Escherichia coli A0 34/86 (EcO83) is a probiotic strain used in newborns to prevent nosocomial infections and diarrhoea. This bacterium stimulates both pro- and anti-inflammatory cytokine production and its intranasal administration reduces allergic airway inflammation in mice. Despite its benefits, there are concerns about the use of live probiotic bacteria due to potential systemic infections and gene transfer. Extracellular vesicles (EVs) derived from EcO83 (EcO83-EVs) might offer a safer alternative to live bacteria. This study characterizes EcO83-EVs and investigates their interaction with host cells, highlighting their potential as postbiotic therapeutics. EcO83-EVs were isolated, purified, and characterised following the Minimal Information of Studies of Extracellular Vesicles (MISEV) guidelines. Ex vivo studies conducted in human nasal epithelial cells showed that EcO83-EVs increased the expression of proteins linked to oxidative stress and inflammation, indicating an effective interaction between EVs and the host cells. Further in vivo studies in mice demonstrated that EcO83-EVs interact with nasal-associated lymphoid tissue, are internalised by airway macrophages, and stimulate neutrophil recruitment in the lung. Mechanistically, EcO83-EVs activate the NF-κΒ signalling pathway, resulting in the nitric oxide production. EcO83-EVs demonstrate significant potential as a postbiotic alternative to live bacteria, offering a safer option for therapeutic applications. Further research is required to explore their clinical use, particularly in mucosal vaccination and targeted immunotherapy strategies.

• Keywords
• EVs, Ec083, NF‐κΒ signalling, bacterial extracellular vesicles, macrophage, nitric oxide, postbiotics, probiotic,
• MeSH
• Administration, Intranasal * MeSH
• Epithelial Cells metabolism   MeSH
• Escherichia coli * metabolism   MeSH
• Extracellular Vesicles * metabolism   MeSH
• Humans MeSH
• Lymphoid Tissue metabolism   MeSH
• Macrophages metabolism   MeSH
• Mice MeSH
• NF-kappa B metabolism   MeSH
• Oxidative Stress MeSH
• Lung microbiology   metabolism   MeSH
• Probiotics * administration & dosage   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• NF-kappa B MeSH

Early postnatal events are important for the development of the neonatal immune system. Harboring the pioneering microorganisms forming the microbiota of the neonatal gastrointestinal tract is important for priming the immune system, as well as inducing appropriate tolerance to the relatively innocuous environmental antigens and compounds of normal healthy microbiota. Early postnatal supplementation of suitable, safe probiotics could accelerate this process. In the current study, the immunomodulatory capacity of the probiotic strain of Escherichia coli O83:K24:H31 (EcO83) was characterized in vitro and in vivo. We compared the capacity of EcO83 with and without hemolytic activity on selected immune characteristics in vitro as determined by flow cytometry and quantitative real-time PCR. Both strains with and without hemolytic activity exerted comparable capacity on the maturation of dendritic cells while preserving the induction of interleukin 10 (Il10) expression in dendritic cells and T cells cocultured with EcO83 primed dendritic cells. Early postnatal supplementation with EcO83 led to massive but transient colonization of the neonatal gastrointestinal tract, as detected by in vivo bioimaging. Early postnatal EcO83 administration promoted gut barrier function by increasing the expression of claudin and occludin and the expression of Il10. Early postnatal EcO83 application promotes maturation of the neonatal immune system and promotes immunoregulatory and gut barrier functions.

• Keywords
• E. coli O83:K24:H31, IL-10, dendritic cell, early postnatal probiotic administration, indol amine 2,3 dioxygenase, luciferase, probiotic,
• MeSH
• Dendritic Cells MeSH
• Escherichia coli MeSH
• Interleukin-10 MeSH
• Humans MeSH
• Microbiota * MeSH
• Infant, Newborn MeSH
• Probiotics * pharmacology   MeSH
• Check Tag
• Humans MeSH
• Infant, Newborn MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Interleukin-10 MeSH

Three Lactobacillus strains (LOCK 0900, LOCK 0908, LOCK 0919) out of twenty-four isolates were selected according to their antagonistic activity against pathogenic bacteria, resistance to low pH and milieu of bile salts. Intragastric administration of a mixture of these strains to Balb/c mice affected cytokine T(H)1-T(H)2 balance toward nonallergic T(H)1 response. Spleen cells, isolated from lactobacilli-treated mice and re-stimulated in vitro with the mixture of heat-inactivated tested strains, produced significantly higher amounts of anti-allergic tumor necrosis factor- and interferon-gamma than control animals whereas the level of pro-allergic interleukin-5 was significantly lower. Lactobacillus cells did not translocate through the intestinal barrier into blood, liver and spleen; a few Lactobacillus cells found in mesenteric lymph nodes could create antigenic reservoir activating the immune system. The mixture of Lactobacillus LOCK 0900, LOCK 0908 and LOCK 0919 strains represents a probiotic bacterial preparation with possible use in prophylaxis and/or therapy of allergic diseases.

• MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Antibiosis MeSH
• Bacterial Translocation MeSH
• Stress, Physiological MeSH
• Interferon-gamma metabolism   MeSH
• Interleukin-5 metabolism   MeSH
• Liver microbiology   MeSH
• Blood microbiology   MeSH
• Cells, Cultured MeSH
• Acids pharmacology   MeSH
• Lactobacillus drug effects   physiology   MeSH
• Leukocytes, Mononuclear immunology   MeSH
• Mice, Inbred BALB C MeSH
• Mice MeSH
• Probiotics administration & dosage   pharmacology   MeSH
• Spleen immunology   microbiology   MeSH
• Tumor Necrosis Factor-alpha metabolism   MeSH
• Bile Acids and Salts pharmacology   MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Interferon-gamma MeSH
• Interleukin-5 MeSH
• Acids MeSH
• Tumor Necrosis Factor-alpha MeSH
• Bile Acids and Salts MeSH

A certain relationship was observed between the gastrointestinal system, arthritis and immune system. Patients with rheumatoid arthritis have an altered microflora composition and disturbed intestinal defensive barrier. Effect of probiotic bacteria (Colinfant; COL) with known favorable effect on intestinal microflora was determined on the methotrexate (MTX) treatment of adjuvant arthritis. Rats with adjuvant arthritis were administered methotrexate 0.5 mg/kg body mass 2-times weekly per os, COL 1 mL/kg body mass every second day per os, and a combination of MTX+COL for a period of 28 d from the immunization. Levels of serum albumin, body mass, changes in hind paw swelling, and arthrogram score were estimated in rats as variables of inflammation and destructive arthritis-associated changes. Treatment with MTX, as well as with the combination treatment with MTX+COL significantly inhibited both inflammation and destructive arthritis-associated changes. The combination treatment inhibited both the hind paw swelling and arthrogram score more remarkably than MTX alone; on the other hand, the difference between combination treatment and MTX alone was not significant. Treatment with COL alone had no effect on adjuvant arthritis in rats. Colinfant can increase the preventive effect of MTX treatment in rat adjuvant arthritis by improving its antiarthritic effects.

• MeSH
• Antirheumatic Agents administration & dosage   MeSH
• Arthritis, Experimental drug therapy   immunology   therapy   MeSH
• Escherichia coli * physiology   MeSH
• Combined Modality Therapy MeSH
• Rats MeSH
• Humans MeSH
• Methotrexate administration & dosage   MeSH
• Disease Models, Animal MeSH
• Rats, Inbred Lew MeSH
• Probiotics administration & dosage   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Humans MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Antirheumatic Agents MeSH
• Methotrexate MeSH

Intestinal microbiota in exclusively breast-fed infants with blood-streaked stools and in healthy exclusively breast-fed babies was compared. Total anaerobes, bifidobacteria, lactobacilli, coliform bacteria, enterococci and clostridia were quantified by cultivation methods in feces of 17 full-term exclusively breastfed patients (aged 16.3 +/- 7.4 weeks) with blood-streaked stools and in the control group of 22 healthy fullterm exclusively breast-fed infants (13.7 +/- 6.4 weeks). Specific fluorescence in situ hybridization kits for Bifidobacterium spp. were used for the quantitative detection of bifidobacteria in samples. Control samples had significantly (p < 0.05) higher counts of total anaerobes. Bifidobacteria were not detected in patients' samples in 65 % and in controls in 36 % (p < 0.01). Bifidobacteria counts were also significantly higher in the control group (p < 0.01). Furthermore, clostridia strains were detected only in feces from bifidobacteria-negative infants reaching counts >8 log CFU/g. Lactobacilli were not detected in 65 % patients and in 45 % control samples. However, this difference was not significant as well as the difference in lactobacilli counts. Eosinophilia was observed in 35 % of patients, low IgA concentration in 71 % and also low IgG concentration in 71 %. pANCA positivity was found in 53 % of patients. In conclusion a significant low proportion of bifidobacterial microbiota in patients with blood-streaked stools was shown in comparison with controls.

• MeSH
• Bacteria isolation & purification   MeSH
• Feces microbiology   MeSH
• Immunoglobulin A blood   MeSH
• Immunoglobulin G blood   MeSH
• Infant MeSH
• Breast Feeding * MeSH
• Humans MeSH
• Proctocolitis immunology   microbiology   MeSH
• Intestines microbiology   MeSH
• Check Tag
• Infant MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Immunoglobulin A MeSH
• Immunoglobulin G MeSH

Twenty-eight exclusively breast-fed healthy infants and 16 infants also exclusively breast-fed with allergic colitis (aged 85 +/- 60 and 98 +/- 58 d, respectively) were screened for differences in fecal flora. Bifidobacteria were detected in 23 healthy infants and only in 4 fecal samples of infants with allergic colitis. All bifidobacteria-free infants possessed Gram-positive regular rods as a major group of their fecal flora. These bacteria were identified as clostridia using genus-specific FISH probe. Infants with allergy colitis possessed significantly lower counts of bifidobacteria and total anaerobes and significantly higher counts of clostridia in their feces. In healthy infants, Bifidobacterium longum was the most frequently found species (54.5% of the samples), followed by B. adolescentis (20.0), B. breve (18.2), B. bifidum (16.4), B. dentium (10.9) and B. pseudocatenulatum (1.80). Bifidobacterial isolates from two babies with allergic colitis were identified as B. longum, one child from patients group contained species B. dentium and one baby B. adolescentis. Our results suggest that there are significantly lower counts of bifidobacteria in infants with allergic colitis than in healthy infants.

• MeSH
• Hypersensitivity microbiology   MeSH
• Bacteria, Anaerobic classification   genetics   isolation & purification   MeSH
• Bifidobacterium classification   genetics   isolation & purification   MeSH
• Feces microbiology   MeSH
• Gram-Positive Bacteria classification   genetics   isolation & purification   MeSH
• In Situ Hybridization, Fluorescence MeSH
• Infant MeSH
• Breast Feeding MeSH
• Colitis microbiology   MeSH
• Culture Media MeSH
• Humans MeSH
• Colony Count, Microbial MeSH
• Intestines microbiology   MeSH
• Check Tag
• Infant MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• Culture Media MeSH

Germ-free immunocompetent (BALB/c) and immunodeficient (SCID) mice were colonized either by E. coli O6K13 or by E. coli strain Nissle 1917 and intestinal inflammation was induced by administering 2.5% dextran sulfate sodium (DSS) in drinking water. Controls were germ-free mice which demonstrated only mild inflammatory changes after induction of an acute intestinal inflammation with DSS as compared with conventional mice in which acute colitis of the colon mucosa similar to human ulcerative colitis is elicited. In mice monocolonized with the nonpathogenic E. coli Nissle 1917 the inflammatory disease did not develop (damage grade 0) while animals monocolonized with uropathogenic E. coli O6K13 exhibited inflammatory changes similar to those elicited in conventionally reared mice (damage grade 3). In the chronic inflammation model, immunocompetent BALB/c mice monocolonized with E. coli Nissle 1917 showed no conspicuous inflammatory changes of the colon mucosa whereas those monocolonized with E. coli O6K13 developed colon inflammation associated with marked infiltration of inflammatory cells. In contrast to germ-free immunodeficient SCID mice that died after application of DSS, the colon mucosa of SCID mice monoassociated with E. coli Nissle 1917 exhibited only moderate inflammatory changes which were less pronounced than changes of colon mucosa of SCID mice monoassociated with E. coli O6K13.

• MeSH
• Escherichia coli growth & development   pathogenicity   MeSH
• Gastrointestinal Tract microbiology   MeSH
• Germ-Free Life MeSH
• Escherichia coli Infections immunology   microbiology   pathology   MeSH
• Colitis chemically induced   immunology   microbiology   pathology   MeSH
• Mice, Inbred BALB C MeSH
• Mice, SCID MeSH
• Mice MeSH
• Dextran Sulfate MeSH
• Intestinal Mucosa immunology   microbiology   pathology   MeSH
• Inflammation immunology   microbiology   pathology   MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Dextran Sulfate MeSH