Kiwifruit improves bowel function in patients with irritable bowel syndrome with constipation.Irritable bowel syndrome (IBS) is a common functional disorder of the gastrointestinal system, and is characterized by abdominal pain, diarrhea (IBS/D), constipation (IBS/C), and alternating diarrhea and constipation (IBSC/A). The purpose of this study was to examine the impact of a four week kiwifruit intervention on bowel function in patients diagnosed with IBS/C. Fifty-four patients with IBS/C and 16 healthy adults participated in this study. All subjects participated in the 6 week, three phase study, which included a baseline phase (1 week), a dietary intervention period (4 weeks), and a post-intervention phase (1 week). Forty-one IBS/C patients and all healthy adults consumed two Hayward green (Actinida deliciosa var) kiwifruits per day for 4 weeks. Thirteen IBS/C patients in the control group took two placebo capsules per day for 4 weeks. Colon transit time was measured immediately prior to and following the intervention period. All subjects completed daily defecation records. After the 4-week intervention, weekly defecation frequency significantly increased in the IBS/C group of participants who consumed kiwifruit (p<0.05). Colon transit time significantly decreased (p=0.026) in the IBS/C group that consumed kiwi fruit. These findings suggest that kiwifruit consumption for 4 weeks shortens colon transit time, increases defecation frequency, and improves bowel function in adults diagnosed with IBS/C.
Defects in the Acquisition of Tumor-Killing Capability of CD8+ Cytotoxic T Cells in Streptozotocin-Induced Diabetic MiceEmerging evidences have shown that diabetes mellitus not only raises risk but also heightens mortality rate of cancer. It is not clear, however, whether antitumor CD8+ cytotoxic T lymphocyte (CTL) response is down-modulated in diabetic hosts. We investigated the impact of hyperglycemia on CTLs' acquisition of tumor-killing capability by utilizing streptozotocin-induced diabetic (STZ-diabetic) mice. Murine diabetes was induced by intraperitoneal injection of STZ (200 mg/kg) in C57BL/6 mice, 2C-T cell receptor (TCR) transgenic and P14-TCR transgenic mice. The study found that, despite harboring intact proliferative capacity measured with CFSE labeling and MTT assay, STZ-diabetic CD8+ CTLs displayed impaired effector functions. After stimulation, STZ-diabetic CD8+ CTLs produced less perforin and TNFα assessed by intracellular staining, as well as expressed less CD103 protein. Furthermore, adoptive transfer of STZ-diabetic P14 CD8+ effector cells showed an insufficient recruitment to the B16.gp33 melanoma and inadequate production of perforin, granzyme B and TNFα determined by immunohistochemistry in the tumor milieu. As a result, STZ-diabetic CD8+ effector cells were neither able to eliminate tumor nor to improve survival of tumor-bearing mice. Taken together, our data suggest that CD8+ CTLs are crippled to infiltrate into tumors and thus fail to acquire tumor-killing capability in STZ-diabetic hosts.