Effects of psychological stress on small intestinal motility and bacteria and mucosa in mice

AIM: To investigate the effects of psychological stress on small intestinal motility and bacteria and mucosa in mice, and to explore the relationship between small intestinal dysfunction and small intestinal motility and bacteria and mucosa under psychological stress. METHODS: Sixty mice were randomly divided into psychological stress group and control group. Each group were subdivided into small intestinal motility group (n= 10), bacteria group (n = 10), and D-xylose administered to stomach group (n= 10). An animal model with psychological stress was established housing the mice with a hungry cat in separate layers of a two-layer cage. A semi-solid colored marker (carbon-ink) was used for monitoring small intestinal transit. The proximal small intestine was harvested under sterile condition and processed for quantitation for aerobes (Escherichia coli) and anaerobes (Lactobacilli). The quantitation of bacteria was expressed as Iog10(colony forming units/g). D-xylose levels in plasma were measured for estimating trie damage of small intestinal mucosa. RESULTS: Small intestinal transit was inhibited (39.80±9.50% vs 58.79±11.47%,P<0.01) in mice after psychological stress, compared with the controls. Psychological stress resulted in quantitative alterations in the aerobes (E.coli). There was an increase in the number of E coli in the proximal small intestinal flora (1.78±0.30 log10(CFU/g) vs 1.37±0.21 log10(CFU/g), P<0.01), and there was decrease in relative proportion of Lactobacilli and E.coli of stressed mice (0.53±0.63 vs 1.14±1.07,P<0.05), while there was no significant difference in the anaerobes (Lactobacilli) between the two groups (2.31±0.70 log10 (CFU/g) vs 2.44±0.37 log10(CFU/g), P>0.05). D-xylose concentrations in plasma in psychological stress mice were significantly higher than those in the control group (2.90±0.89 mmol/L vs 0.97±0.33 mmol/L, P<0.01). CONCLUSION: Small intestinal dysfunction under psychological stress may be related to the small intestinal motility disorder and dysbacteriosis and the damage of mucosa probably caused by psychological stress.

The Influence of Chinese Medicinal Herb on Chicken Immune Organs and Small Intestinal Mucosa Immune Organization

[Objective] The aim was to explore the mechanism of Chinese medicinal herb to enhance the body＇s immune. [Method] The quantitative distribution of immunocytes in chicken small intestinal mucosa lymphoid tissue-secretory type immune globulin cell A were dynamic observed to research chicken immune organ growth with histology conventional slice technology and immunohistochemistry dye. 1 day age healthy roosters were divided into 3 groups： the group 3 was control group. 1% and 0.5% concentration of Chinese herbal medicine immunopotentiator drinking water were added in the group 1 and 2 in continuous 60 d. The immune organ index was determined every 12 d and the histotomy of chicken small intes- tine in group control and 1% were taken for histological observation on day 24, 36 and 48. [ Result] Treatment group immune organ index was significantly higher than that of the control group and 1% group of small intestinal villus inherent intraformational immune cells number significantly increased （P〈0.01） compared with controls. Day 36 age group and day 48 group immune cells were higher than day 24 group of cell number （P〈 0.01 ）. [ Conclusionl Chinese medicinal herb had obvious role in promoting chicken immune organ growth and obvious influence on the quantity change of the intestinal mucosal immune cells.

Decreased expression of serotonin in the jejunum and increased numbers of mast cells in the terminal ileum in patients with irritable bowel syndrome

AIM: To investigate if there are changes in serotonin (5-HT) levels, enterochromaffin (EC) cells and mast cells in small intestinal mucosa of patients with irritable bowel syndrome (IBS). METHODS: Diarrhea-predominant (IBS-D, n = 20), or constipation-predominant (IBS-C, n = 18) IBS patients and healthy controls (n = 20) underwent colonoscopy and peroral small intestinal endoscopy, and mucosal samples were obtained at the descending part of the duodenum, proximal end of jejunum and terminal ileum. High-performance liquid chromatography- electrochemistry and immunohistochemical methods were used to detect 5-HT content, EC cells and mast cells. RESULTS: (1) There were no differences in the number and distribution of EC cells between IBS patients and the normal group. (2) The mucosal 5-HT contents at the duodenum, jejunum and ileum in IBS-C patients were 182 ± 90, 122 ± 54, 61 ± 35 ng/mg protein, respectively, which were all lower than those in the normal group (256 ± 84, 188 ± 91, and 93 ± 45 ng/ mg protein, respectively), with a significant difference at the jejunum (P < 0.05). There were no differences in the small intestinal mucosal 5-HT contents between IBS-D patients and the normal group. The mucosal 5-HT contents at the duodenum were significantly higher than those at the ileum in the three groups (P < 0.001). (3) The numbers of mast cells in patients with IBS-C and IBS-D at the ileum were 38.7 ± 9.4 and 35.8 ± 5.5/highpower field (hpf), respectively, which were significantly more than that in the normal group (29.8 ± 4.4/hpf) (P < 0.001). There was no significant difference in the numbers of mast cells at the other two parts between IBS patients and the normal group. The numbers of mast cells in IBS-C, IBS-D, and normal groups were all significantly higher at the ileum (38.7 ± 9.4, 35.8 ± 5.5, 29.8 ± 4.4/hpf, respectively) than at the duodenum (19.6 ± 4.7, 18.5 ± 6.3, 19.2 ± 3.3/hpf, respectively, P < 0.001). CONCLUSION: The changes in the 5-HT signaling pathway at the jejunum of IBS-C patients and the increase in mast cells in patients with IBS at the terminal ileum may offer evidence to explain the pathogenesis of IBS.