Acute gastroenteritis, characterized by the onset of diarrhea with or without vomiting, continues to be a major cause of morbidity and mortality in children in mostly resource-constrained nations. Although generally a mild and self-limiting disease, gastroenteritis is one of the most common causes of hospitalization and is associated with a substantial disease burden. Worldwide, up to 40% of children aged less than 5 years with diarrhea are hospitalized with rotavirus. Also, some microorganisms have been found predominantly in resource-constrained nations, including Shigella spp, Vibrio cholerae, and the protozoan infections. Prevention remains essential, and the rotavirus vaccines have demonstrated good safety and efficacy profiles in large clinical trials. Because dehydration is the major complication associated with gastroenteritis, appropriate fluid management (oral or intravenous) is an effective and safe strategy for rehydration. Continuation of breastfeeding is strongly recommended. New treatments such as antiemetics (ondansetron), some antidiarrheal agents (racecadotril), and chemotherapeutic agents are often proposed, but not yet universally recommended. Probiotics, also known as “food supplement,” seem to improve intestinal microbial balance, reducing the duration and the severity of acute infectious diarrhea. The European Society for Paediatric Gastroenterology, Hepatology and Nutrition and the European Society of Paediatric Infectious Diseases guidelines make a stronger recommendation for the use of probiotics for the management of acute gastroenteritis, particularly those with documented efficacy such as Lactobacillus rhamnosus GG, Lactobacillus reuteri, and Saccharomyces boulardii. To date, the management of acute gastroenteritis has been based on the option of “doing the least”: oral rehydration-solution administration, early refeeding, no testing, no unnecessary drugs.

/pdf/management-strategies-in-the-treatment-of-neonatal-and-x3eigtqqzw.pdf

Management strategies in the treatment of neonatal and pediatric gastroenteritis.

Background
Accurate assessment of probiotics with targeted anti-Salmonella activity requires suitable models accounting for both, microbe-microbe and host-microbe interactions in gut environments. Here we report the combination of two original in vitro intestinal models closely mimicking the complex in vivo conditions of the large intestine. Effluents from continuous in vitro three-stage fermentation colonic models of Salmonella Typhimurium infection inoculated with immobilized child microbiota and Salmonella were directly applied to confluent mucus-secreting HT29-MTX cell layers. The effects of Salmonella, addition of two bacteriocinogenic strains, Bifidobacterium thermophilum RBL67 (thermophilicin B67) and Escherichia coli L1000 (microcin B17), and inulin were tested on Salmonella growth and interactions with epithelial cell layers. Salmonella adhesion and invasion were investigated and epithelial integrity assessed by transepithelial electrical resistance (TER) measurements and confocal microscopy observation. Data from complex effluents were compared with pure Salmonella cultures.

/pdf/protective-effect-of-probiotics-on-salmonella-infectivity-19s04zi0je.pdf

Protective effect of probiotics on Salmonella infectivity assessed with combined in vitro gut fermentation-cellular models

The present study was undertaken to assess the antimicrobial activity of Lactobacillus spp. (L. salivarius, L. johnsonii, L. reuteri, L. crispatus, and L. gasseri) against Campylobacter jejuni as well as their immunomodulatory capabilities. The results demonstrated that lactobacilli exhibit differential antagonistic effects against C. jejuni and vary in their ability to elicit innate responses in chicken macrophages. All lactobacilli exerted inhibitory effects on C. jejuni growth, abrogated the production of the quorum sensing molecule autoinducer-2 (AI-2) by C. jejuni and inhibited the invasion of C. jejuni in human intestinal epithelial cells. Additionally, all lactobacilli, except L. reuteri, significantly reduced the expression of virulence-related genes in C. jejuni, including genes responsible for motility (flaA, flaB, and flhA), invasion (ciaB), and AI-2 production (luxS). All lactobacilli enhanced C. jejuni phagocytosis by macrophages and increased the expression of interferon (IFN)-γ, interleukin (IL)-1β, IL-12p40, IL-10, and chemokine (CXCLi2) in macrophages. Furthermore, L. salivarius, L. reuteri, L. crispatus, and a mixture of all lactobacilli significantly increased expression of the co-stimulatory molecules CD40, CD80, and CD86 in macrophages. In conclusion, these findings demonstrate that lactobacilli possess anti-Campylobacter and immunomodulatory activities. Further studies are needed to assess their protective efficacy against intestinal colonization by C. jejuni in broiler chickens.

/pdf/in-vitro-assessment-of-immunomodulatory-and-anti-1bkbfgoely.pdf

In vitro assessment of immunomodulatory and anti-Campylobacter activities of probiotic lactobacilli.

The antagonistic activity against gastrointestinal bacterial pathogens is an important property of probiotic bacteria and a desirable feature for pre-selection of novel strains with probiotic potential. Pre-screening of candidate probiotics for antibacterial activity should be based on in vitro and in vivo tests. This study investigated whether the protective activity of probiotic bacteria against gastrointestinal bacterial pathogens can be evaluated using Galleria mellonella larvae as an in vivo model. Larvae were pre-inoculated with either of two widely used probiotic bacteria, Lactobacillus rhamnosus GG or Clostridium butyricum Miyairi 588, and then challenged with Salmonella enterica Typhimurium, enteropathogenic Escherichia coli or Listeria monocytogenes. Survival rates increased in the probiotic pretreated larvae compared with control larvae inoculated with pathogens only. The hemocyte density increased as well in the probiotic pretreated larvae, indicating that both probiotics induce an immune response in the larvae. The antibacterial activity of probiotics against the pathogens was also assayed by an in vitro agar spot test: results were partially consistent with those obtained by the G. mellonella protection assay. The results obtained, as a whole, suggest that G. mellonella larvae are a potentially useful in vivo model that can complement in vitro assays for pre-screening of candidate probiotics.

Galleria mellonella as an in vivo model for assessing the protective activity of probiotics against gastrointestinal bacterial pathogens.

https://ir.library.osaka-u.ac.jp/repo/ouka/all/54098/23279_%E8%A6%81%E6%97%A8.pdf

Synbiotics decrease the incidence of septic complications in patients with severe SIRS : a preliminary report

Section I: Introduction and History of Probiotics.- 1. Probiotics: From the ancient wisdom to the actual therapeutical and nutraceutical perspective.- Section II: The Gut Microorganisms and Probiotics.- 2. The Intestinal Microbiota and Probiotics.- 3. Ecology of Probiotics and Enteric Protection.- Section III: Pathophysiology of Enteric Disorders Due to Disturbed Microbiota.- 4. Factors Causing Disturbances of the Gut Microbiota.- 5. The gut microbiota, probiotics and infectious disease.- Section IV: Application of Molecular Biology and -omics of Probiotics in Enteric Protection.- 6. Application of Molecular Biology and Genomics of Probiotics for Enteric Cytoprotection.- 7. Application of Probiotic Proteomics in Enteric Cytoprotection.- 8. Promoting Gut Health with Probiotic Metabolomics.- Section V: Probiotics, Gut Immunology and Enteric Protection.- 9. Microbiota, Probiotics and Natural Immunity of the Gut.- 10. Interaction of Probiotics with the Acquired Immune System in the Gut.- 11. The Protective Role of Probiotics in Disturbed Enteric Microbiota.- 12. Modulation of Immune System by Probiotics to Protect against Enteric Disorders.- Section VI: Probiotics for Enteric Therapy.- 13. Probiotic-Pathogen Interaction and Enteric Cytoprotection.- 14. Bacteriocins of Probiotics and Enteric Cytoprotection.- 15. Probiotics in Clinical Practice as Therapeutics against Enteric Disorders.- 16. Potential Mechanisms of Enteric Cytoprotection by Probiotics: Lessons from Cultured Human Intestinal Cells.- 17. Probiotics and Enteric Cancers.- Section VII: The Future of Probiotics.- 18. Designer Probiotics and Enteric Cytoprotection.- 19. Future Prospects of Probiotics as Therapeutics against Enteric Disorders.

https://www.gastrojournal.org/article/S0016-5085(11)01261-3/pdf

Romana Marinšek-Logar

Papers

Probiotic bacteria and enteric infections : cytoprotection by probiotic bacteria