Somatization in patients with predominant diarrhoea irritable bowel syndrome: the role of the intestinal barrier function and integrity

Abstract

Background Irritable bowel syndrome (IBS) is characterised by gastrointestinal (GI) and psychological symptoms (e.g., depression, anxiety, and somatization). Depression and anxiety, but not somatization, have already been associated with altered intestinal barrier function, increased LPS, and dysbiosis. The study aimed to investigate the possible link between somatization and intestinal barrier in IBS with diarrhoea (IBS-D) patients. Methods Forty-seven IBS-D patients were classified as having low somatization (LS = 19) or high somatization (HS = 28) according to the Symptom Checklist-90-Revised (SCL-90-R), (cut-off score = 63). The IBS Severity Scoring System (IBS-SSS) and the Gastrointestinal Symptom Rating Scale (GSRS) questionnaires were administered to evaluate GI symptoms. The intestinal barrier function was studied by the lactulose/mannitol absorption test, faecal and serum zonulin, serum intestinal fatty-acid binding protein, and diamine oxidase. Inflammation was assessed by assaying serum Interleukins (IL-6, IL-8, IL-10), and tumour necrosis factor-α. Dysbiosis was assessed by the urinary concentrations of indole and skatole and serum lipopolysaccharide (LPS). All data were analysed using a non-parametric test. Results The GI symptoms profiles were significantly more severe, both as a single symptom and as clusters of IBS-SSS and GSRS, in HS than LS patients. This finding was associated with impaired small intestinal permeability and increased faecal zonulin levels. Besides, HS patients showed significantly higher IL-8 and lowered IL-10 concentrations than LS patients. Lastly, circulating LPS levels and the urinary concentrations of indole were higher in HS than LS ones, suggesting a more pronounced imbalance of the small intestine in the former patients. Conclusions IBS is a multifactorial disorder needing complete clinical, psychological, and biochemical evaluations. Trial registration: https://clinicaltrials.gov/ct2/show/NCT03423069.

Psychological and Gastrointestinal Symptoms of Patients with Irritable Bowel Syndrome Undergoing a Low-FODMAP Diet: The Role of the Intestinal Barrier

“…Somatization, Interpersonal Sensitivity, Anxiety, and Psychoticism scores significantly reduced after diet, while Depression scores showed only a trend toward significance. These modifications refer essentially to those parameters mostly involved in the onset of IBS symptoms, especially in its diarrhea variant [ 41 ].…”

Somatization is associated with altered serum levels of vitamin D, serotonin, and brain‐derived neurotrophic factor in patients with predominant diarrhea irritable bowel syndrome

“…The detection and measurement of skatole in urine were performed by a 3-methylindole kit (Eureka Lab Division, Chiaravalle, AN) using a high-performance liquid chromatography (HPLC) system (Thermo Fisher Scientific) as described previously by our group. 7 Urinary indole and skatole values higher than 20 mg l −1 and 20 μg l −1 are considered fermentative and putrefactive dysbiosis indices, respectively. 32 Lipopolysaccharide (LPS), a bacterial translocation marker, was assayed using an ELISA kit by Cloud-Clone Corp (Katy, TX, USA).…”

“…We recently showed that IBS-D patients with high somatization scores suffered significantly more severe GI symptoms than patients without somatization. 7 This finding was associated with mild inflammation, dysbiosis, and impaired small intestinal permeability (s-IP).…”

“…Although studies have investigated the relationship between somatization and IBS, 5,6 there is little information on the pathophysiological mechanism underlying this relationship. We recently showed that IBS‐D patients with high somatization scores suffered significantly more severe GI symptoms than patients without somatization 7 . This finding was associated with mild inflammation, dysbiosis, and impaired small intestinal permeability (s‐IP).…”

Alisol B 23-Acetate Ameliorates Lipopolysaccharide-Induced Intestinal Barrier Dysfunction by Inhibiting TLR4-NOX1/ROS Signaling Pathway in Caco-2 Cells

“…Numerous TJ proteins have thus been found, such as cytoplasmic proteins zonula occludens-1 (ZO-1), the transmembrane proteins occluding and claudins ( Clark et al, 2006 ). The gut TJ barrier disruption leads to a “leaky” TJ barrier, resulting in a rise in gut permeability, and permitting paracellular permeation of luminal antigens that enhance intestinal inflammation, which is associated with various diseases comprising irritable bowel syndrome, diabetes, coeliac disease, non-alcoholic fatty liver disease, Crohn’s disease and so on ( Barbara et al, 2021 ; Portincasa et al, 2021 ; Prospero et al, 2021 ; Riedel et al, 2021 ; Xu et al, 2021 ).…”