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A new sorbent with a high sorptive capacity and antimicrobial properties against different species of microorganisms (aerobic and anaerobic) is suggested. Its effectiveness has been proved both in vitro and in vivo. The authors consider that the sorbent can be recommended for clinical trials with the aim of its use in preparation of the intestine for the operation.
An abundant microbial growth in the small intestine is called "overgrowth syndrome". The dysbiosis existing hereby is to be characterized by the prevailing of certain sorts of germs. A series of typical symptoms is explained by the metabolic activity of microorganisms, in which case disturbances of absorption are uppermost. Morphological and histochemical changes of the intestinal mucous membrane as well as disturbances of the bile acid metabolism and the absorption of carbohydrates, fats and vitamin B12 are explained. Finally the author deals with the microflora in conditions of malabsorption.
For several centuries, fermented products derived from plant or animal materials have been an acceptable and essential part of the diet in most parts of the world. Health benefits have also often been associated with them. Probiotics can be defined as fermented food containing specific live microorganisms or a live microbial food or feed supplement, which beneficially effects the human or the host animal by improving its intestinal microbial balance. Nearly all probiotics currently on the market contain Lactobacilli, Streptococci, Enterococci or Bifidobacteria. In contrast to Japan, where freeze-dried microorganisms are consumed by a substantial part of the human population, in Europe, probiotic action towards humans are only claimed for certain fermented dairy products (e.g. yoghurts). Those species that have been extensively studied so far, with several experimental trials on man, are the two yoghurt bacteria Streptocaccus thermophilus and Lactobacillus bulgaricus, L. casei and Bifidobacteria. L. acidophilus has also received important scientific interest, however, only a few human studies have been carried out. From the technological point of view a good probiotic should be stable and viable for long periods under storage, should be able to survive the low pH levels of the stomach, be able to colonise the epithelium of the gastro-intestinal tract of the host, should not be pathogenic and, last but not least, must be capable of exerting a growth promoting effect or a resistance to infectious diseases. The beneficial effects of probiotics are mainly contributed to a direct antagonistic effect against specific groups of microorganisms (Enteropathogenes), by an effect on the metabolism in the gut or by a stimulation of systemic or mucosal immunity. We will present major proven health benefits of milks fermented with those bacterial species and discuss, where possible, the impact of the specific selection and utilisation of particular strains.
Pathogens and eucaryotic cells are active partners during the process of pathogenicity. To gain access to enterocytes and to cross the epithelial membrane, many enterovirulent microorganisms interact with the brush border membrane-associated components as receptors. Recent reports provide evidence that intestinal cell differentiation plays a role in microbial pathogenesis. Human enteropathogenic Escherichia coli (EPEC) develop their pathogenicity upon infecting enterocytes. To determine if intestinal epithelial cell differentiation influences EPEC pathogenicity, we examined the infection of human intestinal epithelial cells by JPN 15 (pMAR7) [EAF+ eae+] EPEC strain as a function of the cell differentiation. The human embryonic intestinal INT407 cells, the human colonic T84 cells, the human undifferentiated HT-29 cells (HT-29 Std) and two enterocytic cell lines, HT-29 glc-/+ and Caco-2 cells, were used as cellular models. Cells were infected apically with the EPEC strain and the cell-association and cell-entry were examined by quantitative determination using metabolically radiolabeled bacteria, as well as by light, scanning and transmission electron microscopy. [EAF+ eae+] EPEC bacteria efficiently colonized the cultured human intestinal cells. Diffuse bacterial adhesion occurred to undifferentiated HT-29 Std and INT407 cells, whereas characteristic EPEC cell clusters were observed on fully differentiated enterocytic HT-29 glc-/+ cells and on colonic crypt T84 cells. As shown using the Caco-2 cell line, which spontaneously differentiates in culture, the formation of EPEC clusters increased as a function of the epithelial cell differentiation. In contrast, efficient cell-entry of [EAF+ eae+] EPEC bacteria occurred in recently differentiated Caco-2 cells and decreased when the cells were fully differentiated.(ABSTRACT TRUNCATED AT 250 WORDS)
It is known that the gut may serve as a reservoir for various microorganisms, which under specific circumstances may intrude into the systemic circulation, causing systemic infections. The aim of the present study was to estimate the "critical time" of disruption of the small-intestine mucosal barrier in conditions of experimentally induced intestinal occlusion, based on the histopathological alterations observed under light and electron microscopy. Forty rabbits underwent small-intestine obstruction through ligation with a nonabsorbable suture. Blood cultures from portal vein and inferior vena cava, as well as cultures from the peritoneal fluid, a hepatic fragment, and a mesenteric lymph node, were obtained before the ligation (0 h). The same cultures were repeated at 4 and 8 h (group A, 20 rabbits) and at 6 and 12 h after the ligation (group B, 20 rabbits). Small-intestine specimens proximal to the occlusion were taken for examination under the optic and electronic microscope in the same time intervals. Five of 20 rabbits of group A died within 4 h and 6 of 20 rabbits of group B died within 6 h after the operation. All anaerobic cultures were negative. All aerobic cultures that became positive developed Escherichia coli colonies. Intestinal epithelium of dead animals was transformed to cuboid with destruction of goblet cells and alteration in secretion of acid polysaccharides. The mucosal appearance of all rabbits that survived 12 hours after ligation was the same. The disruption of the mucosal barrier begins 4 h after complete intestinal occlusion. At 12 h after complete intestinal occlusion, the disruption is total with different degrees of severity.
The uses, mechanisms of action, and safety of probiotics are discussed. Probiotics are live microorganisms or microbial mixtures administered to improve the patient's microbial balance, particularly the environment of the gastrointestinal tract and the vagina. The yeast Saccharomyces boulardii and the bacterium Lactobacillus rhamnosus, strain GG, have shown efficacy in clinical trials for the prevention of antimicrobial-associated diarrhea. Other probiotics that have demonstrated at least some promise as prophylaxis for this type of diarrhea are Lactobacillus acidophilus, Bifidobacterium longum, and Enterococcus faecium. The use of S. boulardii as an adjunctive treatment to therapy with metronidazole or vancomycin has been found in controlled studies to decrease further recurrences of Clostridium difficile-associated disease. Other gastrointestinal disorders for which probiotics have been studied include traveler's diarrhea, acute infantile diarrhea, and acute diarrhea in adults. Several Lactobacillus species given in yogurt or in tablet or suppository form have shown clinical efficacy as a treatment for vaginal infections. Lactobacillus strains have also been examined as a treatment for urinary-tract infections. Putative mechanisms of action of probiotics include production of pathogen-inhibitory substances, inhibition of pathogen attachment, inhibition of the action of microbial toxins, stimulation of immunoglobulin A, and trophic effects on intestinal mucosa. The available probiotics are considered nonpathogenic, but even benign microorganisms can be infective when a patient is severely debilitated or immunosuppressed. Probiotics have demonstrated an ability to prevent and treat some infections. Effective use of probiotics could decrease patients' exposure to antimicrobials. Additional controlled studies are needed to clearly define the safety and efficacy of these agents.
To determine the microbial cause and the clinical and pathologic correlates of anorectal and intestinal symptoms in homosexually active men, we performed comprehensive microbiologic studies, anoscopy, sigmoid-oscopy, and rectal biopsy in men examined in a clinic for sexually transmitted diseases. Enteric pathogens were found in 95 of 119 consecutive homosexual men with anorectal or intestinal symptoms and in 29 of 75 randomly selected homosexual men without such symptoms (P less than 0.001). The syndromes of proctitis, proctocolitis, and enteritis were differentiated on the basis of predominant symptoms and findings on anoscopy and sigmoidoscopy. Neisseria gonorrhoeae, herpes simplex virus, Chlamydia trachomatis (non-lymphogranuloma venereum serotypes), and Treponema pallidum were associated with 80 per cent of cases with symptomatic proctitis. Known causes of colitis, including Campylobacter jejuni, Campylobacter fetus fetus, Shigella flexneri, Chl. trachomatis (lymphogranuloma venereum serotypes), Entamoeba histolytica, and Clostridium difficile, were identified in 60 per cent of the cases of proctocolitis. Giardia lamblia was the only agent significantly correlated with enteritis. These data demonstrate that intestinal symptoms in homosexual men are attributable to a complex spectrum of microorganisms, but that careful clinical classification can serve as a guide to the selection of microbiologic studies and to a rational initial choice of therapy.
Effects of long-term inhalation of 100 per cent oxygen on the microbial flora of the rat larynx, trachea, and large intestine were studies. Rats were kept 14 days in an atmosphere of 100 per cent oxygen after being conditioned to high oxygen concentrations by exposure to three cycles of 100 per cent oxygen (two days) alternating with 40 percent oxygen (two days). Controls were kept under similar conditions in normal atmosphere. Rats were sacrificed, and at necropsy laryngotracheal swabs and fecal material from the large intestine were obtained and cultured for bacteria and fungi. Streptobacillus moniliformis, the predominant microorganism in the upper tracheas of controls, was not isolated from the oxygen-treated rats. Alpha-hemolytic streptococcus and Staphylococcus albus were present in control rats, but were found less frequently in rats exposed to oxygen. Pseudomonas and Proteus, infrequently isolated from controls, were predominant and sometimes the only microorganisms isolated from oxygen-treated rats. The data indicate that prolonged exposure of the rat to 100 per cent oxygen shifts the microbial flora in the upper respiratory tract from mainly gram-positive to mainly gram-negative bacteria. In contrast, there was no significant difference between the microbial flora in large intestines of control and oxygen-treated rats. The possibility that similar changes may occur in man should be considered when prolonged oxygen therapy is contemplated.
The normal small intestine in man usually harbours a sparse microflora consisting of Gram-positive microorganisms derived from the oro-pharynx. The concentrations in the upper jejunum are approximately 10(3)-10(4) organisms/ml, whereas in the ileum the concentrations may be higher and faecal type organisms may also be present, such as Enterobacteria, Bifidobacteria, and Bacteroides in concentrations of 10(5)-10(6) organisms per ml of intestinal aspirate [24, 25]. This situation is well maintained unless the integrity of the small intestine is deranged. There are however, certain conditions in which bacterial proliferation in the lumen of the small intestine may occur and give rise to various metabolic abnormalities [2]. In this paper I would like to list some of these conditions, then describe the type of microflora which colonizes the small intestine, and finally discuss a few aspects of the metabolic consequences of these bacteria.
Whipple's disease is an important and fascinating problem of local immunity in the gastrointestinal tract. Does the disease occur when an organism that is rare in nature infects an individual or do patients with Whipple's disease have a definable defect in their immune response that permits infection by a more common agent? Data in recent years indicate that there is only one type of microorganism that causes Whipple's disease. It is rod-shaped by electron microscopy and has a definable antigenic pattern by immunofluorescence. Paradoxically (considering its geometry), it reacts most strongly with antisera directed to streptococcal antigens. Patients with Whipple's disease do not have a disorder of immunoglobulin synthesis and do not have immune complexes present in their gut walls. Further, although earlier studies indicated that a defective response of T-lymphocytes to PHA is consistently present in these patients even years after therapy, more recent studies have found no consistent defect in mitogenic responses to PHA, CON A, or PWM. Also, recent studies indicate that mononuclear cells from patients with Whipple's disease usually mediate antibody-dependent cell-mediated cytotoxicity as well as controls, although spontaneous cell-mediated killing may be decreased. All these studies suggest that the defect is not primarily of lymphocytes, rather it is more likely that a defect exists in monocytes and macrophages. Future studies on Whipple's disease should add to existing knowledge of how the immune processes intracellular microorganisms.
The aim of these investigations was the study of the effect of different antimicrobial preparations on the survival rate and intestinal microflora of mice with experimental acute radiation sickness. These investigations revealed that the survival rate of the animals increased 3.1 times with the use of Supramycin, 2.4 times with the use of Tacef and 1.6 times with the use of Spizef and Pen-bristol. The study of the influence of these preparations on the intestinal microflora revealed that Spizef not only decreased the number of opportunistic microorganisms, but also led to a sharp drop in the level of lactobacteria. The use of Pen-bristol and Tacef led to practically complete elimination of enterobacteria enterococci, staphylococci, as well as lactobacteria. Supramycin essentially suppressed the number of opportunistic microorganisms and did not affect the level of lactobacteria. This was probably the cause of the highest effectiveness of Supramycin in comparison with Tacef, Spizef and Pen-bristol.
The content of large intestine has been studied in persons exposed to radiation injury in consequence of the accident at the Chernobyl Atomic Power Plant. It is stated that bifidobacteria (10(7)-10(10) cells in 1 g of feces) prevailed (as in healthy people), Bifidobacterium indicum being a dominating species. Amount of lactic-acid bacteria in 1 g of defecations of examined patients was within the range of 10(6)-10(9) cells and in certain persons it reached 10(10) cells (primarily fecal Enterococci). A considerable amount of patients with acute radiation sickness of the 3d degree had in their intestine 10(9)/g of lactic-acid bacteria, Lactobacillus casei and L. plantarum prevailing there. The frequency of yeast isolation from defecations of patients constituted 83%, while the number of cells in 1 g of feces--from 10 to 10(4). Yeast of the Candida genus, mainly Candida parapsilosis, prevailed. The species composition of isolated microorganisms has no substantial differences from microcenosis of healthy people. The content of intestine of persons suffered from radiation is characterized only by greater amount of lactic-acid bacteria and enterococci as compared with healthy adults.
We report 3 cases of intestinal spirochetosis in homosexuals infected with the human immunodeficiency virus (2 group III and 1 group IV C1, according to the Centers for Disease Control classification) presenting with moderate, chronic diarrhea. The diagnosis was made based on the histological examination of colorectal biopsies showing a layer of spirochetes carpeting the epithelium. Electron microscopy evaluation and culturing of the microorganism provided information on the bacterium's morphology. Metronidazole effectively treated the diarrhea. Intestinal spirochetes, whose existence has been recognized for more than a century, constitute a heterogeneous group of bacteria whose pathogenic role in man remains controversial. The systemic search for these organisms in a large series of patients would help to situate their place among the various etiologies of infectious diarrhea in immunodepressed subjects.
1. Age-dependent differences in the intestinal hydrolysis of the glucuronide conjugate of valproic acid were evaluated in the Fisher-344 rat at 14 and 40 days, and 24 months of age. 2. Hydrolysis occurred more quickly when incubations were conducted under anaerobic as compared with aerobic conditions. 3. The rate of hydrolysis of valproate glucuronide was most rapid in the contents of the large intestine (caecum and colon); no difference in rate was noted between age groups during incubations with large intestinal contents. 4. Hydrolysis in the tissues of the large and small intestines, and the contents of the small intestine, was more rapid in the 14-day-old rat than in the older age groups. Differences in the rates and sites of hydrolysis in the 14-day-old animal may be due to regional differences in the number and types of microorganisms or mammalian beta-glucuronidase present in the gastrointestinal tract. 5. Differences in intestinal hydrolysis of valproate glucuronide may account in part for age-related changes in enterohepatic recirculation of valproate in young animals; other mechanisms apparently are responsible for altered valproate disposition in senescent animals.
Nutrition plays a key role in maintaining the balance of the intestinal microflora. Malnutrition disturbs the ecological barrier and induces histological damage. We evaluated modifications induced by renutrition with nonfat milk (NFM) and Lactobacillus casei administration (for 2 days) on the bacterial gut population and structural and ultrastructural gut modifications in malnourished mice. Balb/c mice suffering from a malnutrition process immediately after weaning (for 21 days) were divided into four groups and were given NFM for 0, 7, 14, and 21 days. Another group was treated in a similar way, but after different periods of NFM administration, mice in this group received L. casei for two consecutive days. All experimental animals were sacrificed by cervical dislocation, and both the microflora and the histological structure of the intestine were studied. In malnourished animals, a decrease in the numbers of Lactobacillus and anaerobic microorganisms was observed, whereas there was an increase in the number of Enterobacteriaceae. In animals treated with NFM and NFM plus L. casei, we could observe an important improvement in the microflora in the small and large intestines but no differences between both treatments. Structural and ultrastructural studies showed a slight improvement 7 days after treatment with NFM, and for 14 and 21 days after renutrition, the mice showed normal intestinal villi, whereas the additional feeding with L. casei for two consecutive days, after different periods of renutrition, yielded an earlier improvement (7 days).
The aim of the study was to compare the development of intestinal microflora in clinically healthy newborns, born by mothers with physiological pregnancy, and in small premature infants, who were treated in intensive care units (ICU) using various regimens of antibacterial therapy. The study revealed that the most frequent bacteria found in the intestinal tract of healthy infants at the and of neonatal period were bifidobacteria, enterobacteria, and coagulase-negative staphylococci and enterococci. Together with large quantity of autochtonous bacteria, the study revealed conditionally pathogenic microorganisms, such as klebsiella and coagulase-positive staphylococci at the end of neonatal period. The intestinal microflora of premature infants in ICU, treated with a combination of third generation cephalosporins and aminoglycosides from the first hours of life, was characterized by total absence of indigenous microflora, and prevalence of enterococci and staphylococci. The results show that the first stage of antibacterial therapy of preterm infants in ICU should be based upon the principles of selective decontamination.
Microcystin-LR is a cyclic heptapeptide hepatotoxin produced by the cyanobacterium Microcystis aeruginosa. This microorganism often forms toxic blooms in freshwater lakes and reservoirs for drinking water supply, producing serious disorders in humans and animals. Some have suggested that certain biological activities of microcystin may depend upon the stimulation of immune cells. Therefore, the aims of this research were to examine electrogenic intestinal secretion, in vitro, caused by the supernatants from macrophages stimulated with microcystin-LR, as well as to investigate the presence of interleukin-1beta and tumour necrosis factor-alpha in these supernatants. We found that the supernatants of macrophages stimulated with microcystin-LR (0.1, 0.3 and 1.0 microg/ml) caused electrogenic intestinal effects (change in short circuit currents (delta SCC)=57.6, 50.8 and 73.3, respectively, versus control=19.6 microA.cm(-2)) in a time-dependent way (microcystin-LR (1.0 microg/ml)=63.2, 108.8, 120.4 and 132.3 microA.cm(-2) at time 0, 40, 50 and 60 min., respectively). In addition, the intestinal secretory activity present in these supernatants was blocked (57%) by the prior treatment of macrophages with dexamethasone. We also demonstrated that microcystin-LR (0.1, 0.3 and 1.0 ,microg/ml) is capable of stimulating the synthesis of tumour necrosis factor-alpha (375.4, 369.0 and 610.8 pg/ml, respectively, versus control=165.0 pg/ml) and interleukin-1beta (198.9, 189.3 and 522.1 pg/ml, respectively, versus control=39.7 pg/ml). These findings demonstrate that microcystin-LR induces the release of interleukin-1beta and tumour necrosis factor-alpha by peritoneal macrophages in vitro, and that the supernatants from these macrophages induce electrogenic secretion in rabbit ileal mucosa.
Specialized epithelial M cells, a phenotype that occurs only in the epithelium over organized lymphoid follicles, deliver samples of foreign material by transepithelial transport from the lumen to organized lymphoid tissues within the mucosa of the small and large intestines. Mounting evidence indicates that a complex interplay of mucosal lymphoid cells and luminal microorganisms with epithelial cells underlies differentiation of the M cell phenotype. The cellular and molecular features of M cells that promote adherence and transport of antigens and microorganisms are crucial for the design of mucosal vaccines and for understanding the strategies that pathogens use to exploit this pathway.