Protective Effect Of Lactobacillus Research Articles

Probiotic Lactobacilli Do Not Protect Chickens against Salmonella Enteritidis Infection by Competitive Exclusion in the Intestinal Tract but in Feed, Outside the Chicken Host.

Lactobacilli are commonly used as probiotics in poultry to improve production parameters and to increase chicken resistance to enteric infections. However, lactobacilli do not efficiently colonise the chicken intestinal tract, and also, their anti-infection effect in vivo is sometimes questionable. In this study, we therefore evaluated the potential of a mixture of four Lactobacillus species (L. salivarius, L. reuteri, L. ingluviei and L. alvi) for the protection of chickens against Salmonella Enteritidis infection. Whenever the chickens were inoculated by lactobacilli and S. Enteritidis separately, there was no protective effect of lactobacilli. This means that when lactobacilli and S. Enteritidis are exposed to each other as late as in the crop of chickens, lactobacilli did not influence chicken resistance to S. Enteritidis at all. The only positive effect was recorded when the mixture of lactobacilli and S. Enteritidis was used for the inoculation of feed and the feed was anaerobically fermented for 1 to 5 days. In this case, chickens fed such a diet remained S. Enteritidis negative. In vitro experiments showed that the protective effect was caused by acidification of feed down to pH 4.6 due to lactobacilli fermentation and was associated with S. Enteritidis inactivation. The probiotic effect of lactobacilli was thus expressed in the feed, outside the chicken host.

Lactobacillus reuteri maintains intestinal epithelial regeneration and repairs damaged intestinal mucosa

ABSTRACT Little is known about the regulatory effect of microbiota on the proliferation and regeneration of ISCs. Here, we found that L. reuteri stimulated the proliferation of intestinal epithelia by increasing the expression of R-spondins and thus activating the Wnt/β-catenin pathway. The proliferation-stimulating effect of Lactobacillus on repair is further enhanced under TNF -induced intestinal mucosal damage, and the number of Lgr5+ cells is maintained. Moreover, compared to the effects of C. rodentium on the induction of intestinal inflammation and crypt hyperplasia in mice, L. reuteri protected the intestinal mucosal barrier integrity by moderately modulating the Wnt/β-catenin signaling pathway to avoid overactivation. L. reuteri had the ability to maintain the number of Lgr5+ cells and stimulate intestinal epithelial proliferation to repair epithelial damage and reduce proinflammatory cytokine secretion in the intestine and the LPS concentration in serum. Moreover, activation of the Wnt/β-catenin pathway also induced differentiation toward Paneth cells and increased antimicrobial peptide expression to inhibit C. rodentium colonization. The protective effect of Lactobacillus against C. rodentium infection disappeared upon application of the Wnt antagonist Wnt-C59 in both mice and intestinal organoids. This study demonstrates that Lactobacillus is effective at maintaining intestinal epithelial regeneration and homeostasis as well as at repairing intestinal damage after pathological injury and is thus a promising alternative therapeutic method for intestinal inflammation.

Evaluate the Protective Effect of Lactobacillus against Collateral Damage Induced by Ciprofloxacin and Levofloxacin in Iraqi Patients

Abstract: Fluoroquinolones drugs are an important class of wide spectrum antibacterial agents, and active against a wide range of Gram-negative and Gram-positive pathogens, are divided into four generations. Collateral damage is a term used to refer to ecological adverse effects of antibiotic therapy, occurring as drug-resistant organisms and the unwanted development of colonization or infection with multidrug-resistant organisms. This damage is mostly related to levofloxacin and Ciprofloxacin.
 Aim: The aim of the current study was to compare the incidence of collateral damage between two quinolone antibiotic derivatives (ciprofloxacin and Levofloxacin) and evaluate the activity of lactobacillus to reduce the collateral damage. Patients and Methods: This study was carried out on 100 patients. Administration of ciprofloxacin, levofloxacin each alone or in combination with lactobacillus, the character of diarrhea and grade of diarrhea was studied before and after 10 days of administration each dosing protocol. Results: there are a significant increase in the incidence of diarrhea for all groups when compare between before and after treatment diarrhea, Number of patients with diarrhea in group 1 after finish the treatment was not significantly higher when compared with group 2 (p>0.05) meanwhile number of patients with diarrhea in group 4 after finish the treatment was significantly lower when compared with group 3 (p>0.05). Conclusion; The use of ciprofloxacin and levofloxacin associated with incidence of collateral damage represented as diarrhea and levofloxacin is the least risk of this damage, and using of lactobacillus with levofloxacin was better results than the other three groups.

Extracellular vesicles from symbiotic vaginal lactobacilli inhibit HIV-1 infection of human tissues

The vaginal microbiota, dominated by Lactobacillus spp., plays a key role in preventing HIV-1 transmission. Here, we investigate whether the anti-HIV effect of lactobacilli is mediated by extracellular vesicles (EVs) released by these bacteria. Human cervico-vaginal and tonsillar tissues ex vivo, and cell lines were infected with HIV-1 and treated with EVs released by lactobacilli isolated from vaginas of healthy women. EVs released by L. crispatus BC3 and L. gasseri BC12 protect tissues ex vivo and isolated cells from HIV-1 infection. This protection is associated with a decrease of viral attachment to target cells and viral entry due to diminished exposure of Env that mediates virus-cell interactions. Inhibition of HIV-1 infection is associated with the presence in EVs of several proteins and metabolites. Our findings demonstrate that the protective effect of Lactobacillus against HIV-1 is, in part, mediated by EVs released by these symbiotic bacteria. If confirmed in vivo, this finding may lead to new strategies to prevent male-to-female sexual HIV-1 transmission.

Lactobacillus acidophilus Alleviated Salmonella-Induced Goblet Cells Loss and Colitis by Notch Pathway.

The intestinal mucosal barrier, including the mucus layer, protects against invasion of enteropathogens, thereby inhibiting infection. In this study, the protective effect of Lactobacillus on the intestinal barrier against Salmonella infection is investigated. The underlying mechanism of its effect, specifically on the regulation of goblet cells through the Notch pathway, is also elucidated. Here, the protective effect of Lactobacillus on alleviating changes in the intestinal barrier caused by Salmonella infection is explored. It has been found that Salmonella typhimurium colonizes the colon and damages colonic mucosa. However, Lactobacillus acidophilus ATCC 4356 alleviates the colitis caused by Salmonella infection. Moreover, S. typhimurium infection causes colonic crypt hyperplasia with increased PCNA+ cells, while L. acidophilus administration resolves these pathological changes. In addition, it has been further demonstrated that Salmonella results in severe colitis associated with goblet cells, and Lactobacillus improves colitis similarly associated with goblet cells. Salmonella infection induces goblet cell loss and reduces MUC2 expression by increasing Dll1, Dll4, and HES1 expression, while L. acidophilus reverses epithelial damage by balancing the Notch pathway. The study demonstrates that colitis improvement is controlled by Lactobacillus ATCC 4356 by regulation of the Notch pathway; this finding will be useful for prevention against animal S. typhimurium infection.

The protective effect of Lactobacillus and Bifidobacterium as the gut microbiota members against chronic urticaria

BackgroundChronic Urticaria is a common disorder which is defined by recurrent occurrence of wheals and sometimes angioedema. It has a notable influence on the patients' quality of life. Regulation of the immune system is one of the important roles of the gut microbiota. The effect of dysbiosis considering some members of gut microbiota in patients with chronic urticaria has been demonstrated in our previous study. ObjectiveComparing the frequency and bacterial load of Lactobacillus, Bifidobacterium, and Bacteroides between patients with chronic urticaria and healthy controls. Methods20 patients with chronic urticaria and 20 age and sex matched healthy individuals were included in the present study. Stool samples were analyzed for determining the frequency and bacterial load of Lactobacillus, Bifidobacterium, and Bacteroides genera. ResultsThere were no significant differences among the frequencies of detectable Lactobacillus, Bifidobacterium, or Bacteroides in stool samples of patients with chronic urticaria and healthy controls. The relative amounts of Lactobacillus and Bifidobacterium were significantly higher in fecal samples from controls compared to patients with chronic urticaria (P = 0.038 and 0.039, respectively). ConclusionIt is the first study on the implication of Lactobacillus, Bifidobacterium, and Bacteroides genera as gut microbiota members in patients with chronic urticaria.

Effects of Lactobacillus johnsonii and Lactobacillus reuteri on gut barrier function and heat shock proteins in intestinal porcine epithelial cells.

Heat shock proteins (HSPs) are a set of highly conserved proteins that can serve as intestinal gate keepers in gut homeostasis. Here, effects of a probiotic, Lactobacillus rhamnosus GG (LGG), and two novel porcine isolates, Lactobacillus johnsonii strain P47-HY and Lactobacillus reuteri strain P43-HUV, on cytoprotective HSP expression and gut barrier function, were investigated in a porcine IPEC-J2 intestinal epithelial cell line model. The IPEC-J2 cells polarized on a permeable filter exhibited villus-like cell phenotype with development of apical microvilli. Western blot analysis detected HSP expression in IPEC-J2 and revealed that L. johnsonii and L. reuteri strains were able to significantly induce HSP27, despite high basal expression in IPEC-J2, whereas LGG did not. For HSP72, only the supernatant of L. reuteri induced the expression, which was comparable to the heat shock treatment, which indicated that HSP72 expression was more stimulus specific. The protective effect of lactobacilli was further studied in IPEC-J2 under an enterotoxigenic Escherichia coli (ETEC) challenge. ETEC caused intestinal barrier destruction, as reflected by loss of cell–cell contact, reduced IPEC-J2 cell viability and transepithelial electrical resistance, and disruption of tight junction protein zonula occludens-1. In contrast, the L. reuteri treatment substantially counteracted these detrimental effects and preserved the barrier function. L. johnsonii and LGG also achieved barrier protection, partly by directly inhibiting ETEC attachment. Together, the results indicate that specific strains of Lactobacillus can enhance gut barrier function through cytoprotective HSP induction and fortify the cell protection against ETEC challenge through tight junction protein modulation and direct interaction with pathogens.

Effects of a probiotic in combination with prebiotics on intestinal lactobacilli and coliforms and activities of bacterial enzymes in 1,2-dimethylhydrazine exposed rats

Effects of the probiotic (PRO) Lactobacillus plantarum and of the combination of PRO and the prebiotic (PRE) inulin enriched with oligofructose (2%), and PRO with Lini oleum virginale (O) on counts of lactobacilli and coliforms and enzymatic activities in faeces of rats were studied. The rats (n = 60) were divided into 5 groups of 12 subjects. The animals were fed on a high fat diet (10%) for 8 weeks of experiment. Colon cancer was induced by the application of 1,2-dimethylhydrazine (DMH) twice a week in a dose of 20 mg/kg s.c. in groups G2-G5. The rats in group 1 (control 1) received a diet without any supplements. The rats in group 2 (control 2) received 1,2 DMH without any supplements. The rats in group 3 received PRO, group 4 PRO and PRE, and group 5 received PRO and O. A significant decrease (P < 0.05) of coliforms was found out after the application of PRO, PRO-O, and PRO-PRE in comparison with control group G2. Significantly higher (P < 0.05) counts of lactobacilli were determined after the application of PRO-O and PRO-PRE. Significantly lower (P < 0.001) activities of β-galactosidase, β-glucuronidase and α-glucosidase were observed in PRO, PRO-PRE and PRO-O, while in the case of the enzyme β-glucosidase the activity was lower only after the addition of PRO-O. The protective effect of lactobacilli was observed in the order PRO-O, PRO-PRE, and PRO. It was shown that combinations of PRO-O and PRO-PRE had a synergistic effect which was higher than the effect of administering only PRO.

Lactobacilli and the normal human anaerobic microflora.

The normal human microflora is a complex and usually stable ecosystem. The intestinal microflora is important to the host with regard to many metabolic functions and in resistance to bacterial infections. Administration of antimicrobial agents may disrupt the normal microflora, leading to a decrease in colonization resistance and alterations in metabolic activities of the intestinal bacteria. Antimicrobial therapy may also be accompanied by gastrointestinal disturbances and a reduction or elimination of lactobacilli in the intestinal microflora. Lactobacilli are part of the normal gram-positive anaerobic microflora. Through the production of lactic and acetic acids, hydrogen peroxide, and antimicrobial substances, these microorganisms possibly contribute to the maintenance of colonization resistance. Several studies have indicated a protective effect of lactobacilli against potential pathogens in the gastrointestinal tract. In view of these beneficial properties, it is considered important to maintain or increase the levels of lactobacilli in the intestinal microflora.