Investigations of factors protecting epithelial tissues against Phaseolus vulgaris lectin

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In Vitro Prevention of Salmonella Lipopolysaccharide-Induced Damages in Epithelial Barrier Function by Various Lactobacillus Strains

Background. Lactobacillus shows beneficial anti-inflammatory effects on Salmonella infection. The maintenance of the tight junction (TJ) integrity plays an importance role in avoiding bacterial invasion. Whether Lactobacillus could be used to regulate the TJ protein expression and distribution in inflamed intestinal epithelial cells was determined. Methods. Using the transwell coculture model, Salmonella lipopolysaccharide (LPS) was apically added to polarized Caco-2 cells cocultured with peripheral blood mononuclear cells in the basolateral compartment. LPS-stimulated Caco-2 cells were incubated with various Lactobacillus strains. TJ integrity was determined by measuring transepithelial electrical resistance across Caco-2 monolayer. Expression and localization of TJ proteins (zonula-occludens- (ZO-) 1) were determined by Western blot and immunofluorescence microscopy. Results. Various strains of Lactobacillus were responsible for the different modulations of cell layer integrity. LPS was specifically able to disrupt epithelial barrier and change the location of ZO-1. Our data demonstrate that Lactobacillus could attenuate the barrier disruption of intestinal epithelial cells caused by Salmonella LPS administration. We showed that Lactobacillus strains are associated with the maintenance of the tight junction integrity and appearance. Conclusion. In this study we provide insight that live probiotics could improve epithelial barrier properties and this may explain the potential mechanism behind their beneficial effect in vivo

Immune Modulation Effects of Lactobacillus casei Variety rhamnosus on Enterocytes and Intestinal Stem Cells in a 5-FU-Induced Mucositis Mouse Model

Background. Intestinal mucositis remains one of the most deleterious side effects in cancer patients undergoing chemotherapy. We hypothesize that the probiotics could preserve gut ecology, ameliorate inflammation, and protect epithelia via immune modulations of enterocytes and intestinal stem cells. Our aim is to characterize these changes and the safety of probiotics via a 5-fluorouracil- (5-FU-) induced intestinal mucositis mouse model. Methods. 5-FU-injected BALB/c mice were either orally administrated with saline or probiotic suspension of Lactobacillus casei variety rhamnosus (Lcr35). Diarrhea scores, serum proinflammatory cytokines, and T-cell subtypes were assessed. Immunostaining analyses for the proliferation of intestinal stem cells CD44 and Ki67 were processed. Samples of blood and internal organs were investigated for bacterial translocation. Results. Diarrhea was attenuated after oral Lcr35 administration. Serum proinflammatory cytokines were significantly increased in the 5-FU group and were reversed by Lcr35. A tremendous rise of the CD3+/CD8+ count and a significant decrease of CD3+CD4+/CD3+CD8+ ratios were found in the 5-FU group and were both reversed by Lcr35. 5-FU significantly stimulated the expression of CD44 stem cells, and the expression was restored by Lcr35. 5-FU could increase the number of Ki67 proliferative cells. No bacterial translocation was found in this study. Conclusions. Our results showed that 5-FU caused intestinal inflammation mainly via Th1 and Th17 responses. 5-FU could stimulate stem cells and proliferation cells in a mouse model. We demonstrate chemotherapy could decrease immune competence. Probiotics were shown to modulate the immune response. This is the first study to analyze the immune modulation effects and safety of Lactobacillus strain on enterocytes and intestinal stem cells in a mouse model

Characteristics of Gut Microbiota in Small for Gestational Age Infants with Very Low Birth Weight

Small for gestational age (SGA) birth is associated with high rates of mortality and morbidity in preterm infants. The aim of this preliminary observational study was to investigate the difference in gut microbiota between SGA and appropriate for gestational age (AGA) preterm infants with very low birth weight (VLBW). We included 20 VLBW preterm infants (SGA, n = 10; AGA, n = 10) in this study. Stool samples were collected on days 7, 14, and 30 after birth. We performed 16S ribosomal DNA sequencing to compare microbiota composition between both groups. The SGA group exhibited a lower abundance of Klebsiella on day 14 (SGA, 0.57%; AGA, 7.42%; p = 0.037). On day 30, the SGA group exhibited a lower abundance of Klebsiella (SGA 3.76% vs. AGA 16.05%; p = 0.07) and Enterobacter (SGA 5.09% vs. AGA 27.25%; p = 0.011) than the AGA group. Beta diversity demonstrated a separation of the bacterial community structure between both groups on day 30 (p = 0.019). The present study revealed that a distinct gut microbiota profile gradually develops in SGA preterm infants with VLBW during the early days of life. The role of changes in gut microbiota structure warrants further investigation

Amelioration of Chemotherapy-Induced Intestinal Mucositis by Orally Administered Probiotics in a Mouse Model.

Intestinal mucositis is a frequently encountered side effect in oncology patients undergoing chemotherapy. No well-established or up to date therapeutic strategies are available. To study a novel way to alleviate mucositis, we investigate the effects and safety of probiotic supplementation in ameliorating 5-FU-induced intestinal mucositis in a mouse model.Seventy-two mice were injected saline or 5-Fluorouracil (5-FU) intraperitoneally daily. Mice were either orally administrated daily saline, probiotic suspension of Lactobacillus casei variety rhamnosus (Lcr35) or Lactobacillus acidophilus and Bifidobacterium bifidum (LaBi). Diarrhea score, pro-inflammatory cytokines serum levels, intestinal villus height and crypt depth and total RNA from tissue were assessed. Samples of blood, liver and spleen tissues were assessed for translocation.Marked diarrhea developed in the 5-FU groups but was attenuated after oral Lcr35 and LaBi administrations. Diarrhea scores decreased significantly from 2.64 to 1.45 and 0.80, respectively (P<0.001). Those mice in 5-FU groups had significantly higher proinflammatory cytokine levels (TNF-α: 234.80 vs. 29.10, P<0.001, IL-6: 25.13 vs. 7.43, P<0.001, IFN-γ: 22.07 vs. 17.06, P = 0.137). A repairing of damage in jejunal villi was observed following probiotics administration. We also found TNF-α, IL-1β and IL-6 mRNA expressions were up-regulated in intestinal mucositis tissues following 5-FU treatment (TNF-α: 4.35 vs. 1.18, IL-1β: 2.29 vs. 1.07, IL-6: 1.49 vs. 1.02) and that probiotics treatment suppressed this up-regulation (P<0.05). No bacterial translocation was found in this study.In conclusion, our results show that oral administration of probiotics Lcr35 and LaBi can ameliorate chemotherapy-induced intestinal mucositis in a mouse model. This suggests probiotics may serve as an alternative therapeutic strategy for the prevention or management of chemotherapy-induced mucositis in the future

Metabolic Damage Presents Differently in Young and Early-Aged C57BL/6 Mice Fed a High-Fat Diet

Background: Obesity in old individuals is increasing at alarming rates, and this population is more vulnerable to the deleterious metabolic effects of obesity than younger individuals. However, at present, there is no ideal obesity model to evaluate the interaction of aging and obesity. Methods: The development of a metabolic damage model in response to a fixed period of high-fat diet (HFD) feeding was examined in mice of different ages. Mice aged 6 weeks (young group) and 44 weeks (elderly group) were fed a standard diet or HFD for 12 weeks, and their metabolic characteristics were studied. Inflammation was determined by the serum lipopolysaccharide (LPS) level. Gut microbiota composition was analyzed from stool samples. Results: After 12-week feeding, weight gain; elevated serum levels of cholesterol, triglyceride, and LPS; increased homeostasis model assessment-estimated insulin resistance (HOMA-IR); fat accumulation; nonalcoholic fatty liver disease (NAFLD) activity score (NAS); and gut microbiota changes occurred in response to HFD feeding in both young and elderly groups (p<0.05). HFD-induced serum levels of alanine aminotransferase, cholesterol, triglyceride, and insulin; HOMA-IR; fat accumulation; NAS; and gut microbiota changes were significantly higher in the elderly group (p<0.05). Conclusion: Aging in an obese mouse model does not increase LPS but exacerbates NAFLD severity, dyslipidemia, insulin insensitivity, fat accumulation, and gut microbiota changes. This obesity model might help elucidate target or multiple organ alterations associated with metabolic disorder and aging

Fecal Microbiota Transplantation Prevents Intestinal Injury, Upregulation of Toll-Like Receptors, and 5-Fluorouracil/Oxaliplatin-Induced Toxicity in Colorectal Cancer

FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin), a 5-fluorouracil (5-FU)-based chemotherapy regimen, is one of most common therapeutic regimens for colorectal cancer. However, intestinal mucositis is a common adverse effect for which no effective preventive strategies exist. Moreover, the efficacy and the safety of fecal microbiota transplants (FMT) in cancer patients treated with anti-neoplastic agents are still scant. We investigated the effect of FMT on FOLFOX-induced mucosal injury. BALB/c mice implanted with syngeneic CT26 colorectal adenocarcinoma cells were orally administered FMT daily during and two days after five-day injection of FOLFOX regimen for seven days. Administration of FOLFOX significantly induced marked levels of diarrhea and intestinal injury. FMT reduced the severity of diarrhea and intestinal mucositis. Additionally, the number of goblet cells and zonula occludens-1 decreased, while apoptotic and NF-&kappa;B-positive cells increased following FOLFOX treatment. The expression of toll-like receptors (TLRs), MyD88, and serum IL-6 were upregulated following FOLFOX treatment. These responses were attenuated following FMT. The disrupted fecal gut microbiota composition was also restored by FMT after FOLFOX treatment. Importantly, FMT did not cause bacteremia and safely alleviated FOLFOX-induced intestinal mucositis in colorectal cancer-bearing mice. The putative mechanism may involve the gut microbiota TLR-MyD88-NF-&kappa;B signaling pathway in mice with implanted colorectal carcinoma cells