5-Fluorouracil (5-FU) is a commonly used chemotherapy agent in clinical oncology practice. Two of its major side effects are mucositis and diarrhoea. The structure of mucins offers mucosal protection, and allows maintenance of intestinal flora by providing attachment sites and preventing bacterial overgrowth and/or penetration. The aim of this study was to investigate changes in mucin secretion and microflora following treatment with 5-FU. Female DA rats were given a single 150 mg/ kg i.p. dose of 5-FU. Rats were killed at various time points after treatment. Control rats received no treatment. Jejunum, colon and faecal samples were collected. Standard microbiological culture techniques were used to identify bacteria, and real-time PCR was used to quantify bacteria in faecal samples. Goblet cells and cavitated goblet cells (having undergone mucus exocytosis) were also counted. Statistical analysis was carried out using Kruskal-Wallis test, a non-parametric method of testing equality of group medians. Following treatment with 5-FU, we showed decreases in Clostridium spp., Lactobacillus spp. and Streptococcus spp., and an increase in Escherichia spp. in the jejunum. In the colon, 5-FU caused decreases in Enterococcus spp., Lactobacillus spp. and Streptococcus spp. Real-time PCR of faecal samples showed decreasing trends in Lactobacillus spp. and Bacteroides spp., and an increasing trend in E. coli. Significant increases ( P < 0.05) were seen in Clostridium spp. and Staphylococcus spp. at 24 h. Goblet cell numbers decreased significantly in the jejunum from 24–72 h, with a significant increase in the percentage of cavitated goblet cells. In conclusion, 5-FU treatment causes significant changes in intestinal flora and mucin secretion in rats. These changes could result in systemic effects and, in particular, may contribute to the development of chemotherapy-induced mucositis.

Objectives: Chemotherapy-induced diarrhea (CID) is a well recognized side effect of cancer treatment. However, the pathophysiology behind this debilitating side effect remains unclear. Irinotecan causes cholinergic and delayed onset diarrhea in patients, in which β-glucuronidase produced by gut bacteria is thought to be involved. Methods: Rats were treated with 200mg/kg irinotecan and killed at various time points up to 72 h. Rats were monitored for diarrhea. Sections were stained for β-glucuronidase expression, and faecal DNA was analysed using real time PCR. Results: Diarrhea occurred, as expected, following irinotecan treatment. β-glucuronidase expression increased in the jejunum and colon. Faecal flora changed quantitatively after treatment also, with increases in E. coli, Staphylococcus spp., and Clostridium spp. (all β-glucuronidase producing), and decreases in Lactobacillus spp., Bifidobacterium spp. (both beneficial bacteria), and Bacteroides spp. (β-glucuronidase producing, major component of intestinal flora). Conclusions: Irinotecan-induced diarrhea may be caused by an increase in β-glucuronidase producing bacteria. However, the increase in bacteria may also be caused by irinotecan, further exaggerating the toxicity of the drug, and emphasising the need for these specific bacteria to be therapeutically targeted for successful treatment regimens to be accomplished.

The aim of this study was to review the available literature and define clinical practice guidelines for the use of agents for the prevention and treatment of gastrointestinal mucositis.

Introduction:Alimentary tract (AT) mucositis is a serious complication of cancer treatment. Determining changes that occur in the AT can be difficult as invasive procedures are usually contraindicated in these patients. Changes in tissue levels of the transcription factor NF-κB and pro-inflammatory cytokines have been demonstrated. The aims of this study were to determine whether changes in serum levels of NF-κB, TNF, IL-1β and IL-6 following administration of different drugs predicted histological evidence of tissue damage.Materials and Methods:Female DA rats (n=243) were given a single dose of irinotecan (200mg/kg intraperitoneally), methotrexate (1.5mg/kg intramuscularly) or 5-fluorouracil (150mg/kg intraperitoneally) and killed 30, 60, 90 minutes, 2, 6, 12, 24, 48 or 72 hours later. Control rats received no treatment. Blood samples were taken via cardiac puncture and centrifuged at 5000 rpm to collect serum. Serum levels of NF-κB, and pro-inflammatory cytokines were measured by ELISA. Results:Changes ...