Evaluation of two laboratory model methods for diarrheal irritable bowel syndrome

Abstract

Background Diarrheal irritable bowel syndrome (IBS-D) is a common chronic functional gastrointestinal disorder, and the underlying pathogenic mechanism is still unclear. Animal models that mimic the pathological state of IBS-D patients were constructed to provide a reference for later drug research and model development. Methods The IBS-D model was induced using restraint stress and chemical stimulation (rhubarb), and rats were divided into normal control group (NC), chemically stimulated group (CS), and restraint stress group (RS). Visceral motility responses to Colorectal Balloon Dilation (CRD) were measured by Abdominal Withdrawal Reflex (AWR); evaluation of faecal properties and water content; determination of colonic tissue tight junction (TJ) mRNA expression by RT-PCR; measurement of inflammatory cytokines by ELISA; and intestinal flora and short chain fatty acids. Results Compared to NC group, CS and RS group rats showed increased intestinal sensitivity and Bristol stool score, significant diarrheal symptoms and weight loss. Mucin 2, ZO-1, OCLN, CLDN4 mRNA expression was reduced and the intestinal mucosal barrier function was diminished. In addition, the levels of inflammatory factors IL-1β, IL-6, IL-8, IL-10 and TNF-α increased, the abundance and diversity of intestinal flora decreased, the content of beneficial bacteria such as Bifidobacteria decreased, and SCFAs such as acetic acid, propionic acid and butyric acid decreased to different degrees. Although, no significant difference was observed for any molecular and inflammatory marker, but compared to CS group, RS group had less water in the stool, higher visceral sensitivity, and higher relative abundance of beneficial intestinal bacteria such as Actinobacteria. Conclusion In conclusion, restraint stress combined with chemical stimulation can mimic the pathological state of diarrhoea symptoms, visceral hypersensitivity, reduced intestinal mucosal barrier permeability, immune regulatory dysfunction and dysbiosis in IBS-D patients. However, herbs with antibacterial effects such as rhubarb and senna, for example, are not suitable as the first choice for chemical stimulation, as they may lead to a decrease in harmful bacteria and an increase in beneficial bacteria in the intestinal fraction and do not perfectly mimic the imbalanced state of intestinal flora in IBS-D patients, while restraint stress may be a key factor in modelling.

Phenylketonuria (PKU) Urinary Metabolomic Phenotype Is Defined by Genotype and Metabolite Imbalance: Results in 51 Early Treated Patients Using Ex Vivo 1H-NMR Analysis

“…The role of acetic acid produced by bacteria in the gut has recently been investigated in animal models [ 38 ]. It may also play a role in irritable bowel syndrome [ 39 ]. Acetic acid is present in very low concentrations in the cell, but greatly increased by bacteria in urinary tract infections [ 40 ], indicating that acetic acid is mainly derived from bacteria.…”

Activation of ASIC3/ERK pathway by paeoniflorin improves intestinal fluid metabolism and visceral sensitivity in slow transit constipated rats

“…Rat feces were collected individually 24 h after treatment completion, counted, and scored using Bristol fecal typing criteria 21 (Table 1). Feces were measured in wet weight (WW), then dried at a constant temperature of 60°C for 12 h and weighed as dry weight (DW).…”

“…Visceral sensitivity was evaluated using the abdominal withdrawal reflex (AWR) score using the colorectal dilatation method 21 . Rats were anesthetized with ether (LOT: 2204017, Xilong Scientific Co., Ltd, Shantou, China) after 12 h of fasting.…”

“…Visceral sensitivity was evaluated using the abdominal withdrawal reflex (AWR) score using the colorectal dilatation method. 21 Rats were anesthetized with ether (LOT: 2204017, Xilong Scientific Co., Ltd, Shantou, China) after 12 h of fasting. An 8F catheter sheathed with a 6 cm latex finger cuff (balloon), a sphygmomanometer, and a pressurized device were connected via a three-way valve.…”

L‐Theanine alleviates heat stress through modulation of gut microbiota and immunity

“…Studies have indicated that HS can alter the gut microbiota of animals such as mice, rabbits, and chickens. [10][11][12] Dysbiosis of the gut microbiota, characterized by decreased concentrations of beneficial metabolites such as short-chain fatty acids and increased levels of pathogenic metabolites, 13 can trigger excessive activation of the immune system, 14 resulting in intestinal inflammation and discomfort. 15 Secretory immunoglobulin A (sIgA), the primary immunoglobulin in the intestinal mucosa, is produced primarily by B cells and serves as the first line of defense against various endogenous microbial communities and exogenous invasive pathogens.…”