Convergence of neuro-endocrine-immune pathways in the pathophysiology of irritable bowel syndrome

Probiotics an emerging therapeutic approach towards gut-brain-axis oriented chronic health issues induced by microplastics: A comprehensive review

Applications for plastic polymers can be found all around the world, often discarded without any prior care, exacerbating the environmental issue. When large waste materials are released into the environment, they undergo physical, biological, and photo-degradation processes that break them down into smaller polymer fragments known as microplastics (MPs). The time it takes for residual plastic to degrade depends on the type of polymer and environmental factors, with some taking as long as 600 years or more. Due to their small size, microplastics can contaminate food and enter the human body through food chains and webs, causing gastrointestinal (GI) tract pain that can range from local to systemic. Microplastics can also acquire hydrophobic organic pollutants and heavy metals on their surface, due to their large surface area and surface hydrophobicity. The levels of contamination on the microplastic surface are significantly higher than in the natural environment. The gut-brain axis (GB axis), through which organisms interact with their environment, regulate nutritional digestion and absorption, intestinal motility and secretion, complex polysaccharide breakdown, and maintain intestinal integrity, can be altered by microplastics acting alone or in combination with pollutants. Probiotics have shown significant therapeutic potential in managing various illnesses mediated by the gut-brain axis. They connect hormonal and biochemical pathways to promote gut and brain health, making them a promising therapy option for a variety of GB axis-mediated illnesses. Additionally, taking probiotics with or without food can reduce the production of pro-inflammatory cytokines, reactive oxygen species (ROS), neuro-inflammation, neurodegeneration, protein folding, and both motor and non-motor symptoms in individuals with Parkinson's disease. This study provides new insight into microplastic-induced gut dysbiosis, its associated health risks, and the benefits of using both traditional and next-generation probiotics to maintain gut homeostasis.

Irritable bowel syndrome (IBS): could we decide what is behind?

Functional visceral problems are frequently present nowadays in the medical practice probably due to the significant mental and emotional load on people. Although physicians and psychophysiologists are active on the field, still we are far from a complete knowledge, despite the fact that scientists like the Hungarian Professor György Ádám already had initiated a new approach called visceral psychophysiology already a long time ago. In this article, we commemorate Professor Ádám by analyzing one of the most frequent functional disorders, irritable bowel syndrome (IBS), calling psychophysiology for help. First, we try to give a definition, then show the general descriptions and characteristics of IBS. Factors like stress, gender, and gastrointestinal pain are followed by the potential role of the immune system and the neuronal factors as well as the supposed brain mechanisms. We hope that this overview of the IBS-history would show how significant scientists can be decisive in certain fields of the science and practice.

Comorbidities, biomarkers and cause specific mortality in patients with irritable bowel syndrome: A phenome-wide association study

BACKGROUND

Irritable bowel syndrome (IBS) is one of the most common functional digestive disorders. Our understanding about its comorbidities, biomarkers, or long-term risks is still incomplete.

OBJECTIVE

To characterize comorbidities and biomarkers for IBS and establish the effect of IBS on overall- and cause specific mortality.

METHODS

We analyzed data from the population-based cohort of the UK Biobank (UKB) with 493,974 participants, including self-reported physician-diagnosed (n = 20,603) and ICD-10 diagnosed (n = 7656) IBS patients, with a mean follow-up of 11 years. We performed a phenome-wide association study (PheWAS) and competing risk analysis to characterize common clinical features in IBS patients.

RESULTS

In PheWAS analyses, 260 PheCodes were significantly overrepresented in self-reported physician-diagnosed IBS patients, 633 in patients with ICD-10 diagnosed IBS (ICD-10-IBS), with 221 (40%) overlapping. In addition to gastrointestinal diseases, psychiatric, musculoskeletal, and endocrine/metabolic disorders represented the most strongly associated PheCodes in IBS patients. Self-reported physician-diagnosed IBS was not associated with increased overall mortality and the risk of death from cancer was decreased (hazard ratio [HR] = 0.78 [95% CI = 0.7-0.9]). Lastly, we evaluated changes in serum metabolites in IBS patients and identified glycoprotein acetyls (GlycA) as a potential biomarker in IBS. One standard deviation increase in GlycA raised the risk of self-reported IBS/ICD-10 coded by 9%-20% (odds ratio [OR] = 1.09 [95% CI = 1.1-1.1]/OR = 1.20 [95% CI = 1.1-1.3]) and the risk of overall mortality in ICD-10-IBS patients by 28% (HR = 1.28 [95% CI = 1.1-1.5]).

CONCLUSION

Our large-scale association study determined IBS patients having an increased risk of several different comorbidities and that GlycA was increased in IBS patients.

[A Meta-Analysis on the Effects of Mind-Body Therapy on Patients with Irritable Bowel Syndrome]

PURPOSE

Previous randomized controlled trials (RCT) found that mind-body therapy can improve the health outcomes of patients with irritable bowel syndrome (IBS). The purpose of this meta-analysis was to identify the combined effects of mind-body therapy on patients' IBS symptoms, quality of life, anxiety, and depression.

METHODS

A systematic literature search was conducted using various databases such as PubMed, EMBASE, CINAHL CENTRAL, DBpia, RISS, and KISS. The primary outcome variables were IBS symptoms and quality of life; the secondary outcome variables were anxiety and depression. Comprehensive Meta-Analysis version 3.0 was used to analyze the extracted data. The effect size was calculated using standardized mean difference (SMD) and 95% confidence interval (CI).

RESULTS

Eleven final RCTs were used for this meta-analysis. Mind-body therapy was found to have a significant effect on the IBS patients' symptoms (SMD, -0.63; 95% CI, -0.77 to -0.48), quality of life (SMD, 1.03; 95% CI, 0.40 to 1.66), anxiety (SMD, -0.28; 95% CI, -0.47 to -0.09), and depression (SMD, -0.31; 95% CI, -0.06 to -0.12).

CONCLUSION

This meta-analysis reveals that mind-body therapy significantly improves IBS patients' symptoms, quality of life, anxiety, and depression. The results suggest that, in the future, appropriate mind-body therapy should be applied to Koreans suffering from IBS. Moreover, the therapy's long-term effects should be assessed.

Evolutionary Significance of the Neuroendocrine Stress Axis on Vertebrate Immunity and the Influence of the Microbiome on Early-Life Stress Regulation and Health Outcomes

Stress is broadly defined as the non-specific biological response to changes in homeostatic demands and is mediated by the evolutionarily conserved neuroendocrine networks of the hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic nervous system. Activation of these networks results in transient release of glucocorticoids (cortisol) and catecholamines (epinephrine) into circulation, as well as activation of sympathetic fibers innervating end organs. These interventions thus regulate numerous physiological processes, including energy metabolism, cardiovascular physiology, and immunity, thereby adapting to cope with the perceived stressors. The developmental trajectory of the stress-axis is influenced by a number of factors, including the gut microbiome, which is the community of microbes that colonizes the gastrointestinal tract immediately following birth. The gut microbiome communicates with the brain through the production of metabolites and microbially derived signals, which are essential to human stress response network development. Ecological perturbations to the gut microbiome during early life may result in the alteration of signals implicated in developmental programming during this critical window, predisposing individuals to numerous diseases later in life. The vulnerability of stress response networks to maladaptive development has been exemplified through animal models determining a causal role for gut microbial ecosystems in HPA axis activity, stress reactivity, and brain development. In this review, we explore the evolutionary significance of the stress-axis system for health maintenance and review recent findings that connect early-life microbiome disturbances to alterations in the development of stress response networks.

Aberrant Gut-To-Brain Signaling in Irritable Bowel Syndrome - The Role of Bile Acids

Functional bowel disorders such as irritable bowel syndrome (IBS) are common, multifactorial and have a major impact on the quality of life of individuals diagnosed with the condition. Heterogeneity in symptom manifestation, which includes changes in bowel habit and visceral pain sensitivity, are an indication of the complexity of the underlying pathophysiology. It is accepted that dysfunctional gut-brain communication, which incorporates efferent and afferent branches of the peripheral nervous system, circulating endocrine hormones and local paracrine and neurocrine factors, such as host and microbially-derived signaling molecules, underpins symptom manifestation. This review will focus on the potential role of hepatic bile acids in modulating gut-to-brain signaling in IBS patients. Bile acids are amphipathic molecules synthesized in the liver, which facilitate digestion and absorption of dietary lipids. They are also important bioactive signaling molecules however, binding to bile acid receptors which are expressed on many different cell types. Bile acids have potent anti-microbial actions and thereby shape intestinal bacterial profiles. In turn, bacteria with bile salt hydrolase activity initiate the critical first step in transforming primary bile acids into secondary bile acids. Individuals with IBS are reported to have altered microbial profiles and modified bile acid pools. We have assessed the evidence to support a role for bile acids in the pathophysiology underlying the manifestation of IBS symptoms.

Heat Shock Protein 27 Regulates the Inflammatory Response of Intestinal Epithelial Cells by the Nuclear Factor-κB Pathway

BACKGROUND

The specific and accurate pathogenesis of diarrhea-type irritable bowel syndrome is still unclear.

AIMS

We explored the mechanism of heat shock protein 27 (HSP27) in diarrhea-type irritable bowel syndrome to identify the key targets for the disease.

METHODS

The human colonic epithelial cell lines Caco-2 and NCM460 were pretreated with KRIBB3 (a phosphorylation inhibitor of HSP27) and then stimulated with lipopolysaccharide for different times. The apoptosis ratios of Caco-2 and NCM460 cells were examined with Annexin V/PI assays. Cell growth was determined using the cell counting kit-8 assay, and the expression levels of IL-1β and IL-6 in the cell supernatant were analyzed by ELISA. In addition, the expression levels of HSP27 and the nuclear factor-κB (NF-κB) signaling pathway were examined by Western blot assay.

RESULTS

Stimulation with lipopolysaccharide promoted the expression of HSP27 in colonic epithelial cells. HSP27 was phosphorylated at serine 78 and 82 after exposure to LPS. Apoptosis, growth inhibition, and inflammatory factor expression of lipopolysaccharide-induced colonic epithelial cells were greatly exacerbated by KRIBB3 treatment. In addition, KRIBB3 inhibited the phosphorylation of IκB-α and the activation of NF-κB. Gene silencing by small interfering RNA indicated that phosphorylation of HSP27 may regulate the NF-κB pathway.

CONCLUSIONS

HSP27 plays an important role in the inflammatory response of intestinal human colonic epithelial cells. HSP27 may protect intestinal epithelial cells against damage by regulating the NF-κB pathway.

Vagus nerve assessment via ultrasonography in irritable bowel syndrome. Are there any changes of dimension in the vagus nerve?

BACKGROUND/AIM

Irritable bowel syndrome (IBS) is the functional gastrointestinal disorder which has closely relationship with Central Nervous System (CNS). VN is the major connector between CNS and Enteric Nervous System (ENS). The aim of this study was to investigate the possible changes of dimension of Vagus Nerve (VN) with Vagus ultrasonography (VU) in IBS.

MATERIAL AND METHODS

A total 119 patients which is consisted of 66 IBS patients appropriated with Rome IV criterias and 53 patients of control group were enrolled to the study. All patients were underwent to colonoscopy for role-out the organic pathologies, such as polyposis, inflammatory bowel syndromes, diverticulosis and colon cancer. Right Vagus (RV) and left Vagus (LV) nerve areas and diameters were calculated with VU.

RESULTS

There were no statistical difference of RV (p=0.445) and LV (p=0.944) diameter between two groups. There were also no statistical difference of RV (p=0.549) and LV (p=0.874) areas between IBS and control groups.

CONCLUSION

VU clearly depicted that there is no changes of dimension in VN areas and diameters in the IBS. This might show that VN is only a transporter of abnormal neuronal stimulations according to IBS pathophisiology.

Irritable bowel syndrome increases the risk of chronic obstructive pulmonary disease: A retrospective cohort study

Both inflammation and infection are associated with the development of irritable bowel syndrome (IBS) and chronic obstructive pulmonary disease (COPD). The purpose of this study is to further elucidate the association between IBS and COPD through a retrospective cohort study. We enrolled IBS patients diagnosed between 2000 and 2011 with follow-up for at least one year. The non-IBS patients as comparison group were selected with 1:3 matching by propensity score. Statistical analysis was utilized to assess the differences in characteristic distribution, and to compare the cumulative incidence of COPD between the IBS and non-IBS cohorts. We selected 14,021 IBS patients and 42,068 non-IBS patients for comparison. The IBS patients exhibited a significant risk to develop COPD compared with non-IBS patients. Additionally, the cumulative incidence rate of COPD in the IBS cohort increased significantly during the follow-up period of more than ten years, compared to the non-IBS cohort, based on the Kaplan-Meier analysis. The risk of COPD was also significantly decreased in those patients with more than eighteen IBS-related clinical visits. This retrospective cohort study demonstrates the significantly increased risk of COPD in patients with IBS. Therefore, early inspection and prevention of COPD is essential for patients with IBS.

Irritable Bowel Syndrome and Depression: A Shared Pathogenesis

It is common knowledge that dysfunction of the immune and neuroendocrine systems, in addition to neuroplasticity, is among the pathways that underlie irritable bowel syndrome (IBS) and depression. From as early as the 1950s, the association of IBS with psychiatric disease was postulated; however, the exact mechanism remains elusive. There has been considerable research into the association of IBS and depression over the last years; research into the gut-brain axis and alterations in gut microbes have gained momentum to spell out the relationship between depression and IBS. Evidence from these researchers indicate the dysfunction of homeostatic coping mechanisms; corticotropin-releasing factor appears to be at the core of this dysfunction. The multifactorial etiology of both depression and IBS hinders a universal, one-strategy-fits-all treatment approach to patients with comorbid depression and IBS. This review analyzes the pathophysiology that associates these two conditions; it explores the bidirectional communication between the brain and the gastrointestinal tract, and how these influence the endocrine and immune systems. Review articles, clinical trials and randomized controlled trials that analyzed the association of depression and IBS were identified by searching PubMed, Google Scholar, and articles in PMC databases. Full texts written in English and available via these search engines were selected for the synthesis of this review. Alterations to the gut-brain axis, intestinal microbiota, and the neuro-immune system may be the cornerstone to the association of IBS and depression. This literature review opens alternate therapeutic approaches to comorbid IBS and depression and encourages further research into this topic.

Modulation of inflammation by toll-like receptor 4/nuclear factor-kappa B in diarrhea-predominant irritable bowel syndrome

In order to investigate the function of toll-like receptor 4/nuclear factor-kappa B (TLR4/NF-κB) signal pathways in the pathogenesis of diarrhea-predominant irritable bowel syndrome (IBS-D), IBS-D animal models were established in wistar rats challenged with acute and chronic stresses (29 days). Wistar rats without stress-challenged were used as controls. IBS-D models were randomly divided into two groups: one was treated with normal saline, another group was treated with TLR4/NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC) (50mg/kg/week) for continuous four times. Our results demonstrate that continuous stresses can induce the characteristic symptoms of IBS-D, including high wet stool rate and intestinal flora imbalance. Further examinations of colon tissues show that the protein expression levels of TLR4 and NF-κB in IBS-D groups are higher than that in control group. The secretory levels of interleukin (IL-8), tumor necrosis factor α (TNFα), and myeloid differentiation factor 88 (MyD88) are significantly increased in IBS-D group. Administration with PDTC effectively downregulates levels of these inflammatory factors. In contrast, interleukin-10 (IL-10) is in an opposite alteration with lower levels in IBS-D groups and the PDTC treatment increases it to the levels as in control group. Moreover, inhibition of the TLR4/NF-κB by PDTC improves the microstructure of intestinal mucosa mainly by increasing the height of villi. Our results suggest that TLR4/NF-κB signal pathway plays an important role in the modulation of inflammatory responses in IBS-D, which might be a therapeutic target for the IBS-D. All of these findings also provide the evidence concerning an inherent linkage between the axis of stress/NF-κB/inflammation and IBS-D.

Functional Bowel Disorders Are Associated with a Central Immune Activation

Background

Subjects with depression and unexplained neurological symptoms have a high prevalence of gastrointestinal comorbidity probably related to the brain-gut communication. This study explored associations between functional gastrointestinal disorders (FGID) and inflammatory markers in subjects with these disorders.

Methods

The FGID, including irritable bowel syndrome (IBS), were classified according to the Rome III criteria, and degree of symptoms was assessed with IBS symptom severity score (IBS-SSS). A range of interleukins (IL), chemokines and growth factors, tryptophan, and kynurenine were analysed in serum and the cerebrospinal fluid (CSF), and short-chain fatty acids (SCFA) were analysed in the faeces. The results are reported as partial correlation (pc) and p values.

Results

Sixty-six subjects were included. IBS was associated with high levels of tryptophan (p = 0.048) and kynurenine (p = 0.019) and low level of IL-10 (p = 0.047) in the CSF. IBS-SSS was associated with high tumor necrosis factor and low IL-10 in the CSF; pc = 0.341 and p = 0.009 and pc = −0.299 and p = 0.023, respectively. Propionic minus butyric acid in faeces was negatively associated with IL-10 in the CSF (pc = −0.416, p = 0.005).

Conclusions

FGID were associated with a proinflammatory immune activation in the central nervous system and a disturbed tryptophan metabolism that could have been mediated by the faecal microbiota.

Efficacy of individualised diets in patients with irritable bowel syndrome: a randomised controlled trial

Background

Patients with irritable bowel syndrome (IBS) are often placed on diets guided by food intolerance assays, although these have not been validated. We assessed the effects of individualised diets in patients with IBS guided by a leucocyte activation test.

Methods

This is a parallel-group, double-blind, randomised controlled trial of 58 adults with IBS seen at an academic health centre in Northeast USA. Peripheral venous blood was analysed using a leucocyte activation test; individual foods were reported to produce positive or negative results. Participants were randomised to a 4-week diet with either individualised guidance to eliminate foods with positive assay results and allow foods with negative assay results (intervention), or with individualised guidance, matched in rigour and complexity, to eliminate foods with negative assay results and allow foods with positive assay results (comparison). The primary outcome was between-group differences in the IBS Global Improvement Scale (GIS). Secondary outcomes included reductions in IBS Symptom Severity Scale (SSS) scores and increases in IBS Adequate Relief (AR) and Quality of Life (QOL) scores. An aptamer-based proteomic analysis was conducted in strong responders.

Results

The intervention group had significantly greater increases in mean GIS score after 4 weeks (0.86 vs comparison; 95% CI 0.05 to 1.67; p=0.04) and 8 weeks (1.22 vs comparison; 95% CI 0.22 to 2.22; p=0.02). The intervention group also had significantly greater reductions in mean SSS score at 4 weeks (–61.78 vs comparison; 95% CI –4.43 to –119.14; p=0.04) and 8 weeks (–66.42 vs comparison; 95% CI –5.75 to –127.09; p=0.03). There were no significant differences between intervention and comparison groups in mean AR or QOL scores. A reduction in neutrophil elastase concentration was associated with reduced symptoms.

Conclusions

Elimination diets guided by leucocyte activation tests reduced symptoms. These findings could lead to insights into the pathophysiology of IBS.

Trial registration number

NCT02186743.

Relationship of irritable bowel syndrome with sex hormone levels and immunoregulatory factors

Clinically, it has been found that there exist sex differences in irritable bowel syndrome (IBS). Epidemiological evidence confirms that the ratio of males to females with IBS is about 1:2. Previous research on the mechanism of IBS rarely focused on such sex differences. In order to provide a basis for explaining the sex differences in IBS, the authors analyzed the relevant literature and found that several factors such as sex hormones and their receptors, corticotropin releasing factor and immune factors may cause such sex differences. The identification of these factors may help clarify the etiology and pathogenesis of IBS and provide a more accurate strategy for clinical targeted therapy.

Neuroimmune Cross Talk in the Gut. Neuroendocrine and neuroimmune pathways contribute to the pathophysiology of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a common disorder characterized by recurrent abdominal pain, bloating, and disturbed bowel habit, symptoms that impact the quality of life of sufferers. The pathophysiological changes underlying this multifactorial condition are complex and include increased sensitivity to luminal and mucosal factors, resulting in altered colonic transit and visceral pain. Moreover, dysfunctional communication in the bidirectional signaling axis between the brain and the gut, which involves efferent and afferent branches of the peripheral nervous system, circulating endocrine hormones, and local paracrine and neurocrine factors, including immune and perhaps even microbial signaling molecules, has a role to play in this disorder. This minireview will examine recent advances in our understanding of the pathophysiology of IBS and assess how cross talk between hormones, immune, and microbe-derived factors and their neuromodulatory effects on peripheral nerves may underlie IBS symptomatology.

Decoupling social status and status certainty effects on health in macaques: a network approach

BACKGROUND

Although a wealth of literature points to the importance of social factors on health, a detailed understanding of the complex interplay between social and biological systems is lacking. Social status is one aspect of social life that is made up of multiple structural (humans: income, education; animals: mating system, dominance rank) and relational components (perceived social status, dominance interactions). In a nonhuman primate model we use novel network techniques to decouple two components of social status, dominance rank (a commonly used measure of social status in animal models) and dominance certainty (the relative certainty vs. ambiguity of an individual's status), allowing for a more complex examination of how social status impacts health.

METHODS

Behavioral observations were conducted on three outdoor captive groups of rhesus macaques (N = 252 subjects). Subjects' general physical health (diarrhea) was assessed twice weekly, and blood was drawn once to assess biomarkers of inflammation (interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP)).

RESULTS

Dominance rank alone did not fully account for the complex way that social status exerted its effect on health. Instead, dominance certainty modified the impact of rank on biomarkers of inflammation. Specifically, high-ranked animals with more ambiguous status relationships had higher levels of inflammation than low-ranked animals, whereas little effect of rank was seen for animals with more certain status relationships. The impact of status on physical health was more straightforward: individuals with more ambiguous status relationships had more frequent diarrhea; there was marginal evidence that high-ranked animals had less frequent diarrhea.

DISCUSSION

Social status has a complex and multi-faceted impact on individual health. Our work suggests an important role of uncertainty in one's social status in status-health research. This work also suggests that in order to fully explore the mechanisms for how social life influences health, more complex metrics of social systems and their dynamics are needed.

Omics Studies of the Murine Intestinal Ecosystem Exposed to Subchronic and Mild Social Defeat Stress

The microbiota-gut-brain axis plays an important role in the development of stress-induced mental disorders. We previously established the subchronic and mild social defeat stress (sCSDS) model, a murine experimental model of depression, and investigated the metabolomic profiles of plasma and liver. Here we used omics approaches to identify stress-induced changes in the gastrointestinal tract. Mice exposed to sCSDS for 10 days showed the following changes: (1) elevation of cholic acid and reduction of 5-aminovaleric acid among cecal metabolites; (2) downregulation of genes involved in the immune response in the terminal ileum; (3) a shift in the diversity of the microbiota in cecal contents and feces; and (4) fluctuations in the concentrations of cecal metabolites produced by gut microbiota reflected in plasma and hepatic metabolites. Operational taxonomic units within the family Lachnospiraceae showed an inverse correlation with certain metabolites. The social interaction score correlated with cecal metabolites, IgA, and cecal and fecal microbiota, suggesting that sCSDS suppressed the ileal immune response, altering the balance of microbiota, which together with host cells and host enzymes resulted in a pattern of accumulated metabolites in the intestinal ecosystem distinct from that of control mice.

Is irritable bowel syndrome an infectious disease?

Irritable bowel syndrome (IBS) is the most common of all gastroenterological diseases. While many mechanisms have been postulated to explain its etiology, no single mechanism entirely explains the heterogeneity of symptoms seen with the various phenotypes of the disease. Recent data from both basic and clinical sciences suggest that underlying infectious disease may provide a unifying hypothesis that better explains the overall symptomatology. The presence of small intestinal bowel overgrowth (SIBO) has been documented in patients with IBS and reductions in SIBO as determined by breath testing correlate with IBS symptom improvement in clinical trials. The incidence of new onset IBS symptoms following acute infectious gastroenteritis also suggests an infectious cause. Alterations in microbiota-host interactions may compromise epithelial barrier integrity, immune function, and the development and function of both central and enteric nervous systems explaining alterations in the brain-gut axis. Clinical evidence from treatment trials with both probiotics and antibiotics also support this etiology. Probiotics appear to restore the imbalance in the microflora and improve IBS-specific quality of life. Antibiotic trials with both neomycin and rifaximin show improvement in global IBS symptoms that correlates with breath test normalization in diarrhea-predominant patients. The treatment response to two weeks of rifaximin is sustained for up to ten weeks and comparable results are seen in symptom reduction with retreatment in patients who develop recurrent symptoms.

Heart Rate Recovery Is Impaired in Patients with Inflammatory Bowel Diseases

OBJECTIVE

In this study we aimed to investigate heart rate recovery (HRR) in patients with inflammatory bowel disease (IBD).

SUBJECTS AND METHODS

A total of 40 patients with IBD and 30 healthy controls were included in this study. A treadmill stress test was performed in all the patients to calculate the HRR index based on the age-specific maximum heart rate. The HRR indices were calculated as follows: HRR1, 2, 3, 4, 5 = heart rate at peak exercise - heart rate at 1, 2, 3, 4, and 5 min. The independent samples t test was used to compare HRR indices between the patient and control groups. The Pearson correlation coefficient was used to examine the association between the duration of IBD and the HRR indices. Multivariate regression analysis was carried out to identify predictors of impaired HRR in patients with IBD.

RESULTS

HRR indices at various time intervals were significantly lower in the patients with IBD than in the controls: HRR1 (1.18 ± 8 vs. 31 ± 7, p < 0.001), HRR2 (36 ± 12 vs. 51 ± 8, p < 0.001), HRR3 (46 ± 12 vs. 62 ± 11, p < 0.001), HRR4 (54 ± 7 vs. 65 ± 8, p < 0.001), and HRR5 (55 ± 13 vs. 71 ± 15, p < 0.001). Mean duration of IBD was 7.8 ± 3.6 years. In addition, there was a significant negative correlation between disease duration and HRR at the first minute (r = -0.704, p < 0.001). Multivariate logistic regression analysis showed that symptom duration (OR: 1.742, 95% CI: 1.148-2.636, p = 0.009) was an independent predictor of impaired HRR in patients with IBD.

CONCLUSION

In this study, the data showed that the HRR was impaired in patients with IBDs. Hence, given the prognostic value of the test, patients with IBD should be monitored for future cardiovascular events.

Food allergy in irritable bowel syndrome: The case of non-celiac wheat sensitivity

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders, having a prevalence of 12%-30% in the general population. Most patients with IBS attribute their symptoms to adverse food reactions. We review the role of diet in the pathogenesis of IBS and the importance of dietary factors in the management of these patients. The MEDLINE electronic database (1966 to Jan 2015) was searched using the following keywords: "food", "diet", "food allergy", "food hypersensitivity", "food intolerance", "IBS", "epidemiology", "pathogenesis", "pathophysiology", "diagnosis", "treatment". We found 153 eligible papers; 80 were excluded because: not written in English, exclusive biochemical and experimental research, case reports, reviews, and research otherwise not relevant to our specific interest. We selected 73 papers: 43 original papers, 26 reviews and 4 letters to the editor. These papers focused on IBS pathogenesis, the association between IBS and atopy, and between IBS and food allergy, the relationship between IBS and non-celiac wheat sensitivity, the role of diet in IBS. Pending further scientific evidence, a cautious approach is advisable but the concept of food allergy should be included as a possible cause of IBS, and a dietary approach may have a place in the routine clinical management of IBS.

Cognitive Functions and Depression in Patients with Irritable Bowel Syndrome

Background. Irritable bowel syndrome (IBS) is associated with depression and depression with impaired cognitive functions. The primary aim was to study associations between depression and cognitive functions in patients with IBS. Methods. IBS (according to the Rome III criteria), cognitive functions (evaluated with a set of neuropsychological tests), and depression (measured with Beck Depression Inventory II and Montgomery-Åsberg Depression Scale) were analysed in patients with idiopathic depression and in patients with unspecified neurological symptoms. Results. 18 and 48 patients with a mean age of 47 and 45 years were included in the "Depression" and "Neurological" group, respectively. In the "Depression" group, the degree of depression was significantly higher in patients with IBS than in those without. Depression was associated with impaired cognitive function in 6 out of 17 neuropsychological tests indicating reduced set shifting, verbal fluency, attention, and psychomotor speed. IBS was statistically significantly associated with depression but not with any of the tests for cognitive functions. Conclusions. IBS was associated with depression but not with impaired cognitive functions. Since the idiopathic depression was associated with cognitive deficits, the findings could indicate that the depression in patients with IBS differs from an idiopathic depression.