The epidemiology of irritable bowel syndrome

Challenges of recruitment processes to a randomized dietary trial in irritable bowel syndrome

Background

Irritable bowel syndrome (IBS) is common with a global prevalence of 4%. Dietary regimes with a low content of fermentable oligo-, di-, and monosaccharides and polyol (FODMAP) or a starch- and sucrose-reduced diet (SSRD) have proven to be efficient. The aim of the present study was to describe the recruitment process for a randomized dietary trial with low FODMAP or SSRD for 4 weeks with a follow-up period of 5 months. The results of the dietary trial itself are not included in this paper but will be presented in another publication.

Methods

The County of Skåne, with 1,41 million inhabitants, was used as a base to perform a dietary trial in which IBS patients, age 18-70 years, were randomized to either low FODMAP or SSRD for 4 weeks. The estimated number of IBS patients in the actual age span was approximately 32,000. The trial was announced through lectures, letters to all primary healthcare centers (n=203), social media (two campaigns), and invitations to IBS patients identified in medical records (n=744).

Results

Three referrals arrived from the healthcare system, 17 patients contacted the investigators in person after receiving information from their healthcare center, and four patients contacted the investigators after recommendations from friends. Of these, 14 were enrolled in the study. From social media, 218 names were delivered, of which 93 fulfilled the study criteria and were willing to participate when contacted by the investigators (42.7%). Of the 3587 identified IBS patients in medical records in close proximity to the hospital, 744 were randomly contacted. Forty-eight patients (6.5 %) were willing to be included in the study. Thus, 155 patients with IBS were included in this study.

Conclusions

The inclusion rate for dietary intervention was very low considering the large population informed about the study. Announcements on social media seem to be the best way to recruit patients for intervention.

Trial registration

NCT05192603, 29/11/2021, ClinicalTrials.gov. The PRS URL is https://register.clinicaltrials.gov.

A comparison of Swedish IBS patients and general practitioners regarding viewpoints on IBS: a Q-methodology study

OBJECTIVES

Irritable bowel syndrome (IBS) is a common functional gastrointestinal condition. A respectful patient-doctor relationship with good communication is crucial for optimal treatment. Q-methodology is a combination of qualitative and quantitative methods used to study subjectivity. The aim of this study was to compare viewpoints on IBS between patients with IBS and general practitioners (GPs).

METHODS

We conducted a Q-methodology study by including 30 patients and 30 GPs. All participants were asked to complete Q- sorting of 66 statements on IBS using an online software program. Data were processed using factor analysis. In addition, 3 patients and 3 GPs were interviewed.

RESULTS

Three factors were extracted from both groups: Patient Factor 1 'Question the diagnosis of IBS', Patient Factor 2 'Lifestyle changes for a physical disorder', Patient Factor 3 'Importance of a diagnosis', GP Factor 1 'Unknown causes of great suffering', GP Factor 2 'Lifestyle changes are important, stress makes IBS worse', GP Factor 3 'Recognized the way IBS affects patients'. There was a strong and statistically significant correlation between patient Factor 1 and GP Factor 1, with a Pearson's r of 0.81 (p < 0.001). Correlations between other factors varied.

CONCLUSIONS

There was consensus between patients and GPs that IBS is a physical and not a psychiatric disorder of unknown etiology. They also seemed to agree that IBS has a great negative impact on patients' lives and that lifestyle changes are beneficial. There were conflicting opinions regarding gender, cultural factors and the use of antidepressants.

Current and future pharmacotherapies for the management of constipation-predominant irritable bowel syndrome

INTRODUCTION

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder affecting 9-23% of the world's population, with a higher prevalence among women. IBS is a complex disorder influenced by psychosocial, physiological, and genetic factors, exacerbated by stress.

AREAS COVERED

Research confirms that the most common subtype of IBS is IBS-C. Therefore, new therapies are being developed to speed up bowel movement and reduce constipation, with drugs such as linaclotide, plecanatide, lubiprostone, or tegaserod available to reduce IBS-C symptoms. In addition, patients' condition is improved by foods rich in fiber and low in FODMAP and the use of biotics.

EXPERT OPINION

The topic is of great importance due to the growing number of patients suffering from IBS-C and its significant impact on quality of life. Current clinical trials of new therapeutic options are not too successful, and it seems that one of the plausible treatment options could be the multi-drug cocktail with some, or perhaps even all its ingredients emerging from drug re-purposing. Another important path that needs to be explored further in IBS-C patients is the adjustment of dietary habits and/or introduction of dietary or nutritional intervention.

Associations between autistic and comorbid somatic problems of gastrointestinal disorders, food allergy, pain, and fatigue in adults

LAY ABSTRACT

What is already known about the topic?Autistic children frequently often have accompanying physical health problems. However, this has been much less studied in autistic men and women during adulthood.What does this article add?This is one of the first studies to investigate the associations between autistic and somatic problems in adults from the general population. Using a continuous measure of autistic symptom scores and a categorical definition of autism (referred to below as probable autism) which considered symptom severity, childhood age of onset, and functional impairment, we found that autistic problems and irritable bowel syndrome, food allergy, pain, and fatigue were associated in adults. Sex differences were present for pain and fatigue, for which the associations with autistic symptom scores were somewhat stronger in females than males. Regarding age differences, the associations with fatigue and having food allergy were more pronounced in younger adults. Conversely, older individuals had a higher risk of developing irritable bowel syndrome or experiencing pain if they met the criteria for probable autism.Implications for practice, research, or policyThere is a need for providing routine programs of screening, assessment, and treatment of autism-related somatic problems and developing evidence-based interventions for autistic individuals. These could be tailored to the needs of specific autistic populations. For example, autistic females could be given extra attention about the potential presence of pain and fatigue, younger adults about the potential presence of food allergy and fatigue, and older adults concerning the potential presence of irritable bowel syndrome and pain.

Photobiomodulation improves acute restraint stress-induced visceral hyperalgesia in rats

The purpose of this study is to explore the potential application of photobiomodulation to irritable bowel syndrome. We established the following experimental groups: the Non-Stress + Sham group, which consisted of rats that were not restrained and were only subjected to sham irradiation; the Stress + Sham group, which underwent 1 hour of restraint stress followed by sham irradiation; and the Stress + Laser group, which was subjected to restraint stress and percutaneous laser irradiation bilaterally on the L6 dorsal root ganglia for 5 minutes each. The experiment was conducted twice, with three and two laser conditions examined. Following laser irradiation, a barostat catheter was inserted into the rat's colon. After a 30-minute acclimatization period, the catheter was inflated to a pressure of 60 mmHg, and the number of abdominal muscle contractions was measured over a 5-minute period. The results showed that photobiomodulation significantly suppressed the number of abdominal muscle contractions at average powers of 460, 70, and 18 mW. However, no significant suppression was observed at average powers of 1 W and 3.5 mW. This study suggests that photobiomodulation can alleviate visceral hyperalgesia induced by restraint stress, indicating its potential applicability to irritable bowel syndrome.

Infectious etiologies of persistent and chronic diarrhea in Asian developing countries: A systematic review and meta-analysis

Infectious causes of diarrhea contribute significantly to morbidity in Asia. We conducted a systematic review and meta-analysis of the prevalence of infectious etiologies of persistent and chronic diarrhea in Asian adults. Searches were performed on PubMed and Scopus for studies from January 1, 1970, to May 30, 2023. Sixteen studies were identified and included. The meta-analysis was conducted with the random-effects method, estimating the pooled prevalence of groups of infectious pathogens as causes of persistent and chronic diarrhea among Asian adults. The findings were highly heterogeneous and indicative of publication bias. The majority of studies were conducted on persons living with human immunodeficiency virus infection (PLHIV). The studies were predominantly from low-income and middle-income Asian countries. The most common cause was parasitic, with a pooled prevalence of 0.52 (95% confidence interval 0.28-0.65, I2 = 99%, Cochran's Q = 1027.44, P < 0.01), followed by bacterial, fungal, and viral causes, which were substantially rarer. Negative microbiological testing was also common, with a pooled prevalence for a negative test being 0.37 (95% confidence interval 0.17-0.52, I2 = 99%, Cochran's Q = 1027.44, P < 0.01). Subgroup analyses of studies conducted among PLHIV, from year 2000 and among those conducted in Southeast Asia showed a similar prevalence of parasitic causes of diarrhea. In conclusion, in Asian adults with persistent and chronic diarrhea, parasitic causes were most prevalent. However, the estimate of true prevalence is limited by significant heterogeneity among the available studies. More study in this field is required, especially examining PLHIV in the post-antiretroviral therapy era and from high-income countries.

Biobehavioral approach to distinguishing panic symptoms from medical illness

Panic disorder is a common psychiatric diagnosis characterized by acute, distressing somatic symptoms that mimic medically-relevant symptoms. As a result, individuals with panic disorder overutilize personal and healthcare resources in an attempt to diagnose and treat physical symptoms that are often medically benign. A biobehavioral perspective on these symptoms is needed that integrates psychological and medical knowledge to avoid costly treatments and prolonged suffering. This narrative review examines six common somatic symptoms of panic attacks (non-cardiac chest pain, palpitations, dyspnea, dizziness, abdominal distress, and paresthesia), identified in the literature as the most severe, prevalent, or critical for differential diagnosis in somatic illness, including long COVID. We review somatic illnesses that are commonly comorbid or produce panic-like symptoms, their relevant risk factors, characteristics that assist in distinguishing them from panic, and treatment approaches that are typical for these conditions. Additionally, this review discusses key factors, including cultural considerations, to assist healthcare professionals in differentiating benign from medically relevant symptoms in panic sufferers.

GPR84 in physiology-Many functions in many tissues

Members of the GPCR superfamily have a wide variety of physiological roles and are therefore valuable targets for developing effective medicines. However, within this superfamily are receptors that are less well characterized and remain orphans, including GPR84. This receptor is stimulated by ligands derived from dietary nutrients, specifically medium chain fatty acids (C9-14), and novel synthetic agonists. There are data demonstrating the role of GPR84 in inflammatory pathways, in addition to emerging data suggesting a key role for GPR84 as a nutrient-sensing GPCR involved in metabolism by sensing energy load via nutrient exposure and subsequent signalling leading to modulation of food intake. Exploring GPR84 pharmacology, its localization and what drives its expression has revealed multiple roles for this receptor. Here, we will reflect on these various roles of GRP84 demonstrated thus far, primarily by exploring data from pre-clinical and clinical studies in various physiological systems, with a specific focus on the gastrointestinal tract. LINKED ARTICLES: This article is part of a themed issue GPR84 Pharmacology. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.10/issuetoc.

Exploring causality in the association between gut microbiota and irritable bowel syndrome risk: a large Mendelian randomization study

BACKGROUND

In the past, some observational studies have highlighted the correlation between gut microbiota and irritable bowel syndrome (IBS). However, it is still unknown if the composition of gut microbiota shows a causal effect on the risk of IBS.

AIM

To conduct Mendelian randomization (MR) analysis of the samples to study the probable causal relationship between the gut microbiota, their taxonomic groups, and the risk of IBS.

MATERIALS AND METHODS

In this study, the summarized data regarding 211 gut microbiota and their IBS genome-wide association studies (GWAS) were collected from public databases. The causal estimates were determined using five MR techniques, where Inverse Variance Weighted (IVW) regression was employed as the major MR technique. Herein, MR-PRESSO and MR-Egger intercept tests were conducted to prevent horizontal pleiotropy. Cochran's Q test was used to evaluate heterogeneity using the IVW and MR-Egger techniques.

RESULTS

IVW results showed that gut microbes, belonging to Class Gammaproteobacteria (P = 0.04; OR = 1.45), Family XIII (P = 0.03; OR = 1.34), Family Prevotellaceae (P = 0.003; OR =1.24), and Lachnospiraceae UCG004 (P = 0.049; OR = 1.19) increased the risk of IBS, while Alcaligenaceae (P = 0.03; OR = 0.83, 95% CI: 0.69-0.98) and Coprobacter (P = 0.02; OR = 0.86, 95% CI: 0.76-0.98) decreased the risk of IBS.

CONCLUSIONS

This study presented novel insights that highlighted the causal relationship between gut microbiota and IBS, and offered new treatment strategies for preventing or treating IBS.

Female-selective mechanisms promoting migraine

Sexual dimorphism has been revealed for many neurological disorders including chronic pain. Prelicinal studies and post-mortem analyses from male and female human donors reveal sexual dimorphism of nociceptors at transcript, protein and functional levels suggesting different mechanisms that may promote pain in men and women. Migraine is a common female-prevalent neurological disorder that is characterized by painful and debilitating headache. Prolactin is a neurohormone that circulates at higher levels in females and that has been implicated clinically in migraine. Prolactin sensitizes sensory neurons from female mice, non-human primates and humans revealing a female-selective pain mechanism that is conserved evolutionarily and likely translationally relevant. Prolactin produces female-selective migraine-like pain behaviors in rodents and enhances the release of calcitonin gene-related peptide (CGRP), a neurotransmitter that is causal in promoting migraine in many patients. CGRP, like prolactin, produces female-selective migraine-like pain behaviors. Consistent with these observations, publicly available clinical data indicate that small molecule CGRP-receptor antagonists are preferentially effective in treatment of acute migraine therapy in women. Collectively, these observations support the conclusion of qualitative sex differences promoting migraine pain providing the opportunity to tailor therapies based on patient sex for improved outcomes. Additionally, patient sex should be considered in design of clinical trials for migraine as well as for pain and reassessment of past trials may be warranted.

Ashtangayoga for irritable bowel syndrome in a primary care setting: A feasibility study

BACKGROUND

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder characterized by diarrhea or constipation and other symptoms such as pain, bloating, and flatulence. The disease often has a negative effect on quality of life and is also associated with symptoms of anxiety and depression. Pharmacological treatments are not always effective, and complementary and alternative treatments are common.

METHODS

We conducted a study on a group intervention based on the Ashtanga school of yoga. Fourteen participants (three men, 11 women; average age 51.4, SD = 16) were recruited from primary care, and 10 completed treatment. At pre-measurement, 4 participants had severe, 9 moderate, and 1 mild IBS, according to the IBS-SSS scale.

KEY RESULTS

The intervention was regarded as credible (CEQ M = 39.2 SD = 8.8), and no serious adverse events were reported. The intervention showed significant effects on all measurements at post, as follows: IBS-SSS PRE (M = 272.0 SD = 75.5); IBS-SSS POST (M = 177.0 SD = 103.5); GSRS-IBS PRE (M = 48.4 SD = 15.9); GSRS-IBS POST (M = 37.4 SD = 12.4); VSI PRE (M = 38.8 SD = 10.0) VSI POST (M = 25.9 SD = 10.1); PHQ12 PRE (M = 10.0 SD = 4.3); PHQ12 POST (M = 6.9 SD = 4.3); HADS anxiety PRE (M = 8.9 SD = 5.0) HADS anxiety POST (M = 5.7 SD = 3.3) HADS depression PRE (M = 5.6 SD = 3.2) HADS depression POST (M = 3.8 SD = 2.9) IBS-QOL PRE (M = 64.5 SD = 12.5) IBS-QOL POST (M = 72.3 SD = 10.0). The effects were maintained at follow-up, except for general anxiety and depression. Preliminary effects at 3-month follow-up were in the moderate to large range for main outcomes.

CONCLUSION & INFERENCES

A 10-week group Ashtanga intervention was a feasible intervention for participants with IBS. Preliminary effects were promising and should be explored further in a randomized trial.

Lipopolysaccharide, VE-cadherin, HMGB1, and HIF-1α levels are elevated in the systemic circulation in chronic migraine patients with medication overuse headache: evidence of leaky gut and inflammation

OBJECTIVE

Medication overuse headache (MOH) was recently shown to be associated with leaky gut in rodents. We aimed to investigate whether chronic migraine (CM) patients with MOH have elevated lipopolysaccharide levels and inflammatory molecules in blood circulation.

MATERIALS AND METHODS

The study included women participants (40 CM patients with NSAID overuse headache, 35 episodic migraine (EM) patients, and 20 healthy non-headache sufferers). Migraine duration, monthly migraine headache days, MigSCog, HADS-D, HADS-A, and HIT-6 scores were recorded. Serum samples were collected to measure circulating LPS, LPS binding protein (LBP), tight junction protein occludin, adherens junction protein vascular endothelial cadherin (VE-cadherin), CGRP, HMGB1, HIF-1α, IL-6, and IL-17 levels.

RESULTS

Serum LPS, VE-Cadherin, CGRP, HIF-1α, and IL-6 levels were significantly higher in the CM + MOH group compared to the EM group and healthy controls while serum LBP and HMGB1 were higher in the CM + MOH group compared to healthy controls. IL-17 and occludin levels were comparable between the three groups. Serum HMGB1 levels in EM patients were higher compared to the control group. Mig-SCog and HIT-6 scores were higher in the CM + MOH group compared to EM patients. HADS-A and HADS-D scores were significantly higher in the CM + MOH group compared to EM patients and healthy controls, and they were also higher in EM patients compared to healthy subjects. LPS levels were correlated with VE-cadherin and occludin levels. The number of monthly migraine headache days was positively correlated with serum LPS, HIF-1α, VE-cadherin, and IL-6 levels, HADS-A, HADS-D, HIT-6, and MigSCog scores.

CONCLUSION

We have evidence for the first time that CM + MOH is associated with elevated serum LPS and LBP levels suggestive of LPS leak into the systemic circulation. Higher levels of nociceptive and/or pro-inflammatory molecules such as HMGB1, HIF-1α, IL-6, and CGRP may play a role in trigeminal sensitization and neurobiology of MOH. Intestinal hyperpermeability and consequent inflammatory response should be considered as a potential contributory factor in patients with MOH.

Examining interactions of illness perceptions, avoidance behavior and patient status in predicting quality of life among people with irritable bowel syndrome

Background: Illness perceptions (IPs) and avoidance behavior both predict quality of life (QoL) in people with irritable bowel syndrome (IBS). This study examined whether the effects of IPs on QoL are mediated by avoidance behaviors, and whether this mediation is moderated by participant treatment-seeking status. Methods: People with self-reported IBS (n = 253) answered a survey assessing QoL, IPs, avoidance behaviors, and treatment-seeking status. Moderated-mediation analyses investigated the paths from IPs through avoidance behaviors to QoL, with treatment-seeking status entered as a moderator. Results: The final moderated mediation model included the IPs consequences, timeline and emotional representations as independent variables and avoidance behavior and depressive reactions as mediators. This model explained 68.6% of the variance in QoL. Among treatment-seeking participants five significant mediation effects were found, whereas only one significant mediation effect was found among participants who did not report seeking treatment. Conclusions: IPs seem to drive avoidant behavioral responses to IBS symptoms, which in turn predict reductions in QoL. These relationships seem more pronounced among people who seek treatment for their symptoms. In practice, health care practitioners might help improve the QoL of people with IBS by preventing or remedying the development of negative IPs and avoidance behaviors.

A follow-up study of anxiety and depressive symptoms in irritable bowel syndrome

Background

Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder and is closely linked to stress. Psychiatric morbidities such as anxiety and depression are common in IBS. Long-term follow-up studies on anxiety and depressive symptoms in IBS and the impact of treatment are lacking in the Indian scenario.

Aims

This study aimed to assess the various subtypes of IBS according to the Rome IV criteria, assess anxiety and depressive symptoms in patients with IBS at baseline and also at various phases of follow-up over one year, and see the impact of the treatment of both IBS and associated anxiety and depressive symptoms if present, in the severity of IBS and other psychiatric symptoms.

Materials and Methods

Patients with IBS, aged between 18 and 65 years, were enrolled for the study. Subtypes and severity of IBS were assessed. Anxiety and depressive symptoms were assessed by the Hamilton Rating Scale for Anxiety (HAM-A) and the Hamilton Rating Scale for Depression (HAM-D), respectively. The patients were treated with conventional treatment of IBS with concomitant treatment of anxiety and depressive symptoms and were followed up for 1 year.

Results

Thirty-seven patients completed a 1-year follow-up. The mean age was 38.4 ± 11.6 years. The majority were males (81%), and IBS-D (84%) was the most common subtype. Stressful life events (67.6%) and chronic stressors (64.9%) were present in the majority of the patients. The patients had moderate-to-severe anxiety at baseline (HAM-A score 27.8 ± 6.4) and moderate-to-severe depression at baseline (HAM-D score 19.7 ± 6.6). The improvement over 1 year was statistically significant (P = 0.000, two-tailed). A positive correlation between the severity score of IBS and HAM-D (r = 0.604) and HAM-A (r = 0.536) scores was present.

Conclusion

There is a high prevalence of anxiety and depression in patients with IBS. With adequate treatment of both IBS and concomitant anxiety-depressive symptoms, there is a significant decrease in the severity of IBS, anxiety, and depression.

Anxiety-Related Factors Associated With Symptom Severity in Irritable Bowel Syndrome in Jazan, Saudi Arabia

BACKGROUND

 This study in Jazan, Saudi Arabia aims to identify anxiety-related factors associated with symptom severity in irritable bowel syndrome (IBS). IBS is a common gastrointestinal disorder causing abdominal pain and altered bowel habits. The prevalence of IBS in Saudi Arabia is estimated to be 10%-20% among the general population. Therefore, the present study aimed to determine anxiety-related factors associated with symptom severity in irritable bowel syndrome in Jazan, Saudi Arabia. Understanding these factors will provide insights into the overall impact of IBS on patients' quality of life.

METHODS

The study utilized a cross-sectional, descriptive observational design to examine the general population in Jazan, Saudi Arabia. The sample size of 385 individuals was calculated based on the population size and desired error margin. A convenience sampling technique was employed to select participants who met the inclusion criteria. A validated anonymous self-administered electronic survey was distributed through social media channels. The survey consisted of four sections gathering demographic information, personal risk factors, IBS types with anxiety and risk factors, and a questionnaire to determine the level of anxiety. A pilot study was conducted to improve the survey's clarity. Ethical considerations were followed, and data were analyzed using Statistical Package for Social Sciences (SPSS; IBM Corp., Armonk, NY, USA). Descriptive statistics and significance tests were performed.

RESULT

A study with 637 participants found a 31.08% prevalence of IBS, which was more common in females. Participants with IBS had a higher rate of chronic disease. There were no significant differences in demographic factors between IBS and non-IBS participants. The duration of IBS diagnosis varied, with the majority of IBS with diarrhea (IBS-D) sufferers being diagnosed five years prior. Symptom severity differed among IBS types, with those with an unspecified type reporting the highest percentage of severe symptoms. IBS types were also correlated with anxiety levels, with IBS-D sufferers reporting moderate anxiety and those with an unspecified type reporting severe anxiety.

CONCLUSION

A study with 637 participants found the prevalence of IBS to be 31.08%, with higher rates in females. IBS was associated with chronic diseases and higher anxiety levels. The findings emphasize the need for comprehensive management of IBS, including psychological interventions and dietary modifications, to improve patients' overall health and quality of life. Further research on genetic and modifiable risk factors is needed.

Efficacy of Quadruple-coated Probiotics in Patients With Irritable Bowel Syndrome: A Randomized, Double-blind, Placebo-controlled, Parallel-group Study

Background/Aims

To evaluate the efficacy of quadruple-coated probiotics (gQlab) in patients with irritable bowel syndrome (IBS), focusing on sex differences and IBS subtypes.

Methods

One hundred and nine Rome III-diagnosed IBS patients were randomized into either a gQlab or placebo group and received either gQlab or a placebo for 4 weeks. Participants replied to questionnaires assessing compliance, symptoms, and safety. Fecal samples were collected at 0 and 4 weeks to measure the probiotic levels using real-time quantitative polymerase chain reaction (qPCR) and to perform metagenomic analysis via 16S ribosomal DNA sequencing. The primary endpoint was the change in the overall IBS symptoms after 4 weeks of treatment.

Results

Ninety-two subjects (47 and 45 in the gQlab and placebo groups, respectively) completed the study protocol. At week 4, there was a higher relief of the overall IBS symptoms in the gQlab group (P = 0.005). The overall IBS symptom improvement was statistically significant (P = 0.017) in female patients of the gQlab group compared with the placebo group. Among the IBS subtypes, constipation-predominant IBS patients showed significant relief of the overall IBS symptoms (P = 0.002). At week 4, the fecal microbiome profiles between the 2 groups did not differ, but the qPCR levels of Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus helveticus, Bifidobacterium longum, and Bifidobacterium breve were increased in the gQlab group (P < 0.05 by repeated measures ANOVA).

Conclusions

gQlab administration can improve the overall IBS symptoms, especially in female and constipation-predominant IBS patients. Further research is necessary to clarify the pathophysiology behind sex-related treatment responses in IBS patients.

Public knowledge and beliefs about the irritable bowel syndrome - results from the SOMA.SOC study

BACKGROUND

Despite the epidemiological and economic relevance of the irritable bowel syndrome (IBS), there is a lack of research on what the general public knows and thinks about this condition (IBS literacy). Therefore, the aim of this study was to explore public knowledge and beliefs about IBS in Germany. Moreover, associations of knowledge and beliefs about IBS with socio-demographic characteristics as well as illness and treatment experiences were analysed.

METHODS

Analyses made use of a national telephone survey (N = 1,205). A carefully developed vignette describing a person with typical symptoms of IBS was presented. Respondents were then asked to name the disease in question and beliefs about causes and treatment options were assessed. For the analyses respondents were divided into three groups: (1) people who never had IBS symptoms, (2) people who had or have IBS symptoms but never were in treatment and (3) individuals who reported to be or have been treated for IBS symptoms.

RESULTS

Less than 4% of the respondents recognized IBS after presentation of the vignette. About 75% positively evaluated treatability while psychotherapy was evaluated more effective than medication. Stress and unhealthy lifestyle were the most frequently endorsed possible causes of the presented IBS symptoms. There were variations in knowledge and beliefs about IBS according to age, gender, and education. We found minor differences in beliefs and knowledge between individuals who had or have symptoms but never were in treatment and those without respective illness experience. Respondents with illness/treatment experiences rated their knowledge significantly better than those without any experiences.

CONCLUSIONS

Results indicate low levels of public knowledge about IBS regarding illness recognition in Germany. A majority disagreed that they have good knowledge about IBS symptoms. Against this background, it seems reasonable to develop and test interventions to improve IBS literacy by increasing knowledge about symptoms, causes and treatment options.

Assessment of Knowledge, Perception, and Practices Regarding Probiotics and Prebiotics Among Clinicians in Saudi Arabia: A Pilot Study

Probiotics and prebiotics are important in preventing different diseases such as irritable bowel syndrome (IBS), which is a functional bowel disorder characterized by changes in bowel habits. Considering the limited studies on this topic, the present study was conducted to assess both gastroenterologist (GI) physicians' and dietitians' practices in recommending probiotics and prebiotics for IBS patients, as well as to measure their professional educational history on probiotics and prebiotics. A descriptive cross-sectional study was performed to investigate the knowledge, use, and perceptions of probiotics and prebiotics of GI physicians and dietitians at governmental hospitals in Jeddah, Saudi Arabia. A validated questionnaire was sent to 42 participants of both genders selected randomly, who were all qualified healthcare practitioners. The majority of GI physicians demonstrated high levels of knowledge about the health benefits of probiotics and prebiotics (76.2%). In contrast, most dietitians had lower levels of knowledge (52.4%), representing a significant difference between both groups (p<0.01). 83.3% of GI physicians believed that the use of probiotics and prebiotics was required for IBS patients, as compared with 50.0% of dietitians. In conclusion, GI physicians were shown to be more knowledgeable and believed more in the benefits of using probiotics and prebiotics in IBS patients than dietitians, but most participants were not aware of the probiotic products that are available in pharmacies in Saudi Arabia.

A global comparative study of wealth-pain gradients: Investigating individual- and country-level associations

Pain is a significant yet underappreciated dimension of population health. Its associations with individual- and country-level wealth are not well characterized using global data. We estimate both individual- and country-level wealth inequalities in pain in 51 countries by combining data from the World Health Organization's World Health Survey with country-level contextual data. Our research concentrates on three questions: 1) Are inequalities in pain by individual-level wealth observed in countries worldwide? 2) Does country-level wealth also relate to pain prevalence? 3) Can variations in pain reporting also be explained by country-level contextual factors, such as income inequality? Analytical steps include logistic regressions conducted for separate countries, and multilevel models with random wealth slopes and resultant predicted probabilities using a dataset that pools information across countries. Findings show individual-level wealth negatively predicts pain almost universally, but the association strength differs across countries. Country-level contextual factors do not explain away these associations. Pain is generally less prevalent in wealthier countries, but the exact nature of the association between country-level wealth and pain depends on the moderating influence of country-level income inequality, measured by the Gini index. The lower the income inequality, the more likely it is that poor countries experience the highest and rich countries the lowest prevalence of pain. In contrast, the higher the income inequality, the more nonlinear the association between country-level wealth and pain reporting such that the highest prevalence is seen in highly nonegalitarian middle-income countries. Our findings help to characterize the global distribution of pain and pain inequalities, and to identify national-level factors that shape pain inequalities.

Referral challenges for early-onset colorectal cancer: a qualitative study in UK primary care

BACKGROUND

The incidence of early-onset colorectal cancer (EOCRC) in adults aged <50 years has increased in several Western nations. National surveys have highlighted significant barriers to accessing timely care for patients with EOCRC, which may be contributing to a late stage of presentation in this population group.

AIM

To explore awareness of the increasing incidence of EOCRC, and to understand the potential barriers or facilitators faced by GPs when referring younger adults to secondary care with features indicative of EOCRC.

DESIGN & SETTING

Qualitative methodology, via virtual semi-structured interviews with 17 GPs in Northern Ireland.

METHOD

Reflective thematic analysis was conducted with reference to Braun and Clarke's framework.

RESULTS

Three main themes were identified among participating GPs: awareness, diagnostic, and referral challenges. Awareness challenges focused on perceptions of EOCRC being solely associated with hereditary cancer syndromes, and colorectal cancer being a condition of older adults. Key diagnostic challenges centred around the commonality of lower gastrointestinal complaints and overlap in EOCRC symptoms with benign conditions. Restrictions in age-based referral guidance and a GP 'guilt complex' surrounding over-referral to secondary care summarised the referral challenges. Young females were perceived as being particularly disadvantaged with regard to delays in diagnosis.

CONCLUSION

This novel research outlines potential reasons for the diagnostic delays seen in patients with EOCRC from a GP perspective, and highlights many of the complicating factors that contribute to the diagnostic process.

Knowledge, Attitude, and Practices Regarding the Rome IV Criteria for the Diagnosis of Irritable Bowel Syndrome Among Primary Healthcare Physicians in Saudi Arabia

INTRODUCTION

Irritable bowel syndrome (IBS) presents a significant challenge in the medical field due to its complex nature as a functional gastrointestinal illness (FGID) without clear biological markers. Diagnosis often involves ruling out other potential causes, leading to frustration for patients and difficulty in effective treatment. Given its high prevalence among FGIDs, primary healthcare (PHC) physicians play a crucial role in its initial assessment and management.

METHODS

This cross-sectional study surveyed 623 PHC physicians using a structured, closed-ended questionnaire. Employing a multistage sampling approach, physicians were selected from various provinces and cities in Saudi Arabia. Clusters within these cities were also sampled.

RESULTS

The research revealed that a majority of physicians (n = 411, 66%) exhibited a strong awareness of the Rome IV criteria, essential for diagnosing IBS. This awareness correlated significantly with variables, such as age, nationality, marital status, specialty, classifications, and years of experience.

CONCLUSION

PHC physicians in the study demonstrated a commendable level of familiarity with the Rome IV criteria for diagnosing IBS. Their knowledge was particularly robust concerning symptoms outlined in these criteria. However, there is room for improvement in their understanding, attitude, and application of the Rome IV guidelines in practice. Addressing these gaps could enhance the overall management of IBS cases by these physicians.

Importance of different electronic medical record components for chronic disease identification in a Swiss primary care database: a cross-sectional study

BACKGROUND

Primary care databases collect electronic medical records with routine data from primary care patients. The identification of chronic diseases in primary care databases often integrates information from various electronic medical record components (EMR-Cs) used by primary care providers. This study aimed to estimate the prevalence of selected chronic conditions using a large Swiss primary care database and to examine the importance of different EMR-Cs for case identification.

METHODS

Cross-sectional study with 120,608 patients of 128 general practitioners in the Swiss FIRE ("Family Medicine Research using Electronic Medical Records") primary care database in 2019. Sufficient criteria on three individual EMR-Cs, namely medication, clinical or laboratory parameters and reasons for encounters, were combined by logical disjunction into definitions of 49 chronic conditions; then prevalence estimates and measures of importance of the individual EMR-Cs for case identification were calculated.

RESULTS

A total of 185,535 cases (i.e. patients with a specific chronic condition) were identified. Prevalence estimates were 27.5% (95% CI: 27.3-27.8%) for hypertension, 13.5% (13.3-13.7%) for dyslipidaemia and 6.6% (6.4-6.7%) for diabetes mellitus. Of all cases, 87.1% (87.0-87.3%) were identified via medication, 22.1% (21.9-22.3%) via clinical or laboratory parameters and 19.3% (19.1-19.5%) via reasons for encounters. The majority (65.4%) of cases were identifiable solely through medication. Of the two other EMR-Cs, clinical or laboratory parameters was most important for identifying cases of chronic kidney disease, anorexia/bulimia nervosa and obesity whereas reasons for encounters was crucial for identifying many low-prevalence diseases as well as cancer, heart disease and osteoarthritis.

CONCLUSIONS

The EMR-C medication was most important for chronic disease identification overall, but identification varied strongly by disease. The analysis of the importance of different EMR-Cs for estimating prevalence revealed strengths and weaknesses of the disease definitions used within the FIRE primary care database. Although prioritising specificity over sensitivity in the EMR-C criteria may have led to underestimation of most prevalences, their sex- and age-specific patterns were consistent with published figures for Swiss general practice.

Prevalence, Risk Factors, and Management of Irritable Bowel Syndrome in Saudi Arabia: A Systematic Review

The prevalence and associated risk factors of irritable bowel syndrome (IBS) have been a significant area of focus in several studies conducted in Saudi Arabia. These studies have looked at varied populations, including school teachers, university students, and the general populace. The reported prevalence rates for IBS vary substantially across studies, ranging from 7.9% to an astounding 49.3%. The average prevalence noted across these studies is about 24%. The aim of this review is to collate, compare, and analyze data from these studies, hoping to shed light on the key risk factors and demographic trends associated with IBS in Saudi Arabia. This review encompasses data from 20 studies, aggregating information from 17,018 participants. The research methodologies adopted by each of these studies have been analyzed, especially focusing on their sample sizes, which vary significantly. Furthermore, the review incorporates details on the socio-demographic attributes of the participants, including age specifics, gender representation, and geographical distribution within Saudi Arabia. The results demonstrate a wide variability in IBS prevalence among different groups. The overall prevalence of IBS in Saudi Arabia based on the provided data is approximately 24%. Gender-based breakdown in some studies indicated varying prevalence among males and females, which indicated that females are more prone to the disease. The same for certain age groups, specifically between 51 and 60 years, which showed slightly higher rates. Factors such as educational discipline, living conditions, mental health, dietary habits, family history of IBS, and certain comorbidities such as diabetes mellitus were found to influence the occurrence of IBS in different cohorts. Moreover, lifestyle factors such as low water intake, lack of dietary fiber, stress, and even caffeine intake were associated with IBS. Socioeconomic aspects, including family income levels and academic performance, were also hinted to have a potential link with IBS prevalence. In light of the presented data, it is evident that IBS prevalence in Saudi Arabia is influenced by a multitude of factors, ranging from genetic and dietary to psychological and socioeconomic. The substantial variations in prevalence across different cohorts suggest the need for a more nuanced understanding of this condition, specifically tailored to the unique demographics and cultural contexts of Saudi Arabia. Early diagnosis and tailored interventions, considering these multifaceted determinants, are crucial for the effective management of IBS in the region.

Systematic review with meta-analysis: Stress-management interventions for patients with irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common chronic gastrointestinal disorder of unknown pathological origin that is associated with psychological distress and reduced health-related quality of life (HRQoL). We investigated the effects of stress-management for adults with IBS on typical symptoms, HRQoL and mental health. With predefined criteria (patients: adults with IBS; intervention: stress-management; control: care as usual or waitlist; outcome: patient-relevant; study-type: controlled trials), we registered the study with PROSPERO (168030) and searched the main medical databases. Two researchers independently reviewed the publications and assessed the risk of bias using the Scottish Intercollegiate Guidelines Network checklist. We performed meta-analysis with homogeneous trials of acceptable quality. After screening 6656 publications, ten suitable randomized trials of acceptable (n = 5) or low methodological quality (n = 5) involving 587 patients were identified. Our meta-analysis showed no effect of stress-management on IBS severity 1-2 months after the intervention (Hedges' g = -0.23, 95%-CI = -0.84 to -0.38, I2  = 86.1%), and after 3-12 months (Hedges' g = -0.77, 95%-CI = -1.77 to -0.23, I2  = 93.3%). One trial found a short-term reduction of symptoms, and one trial found symptom relief in the long-term (at 6 months). One of two studies that examined HRQoL found an improvement (after 2 months). One of two studies that examined depression and anxiety found a reduction of these symptoms (after 3 weeks). Stress-management may be beneficial for patients with IBS regarding the short-term reduction of bowel and mental health symptoms, whereas long-term benefits are unclear. Good quality RCTs with more than 6 months follow-up are needed.

Translation and validation of the Ukrainian version of the visceral sensitivity index for patients with irritable bowel syndrome

Introduction

Gastrointestinal-specific anxiety (GSA) is considered as an important factor in the course of irritable bowel syndrome (IBS). GSA may be evaluated by the visceral sensitivity index (VSI).

Aim

To translate original English version of the VSI into Ukrainian language (VSI-UA) and then to test its validity and reliability in patients with IBS.

Material and methods

108 patients of both sexes, aged 18-44 years, with IBS were assessed by the VSI-UA, Patient Health Questionnaire-9 (PHQ-9), Beck's Depression Inventory (BDI), and the Hospital Anxiety and Depression Scale: depression (HADS-Dep) and anxiety (HADS-Anx). Reliability was checked by Cronbach's α and test-retest method with calculation of the intraclass correlation coefficient (ICC). Content validity was assessed by calculation of the content validity ratio (CVR) and content validity index (CVI). The construct validity was assessed by estimating Pearson`s correlation between VSI-UA, PHQ-9, BDI, HADS-Anx, and HADS-Dep.

Results

Cronbach's α for VSI-UA was 0.84; the ICC between the first measurement and the one repeated 4 weeks after administration of VSI-UA was 0.92 (95% CI: 0.87-0.95). The calculated CVR for each item of the VSI-UA was higher than the critical value of 0.56, and the CVI was 0.94. A moderate positive correlation was found between VSI-UA and PHQ-9 (r = 0.65), BDI (r = 0.69), HADS-Anx (r = 0.61), and HADS-Dep (r = 0.48); p < 0.05 in all correlations.

Conclusions

VSI-UA is a reliable and valid tool for the assessment of GSA in Ukrainian-language patients with IBS, and it could be implemented in routine clinical practice to manage patients with IBS.

Patients' perspectives on irritable bowel syndrome: a qualitative analysis based on social media in China

AIM

To explore the perspectives, experience, and concerns of patients with irritable bowel syndrome (IBS) in China.

METHODS

We used data mining to investigate posts shared in Baidu Tieba concerned with IBS; we collected the data through the crawler code, and mined the cleaned data's themes based on Latent Dirichlet allocation (LDA) and the Grounded theory.

RESULTS

We found 5746 network posts related to IBS. LDA analysis generated 20 topics, and grounded theory analysis established eight topics. Combining the two methods, we finally arranged the topics according to five concepts: difficulty in obtaining disease information; serious psychosocial problems; dissatisfied with the treatment; lack of social support; and low quality of life.

CONCLUSION

Social media research improved patient-centric understanding of patients' experiences and perceptions. Our study may facilitate doctor-patient communication and assist in the formulation of medical policies.

Migraine and Irritable Bowel Syndrome Among the General Population in Aseer Region

BACKGROUND

Limited research has been conducted in Saudi Arabia to investigate the incidence and understanding of migraines and irritable bowel disease (IBS) among the population. This study aimed to quantify the prevalence of migraine and IBS within the Aseer region. Furthermore, it aimed to explore the potential association between migraine and IBS.

METHODS

The survey questionnaire was distributed through various social media platforms such as Facebook (Meta Platforms, Inc., Menlo Park, California, United States), Twitter/X (X Corp., San Francisco, California, United States), LinkedIn (Microsoft Corporation, Sunnyvale, California, United States), and WhatsApp (Meta Platforms, Inc.) to maximize the reach and engagement of potential participants. The Migraine Screen Questionnaire (MS-Q) assessed the type and frequency of headache pain, along with intensity and impact on daily activities. The questionnaire also incorporated the Rome IV diagnostic criteria for IBS.

RESULTS

 A total of 683 participants were included in this study; 65.2% were aged 21-39 years, 85.5% were females, 61.6% were single, and 73.1% had a university degree or higher. Of the participants, 45.97% experienced migraines, while 39.97% exhibited symptoms of IBS. There was a statistically significant association between having IBS and migraine (χ2 = 11.88, p 0.001). Migraine was significantly associated with female sex (p = 0.049), history of psychiatric disease (p < 0.001), and family history of migraines (p < 0.001). IBS was significantly associated with age (p = 0.042), history of psychiatric disease (p = 0.015), and sleeping hours (p = 0.038).

CONCLUSIONS

This study reveals a high prevalence of migraine and IBS, underlining their interconnection. Key risk factors include age, gender, family history, and psychiatric disorders. Targeting high-risk groups is crucial due to the substantial impact on daily life and performance.

The Prevalence of Irritable Bowel Syndrome and Its Co-existence With Migraine in Medical and Non-medical Students at Al-Baha University, Saudi Arabia

BACKGROUND

It was hypothesized that the prevalence of irritable bowel syndrome (IBS) and migraine and their co-existence are higher among medical students. In this study, we aim to establish the prevalence of IBS and migraine in the medical and non-medical students at Al-Baha University, Saudi Arabia, and to observe the association and relationship between IBS and migraine using the Rome IV diagnostic criteria for IBS and the International Classification of Headache Disorders (ICHD)-3 criteria for migraine.

METHODOLOGY

This cross-sectional study was done on the Saudi Arabian campus of Al-Baha University between July 2022 and July 2023. Al-Baha city-dwelling male and female college students aged 18 to 29 comprised the study population. A self-administered electronic questionnaire was sent online to determine the prevalence of IBS and migraine, in addition to associated risk factors. The questionnaire consisted of three sections: demographic and lifestyle data, the Rome IV criteria for diagnosing and subclassifying IBS, and the ICHD-3 criteria for diagnosing migraine.

RESULTS

The study was conducted among 452 participants with a mean age of 21.64 years. The majority of participants were not from medical schools. The majority of medical and non-medical participants were male, at 66.6% and 63.1%, respectively. In our study, 36.9% of the individuals reported having a first-degree relative diagnosed with IBS, whereas 2.7% reported having IBS themselves. Regarding migraine, 17.9% of respondents claimed to have a first-degree relative with migraine, while 6.9% of respondents themselves reported experiencing migraine. Regarding IBS prevalence, there was no significant difference between participants from non-MBBS colleges and MBBS colleges. Similarly, there was no significant difference in migraine prevalence between these two groups (92.0% vs. 95.4%, p=0.185).

CONCLUSION

The current study contributes significantly to our understanding of the prevalence of IBS and migraines among medical students, as well as these individuals' demographic characteristics, familial histories, and aggravating variables.

Revolutionizing Inflammatory Bowel Disease Management: A Comprehensive Narrative Review of Innovative Dietary Strategies and Future Directions

This comprehensive narrative review delves into the intricate interplay between diet and inflammatory bowel disease (IBD), shedding light on the potential impact of dietary interventions in disease management. By analyzing nutritional interventions, risks, challenges, and future perspectives, this review serves as a vital resource for clinicians, researchers, and patients alike. The amalgamation of evidence underscores the significance of customizing dietary strategies for individual patients, considering disease phenotype and cultural factors. Through an exploration of dietary components' effects on IBD, including exclusive enteral nutrition and omega-3 fatty acids, this review offers pragmatic implementation advice and outlines avenues for further research. Bridging the gap between research findings and clinical applications, the review facilitates informed decision-making and patient-centric care. In the face of escalating IBD prevalence, this review emerges as an indispensable guide for healthcare professionals, empowering them to navigate the complexities of dietary management while enabling patients to actively participate in their care trajectory. Ultimately, this narrative review advances the understanding of diet's pivotal role in IBD management, fostering a more integrated approach to patient care and paving the way for improved research and policy initiatives in the field of inflammatory bowel diseases.

Disordered eating and eating competence in members of online irritable bowel syndrome support groups

BACKGROUND

This study seeks to evaluate eating competence and disordered eating likelihood among members of online support groups for irritable bowel syndrome (IBS) and determine whether eating competence and disordered eating likelihood varies according to IBS symptom severity and subtype.

METHODS

This cross-sectional study is based on an anonymous survey conducted from August to September 2021. Adults with IBS (N = 225) were recruited from online and social media IBS support forums. IBS symptom severity was assessed using the validated IBS Severity Scoring System (IBS-SSS), likelihood of disordered eating was assessed using the validated Eating Attitudes Test (EAT-26), and eating competence was assessed using the validated Satter Eating Competence Inventory (ecSI 2.0™). Multiple linear regression was used to predict EAT-26 total score from IBS-SSS score, age, and IBS subtype. ANOVAs were used to examine the relationships between IBS severity level, IBS subtype, and ecSI 2.0™ total score.

KEY RESULTS

Eating competence among the sample was low at 17% while 27% was classified as likely or very likely disordered eating. IBS severity was positively associated with EAT-26 score (p = 0.011) and ecSI 2.0™ score was significantly lower in the severe IBS group compared to the moderate IBS group (p = 0.016). No relationship was detected between IBS subtype and EAT-26 or ecSI 2.0™ scores.

CONCLUSIONS & INFERENCES

IBS severity was positively associated with disordered eating likelihood and negatively associated with eating competence. This sheds light on the importance of assessing eating competence and screening for disordered eating prior to selecting therapies for patients with IBS, particularly in females with severe symptoms.

Molecular signalling during cross talk between gut brain axis regulation and progression of irritable bowel syndrome: A comprehensive review

Irritable bowel syndrome (IBS) is a chronic functional disorder which alters gastrointestinal (GI) functions, thus leading to compromised health status. Pathophysiology of IBS is not fully understood, whereas abnormal gut brain axis (GBA) has been identified as a major etiological factor. Recent studies are suggestive for visceral hyper-sensitivity, altered gut motility and dysfunctional autonomous nervous system as the main clinical abnormalities in IBS patients. Bidirectional signalling interactions among these abnormalities are derived through various exogenous and endogenous factors, such as microbiota population and diversity, microbial metabolites, dietary uptake, and psychological abnormalities. Strategic efforts focused to study these interactions including probiotics, antibiotics and fecal transplantations in normal and germ-free animals are clearly suggestive for the pivotal role of gut microbiota in IBS etiology. Additionally, neurotransmitters act as communication tools between enteric microbiota and brain functions, where serotonin (5-hydroxytryptamine) plays a key role in pathophysiology of IBS. It regulates GI motility, pain sense and inflammatory responses particular to mucosal and brain activity. In the absence of a better understanding of various interconnected crosstalks in GBA, more scientific efforts are required in the search of novel and targeted therapies for the management of IBS. In this review, we have summarized the gut microbial composition, interconnected signalling pathways and their regulators, available therapeutics, and the gaps needed to fill for a better management of IBS.

Loose ends in the differential diagnosis of IBS-like symptoms

Two thirds of the patients we believed to have IBS in the 1970's have since been possible to diagnose with treatable conditions like bile acid diarrhea, inflammatory bowel disease, microscopic colitis, celiac disease, disaccharide malabsorption, exocrine pancreatic insufficiency, or rare genetic variants. Despite advances in diagnostic techniques a substantial proportion of patients continue suffering from IBS-like symptoms that cannot be explained by current knowledge. Although it is likely that further research will reveal small but important subgroups of patients with treatable mechanisms for IBS-like symptoms, we propose that only two large groups remain for being addressed in the clinic: those with connective tissue disorders such as Ehlers-Danlos syndrome or hypermobility spectrum disorders and those with autism spectrum disorders. Patients with connective tissue disorders exhibit identifiable disturbances of gut motor function and possibly increased gut permeability as underlying mechanisms for IBS-like symptoms. Autism spectrum disorders pose a much more difficult problem in the clinic. Disturbances of perception combined with anxiety and excessive worry about signals from the gut can lead to an endless but futile search for something being wrong. The search can involve large numbers of care givers, no one understanding the patient's suffering. Others may try to change their diet to lessen symptoms, only to find that almost all foods may cause worrying perceptions from the gut. Early recognition of autism spectrum disorders is essential for finding better ways to help patients with gastrointestinal and, as is often the case, extraintestinal symptoms.

Assessment of Sleep Quality Among Adolescents and Adults With Self-Diagnosed Irritable Bowel Syndrome, in Jeddah, Saudi Arabia

Background The frequency of irritable bowel syndrome (IBS) has increased significantly in the last ten years. Few studies were done in Saudi Arabia to assess the relationship between sleep quality and IBS. This study aims to assess the prevalence of IBS and its association with sleep quality among adolescents and adults in Saudi Arabia. Methods A cross-sectional study was done on 651 participants aged 15-65 years. An online questionnaire was used to collect data, including demographics; the Rome IV criteria (R4DQ) was used in the diagnosis of IBS, the IBS symptoms severity scale (IBS-SSS) assessed IBS symptoms and severity, and the Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. Results Based on the Rome IV criteria, 25.7% of the participants had IBS. Among them, 23.3%, 17.9%, 47.3%, and 11.5% had IBS types constipation (C), diarrhea (D), mixed bowel habits (M), and undefined subtype (U), respectively. Mild, moderate, and severe IBS were found among 43.1%, 39.5%, and 17.4% of IBS cases, respectively. About 46% had poor sleep quality, which was significantly higher among those with younger mean age, females, and students. Patients with IBS exhibited a considerably greater prevalence of poor sleep quality, and IBS-C had the highest prevalence. Conclusion A correlation was found between poor sleep quality and the positive status of IBS diagnosis among adolescents and adults. An evaluation of specific sleep disorders among IBS patients is needed.

The Effects of Serotonin Receptor Type 7 Modulation on Bowel Sensitivity and Smooth Muscle Tone in Patients With Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a gut-brain disorder involving alterations in intestinal sensitivity and motility. Currently, IBS has no cure, and treatment focuses on the management of symptoms. The diverse, and sometimes contradictory, collections of symptoms reported across the different subtypes of IBS make treatment, as well as diagnosis, difficult for physicians. All subtypes of IBS have one symptom in common: abdominal pain caused by differences in the level of visceral sensitivity. Though current research on this topic is in its infancy, some researchers have proven, through experimental studies, that 5-hydroxytryptamine (serotonin) receptor type 7 (5-HT7) affects both visceral sensitivity and smooth muscle tone in the bowel. Therefore, this review will be discussing the future possibility of alleviating abdominal pain in patients with IBS and related disorders by modulating the 5-HT7 receptor.

Emerging role of the gut microbiome in post-infectious irritable bowel syndrome: A literature review

Post-infectious irritable bowel syndrome (PI-IBS) is a particular type of IBS, with symptom onset after an acute episode of infectious gastroenteritis. Despite infectious disease resolution and clearance of the inciting pathogen agent, 10% of patients will develop PI-IBS. In susceptible individuals, the exposure to pathogenic organisms leads to a marked shift in the gut microbiota with prolonged changes in host-microbiota interactions. These changes can affect the gut-brain axis and the visceral sensitivity, disrupting the intestinal barrier, altering neuromuscular function, triggering persistent low inflammation, and sustaining the onset of IBS symptoms. There is no specific treatment strategy for PI-IBS. Different drug classes can be used to treat PI-IBS similar to patients with IBS in general, guided by their clinical symptoms. This review summarizes the current evidence for microbial dysbiosis in PI-IBS and analyzes the available data regarding the role of the microbiome in mediating the central and peripheral dysfunctions that lead to IBS symptoms. It also discusses the current state of evidence on therapies targeting the microbiome in the management of PI-IBS. The results of microbial modulation strategies used in relieving IBS symptomatology are encouraging. Several studies on PI-IBS animal models reported promising results. However, published data that describe the efficacy and safety of microbial targeted therapy in PI-IBS patients are scarce. Future research is required.

Investigating the association between the COVID-19 vaccination and incident gastrointestinal symptomology: A comprehensive dataset

The coronavirus disease of 2019 (COVID-19) pandemic created a variety of symptoms from mild to acute in the general population. Additional disease burden was experienced in high-risk populations, such as older adults, people with disabilities or overweight, those from racial and ethnic minority groups, and patients with cancer, chronic kidney, lung or liver disease, or diabetes. Although it is well-known that SARS-CoV-2 mostly affects the respiratory tract, studies have revealed the presence of gastrointestinal (GI) symptoms in those patients diagnosed with COVID-19. The best protection against infection is through receipt of the COVID-19 vaccine, which is associated with a low incidence of adverse events. However, there is limited research on the lesser-known side effects experienced following receipt of the COVID-19 vaccination, amongst healthy and special needs populations. This study investigated the association between the COVID-19 vaccination and, when it occurred, infection, and resulting gastrointestinal (GI) symptomology, focusing on both the general population and on those previously diagnosed with GI disorders, Irritable Bowel Syndrome (IBS) and Inflammatory Bowel Disease (IBD). Through a short, anonymous survey, 215 participants were assessed for acute onset of GI issues and/or worsening of pre-existing GI issues following the receipt of one or more COVID-19 vaccine doses and following contraction of COVID-19 itself, when applicable. All analyses were performed using SAS version 9.4, and prior to study initiation, the study protocol was reviewed and approved as exempt by the Stamford Hospital's Institutional Review Board of record. Data analysis included reporting of demographic variables as well as descriptive statistics regarding side effects experienced after receipt of the COVID-19 vaccine, as well as after contracting COVID-19, if it occurred. To assess for statistically significant differences between the groups, ANOVA was conducted for each survey item. Reporting of results consisted of the mean and standard deviation within each of the groups, and an omnibus p-value less than 0.05 (p <0.05) was considered statistically significant. For the purposes of this report, a greater than 0.50 response difference between highest and lowest mean value will be presented. In the event of a statistically significant omnibus p-value, the Scheffe test was used as the post-hoc procedure. The database created through this research demonstrates the prevalence of post-COVID-19 vaccination side effects and can serve as preliminary data for gaining a better understanding of how both general and populations with a higher disease burden are being affected by the COVID-19 vaccine, booster doses, and incident COVID-19 infection in vaccinated individuals.

Irritable Bowel Syndrome Is Not Associated with an Increased Risk of Polyps and Colorectal Cancer: A Systematic Review and Meta-Analysis

OBJECTIVES

Colorectal cancer (CRC) is the third most common malignancy in the US. Several factors are associated with increased/decreased CRC risk and often linked to adenomatous colorectal polyps (CRP). Recent studies suggest a lower risk of neoplastic lesions among irritable bowel syndrome (IBS) patients. We aimed to systematically assess the occurrence of CRC and CRP in IBS patients.

METHODS

Searches of the Medline, Cochrane, and EMBASE databases were performed, blindly and independently, by two investigators. Studies of CRC or CRP incidence in IBS patients (diagnosed by Rome or other symptom-based criteria) were eligible for inclusion. CRC and CRP effect estimates were pooled in meta-analyses using random models.

RESULTS

Of 4941 non-duplicate studies, 14 were included, comprising 654,764 IBS patients and 2,277,195 controls in 8 cohort studies, and 26,641 IBS patients and 87,803 controls in 6 cross-sectional studies. Pooled analysis revealed a significantly decreased prevalence of CRP in IBS subjects vs. controls, with a pooled odds ratio (OR) of 0.29 (95% CI (0.15, 0.54)). There was significant heterogeneity between studies (I2 = 96%, p < 0.01). This finding persisted when studies which did not report pre-cancerous polyps separately were excluded (OR 0.23, 95% CI (0.15, 0.35), I2 = 85%, p < 0.01). CRC prevalence was lower in IBS subjects, but this did not reach statistical significance (OR 0.40, 95% CI (0.09, 1.77]).

CONCLUSION

Our analyses reveal a decreased incidence of colorectal polyps in IBS, although CRC did not reach significance. Mechanistic studies with detailed genotypic analysis and clinical phenotyping are needed to better elucidate the potentially protective effect of IBS on CRC development.

Irritable Bowel Syndrome: Prevalence and Determinants Among Adults in the Makkah Region, Saudi Arabia

BACKGROUND

Irritable bowel syndrome (IBS) is among the most prevalent gut-brain interaction disorders and one of the most expensive in terms of money and health. Despite their widespread occurrence in society, these disorders have only recently been subjected to rigorous scientific inquiry, classification, and treatment. Although IBS does not lead to future complications, such as bowel cancer, it can impact work productivity and health-related quality of life and increase medical costs. Both young and older people with IBS have worse general health than the general population.

AIMS

To determine the prevalence of IBS among adults aged 25 to 55 years in the Makkah region, as well as the risk factors that may contribute to it.

METHODOLOGY

A cross-sectional web-based survey with a representative sample (n = 936) of individuals in the Makkah region was carried out from November 21, 2022, to May 3, 2023.

RESULTS

In Makkah, 420 out of 936 persons have IBS, making it 44.9% common. Most of the IBS patients in the study were women, aged 25 to 35 years, married, and suffering from mixed IBS. Age, gender, marital status, and occupation were found to be associated with IBS. It was discovered that there is an association between IBS and insomnia, medication use, food allergies, chronic diseases, anemia, arthritis, gastrointestinal surgery, and a family history of IBS.

CONCLUSION

The study highlights the importance of addressing the risk factors of IBS and developing supportive environments to alleviate its effects in Makkah. The researchers hope the findings inspire further research and action to improve the lives of people with IBS.

Social inequalities in aggravating factors of somatic symptom persistence (SOMA.SOC): study protocol for a mixed-method observational study focusing on irritable bowel syndrome and fatigue

INTRODUCTION

Some studies indicate that persistent somatic symptoms (PSS) are more prevalent among individuals with a low socioeconomic status (SES) and a migration background. However, factors explaining social inequalities in PSS are largely unknown. It is expected that aggravating factors of PSS like illness perception, illness beliefs (health literacy, stigma), illness behaviour and health anxiety may play an important role for this explanation. The SOMA.SOC study will examine social inequalities (according to SES and migration) in factors contributing to symptom persistence in irritable bowel syndrome (IBS) and fatigue.

METHODS AND ANALYSIS

The project will collect both quantitative and qualitative data. Quantitative data will be gathered via a representative telephone survey in Germany (N=2400). A vignette design will be used depicting patients varying in sex, condition (IBS/fatigue), occupational status (low/high) and migration (yes/no). In the survey, we will assess public knowledge and beliefs (eg, health literacy), attitudes (stigma) and personal experiences with the condition (eg, somatic symptom burden). Complementary, longitudinal qualitative interviews will be conducted with patients (n=32 at three time points, resulting in N=96 interviews) who will also vary according to sex, condition, occupational status and migration. Patients will be recruited from primary care practices in Hamburg. The interviews will cover origin and development of the condition, coping and help-seeking as well as social interactions and perception of the disease by others (eg, perceived stigma). SOMA.SOC is part of the interdisciplinary SOMACROSS (Persistent SOMAtic Symptoms ACROSS Diseases) research unit.

ETHICS AND DISSEMINATION

The study protocol was approved by the Ethics Committee of the Hamburg Medical Association on 25 January 2021 (reference number: 2020-10194- BO-ff). Informed consent will be obtained from all participants. The main findings will be submitted for publication in peer-reviewed journals within 12 months of study completion.

Genome-wide multi-trait analysis of irritable bowel syndrome and related mental conditions identifies 38 new independent variants

BACKGROUND

Irritable bowel syndrome (IBS) is a chronic disorder of gut-brain interaction frequently accompanied by mental conditions, including depression and anxiety. Despite showing substantial heritability and being partly determined by a genetic component, the genetic underpinnings explaining the high rates of comorbidity remain largely unclear and there are no conclusive data on the temporal relationship between them. Exploring the overlapping genetic architecture between IBS and mental conditions may help to identify novel genetic loci and biological mechanisms underlying IBS and causal relationships between them.

METHODS

We quantified the genetic overlap between IBS, neuroticism, depression and anxiety, conducted a multi-trait genome-wide association study (GWAS) considering these traits and investigated causal relationships between them by using the largest GWAS to date.

RESULTS

IBS showed to be a highly polygenic disorder with extensive genetic sharing with mental conditions. Multi-trait analysis of IBS and neuroticism, depression and anxiety identified 42 genome-wide significant variants for IBS, of which 38 are novel. Fine-mapping risk loci highlighted 289 genes enriched in genes upregulated during early embryonic brain development and gene-sets related with psychiatric, digestive and autoimmune disorders. IBS-associated genes were enriched for target genes of anti-inflammatory and antirheumatic drugs, anesthetics and opioid dependence pharmacological treatment. Mendelian-randomization analysis accounting for correlated pleiotropy identified bidirectional causal effects between IBS and neuroticism and depression and causal effects of the genetic liability of IBS on anxiety.

CONCLUSIONS

These findings provide evidence of the polygenic architecture of IBS, identify novel genome-wide significant variants for IBS and extend previous knowledge on the genetic overlap and relationship between gastrointestinal and mental disorders.

Irritable bowel syndrome-like symptoms before and after bariatric surgery and association with short-chain fermentable carbohydrates consumption: an observational prospective study

Background and aims

Irritable Bowel Syndrome (IBS)-like symptoms are frequent following bariatric surgery. This study aims to evaluate the frequency of IBS symptoms severity before and after bariatric surgery and their association with short-chain fermentable carbohydrates (FODMAPs) consumption.

Patients and methods

IBS symptoms severity in a cohort of obese patients was evaluated prospectively before, 6 and 12 months after bariatric surgery by validated questionnaires and tools (Irritable Bowel Syndrome Severity Scoring System (IBS SSS), Bristol Stool Scale (BSS), Quality of Life Short- Form-12 (SF-12), Hospital Anxiety and Depression scale (HAD)). FODMAPs consumption and its association with IBS symptom severity was evaluated by using a food frequency questionnaire focused on high-FODMAPs food consumption.

Results

Fifty-one patients were included (41 female; mean age 41 years (SD: 12)), 84% received a sleeve gastrectomy, and 16% a Roux-en-Y gastric bypass. Symptoms compatible with IBS were observed in 43% of patients before surgery, in 58% of patients at 6 months and 33% at 12 months (NS, p-value=0,197 and 0,414). In a multivariate model, a significant association was found between the IBS SSS score and lactose consumption at 6 months (β = + 58, 1; p = 0.03), and with polyols consumption at 12 months (β = + 112,6; p = 0.01).

Conclusions

Mild to moderate IBS symptoms are frequent in obese patients before bariatric surgery. A significant association between lactose and polyols consumption and IBS SSS score was observed after bariatric surgery, suggesting a potential link between the severity of IBS symptoms and some specific FODMAPs consumption.

Apigenin reduces the suppressive effect of exosomes derived from irritable bowel syndrome patients on the autophagy of human colon epithelial cells by promoting ATG14

BACKGROUND

Inflammatory bowel disease (IBS) is a chronic disorder of the gastrointestinal tract. Exosomes have been involved in various pathological processes including IBS. Apigenin has been reported to suppress inflammatory bowel disease (IBS). However, the regulatory roles of exosomes derived from IBS patients (IBS-exos) on human colon epithelial cells are still unclear.

METHODS

Exosomes were collected from IBS patients (IBS-exos) and co-cultured with CACO-2 cells. Apigenin was used to treat IBS-exos-treated CACO-2 cells. By exploring the public data bank, we figured out the regulators control the autophagy of CACO-2 cells.

RESULTS

Administration of apigenin dose-dependently abolished the inhibitory effect of IBS-exo on the autophagy of CACO-2 cells. A mechanistic study showed that miR-148b-3p bound to 3'UTR to suppress ATG14 and decrease autophagy. Moreover, results suggested that ATG14 overexpression promoted the autophagy of CACO-2 cells in the presence of miR-148b-3p mimic.

CONCLUSION

The current study showed that apigenin dose-dependently abolished the inhibitory effect of IBS-exo on CACO-2 cell autophagy by regulating miR-148b-3p/ATG14 signaling.

Bladder Pain Sensitivity Is a Potential Risk Factor for Irritable Bowel Syndrome

BACKGROUND

Although dysmenorrhea is a highly prevalent risk factor for irritable bowel syndrome (IBS), the factors underlying this risk are not fully understood. Prior studies support a hypothesis that repeated distressing menstrual pain promotes cross-organ pelvic sensitization with heightened visceral sensitivity.

AIMS

To further explore cross-organ pelvic sensitization we examined the association of dysmenorrhea, provoked bladder pain, and other putative factors with self-reported IBS-domain pain frequency and new onset after 1-year follow up.

METHODS

We measured visceral pain sensitivity with a noninvasive provoked bladder pain test in a cohort of reproductive-aged women, enriched for those reporting moderate-to-severe menstrual pain intensity but without any prior IBS diagnosis (n = 190). We analyzed the relationship between menstrual pain, provoked bladder pain, pain catastrophizing, anxiety, and depression with primary outcomes: (1) frequency of self-reported IBS-domain pain and (2) new onset of IBS-domain pain after 1-year follow up.

RESULTS

All hypothesized factors correlated with the frequency of IBS-domain pain (p's ≤ 0.038). In a cross-sectional model, only menstrual pain (standardized adjusted odds ratio 2.07), provoked bladder pain (1.49), and anxiety (1.90) were independently associated with IBS-domain pain ≥ 2 days/month (C statistic = 0.79). One year later, provoked bladder pain (3.12) was the only significant predictor of new onset IBS-domain pain (C statistic = 0.87).

CONCLUSION

Increased visceral sensitivity among women with dysmenorrhea could lead to IBS. Because provoked bladder pain predicted subsequent IBS, prospective studies should be performed to see if the early treatment of visceral hypersensitivity mitigates IBS.

[Irritable bowel syndrome in the Russian Federation: results of the ROMERUS multicenter observational study]

BACKGROUND

Irritable bowel syndrome (IBS) is one of the most common functional disorders of the gastrointestinal tract. According to Russian guidelines, a standard examination using laboratory and instrumental evaluation methods, including colonoscopy, should be performed to establish the diagnosis of IBS.

AIM

To characterize the Russian population of IBS patients.

MATERIALS AND METHODS

A multicenter observational prospective study ROMERUS was conducted at 35 clinical centers in the Russian Federation. The study included male and female patients aged 18 to 50 with a diagnosis of IBS based on the Rome IV criteria, with no signs of structural gastrointestinal disease. The follow-up duration was 6 months and included three patients' visits to the study site. During the study, data were collected on patients' demographic and clinical characteristics, medical history, and drug therapy. The secondary parameters included the assessment of the proportion of patients with a diagnosis of IBS confirmed by a standard examination among all patients meeting the Rome IV criteria, the evaluation of the change over time of the IBS symptoms, quality of life (QoL), and adherence to therapy. Characterization of the population was performed using descriptive statistics methods. The standard examination results were presented as the percentage of patients with IBS confirmed by the standard examination among all patients meeting the Rome IV criteria, with a two-sided 95% confidence interval.

RESULTS

The study included 1004 patients with a diagnosis of IBS according to the Rome IV criteria, with 790 (78.7%) patients included in the final analysis. The mean age of patients was 34.0±7.5 years; they were predominantly female (70.4%), Caucasian (99.4%), married (55.1%), urban residents (97.5%) with higher education (64.5%) and a permanent position (74.9%). Patients enrolled in the study have low physical activity and lack a healthy diet. The smoking rate was 26.3%. IBS symptoms with predominant constipation (IBS-C) were observed in 28.1% of patients; 28.9% had IBS with predominant diarrhea (IBS-D), 11.9% had mixed-type IBS, and 31.1% had non-classified IBS. The main IBS symptoms were pain (99.7%), abdominal distension (71.1%), and fullness (36.8%). Biliary tract dysfunction (18.9%) and gastritis (17.2%) were the most frequently reported comorbidities. Prior to enrollment, 28% of patients received drug therapy. The most commonly prescribed drug during the study was mebeverine (54.1%). At 6 months of follow-up, there was a significant reduction of abdominal pain, bloating, and distention, and a twofold reduction in the incidence of constipation and diarrhea in the subgroups of patients with IBS-C and IBS-D, respectively. The overall QoL score measured by the IBS-QoL questionnaire increased from 83.0 to 95.2 points (p<0.05) during the study. In the overall assessment of their condition, 69.6% of patients noted no symptoms and 25.3% reported marked improvement, 35% were asymptomatic according to the physician's overall assessment of the patient's condition, and 51.8% showed significant improvement.

CONCLUSION

IBS patients in the Russian Federation were characterized. The diagnosis of IBS, established following the Rome IV criteria, is confirmed by the results of a standard examination in 96.3% of patients. The Rome IV criteria for the IBS diagnosis make it possible to establish a diagnosis with a probability of 94.7%. For 6 months of follow-up, there was a clinical improvement with a decrease in the severity of symptoms and a QoL improvement.

Assessing the relationship between burnout syndrome and irritable bowel syndrome among medical health providers and medical students in Saudi Arabia

Burnout syndrome, characterized by chronic unmanageable workplace stress, has been linked to lower gastrointestinal disorders, including irritable bowel syndrome. However, the relationship between burnout syndrome and irritable bowel syndrome among medical health providers and medical students in Saudi Arabia has not been fully explored. This cross-sectional correlational study was conducted in Southern Saudi Arabia from 2021 to 2022 and involved 931 medical health providers and medical students who completed an electronic questionnaire. The study assessed the presence and severity of burnout and irritable bowel syndrome and examined their relationship. Burnout syndrome was evaluated using the Maslach Burnout Inventory-Student Survey (MBI-SS), while irritable bowel syndrome criteria and severity were assessed using validated tools. The study found that 85% of medical health providers and medical students experienced high levels of burnout and irritable bowel syndrome severity, with physicians and nurses mainly affected. Occupational exhaustion was high in 44.4% of participants, while depersonalization was high in 53% of participants. Personal accomplishment was low in 73.5% of participants. Mild, moderate, and severe irritable bowel syndrome was reported in 25.6%, 23.8%, and 12% of participants, respectively. The study highlights a significant association between burnout syndrome and irritable bowel syndrome severity among medical health providers and medical students in Saudi Arabia. These findings underscore the importance of developing effective interventions to prevent and manage burnout syndrome and related health issues among healthcare professionals and medical students in the region.

People with early-onset colorectal cancer describe primary care barriers to timely diagnosis: a mixed-methods study of web-based patient reports in the United Kingdom, Australia and New Zealand

BACKGROUND

People with early-onset colorectal cancer, under the age of 50, are more likely to experience diagnostic delay and to be diagnosed at later stages of the disease than older people. Advanced stage diagnosis potentially requires invasive therapeutic management at a time of life when these patients are establishing intimate relationships, raising families, building careers and laying foundations for financial stability. Barriers to timely diagnosis at primary care level have been identified but the patient perspective has not been investigated.

METHODS

Personal accounts of cancer care are increasingly accessed as rich sources of patient experience data. This study uses mixed methods, incorporating quantitative content analysis and qualitative thematic analysis, to investigate patients' accounts of early-onset colorectal cancer diagnosis published on prominent bowel cancer support websites in the United Kingdom, Australia and New Zealand.

RESULTS

Patients' perceptions (n = 273) of diagnostic barriers at primary care level were thematically similar across the three countries. Patients perceived that GPs' low suspicion of cancer due to age under 50 contributed to delays. Patients reported that their GPs seemed unaware of early-onset colorectal cancer and that they were not offered screening for colorectal cancer even when 'red flag' symptoms were present. Patients described experiences of inadequate information continuity within GP practices and across primary, specialist and tertiary levels of care, which they perceived contributed to diagnostic delay. Patients also reported tensions with GPs over the patient-centredness of care, describing discord related to symptom seriousness and lack of shared decision-making.

CONCLUSIONS

Wider dissemination of information about early-onset colorectal cancer at primary care level is imperative given the increasing incidence of the disease, the frequency of diagnostic delay, the rates of late-stage diagnosis and the dissatisfaction with patient experience reported by patients whose diagnosis is delayed. Patient education about diagnostic protocols may help to pre-empt or resolve tensions between GPs' enactment of value-based care and patients' concerns about cancer. The challenges of diagnosing early-onset colorectal cancer are significant and will become more pressing for GPs, who will usually be the first point of access to a health system for this growing patient population.

cFOS expression in the prefrontal cortex correlates with altered cerebral metabolism in developing germ-free mice

Introduction

The microbiota plays a critical role in modulating various aspects of host physiology, particularly through the microbiota-gut-brain (MGB) axis. However, the mechanisms that transduce and affect gut-to-brain communication are still not well understood. Recent studies have demonstrated that dysbiosis of the microbiome is associated with anxiety and depressive symptoms, which are common complications of metabolic syndrome. Germ-free (GF) animal models offer a valuable tool for studying the causal effects of microbiota on the host.

Methods

We employed gene expression and nuclear magnetic resonance (NMR)-based metabolomic techniques to investigate the relationships between brain plasticity and immune gene expression, peripheral immunity, and cerebral and liver metabolism in GF and specific pathogen-free (SPF) mice.

Results

Our principal findings revealed that brain acetate (p = 0.012) was significantly reduced in GF relative to SPF mice, whereas glutamate (p = 0.0013), glutamine (p = 0.0006), and N-acetyl aspartate (p = 0.0046) metabolites were increased. Notably, cFOS mRNA expression, which was significantly decreased in the prefrontal cortex of GF mice relative to SPF mice (p = 0.044), correlated with the abundance of a number of key brain metabolites altered by the GF phenotype, including glutamate and glutamine.

Discussion

These results highlight the connection between the GF phenotype, altered brain metabolism, and immediate-early gene expression. The study provides insight into potential mechanisms by which microbiota can regulate neurotransmission through modulation of the host's brain and liver metabolome, which may have implications for stress-related psychiatric disorders such as anxiety.