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PubMed2004

Probiotic effects on experimental graft-versus-host disease: let them eat yogurt.

Acute graft-versus-host disease (aGVHD) often limits feasibility and outcome of allogeneic bone marrow transplantation. Current pathophysiologic concepts of aGVHD involve conditioning regimens, donor-derived T cells, proinflammatory cytokines, and bacterial lipopolysaccharide (LPS) as a major trigger for aGVHD. LPS derives mostly from gram-negative bacteria and can enter circulation through the impaired mucosal barrier after the conditioning regimen. Probiotic microorganisms have been shown to alter the composition of the intestinal microflora and thereby mediate anti-inflammatory effects. We hypothesized that modifying the enteric flora using the probiotic microorganism Lactobacillus rhamnosus GG, would ameliorate aGVHD. Here we show that oral administration of Lactobacillus rhamnosus GG before and after transplantation results in improved survival and reduced aGVHD. Furthermore, subculturing of mesenteric lymph node tissue revealed a reduced translocation of enteric bacteria. Our findings suggest that alteration of the intestinal microflora plays an important role in the initiation of experimental aGVHD.

Animals↗
PubMedDate not supplied

[Properties of the isolated Bacillus subtilis strains and their influence on the intestinal microflora of experimental mice].

The cultural, physiologo-biochemical adhesive and antagonistic properties of B. subtilis strains with good prospects for use as biotherapeutic preparations were studied. For further studies B. subtilis strain No. 1719 was chosen. In experiments on non-inbred white mice the animals were treated by the preparation Cifran used for their selective decontamination from opportunistic microflora and for the creation of the state of dysbiosis. The influence of the spore-forming microbe on the parietal microflora of the large intestine of the animals was shown. Reliable data on the changes in the number of microorganisms (CFU/ml) per 1 cm of the surface of the large intestine were established. As markers making it possible to evaluate the action of biotherapeutic and other medicinal remedies, easily determinable ratios of lac+/lac- of bacteria and Staphylococcus aureus/Staphylococcus spp. was proposed.

Animals↗
PubMed1985

Effects of sorbic acid feed fungistat on the intestinal microflora of floor-reared broiler chickens.

The intestinal microflora of a group of broilers fed a diet containing .04% sorbic acid from Days 1 through 49 of their lives was compared with broilers given a diet without the fungistat. Four broilers from each group were killed at 7, 21, 35, and 49 days, and intestinal sections of the duodenum, the lower small intestine, and both ceca were removed aseptically. Samples of the contents of the intestinal sections were analyzed microbiologically. Groups of microorganisms analyzed included total aerobes, total anaerobes, coliforms, streptococci, lactobacilli, clostridia, Bacteroides, Bifidobacterium, yeasts, and molds. Generally, there was a large variation in viable counts of microorganisms for birds of the same treatment. Of the nine groups of microorganisms analyzed the highest counts obtained (greater than 10(6)/g) were for total aerobes, total anaerobes, lactobacilli, and Bifidobacterium. Coliforms, streptococci, and clostridia showed intermediate counts (greater than 10(3)/g), while yeasts and molds and Bacteroides showed the lowest counts (greater than 10(2)/g). Total microbial numbers, in most cases and irrespective of sorbic acid treatment, were highest in the ceca, lower in the small intestine, and still lower in the duodenum. There were no major trends of microbial population changes observed in a given treatment, intestinal location, or group of organisms with age and time on feed. Inclusion of sorbic acid in the feed did not influence total aerobes, total anaerobes, lactobacilli, streptococci, Bifidobacterium, and clostridia. However, broilers on sorbic acid-containing feed had, at 49 days of age, lower coliform counts in the duodenum, lower yeast and mold counts in the ceca, and higher Bacteroides counts in the ceca.

Animal Feed↗
PubMed1987

Output of bacterial metabolites as a diagnostic means.

Output of bacterial metabolites reflects not only the number but the metabolic activity of certain microorganisms. In case of excess of a substrate one can observe the increased output of metabolite(s) without the overgrowth of intestinal bacteria. This matter is used for detection of malabsorption of some carbohydrates (lactose, glucose) by increased excretion of hydrogen in expired air. Another group of so-called breath tests (14C-cholylglycine, 14C-xylose) is designed to detect the bacterial overgrowth in the small intestine by measuring the rise of the concentration of 14CO2 in alveolar air. All the tests basing on the decomposition of the test substance by intestinal bacteria, have some limitations. Little is known about the microorganisms decomposing the different test substances. Significant correlations between the urinary phenols (p-cresol, phenol) and certain groups of mucosal flora (staphylococci, bacteroides) of the small intestine of rats could be found. Therefore one suggests that elucidating the origin of a bacterial metabolite is still possible in some instances, although very complicated. In conclusion, the authors refer to several reasons for failure to obtain correlations between the output of the metabolite(s) and data of bacteriological investigation.

Animals↗
PubMedDate not supplied

[Influence of classic enteropathogenic Escherichia coli on small bowel bacterial proliferation in infant's acute and persistent diarrhea].

UNLABELLED: Bacterial proliferation of the colonic microflora can occur in up to 50% of the infants with acute and persistent diarrhea. EPEC strains are frequently associated with bacterial proliferation in the small bowel lumen. The persistence of diarrhea might be due to the proliferation of EPEC in the intestinal lumen. PURPOSE: The present study was aimed at comparing the magnitude of the bacterial proliferation in the small bowel lumen in infants with acute and persistent diarrhea due to EPEC and other agents. PATIENTS AND METHODS: Fourty infants with diarrhea (23 with acute diarrhea and 17 with persistent diarrhea) underwent a naso-jejunal intubation for intestinal secretion culture of aerobes and anaerobes microorganisms. Stool samples were also collected for the investigation of enteropathogenic agents. RESULTS: Bacterial proliferation in the small bowel was detected in 32 (80%) infants; in 30 (75%) infants there was proliferation of aerobic microorganisms while in 17 (43%) infants there was proliferation of microorganisms belonging to the anaerobic microflora. There was no statistical difference in the bacterial proliferation between patients with acute and persistent diarrhea. In 16 patients EPEC strains were identified in the stool culture, and all of them showed bacterial overgrowth above 10(3) microorganisms/mL. In contrast in the 24 patients without EPEC in the stools only 16 (67%) showed bacterial overgrowth in the small bowel lumen (p < 0.01). The mean concentration of E. coli in the intestinal secretion was 8 x 10(5) microorganisms/mL among the patients with EPEC in the stools and 3 x 10(2) microorganisms/mL among the patients with no EPEC in the stools (p < 0.05). CONCLUSIONS: EPEC infection either acute or persistent induce favorable conditions for bacterial proliferation in the small bowel secretion in infants with diarrhea.

Acute Disease↗
PubMed1985

Pathogenesis of Yersinia-triggered reactive arthritis: immunological, microbiological and clinical aspects.

When a patient develops reactive arthritis after Yersinia enteritis, the following conditions are often fulfilled: the patient is HLA-B27-positive; however, some B27-negative individuals develop severe arthritis and some positives do not, in the initial phase, the diarrhea is milder, the anti-Yersinia antibody response of IgG class is more vigorous and persists longer, the anti-Yersinia antibody response of IgA class is more vigorous and persists much longer, the anti-Yersinia antibodies of IgA1 and IgA2 subclass, those with J-chain and, especially, those with secretory piece are produced more vigorously, indicating local immunostimulation close to the intestinal epithelium, in the early phase, Yersinia-IgM immune complexes are found in the circulation, and the lymphocyte transformation response against not only Yersinia but also against other gram-negative enteric bacteria is weaker. When all these aspects are considered together a strong suspicion arises that the patients who are destined to develop reactive arthritis fail in their first line of defense against the invading organism when contracting a Yersinia enteritis. This may lead to persistence of the microorganism within the body, e.g., in the intestinal epithelium or in the mesenteric lymphoid tissues, maintaining a stimulus for a prolonged--apparently futile and perhaps harmful--antibody production. Finally, the initiating and decisive factor should not be forgotten: the Yersinia. Why and how it triggers the process is at present one of the enigmas of the pathogenesis of reactive arthritis.

Antibodies, Bacterial↗
PubMed2002

Effect of addition of "Greenline" preparations to feed mixtures for broilers on the composition of their intestinal microflora.

The current study deals with the possibility of replacing the antibiotic growth stimulator avilamycin, a mixture of oligosaccharides of the orthosomycin group, with the herbal preparations Greenline 1 and 2. The microbiological part of the study embraced examination of the intestinal microflora of broilers. The birds in the study belonged to four experimental groups, distinguished on the basis of feed supplements used. For the microbiological determination five birds from each group were selected at random and the contents of their small intestine was examined for given groups of microorganisms. The remaining birds in each group were examined and evaluated on the basis of zootechnical indices. Our results suggest that Greenline 1 efficiently eliminates certain pathogenic bacteria, above all lactose-positive bacteria belonging to the family Enterobacteriaceae and Staphylococci. It seems that the presence of Greenline 1 in the feed mix used enhances the colonisation of the mucous membrane of the studied chicken with Lactobacillus lactic acid bacteria. This is indicated by the considerably higher number of these bacteria in the small intestine of the birds receiving the supplement Greenline 1.

Animal Feed↗
PubMed2026

Probiotic Lacticaseibacillus casei 2S-1 Attenuates Escherichia coli-Induced Enteritis via Gut Microbiota Modulation and Host Gene Regulation.

Maintaining gut microbial homeostasis is crucial for host health, whereas infection with Escherichia coli (E. coli) is a major contributor to intestinal inflammation and microbial dysbiosis. Recent research has focused on probiotic strategies for managing enteric inflammatory disorders. Previous studies have shown that beneficial microorganisms show protection through modulating host immune responses, enhancing intestinal epithelial barrier integrity, and inhibiting pathogenic bacteria. To evaluate the prophylactic effectiveness of a recently isolated strain, Lacticaseibacillus casei 2S-1, in a murine model of E. coli-induced enteritis, this study focuses on interactions within the microbiota-intestinal-immune axis, together with host transcriptional responses and pathway enrichment associated with oxidative stress and mitochondrial function. In vitro analysis of probiotic features, including growth dynamics, acidogenic capacity, and tolerance to acidic and bile salt environments, as well as genetic safety profiling, followed the methodical isolation and taxonomic identification of L. casei 2S-1. A preventive intervention protocol was established, and a murine model of enteritis was induced by exposure to E. coli. Histopathological analyses were performed to observe in vivo safety and protective efficacy. Changes in gut microbial structure were characterized by 16S rRNA gene sequencing, while host responses were identified by intestinal immunohistochemistry and transcriptome profiling. L. casei 2S-1 showed probiotic properties. In vitro analyses showed that the strain exhibited tolerance to acidic and bile salt conditions, and its untreated culture supernatant showed antimicrobial activity against pathogenic bacteria. Its safety profile was supported by genomic analysis, which verified the lack of virulence-associated genes and antibiotic resistance factors. In vivo, L. casei 2S-1 pretreatment reduced mortality and intestinal inflammation, modulated gut microbial composition, and preserved intestinal barrier-associated protein expression in infected mice. This study provides experimental evidence supporting the prophylactic effects of L. casei 2S-1 and its associations with gut microbiota modulation and host transcriptional responses, providing a foundation for further investigation of probiotic-based preventive strategies against intestinal infections.

Animals↗
PubMed1992

Intestinal permeability in pediatric gastroenterology.

The role of the physiologic barrier function of the small bowel and its possible role in health and disease has attracted much attention over the past decade. The intestinal mucosal barrier for luminal macromolecules and microorganism is the result of non-immunologic and immunologic defense mechanisms. The non-immunologic mechanisms consist of intraluminal factors such as gastric acid, proteolytic activity, and motility and of mucosal surface factors like mucin and the microvillous membrane. The immunologic mechanisms include secretary IgA and cell-mediated immunity. Both types of mechanism are not completely mature at birth. Maturation of this barrier is not finished before the 2nd year of life. One of the aspects of the mucosal barrier function can be estimated by the intestinal permeability (IP) for macromolecules. We use the differential sugar absorption test (SAT), in which the ratio of urinary excretion of a relatively large molecule, lactulose, is compared with that of a relatively small molecule, mannitol, after oral ingestion. Although the small intestine is permeable to certain macromolecules in normal developmental conditions, an increased IP could be involved in the pathophysiology of several diseases, including infectious diarrhea, food allergy, celiac disease, and Crohn's disease. It can be concluded that IP, as measured with the SAT, reflects the state of the mucosal barrier and is altered in several gastrointestinal diseases. The SAT is a non-invasive IP test that can be of diagnostic help to demonstrate alterations in the small-mucosal barrier function and may be useful to evaluate therapeutic interventions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Effects of fecal microorganisms and their chloroform-resistant variants derived from mice, rats, and humans on immunological and physiological characteristics of the intestines of ex-germfree mice.

In order to elucidate the nature of intestinal flora affecting the immunological and physiological parameters of the intestine, we produced several kinds of ex-germfree mice associated with fecal organisms and their chloroform-resistant variants derived from mice, rats, and humans. The phenotypes of intraepithelial lymphocytes were changed to those in conventional mice, particularly the increased positive percentage of alpha beta T-cell-receptor and Thy-1-bearing T cells, on association of the microorganisms (MF) and their chloroform resistant variants (MChl) derived from mice, but not rats and humans, with germfree mice. The cytolytic activity of intraepithelial lymphocytes was expressed only in the MF and MChl groups. The induction of the synthesis of fucosyl asialo GM1 glycolipid, the expression of major histocompatibility complex class II molecule, an increase in the mitotic indices of colonic epithelial cells, and a decrease in lactase activity of the small intestinal epithelial cells also occurred only in the two groups. On the other hand, the cecal size (cecal weight/body weight ratio) was reduced in the mice of all groups examined here, there being approximately the same amount and composition of organic acids, such as acetic acid, butyric acid, and propionic acid, in the cecal contents. Taken together, the results suggest that mouse-specific and chloroform-resistant microorganisms, which are difficult to cultivate at present, may contribute to alteration of the immunological and epithelial characteristics of the mouse intestine. Another factor derived from the intestinal flora, for example, bacterial metabolites such as organic acids, may also affect the cecal size.

Animals↗
PubMed2003

Clinical significance of human intestinal spirochetosis--a morphologic approach.

Intestinal spirochetosis (IS) is a condition defined morphologically by the presence of spirochetal microorganisms attached to the apical cell membrane of the colonic and rectal epithelium. Intestinal spirochetes comprise a heterogeneous group of bacteria. In humans Brachyspira aalborgi and Brachyspira pilosicoli predominate. Prevalence rates of IS are low where living standards are high, in contrast to poorly developed areas where IS is common. Homosexuals and HIV-infected individuals are at high risk of being colonized. Clinical significance in individual cases has remained unclear up to now. A review of the literature reveals that invasion of spirochetes beyond the surface epithelium is associated with gastrointestinal symptoms which respond to antibiotic treatment (metronidazole), whereas patients lacking this feature are mostly asymptomatic. Homosexual and HIV-positive men are more likely to be symptomatic irrespective of invasion. Rare cases of spirochetemia and multiple organ failure have been reported in critically ill patients.

Bacteremia↗
PubMed1989

Polychlorinated biphenyl-degrading pseudomonads: survival in mouse intestines and competition with normal flora.

Although naturally occurring and mutant organisms, historically, have been released into the environment for various purposes, health concerns associated with the release of microorganisms have recently resurfaced. Federal agencies have been given the task of reassuring society that any released organisms are not likely to produce adverse health effects. Methods, therefore, for evaluating the potential health effects due to environmental release of mutant and genetically engineered microorganisms are under investigation. A mouse model was developed that examines morbidity, mortality, and more indirect effects such as colonization potential of the intestinal tract, as well as competition with and alteration of the intestinal microbiota populations. The Pseudomonas spp. used in this study were isolated from a commercial product and used for degrading polychlorinated biphenyls. Mice were dosed individually with 10(3), 10(6), and 10(9) colony-forming units of each microorganism. At specific time intervals the intestines were removed and examined for the presence of the dosed microorganism. At the two higher doses, 10(6) and 10(9) colony-forming units, P. maltophilia strain BC6 and two P. aeruginosa strains, BC16 and BC18, were recoverable 48 h after dosing. The naturally occurring P. aeruginosa strain, PAMG, isolated from a mouse intestinal homogenate produced a similar response. Statistical analysis indicated that in some of the dosed animals, an alteration in the distribution of normal intestinal microflora occurred. Pseudomonas maltophilia strain BC6 and P. aeruginosa strains BC16 and BC17 caused a change in the obligately anaerobic predominantly gram-negative rod counts, and P. aeruginosa strain BC17 produced a dose effect on the total anaerobic count at the 10% confidence level. The total aerobic count was unaffected by the presence of the dosed pseudomonads.

Animals↗
PubMed1989

[Characteristics of the course of peritonitis in relation to the degree of perforation of the gastrointestinal tract].

An examination and treatment of 80 patients with general forms of peritonitis has shown that the course of the disease is greatly dependent on the character of the bacterial dissemination of the abdominal cavity. A microbiological examination has shown that in all the levels of perforation of the gastro-intestinal tract there are associations of various microorganisms. The most severe course of peritonitis is observed when caused by infection by colonic contents with prevailing anaerobic ++non-clostridial microflora in the exudate. The method of repeated revisions of the abdominal cavity should be used for these forms of peritonitis.

Abscess↗
PubMedDate not supplied

[Lactobacilli of freshwater fishes].

Normal microflora in the intestinal tract of fishes inhabiting fresh-water reservoirs includes lactic bacteria. The number of the bacteria depends on the animal species, the composition of food, the age, and the season. The highest number of these microorganisms (hundreds of millions per gram of the intestinal content) is found in carps. Enterococci are most often encountered in fishes inhabiting ponds: Streptococcus faecalis Andrewes a. Horder, Str. faecium Orla-Jensen, Str. bovis Orla-Jensen. Lactobacilli are more typical of fishes in water reserviors: Lactobacillus plantarum (Orla-Jensen) Bergey et al., L. casei (Orla-Jensen) Hansen a. Lessel, L. casei var. casei, L. casei var. rhamnosus, L. Casei var. alactosus, L. leichmannii (Henneberg) Bergey et al., L. acidophillus (Moro) Hansen a. Mocquot, L. Fermenti Beijerinck, L. cellobiosus Rogosa et al., L. Buchneri (Henneberg) Bergey et al. The content of lactic bacteria varies in water reservoirs; their highest content is found in ooze (tens of thousands per gram).

Animals↗
PubMed1988

Intestinal microvascular exchange in the rat during luminal perfusion with formyl-methionyl-leucyl-phenylalanine.

Formyl-methionyl-leucyl-phenylalanine (FMLP), a peptide released from bacteria in the gut lumen, is known to both attract and activate neutrophils. The aim of this study was to determine whether luminal perfusion with 1 microM FMLP alters microvascular permeability, blood flow, and neutrophil migration in the small intestine of control rats and rats treated with antineutrophil serum. Microvascular permeability to total plasma proteins was determined from an analysis of lymphatic protein fluxes. Myeloperoxidase activity was used as an index of tissue neutrophil count. Intestinal blood flow was measured using radiolabeled microspheres and the reference blood sample method. In control rats, luminal perfusion with FMLP caused significant increases in blood flow, lymph flow, lymph protein clearance, and microvascular permeability, but it did not alter tissue myeloperoxidase activity. In rats treated with antineutrophil serum, tissue myeloperoxidase levels were reduced by approximately 55%, and the FMLP-induced changes in lymph flow, lymph protein clearance, and microvascular permeability were significantly attenuated. In vitro experiments with isolated rat neutrophils revealed that 1 microM FMLP elicits significant chemotaxis and degranulation yet minimally enhances superoxide production. The results of this study indicate that peptides produced by microorganisms in the gut lumen can increase intestinal microvascular permeability. The FMLP-induced alterations in microvascular exchange appear to be mediated by activated neutrophils.

Animals↗
PubMed1989

[Ultrastructural study of the colon after massive intestinal resection in rats].

The modifications suffered by the colon after massive intestinal resection (RIM) have been barely studied, especially from the ultrastructural point of view. On the basis of optical microscope studies we planned this experimental study to evaluate fundamentally the ultrastructural changes in the colonic mucosa and its cellular elements. A total of 115 Wistar rats weighing 350 to 550 grams were used. Twenty animals constituted group 0 (controls), 30 underwent intestinal section (group I) and 65 were submitted to resection of 90% of the intestine (group II). After weighing, the animals were sacrificed by groups on days 15, 30, 45 and 60 of the operation to obtain histologic samples of the ascendant colon for study by transmission (MET) and scanning (MEB) electron microscopy. All the animals resected showed statistically significant weight loss (p less than 0.001), an expression of short intestine syndrome. Groups 0 (controls) and I (intestinal section) did not evidence important ultrastructural changes. In contrast, although in the initial electron microscopic scan the colonic mucosal surface offered a normal aspect, at 45 days it presented irregularities, without the appearance of villi. Days 60 there were deep folds and the mucosal surface had acquired a foliaceous aspect similar to that of the surface of the small intestine of the rat. The abundance of microorganisms adhered to the surface, constituting clumps of bacteria, was striking. Transmission electron microscopy confirmed the greater number and height of the enterocytes, covered by well-developed apical microvilli with dimensions that increased throughout the experiment. The cellular nuclei are voluminous and occasionally have various nucleoli. The cytoplasm showed changes that affected fundamentally the mitochondria.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed2006

In situ characterisation of a microorganism surface by Raman microspectroscopy: the shell of Ascaris eggs.

Intestinal nematodes are very common human parasites and a single species, Ascaris lumbricoïdes, is estimated to infect a quarter of the world's population. A sticky external layer covers their eggs. This work shows that Raman vibrational confocal spectroscopy is able to give information on the biochemical composition of the shell of Ascaris eggs. The biochemical localised characterisation of Ascaris eggs was performed directly on the eggs in their aqueous environment. The studied parasites came from two origins: dissections of adult females and extractions from biosolid sludges. The presence of mucopolysaccharides, proteins and chitin in the shell was demonstrated. The presence of ascaroside compounds was shown particularly via the narrow and intense bands from the organised long CH2 chains. To the best of our knowledge, this is the first time that the latter have been observed in Raman vibrational spectra of microorganisms. Hydration of the shell was different depending on the intensity of the colour of the sludge eggs. Knowledge of the biochemical structural properties of egg surfaces would be useful to understand the egg adhesion phenomena on vegetables contaminated by reused wastewater.

Animals↗
PubMed2004

Bacterial probiotic modulation of dendritic cells.

Intestinal dendritic cells are continually exposed to ingested microorganisms and high concentrations of endogenous bacterial flora. These cells can be activated by infectious agents and other stimuli to induce T-cell responses and to produce chemokines which recruit other cells to the local environment. Bacterial probiotics are of increasing use against intestinal disorders such as inflammatory bowel disease. They act as nonpathogenic stimuli within the gut to regain immunologic quiescence. This study was designed to determine the ability of a bacterial probiotic cocktail VSL#3 to alter cell surface antigen expression and cytokine production in bone marrow-derived dendritic cell-enriched populations. Cell surface phenotype was monitored by monoclonal fluorescent antibody staining, and cytokine levels were quantitated by enzyme-linked immunosorbent assay. High-dose probiotic upregulated the expression of C80, CD86, CD40, and major histocompatibility complex class II I-Ad. Neither B7-DC or B7RP-1 was augmented after low-dose probiotic or Lactobacillus casei treatment, but B7RP-1 showed increased expression on dendritic cells stimulated with the gram-negative bacterium Escherichia coli. Functional studies showed that probiotic did not enhance the ability of dendritic cells to induce allogeneic T-cell proliferation, as was observed for E. coli. Substantial enhancement of interleukin-10 release was observed in dendritic cell-enriched culture supernatants after 3 days of probiotic stimulation. These results demonstrate that probiotics possess the ability to modulate dendritic cell surface phenotype and cytokine release in granulocyte-macrophage colony-stimulating factor-stimulated bone marrow-derived dendritic cells. Regulation of dendritic cell cytokines by probiotics may contribute to the benefit of these molecules in treatment of intestinal diseases.

Animals↗