Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “INTESTINAL MICROORGANISMS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,423 records · Page 79Linked to original sources
PubMedDate not supplied

[Biological activity of Spirulina].

In this review information of Spirulina platensis (SP), a blue-green alga (photosynthesizing cyanobacterium) having diverse biological activity is presented. Due to high content of highly valuable proteins, indispensable amino acids, vitamins, beta-carotene and other pigments, mineral substances, indispensable fatty acids and polysaccharides, PS has been found suitable for use as bioactive additive. SP produces an immunostimulating effect by enhancing the resistance of humans, mammals, chickens and fish to infections, the capacity of influencing hemopoiesis, stimulating the production of antibodies and cytokines. Under the influence of SP macrophages, T and B cells are activated. SP sulfolipids have proved to be effective against HIV. Preparations obtained from SP biomass have also been found active against herpesvirus, cytomegalovirus, influenza virus, etc. SP extracts are capable in inhibiting cancerogenesis. SP preparations are regarded as functional products contributing to the preservation of the resident intestinal microflora, especially lactic acid bacilli and bifidobacteria, and to a decrease in the level of Candida albicans. The biological activity of SP with respect to microorganisms holds good promise for using these microalgae as components of culture media.

Adjuvants, Immunologic↗
PubMedDate not supplied

Resistance of Enterococcus strains isolated from pigs to gastrointestinal tract and antagonistic effect against Escherichia coli K88.

The intestinal flora plays an important role in health and wellbeing of different organisms. Indigenous microflora can be innocuous or pathogenic. Consumption of food supplemented with beneficial microorganisms as probiotics provides a good health state and this can be maintained and recovered. Currently, probiotic strains of Bifidobacterium and Lactobacillus are widely used in humans as well as animals. Swine industry would benefit with the application of probiotics, mainly to overcome diarrheal diseases produced by different causes, as a pathogenic E. coli K88. The aim of this work was to isolate strains of Enterococcus from gastrointestinal tract of pigs to use them as probiotic. Two strains of E. faecalis, 2 of E. mundii and 7 of E. faecium were isolated with characteristics of resistance to acid pH, tolerance to biliary salts and a high antagonistic activity (>80%) against E. coli K88. Based on their characteristics and species affinity, we believe that these strains could be administered to pigs as a probiotic.

Animals↗
PubMedDate not supplied

Gastric carcinoma: the Helicobacter pylori trail.

Gastric carcinoma is the world's overall second most common cancer. Besides obvious environmental factors, recent epidemiological studies and a better knowledge of Helicobacter Pylori biological properties revealed that the microorganism is involved in the first steps of gastric carcinogenesis as proposed by the Correa model (from normal gastric tissue through superficial gastritis, multifocal atrophic gastritis, intestinal metaplasia and dysplasia to carcinoma). Significant correlation between the prevalence of H. pylori infection and incidence of gastric carcinoma (mainly the intestinal type) in various geographical areas has been reported. The high prevalence of HP in pre-neoplastic states and in cases of early gastric cancer indicates the infection would precede the development of gastric cancer. HP-related chronic inflammation of gastric mucosa with increased mucosal cell proliferation, deficit in local ascorbic acid concentration, topical ammonia toxicity are putative mechanisms that overexpose a weakened gastric mucosa to environmental carcinogens.

Epidemiologic Methods↗
PubMed2001

Molecular diversity in the biosynthesis of GI tract glycoconjugates. A blood-group-related chart of microorganism receptors.

This paper examines the potential of carbohydrate blood-group antigens present on mucosal surfaces in acting as receptors for microorganisms. Mucosal surfaces express significant amounts of carbohydrate blood-group antigens under the control of the Secretor, Lewis and ABO systems. The exact glycoconjugate profile an individual presents to the lumen is complex, and can only be correctly determined by a combination of serology and genotyping. We have isolated and structurally resolved the glycolipids expressed in the small intestine of group O individuals having various common or rare phenotypes. Using this information, we have been able to construct a biosynthetic pathway and propose that the type, size and glycotopes expressed, are controlled to a major extent by blood-group-related glycosyltransferases. Many of these glycotopes are potential receptors for microorganisms; some resemble tumour antigens, while others resemble the lipopolysaccharides of some pathogens. Although the origins of the blood-group glycosyltransferases remain uncertain, it is evident that they significantly diversify the mucosal glycotopes exposed to microbes; and therein may be found a potential explanation for their existence.

ABO Blood-Group System↗
PubMed1991

[The effect of chemical preparations on the biological properties of the intestinal lactobacilli in experimental animals].

The oral administration of the therapeutic doses of tetracycline, pefloxacin, ampicillin, cephalexin, rifampicin, sisomicin to Wistar rats for 5 days was accompanied by a decrease in the total number of lactobacilli in feces and by changes of the species spectre of these microorganisms. In those rats species, never found in intact animals, could be revealed rather frequently. All antimicrobial preparations administered in this investigation induced a decrease in the proportion of antibiotic-sensitive cultures and led to the selection of strains having multiresistance and increased antagonistic activity with respect to Pseudomonas indicator strain. The possible relationship between the markers antibiotic resistance and antagonistic activity in lactobacilli is discussed.

Administration, Oral↗
PubMedDate not supplied

Impact of oral ciprofloxacin on the faecal flora of healthy volunteers.

The intestinal flora was studied in 12 volunteers after the administration of 400 mg ciprofloxacin b.i.d. over seven days. Stool samples were taken prior to and several times after the initiation of therapy, and qualitative and quantitative analyses of microorganisms were performed. Escherichia coli was eliminated in all volunteers after two days of treatment. A selection of resistant enterobacteria could not be observed. A higher incidence of Streptococcus faecium was seen, mainly after the end of drug application. The number of cfu of Bacteroides and Bifidus species remained unchanged during the trial. There was no selection of Clostridium difficile. Based on this pattern of activity on the stool flora we suggest that ciprofloxacin could represent an appropriate drug for the therapy of bacterial intestinal infections as well as for selective decontamination in immunosuppressed patients.

Administration, Oral↗
PubMed2005

Isoflavones and functional foods alter the dominant intestinal microbiota in postmenopausal women.

Dietary phytoestrogens, such as isoflavones, are used as food additives to prevent menopause-related disorders. In addition to other factors, their bioavailability strongly depends on the activity of intestinal bacteria but the underlying interactions remain poorly understood. A randomized, double-blind, placebo-controlled study was undertaken with 39 postmenopausal women to characterize changes in the dominant microbial communities of the intestinal tract after 2 mo of isoflavone supplementation with and without pro- or prebiotic. The diversity and composition of the dominant microbiota were analyzed by temporal temperature-gradient gel electrophoresis (TTGE) and fluorescent in situ hybridization. Isoflavones alone stimulated dominant microorganisms of the Clostridium coccoides-Eubacterium rectale cluster, Lactobacillus-Enterococcus group, Faecalibacterium prausnitzii subgroup, and Bifidobacterium genus. The stimulation of the Clostridium coccoides-Eubacterium rectale cluster depended on the women's equol excretion and was transient, with the exception of a prolonged bifidogenic effect. Lasting changes in the diversity of the dominant species were also observed. The probiotic strain supplied could be detected by TTGE during its passage through the intestinal tract, and ingestion of fructooligosaccharides triggered a marked and specific bifidogenic effect. In conclusion, this is the first human study that shows changes in the diversity and composition of dominant bacterial communities in response to dietary supplementation with hormone-related compounds combined with functional foods.

Aged↗
PubMed1991

The scanning electron microscope: how valuable in the evaluation of small bowel mucosal pathology in chronic childhood diarrhea?

Data are presented on scanning electron microscopy (SEM) on small intestinal biopsies of children with chronic diarrhea. In particular, there were 230 patients aged 3 months to 13 years with the following diagnoses: chronic nonspecific diarrhea, cow's milk protein intolerance, soy protein intolerance, giardiasis, cystic fibrosis, gluten-sensitive enteropathy, isolated lactase deficiency, isolated sucrase-isomaltase lactase deficiency, microvillus inclusion disease, rotavirus enteritis, protracted diarrhea of infancy, chylomicron retention disease, visceral myopathy and villous asthenia. Examination of biopsied intestinal mucosa by SEM has yielded important new information and insights on structural pathology and ultrastructural topography. Many of the observed changes helped to better understand the pathophysiology of some of the diarrheal disorders. SEM was also able to detect new features such as mycoplasma-like microorganisms and the absence of the glycocalyx. To adequately assess small bowel mucosal pathology at the ultrastructural level, scanning electron microscopy is an indispensable tool.

Adolescent↗
PubMedDate not supplied

[Probiotics--possibilities and limitations of their application in food, animal feed, and in pharmaceutical preparations for men and animals].

Probiotics are cultures of special microorganisms, which have been used as feed additives since the seventies of the past century and already since the twenties in food specimen and in pharmaceuticals. The definition of "Probioticum" was formulated in 1974 simultaneously with the use of living cultures in feed for various animals in order to substitute the application of nutritive antibiotics or chemotherapeutics. In the meantime probiotics are applied not only as feed supplements or pharmaceuticals but increasingly in suitable food specimens such as dairy products, fruit juices, chocolates, and even meat products. Of course, heating of such products prior to consumption or application must be ruled out. The selection of a suitable strain of a microorganism can be regarded as the primary requirement for the use as a probiotic. These cultures must be able to pass the stomach-duodenum barrier in a viable state and to multiply at the site of destination in the intestine. Additionally, they must be capable of producing antagonistic metabolites against a dominating saprophytic microflora resulting in a competitive growth. These abilities are common among lactic acid bacteria, e.g. lactobacilli and bifidobacteria. Yet, intended autochthonous species do not possess very good technological features for the enrichment in food specimens, because their viability will decrease rapidly under unfavourable conditions as it is the case with mineral supplements in feed or with low acidity in fermented dairy products. Therefore, some other microorganisms like spore-forming species or yeast cultures were introduced as probiotic components. These possess some similar features which render them suitable for probiotic use. But their physiological and ecological traits do not qualify them as probiotics of first choice. The special efficacy of probiotics must be strictly verified in animal nutrition due to restrictive EC-regulations, in pharmacy due to legal restraints, and in food applications in accordance with food law regulations. Safety aspects are considered very restrictively in feed applications, in the food and pharmaceutical sector they should be in accordance with the intended purpose of "fulfilling health claims". In the presented review the different requirements for the application of probiotics in animal nutrition, in food, and in pharmaceuticals will be provided. The special effect of competitive exclusion of pathogenetic and toxinogenic microorganisms in fowl performance are mentioned and even the application of probiotics as marine aquacultures of fish and Crustaceae will be included. Furthermore, the safety aspects resulting from the tremendous amount of industrially produced cultures which are distributed into the environment will be discussed. In conclusion it may be pointed out that probiotics may serve to partially replace the presently reduced or even prohibited application of nutritive antibiotics or chemotherapeutics in animal nutrition and in fulfillment of health claims in man and animals. Economic and environmental aspects will reduce the overall application of probiotics world-wide. Restrictions of use and controls of efficacy and safety are essential and must be implemented periodically.

Animal Feed↗
PubMedDate not supplied

Microencapsulation of L. acidophilus (La-05) and B. lactis (Bb-12) and evaluation of their survival at the pH values of the stomach and in bile.

Microcapsules were prepared using the probiotic microorganisms Lactobacillus acidophilus (La-05) and Bifidobacterium lactis (Bb-12) and the spray drying technique and cellulose acetate phthalate as the wall material. This study evaluated the resistance of these microorganisms to drying at three temperatures and also the in vitro tolerance of the free and microencapsulated form to pH values and bile concentrations similar to those found in the human stomach and intestine. With an air entry temperature of 130 degrees C and exit temperature of 75 degrees C, the number of viable cells of B. lactis was practically unaltered, whereas the population of L. acidophilus was reduced by two logarithmic cycles. B. lactis was more resistant to the drying process than L. acidophilus under all conditions tested. The morphology of the microcapsules was determined by scanning electron microscopy and the microcapsules presented a rounded external surface containing concavities, a continuous wall with no apparent porosity, average size of 22 microm, moisture content varying from 5.3 to 3.2% and water activity between 0.230 and 0.204. After inoculation into HCl solutions with pH values adjusted to 1 and 2, incubated anaerobically at 37 degrees C, and plated after 0, 1 and 2 h of incubation, microcapsules were effective in protecting the microorganisms, while the populations of both free microorganisms were eliminated after only 1 h at the acidic conditions. Microencapsulated B. lactis and L. acidophilus, both free and microencapsulated, were also resistant after 12h to bile solutions.

Bifidobacterium↗
PubMedDate not supplied

[The intestinal microflora of patients with inflammatory diseases of the maxillofacial area].

The microflora of the large intestine in patients with odontogenic phlegmons of different localization were studied. 80.8% of such patients were found to have microecological disturbances, characterized by a decrease in the number of bacteria belonging to the genera Bifidobacterium, Lactobacillus, Enterococcus and Bacteroides and by an increase in the number of opportunistic microorganisms.

Acute Disease↗
PubMed1979

Ultrastructural features of spironucleosis (hexamitiasis) in x-irradiated rat small intestine.

An alteration in the host response to the intestinal protozoan Spironucleus (Hexamita) muris was noted in x-irradiated rat small intestine. When few were present in the crypt lumina, the intestinal microvillar border was normal. However, when larger numbers were present, the microvilli were greatly reduced in numbers or entirely absent in some regions. The organism was identified in the base of the crypt lumen, in apical portions of mucous cells, and near the basement membrane. Spironucleus enclosed by digestive vacuoles occasionally appeared to be in the process of being extruded through the basement membrane. Not all intracellular protozoa were surrounded by such digestive vacuoles. Spironucleus was never seen in association with the digestive vacuoles of Paneth cells. Since it has been suggested that Paneth cells have a role as a fixed phagocyte, ingesting protozoa and other microorganisms, the results presented here suggest that this function may have been impaired in irradiated animals.

Animals↗
PubMed1990

[Intestinal spirochetosis in HIV infection: prevalence, isolation and morphology of spirochetes].

The prevalence of intestinal spirochaetosis was investigated in 39 HIV-positive homosexual males (mean age 39 [24-65] years) in different stages of HIV infection (3 with the lymphadenopathy syndrome, 8 with AIDS-related complex and 28 with AIDS). Biopsies for cultural and histological demonstration of spirochaetes were obtained during routine ileoscopies. At the time of examination 35 of the 39 patients had intestinal symptoms. 27 patients had had no previous antimicrobial treatment. In 12 of the 27 previously untreated patients with intestinal symptoms spirochaetes were demonstrated, to different extent, from the terminal ileum to the rectum, while the treated group of eight and the control group of four were negative. There were no significant inflammatory changes histologically. Treatment with metronidazole in most cases improved symptoms. In their ultrastructure the microorganisms showed several complete convolutions, cone-shaped cell endings, cell length of 4-18 microns, cell diameter of 0.21-0.35 microns and five subterminal flagella. Morphological considerations favour the inclusion of these microorganisms in the genus Treponema rather than Brachyspira.

AIDS-Related Complex↗
PubMed2006

Transcriptome and phenotypic responses of Vibrio cholerae to increased cyclic di-GMP level.

Vibrio cholerae, the causative agent of cholera, is a facultative human pathogen with intestinal and aquatic life cycles. The capacity of V. cholerae to recognize and respond to fluctuating parameters in its environment is critical to its survival. In many microorganisms, the second messenger, 3',5'-cyclic diguanylic acid (c-di-GMP), is believed to be important for integrating environmental stimuli that affect cell physiology. Sequence analysis of the V. cholerae genome has revealed an abundance of genes encoding proteins with either GGDEF domains, EAL domains, or both, which are predicted to modulate cellular c-di-GMP concentrations. To elucidate the cellular processes controlled by c-di-GMP, whole-genome transcriptome responses of the El Tor and classical V. cholerae biotypes to increased c-di-GMP concentrations were determined. The results suggest that V. cholerae responds to an elevated level of c-di-GMP by increasing the transcription of the vps, eps, and msh genes and decreasing that of flagellar genes. The functions of other c-di-GMP-regulated genes in V. cholerae are yet to be identified.

Biofilms↗
PubMedDate not supplied

[In vitro evaluation of influence of medicinal plant decoctions and antibacterial antibodies to bifidobacteria on bifidobacterium adhesion].

Natural antibodies to the surface antigens of bifidobacteria contained in blood sera and determined in the passive hemagglutination test blocked the adhesion of bifidobacteria to human red blood cells in vitro. The decoctions of medicinal plants, often used by pediatricians for therapeutic purposes, were found to have a pronounced inhibiting effect on the adhesion of bifidobacteria after the preliminary treatment of both microorganisms and human red blood cells by these decoctions. Suggestion was made on the possible role of natural human antibodies in changing the contents of the indigenous intestinal microflora; the prolonged use of preparations obtained from medicinal plants could probably produce negative influence on the microbiocenosis of the intestine.

Adolescent↗
PubMed1993

Intracellular bacteria of porcine proliferative enteropathy: cultivation and maintenance in vitro.

An obligate intracellular bacterium was isolated from the intestines of all 10 cases of porcine proliferative enteropathy from four different pig farms. The organism grew in a rat enterocyte cell line (IEC-18) and was maintained over 20 passages. The growth of the bacteria was assessed by immunostaining of cells exposed to infection. Infection was not associated with morphological cell change, and growth was confined to cells infected at the time of each transfer of infection and the progeny of these cells. The bacterium is a microaerophilic, cell dependent, curved or rod-shaped, gram-negative bacillus that multiplies freely in the enterocyte cytoplasm. Cell cultures containing the intracellular bacteria appear to be free of other microorganisms, including chlamydiae and viruses.

Animals↗