not the initiator. This paper reviews literature on the translocation of gut flora and its role in causing sepsis.
Topics: Bacterial Translocation; Gastrointestinal Tract; Humans; Sepsis
PubMed: 24064638
DOI: 10.4103/0255-0857.118870 -
Infectious Disease Clinics of North... Mar 1988The study of the human resident flora has grown from Antony van Leeuwenhoek's simple descriptions some 300 years ago to the sophisticated investigations being done... (Review)
Review
The study of the human resident flora has grown from Antony van Leeuwenhoek's simple descriptions some 300 years ago to the sophisticated investigations being done today. The acquisition of organisms and the subsequent course of either stable colonization or invasion of the host involve complex host-parasite interactions. From one perspective, clearly host factors are operative that appear to select against certain species while being permissive for others. From another perspective, microbial species that are successful at colonization must overcome certain host factors to maintain a selective advantage and flourish within a particular body habitat. It is intriguing that whereas host mucosal defenses are a significant influence contributing to selection of the resident flora, it is this established flora that provides the host with perhaps its most important local defense system. In the head and neck areas, many of these mucosal surfaces are contiguous and thus for the most part share a common resident flora. These organisms are rarely involved in infection unless some breach of the mucosal surface or some upset in the balance of the normal flora occurs. On these occasions, the host is susceptible to infection from both newly acquired organisms and those previously present, which may now become invasive. In any event, it is clear that improved knowledge of the normal flora of the head and neck is essential for understanding and for effective treatment of infectious processes in this area. It is hoped that a better appreciation of the important role of the normal flora in maintaining the host mucosal defenses will further focus our attention on its preservation.
Topics: Head; Humans; Immunity, Innate; Mucous Membrane; Neck
PubMed: 3074102
DOI: No ID Found -
Anaerobe Dec 2011When investigating different disturbances of the normal intestinal flora causing disorders and/or diseases in man and animal, these studies include comparisons of...
When investigating different disturbances of the normal intestinal flora causing disorders and/or diseases in man and animal, these studies include comparisons of results with control materials, i.e., materials from conventional laboratory animals or healthy human beings. However, how "normal" is the control group's flora? In this paper two different examples will be discussed; one investigation with laboratory animals and one from a human study.
Topics: Animals; Bacteria; Bacterial Load; Biota; Female; Gastrointestinal Tract; Humans; Male; Middle Aged; Rats; Rats, Sprague-Dawley
PubMed: 21621623
DOI: 10.1016/j.anaerobe.2011.05.003 -
Veterinary Research 2001The normal bacterial flora contains antibiotic resistance genes to various degrees, even in individuals with no history of exposure to commercially prepared antibiotics.... (Review)
Review
The normal bacterial flora contains antibiotic resistance genes to various degrees, even in individuals with no history of exposure to commercially prepared antibiotics. Several factors seem to increase the number of antibiotic-resistant bacteria in feces. One important factor is the exposure of the intestinal flora to antibacterial drugs. Antibiotics used as feed additives seem to play an important role in the development of antibiotic resistance in normal flora bacteria. The use of avoparcin as a feed additive has demonstrated that an antibiotic considered "safe" is responsible for increased levels of antibiotic resistance in the normal flora enterococci of animals fed with avoparcin and possibly in humans consuming products from these animals. However, other factors like stress from temperature, crowding, and management also seem to contribute to the occurrence of antibiotic resistance in normal flora bacteria. The normal flora of animals has been studied with respect to the development of antibiotic resistance over four decades, but there are few studies with the intestinal flora as the main focus. The results of earlier studies are valuable when focused against the recent understanding of mobile genetics responsible for bacterial antibiotic resistance. New studies should be undertaken to assess whether the development of antibiotic resistance in the normal flora is directly linked to the dramatic increase in antibiotic resistance of bacterial pathogens. Bacteria of the normal flora, often disregarded scientifically, should be studied with the intention of using them as active protection against infectious diseases and thereby contributing to the overall reduction of use of antibioties in both animals and humans.
Topics: Animal Diseases; Animal Feed; Animals; Anti-Bacterial Agents; Drug Resistance, Microbial; Escherichia coli; Feces; Intestines; Respiratory System; Skin
PubMed: 11432415
DOI: 10.1051/vetres:2001121 -
Annali Dell'Istituto Superiore Di Sanita 1979The A. reports on the composition of the bacterial flora being present all through the intestine of normal adults in the United Kingdom, listing the number and families... (Review)
Review
The A. reports on the composition of the bacterial flora being present all through the intestine of normal adults in the United Kingdom, listing the number and families of the aerobes and anaerobes occupying the various portions of the alimentary tract. Emphasis is then laid on a comparison between the normal "British" flora in the colon and rectum, where the ratio of anaerobes to aerobes is 100 to 1, and the flora found in normal adults in Africa, India and Japan, stressing the major differences in the numbers of clostridia and non-sporing anaerobes. The A. finally highlights the importance of the factors governing the intestinal bacterial ecology, as well as the serious consequences likely to arise from the alteration of such flora.
Topics: Actinomycetaceae; Adult; Anaerobiosis; Bacteria; Bacteroidaceae; Diet; Enterobacteriaceae; Feces; Humans; Intestines; Mouth; Stomach; United Kingdom
PubMed: 399836
DOI: No ID Found