Changes in these microbial communities may be responsible for digestive disorders, skin diseases, gum disease and even obesity. Despite their vital imporance in human health and disease, these communities residing within us remain largely unstudied and a concerted research effort needs to be made to better understand them, say researchers today at the th General Meeting of the American Society for Microbiology in Boston.
Int J Mol Sci. Published online Apr 2. Received Feb 5; Accepted Mar This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license http: This article has been cited by other articles in PMC.
Abstract Gut bacteria are an important component of the microbiota ecosystem in the human gut, which is colonized by microbes, ten times more than the human cells. Gut bacteria play an important role in human health, such as supplying essential nutrients, synthesizing vitamin K, aiding in the digestion of cellulose, and promoting angiogenesis and enteric nerve function.
However, they can also be potentially harmful due to the change of their composition when the gut ecosystem undergoes abnormal changes in the light of the use of antibiotics, illness, stress, aging, bad dietary habits, and lifestyle.
Dysbiosis of the gut bacteria communities can cause many chronic diseases, such as inflammatory bowel disease, obesity, cancer, and autism. This review summarizes and discusses the roles and potential mechanisms of gut bacteria in human health and diseases.
Introduction The human gut mucosa consists of epithelial cells, lamia propria, and the muscularis mucosae, which is colonized by microbes [ 1 ]. The number of these microbes is ten times more than the human cells. Gut bacteria are important components of the microbiota ecosystem in the human gut.
Commensal bacteria colonize in the gut shortly after birth and comprise approximate species, most of which are unknown species belonging to anaerobic strains [ 23 ].
The composition and temporal patterns of gut microbiota in infants varies widely and is very different from those in adults.
Furthermore, the intestinal microbiota stabilizes to a more adult-like profile around the age of one year, usually after the introduction of solid foods [ 4 ]. In addition, the composition of the gut bacteria community in the stomach and colon is distinctive, which is mainly due to different physicochemical conditions, such as intestinal motility, pH value, redox condition, nutrients, host secretions e.
Additionally, they can be influenced by many factors, such as the use of antibiotics, illness, stress, aging, bad dietary habits and lifestyle [ 56 ]. Usually, gut bacteria and the host live in a commensal manner. On the one hand, they can supply essential nutrients, synthesize vitamin K, aid in the digestion of cellulose, and promote angiogenesis and enteric nerve function [ 789 ].
Bacteroidetes and Firmicutes are the main bacteria in the metabolism of undigested food remnants. They help to digest dietary fiber and polyphenols by a complex metabolic energy-harvesting mechanism, which is based on cross-feeding and co-metabolism.
In return, commensal bacteria take advantage of theprotective and nutrient-rich environment of the host [ 10 ]. Yet, specialized gut bacteria perform reductive reactions such as methanogenesis, acetogenesis, nitrate reduction, and sulfate reduction [ 11 ].
On the other hand, commensal bacteria and probiotics can promote barrier integrity, and prevent antigens and pathogens from entering the mucosal tissues [ 12 ].
Besides, commensal bacteria contribute to the host defense by regulating the homeostasis of the host immune system [ 13 ].
However, gut bacteria can be potentially harmful when the gut ecosystem undergoes abnormal changes. Dysbiosis of the gut bacteria communities in patients or animal models may cause allergy, inflammatory bowel disease IBDobesity, diabetes, and even cancer [ 89 ].
The composition of gut bacteria can indicate the risk of diseases in each person [ 14 ]. Herein, this review summarizes and highlights the roles and potential mechanisms of gut bacteria in human health and diseases. Understanding of the relationship between gut bacteria and human health can be helpful for targeting new probiotic treatments and novel strategies in treating and managing a wide variety of human diseases.
The literature was sought from the databases PubMed and ISI Web of Knowledge, and the references cited were mainly original articles from — Gut Bacteria in Health The main gut bacterial phyla, in the order of numerical importance, are Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria, Verrucomicrobia and Fusobacteria [ 15 ].
Lactic acid bacteria and Bifidobacteria are two important types of gut bacteria, which are autochthonous ones from birth or acquired from digested food.
Lactobacillus and Leuconostoc spp. Gut bacteria play an important role in human health, including contributing to the host gut defense system and helping the gut to maintain normal function, while its composition can be influenced by the host Figure 1.Jan 05, · Galleria mellonella infection models for the study of bacterial diseases and for antimicrobial drug testing Catherine Jia-Yun Tsai, a, b Jacelyn Mei San Loh, a, b and Thomas Proft a, b a Department of Molecular Medicine & Pathology, School of Medical Sciences, University of Auckland, Auckland, New Zealand.
The study of bacteria is known as bacteriology, a branch of microbiology.
Bacterial diseases are also important in agriculture, with bacteria causing leaf spot, fire blight and wilts in plants, as well as Johne's disease, mastitis, salmonella and anthrax in . 1.
bacterial isolate is spread evenly onto the surface of an agar plate so that when the bacteria grown, it will forma a confluent lawn 2. paper disks impregnated with various antibiotics are placed on the surface of the plate and the antibiotic is allowed to diffuse into the culture medium.
Clinical Research and Field Studies of Infectious Diseases Study Section – CRFS The Clinical Research and Field Studies of Infectious Diseases [CRFS] Study Section reviews translational and applied applications that address population-based studies on the emergence, transmission, spread, control, and prevention of infectious diseases that affect humans.
A new study finds that long-term exposure to periodontal bacteria leads to inflammation and degeneration in brain neurons in mice similar to the effects of Alzheimer's disease in humans. Bacterial Skin Diseases Although the skin normally provides a barrier to infection, when it is penetrated by microorganisms, infection develops.
Diseases of the eye are considered with the skin diseases because both occur at the surface of the body.