Cognitive Functions and Depression in Patients with Irritable Bowel Syndrome

Psychopathological and neuropsychological disorders associated with chronic primary visceral pain: Systematic review

The World Health Organization (WHO), in its last review of its International Classification of Diseases, established a new classification for chronic pain. Among the principal categories, of particular interest is chronic primary pain as a new type of diagnosis in those cases in which the etiology of the disease is not clear, being termed as chronic primary visceral pain when it is situated in the thorax, abdomen, or pelvis. Due to the novelty of the term, the objective of the systematic review was to examine the psychopathological and neuropsychological disorders associated with chronic primary visceral pain. We carried out a search of the scientific literature following the PRISMA directives using the Pubmed, Medline, PsycInfo and Scopus databases. A total of 33 articles were selected after applying the inclusion and exclusion criteria. The analysis of the studies showed that most persons with chronic primary visceral pain suffer from at least one psychological disorder; the most prevalent being anxiety, depressive or somatoform disorders. The most frequent psychopathological symptoms are anxiety, depression and somatization. Similarly, the findings are insufficient to determine the existence of deficits in the domains of executive functioning, memory and intelligence. However, the existence of attention biases does seem to be clear. This review supposes a starting point for conceptualizing chronic primary visceral pain. It is necessary to continue further research so as to obtain a better understanding of this pathology and the disorders associated.

Role of Traumatic Events and Motivational Structure in Ambiguity Tolerance of Irritable Bowel Syndrome

Background: The main purpose of this study was to delineate the role of motivational structure and traumatic events in the prediction of ambiguity tolerance in patients with irritable bowel syndrome (IBS). Methods: A total of 200 patients with the diagnosis of IBS, referred to the Shariati hospital in 2018, were enrolled using a correlational design and convenience sampling. All participants were asked to complete the ambiguity tolerance questionnaire, the life event checklist, and the personal concerns inventory. Data analysis was performed by Pearson correlation method and regression analysis test in SPSS software. Results: Findings showed that there was a significant relationship between traumatic events (r=- 0.66, P=0.01) and adaptive (r=0.24, P=0.01) and non-adaptive motivational structure (non-AMS) (r=- 0.10, P=0.01) with tolerance of ambiguity (P<0.05). With increasing non-AMS and with decreasing non-AMS and traumatic events, the tolerance of ambiguity is increased. Moreover, the motivational structure (adaptive and non-adaptive) and traumatic events could define and predict 43% of the variance in ambiguity tolerance. Conclusion: Thus, regarding the important role of motivational structure and traumatic events in predicting ambiguity tolerance in IBS patients, it is prudent to put emphasis on these measures to improve patients' overall health and probably alleviate symptoms and provide psychologic rehabilitation.

Psychosocial and Sensory Factors Contribute to Self-Reported Pain and Quality of Life in Young Adults with Irritable Bowel Syndrome

AIMS

Psychosocial and sensory factors, including anxiety, depression, and pressure pain threshold have been used to cluster chronic symptoms in irritable bowel syndrome (IBS). This study examined the contribution of psychosocial sensory factors on pain interference and quality of life (QOL) in this population.

DESIGN

We performed a cross-sectional analysis of baseline data from a randomized controlled trial.

SETTINGS

Two gastrointestinal clinics, general communities, and two large campuses of a public university in the Northeastern United States.

PARTICIPANTS/SUBJECTS

Eighty young adults with IBS aged 21 ± 2.57 years (76.25% female).

METHODS

Demographic and psychosocial factors including anxiety, depression, fatigue, cognition or general concerns, sleep disturbance, self-efficacy, coping, and food intake were measured as independent variables. Quantitative sensory testing was conducted to measure mechanical, thermal, and pressure pain thresholds. Self-reported pain measured by the brief pain inventory (BPI) and IBS-QOL were assessed as the outcome variables. Regression analysis and mediation analysis were conducted to determine the associated factors of IBS pain and QOL.

RESULTS

Age, sex, and psychosocial factors including coping, self-efficacy, alcohol intake, mechanical pain sensitivity, and cold pain threshold were significantly associated with pain interference (all p < 0.05). Coping, and self-efficacy were significantly associated with IBS-QOL (all p < 0.05). In the mediation analysis, coping catastrophizing and self-efficacy were indirectly associated with IBS-QOL mediated by fatigue.

CONCLUSIONS

Psychosocial factors including coping and self-efficacy, and quantitative sensory testing factors significantly correlate with self-reported pain and QOL among young adults with IBS. This preliminary research calls for further interventional studies that target personalized psychosocial and quantitative sensory factors to improve pain management and quality of life in IBS patients.

Irritable Bowel Syndrome, Depression, and Neurodegeneration: A Bidirectional Communication from Gut to Brain

Patients with irritable bowel syndrome (IBS) are increasingly presenting with a wide range of neuropsychiatric symptoms, such as deterioration in gastroenteric physiology, including visceral hypersensitivity, altered intestinal membrane permeability, and gastrointestinal motor dysfunction. Functional imaging of IBS patients has revealed several abnormalities in various brain regions, such as significant activation of amygdala, thinning of insular and anterior cingulate cortex, and increase in hypothalamic gray matter, which results in poor psychiatric and cognitive outcomes. Interrelations between the enteric and central events in IBS-related gastrointestinal, neurological, and psychiatric pathologies have compelled researchers to study the gut-brain axis-a bidirectional communication that maintains the homeostasis of the gastrointestinal and central nervous system with gut microbiota as the protagonist. Thus, it can be disrupted by any alteration owing to the gut dysbiosis or loss of diversity in microbial composition. Available evidence indicates that the use of probiotics as a part of a balanced diet is effective in the management of IBS and IBS-associated neurodegenerative and psychiatric comorbidities. In this review, we delineate the pathogenesis and complications of IBS from gastrointestinal and neuropsychiatric standpoints while also discussing the neurodegenerative events in enteric and central nervous systems of IBS patients and the therapeutic potential of gut microbiota-based therapy established on clinical and preclinical data.

Camelina sativa Methanolic and Ethanolic Extract Potential in Alleviating Oxidative Stress, Memory Deficits, and Affective Impairments in Stress Exposure-Based Irritable Bowel Syndrome Mouse Models

Camelina sativa is mainly used as an oilseed crop; its edible oil is being also used as a traditional home remedy for the treatment of ulcers, wounds, and eye inflammations, due to the antioxidant activities. In the present study, the chemically characterized alcoholic extracts of Camelina sativa var. Madalina defatted seeds (5 g/kg body weight p.o., suspended in CMC-Na 0.1%) were administered to stress-induced animal models of irritable bowel syndrome (based on combinations of contention stress and multifactorial stress and maternal stress) and evaluated for the behavioural (short-term memory by the Y maze test, the anxious behaviour using the elevated plus maze test, and the antidepressant effect using the forced swimming test) and brain and bowel tissue oxidative status (superoxide dismutase and glutathione peroxidase enzymes activities and malondialdehyde and total soluble protein levels) improving effects. According to the chemical characterization, the extracts were rich in sinapine, glucosinolates, and flavonol glycosides. Moreover, this study showed the beneficial effects of Camelina sativa seed methanolic and ethanolic extracts on the behaviour and brain and bowel tissues oxidative stress status of stress exposure-based IBS mouse models. Despite the slight differences in the chemical composition of the methanolic and ethanolic extracts, the results suggested that the Camelina sativa extracts could reverse the short-term memory impairments caused by stress exposure and also could decrease the intensity and frequency of the anxiety and depressive-like behaviours observed in the stress-exposed animal models of IBS. Furthermore, the Camelina sativa extracts showed a significant effect on the oxidative stress markers in the brain and bowel tissues of the studied animal model by decreasing the superoxide dismutase activity and increasing the glutathione peroxidase activity. However, the results suggested that the extracts could also increase lipid peroxidation in bowel tissues. In this way, this study provides additional evidence that the administration of Camelina sativa seed alcoholic extracts could improve cognitive performances and mood and exhibit the antioxidant capacity in both the brain and bowel tissues.

Antioxidant Capacity and Behavioral Relevance of a Polyphenolic Extract of Chrysanthellum americanum in a Rat Model of Irritable Bowel Syndrome

Chrysanthellum americanum L. (Vatke) is a medicinal plant from the Compositae family used in west-African traditional medicine, known for its flavonoid and saponin richness and for its strong antioxidant potential. In the present study, we assessed the effects of Chrysanthellum americanum polyphenolic extract in the psychological stress-induced rat model of irritable bowel syndrome (IBS), a chronic functional digestive tract disorder marked by immune and inflammatory-related disturbances of central nervous and peripheral intestinal systems, which is often associated with mood disorders including depression and anxiety. Consequently, memory impairment, anxiety and depression behavioral indicators, and cerebral oxidative stress biomarker dynamics were evaluated in a multifactorial heterotypic stress-exposed IBS rats after 6-day gavage with polyphenolic C. americanum extract (100 mg/kg body weight). Y-maze, elevated plus maze, and forced swimming tests were used for assessing behavioral responses. Administration of the extract exhibited significant anxiolytic and antidepressant-like effects coupled with significantly increased temporal lobe antioxidant enzyme specific activity (superoxide dismutase and glutathione peroxidase) and decreased malondialdehyde levels, a well-known lipid peroxidation marker. Furthermore, linear regression statistical analyses showed significant correlations between the oxidative stress parameters and behavioral tests. In conclusion, our results suggest that the administration of Chrysanthellum americanum polyphenolic extract could ameliorate mood and cognitive disturbances related to stress-induced in an IBS rat model. This could be also related to cerebral oxidative stress status attenuation.

The Relationships among Tryptophan, Kynurenine, Indoleamine 2,3-Dioxygenase, Depression, and Neuropsychological Performance

It has been suggested that the metabolic enzyme indoleamine 2,3-dioxygenase (IDO) is a biological mediator of inflammation related to the psychopathology of depression, with a Kynurenine (KYN) increase in the Tryptophan (TRP) metabolic pathway, resulting in reduced Serotonin. In this study, we examined KYN, TRP, and the ratio of KYN to TRP concentrations × 10³ (KT Ratio) in serum and cerebrospinal fluid (CSF) in (a) a group of depressed patients and (b) a control group of patients referred to a neurologic outpatient clinic for whom no specific diagnosis could be established. The KT Ratio is considered an index that represents IDO. The participants were examined with the Beck Depression Inventory II (BDI-II), the Montgomery Aasberg Depression Rating Scale (MADRS), and a neuropsychological test battery. We found no significant differences between the two study groups with respect to TRP, KYN, or KT Ratio in serum or CSF. Differences in neuropsychological performance between the two patient groups could be seen in the following tests: Animal Fluency, Digit Symbol, the DKEFS Color-Interference Test (Naming Part), Trail Making Test A and B, and the Grooved Pegboard Non-dominant Hand. KYN in serum correlated highly with KYN in CSF. KYN in serum correlated significantly with both age and gender. When analyzing males and females separately, we found that women had a lower level of TRP in both serum (Mann-Whitney U-test: TRP in Serum; p = 0.001) and CSF (Mann-Whitney U-test: TRP in CSF; p = 0.003). Women had a lower level of KYN in serum (p = 0.029) than men did. Age was positively associated with KYN. KYN in CSF correlated only with age, however; there were no gender differences. No significant relationship was seen between BDI-II and MADRS on the one hand, and KYN and TRP on the other. KYN in CSF as the KT Ratio in both serum and CSF was associated with neuropsychological performance. Thus, we suggest that KYN and KT Ratio are related more strongly to neuropsychological performance than to affective symptoms in depression.

Faecal short-chain fatty acids - a diagnostic biomarker for irritable bowel syndrome?

Background

The diagnosis of irritable bowel syndrome (IBS) relies on symptom-based criteria. A valid and reliable biomarker that could confirm the diagnosis is desirable. This study evaluated the properties of faecal short-chain fatty acids (SCFA) as diagnostic biomarkers for IBS.

Methods

Twenty-five subjects with IBS and 25 controls were included in this explanatory case–control study. Stool samples were analysed for SCFA (acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, and isovaleric acid) with gas chromatography and reported as mmol/l and molar%. In the search for the best way to distinguish between subjects with and without IBS, the total amount and the amount of each of the SCFA were measured, and the proportions and differences between the SCFA were calculated.

Results

In the IBS and control group, the mean age was 46.2 (SD 12.9) and 49.2 (SD 14.6), and the number of females was 13/25 (52 %) and 15/25 (60 %) respectively. The difference between propionic and butyric acid (mmol/l) had the best diagnostic properties, the area under the Receiver Operating Characteristic curve was 0.89 (95 % CI: 0.80–0.98) (p < 0.001). With a cut-off value > 0.015 mmol/l indicating IBS, the sensitivity, specificity, positive and negative likelihood ratio, and diagnostic odds ratio were 92 %, 72 %, 3.29, 0.11 and 29.6 respectively. Similar diagnostic properties were shown for all the IBS subgroups.

Conclusions

The study indicated that faecal SCFA could be a non-invasive, valid and reliable biomarker for the differentiation of healthy subjects from subjects with IBS.