Vitamin D associates with improved quality of life in participants with irritable bowel syndrome: outcomes from a pilot trial

A systematic review and meta-analysis of diet and nutrient intake in adults with irritable bowel syndrome

BACKGROUND

Numerous individual and environmental factors including diet may play an important role in the pathophysiology of irritable bowel syndrome (IBS). It is unclear to what degree dietary intake is affected in individuals with IBS. We aimed to perform a systematic review and meta-analysis to summarize dietary intake of adults with IBS and to compare dietary intake between adults with IBS and non-IBS controls.

METHODS

Ovid MEDLINE, Embase, Cochrane, CINAHL, and Scopus were searched through February 2023 for clinical trials and observational studies measuring usual diet in adults with IBS. Pooled weighted averages were estimated for total energy, macronutrient, and micronutrient data. Mean differences (MD) in nutrient intake were estimated for adults with IBS versus non-IBS controls using a random effects model. Heterogeneity was assessed by the inconsistency index (I2).

KEY RESULTS

Sixty-three full-text articles were included in the review of which 29 studies included both IBS and control subjects. Nutrients not meeting the recommended intake level for any dietary reference values in the IBS population were fiber and vitamin D. Meta-regression by female proportion was positively correlated with total fat intake and negatively correlated with carbohydrate intake. Comparisons between participants with IBS and controls showed significantly lower fiber intake in participants with IBS with high heterogeneity (MD: -1.8; 95% CI: -3.0, -0.6; I2 = 85%).

CONCLUSIONS AND INFERENCES

This review suggests that fiber and vitamin D intake is suboptimal in IBS; however, overall dietary intake does not appear to be comprised. Causes and consequences of reduced fiber in IBS deserve further study. Results of this systematic review and meta-analysis suggest that fiber and vitamin D intake is suboptimal in IBS. However, overall intake of other macro- and micronutrients does not appear to be compromised. Causes and consequences of reduced fiber and Vitamin D intake in IBS deserve further study.

Vitamin D improves irritable bowel syndrome symptoms: A meta-analysis

Background & aims

Approximately 5%-10% of the population in most geographical regions suffer from irritable bowel syndrome (IBS), which creates a significant burden on individual patients, their families, and society. Recent advances in IBS therapies have indicated that vitamin D supplementation is potential to relieve its symptoms, but evidence of this is lacking. This meta-analysis aimed to estimate the effect of vitamin D on gastrointestinal (GI) symptoms in IBS patients.

Methods

The PubMed, Embase, and Cochrane Central Register of Controlled Trials databases were searched from their inception to March 2022. Statistical analyses were performed with Stata 12.0 and Review Manager 5.4, and statistical significance was defined as P < 0.05. The pooled results are presented as weighted mean differences (WMD) and 95% confidence intervals (CI).

Results

The meta-analysis including 6 randomized controlled trials (RCT) with 572 patients found a significant difference in IBS symptom severity score (WMD, -34.88; 95% CI, -62.48 to -7.27; P = 0.013; random-effects model) but no significant difference in IBS quality of life score (WMD, 3.33; 95% CI, -5.12 to -11.77; P = 0.440; random-effects model).

Conclusions

Overall, IBS patients may benefit from vitamin D supplementation to reduce the GI symptoms.

Association of Vitamin D Deficiency and Insufficiency with Pathology in Hospitalized Patients

Vitamin D deficiency is one of the most common medical conditions, with approximately one billion people having low vitamin D levels. Vitamin D is associated with a pleiotropic effect (immunomodulatory, anti-inflammatory and antiviral), which can be essential for a better immune response. The aim of this research was to evaluate the prevalence of vitamin D deficiency/insufficiency in hospitalized patients focusing on demographic parameters as well as assessing the possibility of its associations with different comorbidities. Of 11,182 Romanian patients evaluated in the study over 2 years, 28.83% had vitamin D deficiency, 32.11% insufficiency and 39.05% had optimal vitamin D levels. The vitamin D deficiency was associated with cardiovascular disorders, malignancies, dysmetabolic disorders and SARS-CoV2 infection, older age and the male sex. Vitamin D deficiency was prevalent and showed pathology association, while insufficiency of vitamin D (20-30 ng/mL) had lower statistical relevance and represents a grey zone in vitamin D status. Guidelines and recommendations are necessary for homogeneity of the monitoring and management of inadequately vitamin D status in the risk categories.

Strategies for Producing Low FODMAPs Foodstuffs: Challenges and Perspectives

In recent years, there has been a growing interest in a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) as a promising therapeutic approach to reduce the symptoms associated with irritable bowel syndrome (IBS). Hence, the development of low FODMAPs products is an important challenge for the food industry, and among the various foodstuffs associated with the intake of FODMAPs, cereal-based products represent an issue. In fact, even if their content in FODMAPs is limited, their large use in diet can be an important factor in developing IBS symptoms. Several useful approaches have been developed to reduce the FODMAPs content in processed food products. Accurate ingredient selection, the use of enzymes or selected yeasts, and the use of fermentation steps carried out by specific lactic bacteria associated with the use of sourdough represent the technical approaches that have been investigated, alone or in combination, to reduce the FODMAPs content in cereal-based products. This review aims to give an overview of the technological and biotechnological strategies applicable to the formulation of low-FODMAPs products, specifically formulated for consumers affected by IBS. In particular, bread has been the foodstuff mainly investigated throughout the years, but information on other raw or processed products has also been reported. Furthermore, taking into account the required holistic approach for IBS symptoms management, in this review, the use of bioactive compounds that have a positive impact on reducing IBS symptoms as added ingredients in low-FODMAPs products is also discussed.

Identification of putative transcriptomic biomarkers in irritable bowel syndrome (IBS): Differential gene expression and regulation of TPH1 and SERT by vitamin D

Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders and affects approximately 4% of the global population. The diagnosis of IBS can be made based on symptoms using the validated Rome criteria and ruling out commonly occurring organic diseases. Although biomarkers exist for "IBS mimickers" such as celiac disease and inflammatory bowel disease (IBD), no such test exists for IBS. DNA microarrays of colonic tissue have been used to identify disease-associated variants in other gastrointestinal (GI) disorders. In this study, our objective was to identify biomarkers and unique gene expression patterns that may define the pathological state of IBS. Mucosal tissue samples were collected from the sigmoid colon of 29 participants (11 IBS and 18 healthy controls). DNA microarray analysis was used to assess gene expression profiling. Extraction and purification of RNA were then performed and used to synthesize cDNA. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) was employed to identify differentially expressed genes in patients diagnosed with IBS compared to healthy, non-IBS patient-derived cDNA. Additional testing probed vitamin D-mediated regulation of select genes associated with serotonergic metabolism. DNA microarray analyses led to the identification of 858 differentially expressed genes that may characterize the IBS pathological state. After screening a series of genes using a combination of gene ontological analysis and RT-qPCR, this spectrum of potential IBS biomarkers was narrowed to 23 genes, some of which are regulated by vitamin D. Seven putative IBS biomarkers, including genes involved in serotonin metabolism, were identified. This work further supports the hypothesis that IBS pathophysiology is evident within the human transcriptome and that vitamin D modulates differential expression of genes in IBS patients. This suggests that IBS pathophysiology may also involve vitamin D deficiency and/or an irregularity in serotonin metabolism.

The Effect of Vitamin D Supplementation on the Severity of Symptoms and the Quality of Life in Irritable Bowel Syndrome Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Irritable bowel syndrome (IBS), a gastrointestinal disorder affecting 7–12% of the population, is characterized by abdominal pain, bloating, and alternating bowel patterns. Data on risk and protective influences have yielded conflicting evidence on the effects of alternative interventions, such as vitamin D. This review focuses on the effects of vitamin D on IBS. A systematic review and meta-analysis considered all articles published until 4 April 2022. The search for randomized controlled trials assessing vitamin D efficacy in IBS with outcomes, primary (Irritable Bowel Severity Scoring System (IBS-SSS)) and secondary (IBS quality of life (IBS-QoL) and serum level of calcifediol (25(OH)D)), was performed on six databases, Google Scholar, Web of Science, SCOPUS, EMBASE, PubMed (MEDLINE), and Cochrane Central Register of Controlled Trials. We included six trials with 616 patients. The pooled analysis found no difference between vitamin D and placebo in improving IBS-SSS (MD: −45.82 with 95% CI [−93.62, 1.98], p = 0.06). However, the pooled analysis favored vitamin D over placebo in improving the IBS-Qol (MD: 6.19 with 95% CI [0.35, 12.03], p = 0.04) and serum 25(OH)D (MD: 25.2 with 95% CI [18.41, 31.98], p = 0.00001). Therefore, further clinical trials are required to reach clinically applicable and generalizable findings.

Probiotics and Vitamin D/Vitamin D Receptor Pathway Interaction: Potential Therapeutic Implications in Inflammatory Bowel Disease

Inflammatory bowel diseases (IBD) are chronic conditions of unknown etiology and immunomediated pathogenesis. In the last years, the comprehension of the complex mechanisms involved in the intestinal mucosal homeostasis, and the analysis of the alterations potentially leading to inflammatory pathologic states, has consistently increased. Specifically, the extraordinary impulse in the field of research of the intestinal microbiome has opened the door to the investigation of possible novel approaches to the diagnosis, management and therapeutic applications in IBD. In line with that, administration of probiotic bacteria has been intensely evaluated, leading to much more exciting results in experimental models than in clinical practice. Considering the consistent heterogeneity of the available studies on probiotics, the increased knowledge of the properties of the single bacterial species would ideally lead to unravel potential mechanisms of action that may bring therapeutic applications in specific pathologic condition. Among the relevant molecular pathways for mucosal homeostasis maintenance, the vitamin D/vitamin D receptor (VDR) pathway has been intensely studied in the very last years. In fact, besides osteometabolic functions, the vitamin D exerts important homeostatic effects in the organism at multiple levels, such as immunomodulation, inflammation control, and microbiota regulation, which are likely to play a relevant role in intestinal mucosa protection. In the present review, recent findings about probiotic applications in IBD and mechanisms of action linking vitamin D/VDR pathway to IBD are reported. Available evidence for probiotic effect on vitamin D/VDR are reviewed and potential future application in IBD patients are discussed. At present, many aspects of IBD pathogenesis are still obscure, and current therapeutic options for IBD treatment are at best suboptimal. The increasing comprehension of the different pathways involved in IBD pathogenesis will lead to novel findings ideally leading to potential clinical applications. Microbiota manipulation and vitamin/VDR pathway appear a promising field for future research and therapeutic developments.

Early Evidence Indicates Vitamin D Improves Symptoms of Irritable Bowel Syndrome: Nursing Implications and Future Research Opportunities

Irritable bowel syndrome (IBS) affects approximately 11.2% of the population. Yet, full understanding of its etiology and optimal treatment remains elusive. Understanding of the underlying pathophysiology of IBS has been limited. However, research is beginning to identify the cause as multifactorial (e.g., low-grade local mucosal inflammation, systemic immune activation, altered intestinal permeability, intestinal hypersensitivity, altered central nervous system processing, changes in intestinal microbiota). Understanding of the role of vitamin D in intestinal inflammation, immunity, and gastrointestinal conditions is increasing but is not yet fully understood. Growing evidence has linked vitamin D deficiency with a variety of gastrointestinal disorders, including inflammatory bowel disease, diverticulitis, colorectal cancer, and IBS. Several studies have demonstrated that individuals with IBS are more likely to have vitamin D deficiency than healthy controls. Recent vitamin D supplementation studies have shown improvement in quality of life and reduction in IBS symptoms (including abdominal pain, distention, flatulence, constipation, and visceral sensitivity) but the mechanism remains unclear. Nurses are well positioned to educate patients about the importance of sufficient vitamin D for overall health in individuals with IBS as well as participate in well-designed therapeutic studies to explore whether enhanced vitamin D status will ultimately help treat IBS more effectively.

Vitamin D Supplementation and Mental Health in Inflammatory Bowel Diseases and Irritable Bowel Syndrome Patients: A Systematic Review

Inflammatory bowel diseases (IBDs) and irritable bowel syndrome (IBS) are associated with decreased quality of life and mental health problems. Among various approaches to supportive therapy that aims to improve mental health in affected individuals, vitamin D supplementation is considered to be an effective method which may also be beneficial in alleviating the symptoms during the course of IBDs and IBS. The aim of the present study was to conduct a systematic review of the literature presenting the data regarding the influence of vitamin D supplementation on mental health in adults with inflammatory and functional bowel diseases, including IBDs and IBS. This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (Registration number CRD42020155779). A systematic search of the PubMed and Web of Science databases was performed, and the intervention studies published until September 2021 were included. The human studies eligible to be included in the review should have described any intervention involving vitamin D as a supplement in a group of adult patients suffering from IBDs and/or IBS and should have assessed any component of mental health, but studies presenting the effects of combined supplementation of multiple nutrients were excluded. After eliminating the duplicates, a total of 8514 records were screened and assessed independently by two researchers. Further evaluation was carried out on the basis of title, abstract, and full text. Finally, 10 studies (four for IBDs and six for IBS) were selected for the current systematic review, and their quality was assessed using the Newcastle-Ottawa Scale (NOS). The studies analyzed the influence of various doses of vitamin D on bowel diseases, compared the results of vitamin D supplementation with placebo, or administered specific doses of vitamin D to obtain the required level in the blood. Supplementation was performed for at least 6 weeks. The analyzed mental health outcomes mainly included disease-specific quality of life/quality of life, anxiety, and depression. The majority of studies (including high-quality ones) confirmed the positive effect of vitamin D supplementation on the mental health of IBD and IBS patients, which was proven by all research works evaluating anxiety and depression and by the majority of research works evaluating quality of life. Although the studies followed different dosage regimens and supplementation protocols, the positive influence of vitamin D on mental health was found to be consistent. The number of studies on patients suffering from ulcerative colitis and the availability of trials randomized against the placebo group was low in the current review, which is considered to be a limitation of the present study and could also reflect the final outcome of the analysis. The conducted systematic review established the positive effect of vitamin D supplementation on the mental health of IBD and IBS patients, but this result requires further investigation, particularly in relation to other mental health outcomes.

Vitamin D supplementation in people with IBS has no effect on symptom severity and quality of life: results of a randomised controlled trial

Purpose

Several small trials suggest a benefit of vitamin D supplementation in irritable bowel syndrome (IBS). The generalisability of these reports is limited by their design and scale. This study aimed to assess whether vitamin D supplementation improved IBS symptoms in a UK community setting.

Methods

This was a randomised, double-blind, placebo-controlled study. Participants were recruited from the community in winter months between December 2017 and March 2019. 135 participants received either vitamin D (3,000 IU p.d.) or placebo for 12 weeks. The primary outcome measure was change in IBS symptom severity; secondary outcomes included change in IBS-related quality of life.

Results

The participants were analysed on an intent-to-treat basis. 60% of participants were vitamin D deficient or insufficient at baseline. Although vitamin D levels increased in the intervention arm relative to placebo (45.1 ± 32.88 nmol/L vs 3.1 ± 26.15 nmol/L; p < 0.001). There was no difference in the change of IBS symptom severity between the active and placebo trial arms (− 62.5 ± 91.57 vs – 75.2 ± 84.35, p = 0.426) over time. Similarly there was no difference between trial arms in τhe change in quality of life (− 7.7 ± 25.36 vs – 11.31 ± 25.02, p = 0.427).

Conclusions

There is no case for advocating use of vitamin D in the management of IBS symptoms. The prevalence of vitamin D insufficiency suggests routine screening and supplementation should be implemented in this population for general health reasons.

This trial was retrospectively registered with ISRCTN (ISRCTN13277340) on 24th April 2018 after recruiting had been initiated.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02633-w.

The Relationship between Low Serum Vitamin D Levels and Altered Intestinal Barrier Function in Patients with IBS Diarrhoea Undergoing a Long-Term Low-FODMAP Diet: Novel Observations from a Clinical Trial

Decreased serum vitamin D (VD) levels have been associated with gastrointestinal (GI) disorders, including irritable bowel syndrome (IBS). VD can also modulate the intestinal barrier. Given the link between the GI barrier’s alterations and diet, attention has aroused the positive effects of the Low FODMAP Diet (LFD) on IBS patients’ symptom profile. We evaluated the GI symptoms and the urinary and circulating markers of GI barrier function, the markers of inflammation and intestinal dysbiosis in 36 IBS patients with predominant diarrhea (IBS-D) (5 men and 31 women, 43.1 ± 1.7 years) categorized for their circulating VD levels in low (L-VD) and normal (N-VD) (cutoff = 20 ng/mL). Evaluations were performed before and after 12 weeks of LFD. At the baseline, L-VD patients showed a significantly worse symptom profile and altered small intestinal permeability (s-IP) than N-VD. After LFD, a significant increase in the circulating VD levels in both the subgroups and a significant improvement of s-IP in L-VD patients occurred. Finally, VD levels negatively correlated with the symptom score and fecal zonulin. These data highlight the close relationship between VD and the intestinal barrier and support their involvement in IBS-D pathophysiology. Moreover, the potentially positive role of LFD in the management of IBS-D was confirmed.

The Health Effects of Vitamin D and Probiotic Co-Supplementation: A Systematic Review of Randomized Controlled Trials

Evidence of synergic health effects of co-supplementation with vitamin D and probiotics is emerging. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses PRISMA statement, scientific databases and the grey literature were searched, and a narrative review and risk of bias assessment were conducted. Seven randomized controlled trials were included, which had low risk of bias. Six studies were double-blind, and once single-blind, extended over 6–12 weeks, and included 50–105 participants. Conditions explored included schizophrenia, gestational diabetes, type 2 diabetes and coronary heart disease, polycystic ovarian syndrome, osteopenia, irritable bowel syndrome (IBS), and infantile colic. Supplementation frequency was daily or bi-monthly, with mainly vitamin D3, and Lactobacillus, Bifidobacterium, and Streptococcus. Comparators were placebo, vitamin D, lower vitamin D dose, and probiotics and lower vitamin D dose. The co-supplementation yielded greater health benefits than its comparators did in all studies except in one assessing IBS. Beneficial effects included decreased disease severity, improved mental health, metabolic parameters, mainly insulin sensitivity, dyslipidemia, inflammation, and antioxidative capacity, and lower use of healthcare. Co-supplementation of vitamin D and probiotics generated greater health benefits than its comparators did. More studies in other diseases and various populations are needed to confirm these findings and to elucidate the optimal form, composition, and frequency of this co-supplementation.

The Association Between Serum Vitamin D3 Levels and Autism Among Jordanian Boys

This study assesses the correlation between vitamin-D deficiency and autism spectrum disorder (ASD) in Jordan. We performed a case-controlled cross-sectional analysis to assess vitamin D levels in 83 children with ASD aged less than 8 years old compared to 106 healthy controls. In addition, the association between vitamin D deficiencies and gastrointestinal (GI) complains and electroencephalogram (EEG) abnormalities commonly found in children with ASD was investigated. Vitamin D levels in ASD patients were significantly lower. Also, Vitamin D levels in ASD patients had significant correlation with GI complains, but no correlation between vitamin D levels and Ca²⁺or EEG abnormalities was detected. These data suggest a possible role for vitamin D deficiency in the pathophysiology of ASD.

Effects of vitamin D3 supplementation on clinical symptoms, quality of life, serum serotonin (5-hydroxytryptamine), 5-hydroxy-indole acetic acid, and ratio of 5-HIAA/5-HT in patients with diarrhea-predominant irritable bowel syndrome: A randomized clinical trial

Vitamin D deficiency, common in the population with irritable bowel syndrome (IBS), can induce the main factors that lead to IBS clinical symptoms, such as depression, anxiety, and inflammation. Serotonin (5-HT) plays an important role in the pathophysiology of IBS, and its production and secretion are increased from the lumen due to stress and inflammation. The aim of this study was to evaluate the effect of vitamin D3 supplementation on the pathogenesis of diarrhea-predominant IBS (IBS-D). Seventy-four IBS-D patients (age: 18-65 y) participated in a randomized, double-blind, placebo-controlled trial study from February 2017 to May 2018, at Rasoul-e-Akram Hospital, Tehran, Iran. Subjects were allocated into two groups receiving 50,000 IU/week of vitamin D3 or placebo for 9 weeks. IBS severity score system (IBS-SSS), IBS-quality of life questionnaire (QoL), hospital anxiety and depression Scale (HADs), visceral sensitivity index (VSI) and serum 25(OH) vitamin D3, serotonin, 5-hydroxy-indole acetic acid and ratio of 5-HIAA/5-HT were evaluated before and after the interventions. Symptoms severity, QoL, HADs-depression, and VSI score improved significantly in the vitamin D group as compared to the placebo group (P-values: <0.001, 0.049, 0.023, and 0.008; respectively). There were no significant differences in abdominal bloating, HADs-anxiety, serum 5-HT, 5-HIAA, and 5-HIAA/5-HT between the two groups at the end of the study. Based on our results, we recommend serum vitamin D be evaluated in the process of treatment of these patients to ameliorate symptoms and quality life of IBS-D patients with vitamin D deficiency and/or insufficiency.

Vitamin D Deficiency and Unclear Abdominal Pain in Patients from Low- and Middle-Income Countries

Background: Abdominal pain is one of the commonest symptoms in emergency departments (EDs). Diagnosis demands full attention and critical thinking, since many diseases manifest atypically and the consequences of overlooking the symptoms may be disastrous. Despite intensive diagnostic procedures, some cases remain elusive and unclear abdominal pain (UAP) is not infrequent. Emerging evidence supports the hypothesis that functional pain might be attributed to vitamin D deficiency (VDD). People with darker or covered skin are predisposed to developing VDD. Patients in Switzerland stemming from low- and middle-income countries (LMIC) are such a population. Aim: To identify cases with UAP in LMIC patients and to compare vitamin D status with a control group. Methods: A retrospective single-center case-control study was carried out from 1 January 2013 to 31 August 2016 in all adult patients (more than 16 years old) stemming from LMIC and presenting at the university ED of Bern with abdominal pain. Vitamin D status was retrieved from these cases when available. The control group consisted of patients without abdominal pain or metabolic diseases and was matched (1:1) to the cases for age, gender, body mass index, geographic distribution, and season of vitamin D estimation. Results: A total of 10,308 cases from LMIC were reported to the ED. In total, 223 cases were identified with UAP. The status of vitamin D was available for 27 patients; 27 matched individuals were subsequently retrieved for the control group. Women made up 56.7% of the UAP group and 43.3% of the control group. The most common origin of the LMIC subjects was southern Europe (20.4%), followed by southern Asia (16.7%) and Eastern Europe (13%). Fourteen UAP patients exhibited severe VDD (<25 nmol/L) versus one in the control group (p = 0.001). The difference remained significant if the patients were identified as having VDD (<50 nmol/L) or not (p = 0.024). Comparison of the means indicated that the UAP group had lower vitamin D levels than the control group (41.3 vs. 53.7 nmol/L, respectively), but this difference was marginal (p = 0.060) and not statistically significant. After adjustment for potential confounders, including gender, mean vitamin D levels remained non-significantly different between groups. In the sub-group analysis, vitamin D levels were lower in women than in men (p = 0.037), compared to the respective controls. Conclusion: This study showed for the first time that patients from LMIC who presented to ED with UAP displayed VDD. Validation from larger studies is warranted to evaluate the linkage of VDD with UAP.

Quality of Life Is Associated With Wearable-Based Physical Activity in Patients With Inflammatory Bowel Disease: A Prospective, Observational Study

OBJECTIVES

Patient-reported outcomes such as quality of life are gaining importance in the assessment of patients suffering from inflammatory bowel disease (IBD). The association of objectively measured physical activity and quality of life in patients with IBD has not been studied in depth. To investigate the association of disease-specific quality of life and physical activity as well as clinical and biochemical disease activity in patients with IBD.

METHODS

A total of 91 patients with IBD were stratified into 4 groups (Crohn's disease and ulcerative colitis, in remission and with moderate-severe activity, respectively) and evaluated in terms of disease-specific quality of life (Inflammatory Bowel Disease Questionnaire [IBDQ]), physical activity (accelerometry), body composition (bioelectrical impedance analysis), as well as clinical (Harvey-Bradshaw Index and Simple Clinical Colitis Activity Index) and biochemical (C-reactive protein and fecal calprotectin) parameters of disease activity.

RESULTS

In patients with moderate-severe disease activity, the IBDQ was significantly lower as compared to patients in remission (Mann-Whitney U test and Kruskal-Wallis test, P < 0.001). The physical activity level was higher in remission than in active disease (Mann-Whitney U test, P < 0.05). The IBDQ was significantly correlated with the duration of strenuous physical activity per day (P = 0.029178, r = 0.235), skeletal muscle mass (P = 0.033829, r = 0.229), and biomarkers of inflammation (C-reactive protein: P < 0.005, r = -0.335 and fecal calprotectin: P < 0.005, r = -0.385).

DISCUSSION

In this prospective, cross-sectional study, disease-specific quality of life was significantly associated with accelerometrically determined physical activity and disease activity in patients with IBD. This may be related to a reciprocal impact of these factors (DRKS00011370).

Chronic functional constipation is strongly linked to vitamin D deficiency

BACKGROUND

Few studies have examined intestinal motility disorders, which are disabling conditions associated with chronic functional constipation, whose pathogenesis is actually not well-defined.

AIM

To investigate the relationship between serum 25-hydroxyvitamin D levels and functional chronic constipation associated to intestinal motility disorders.

METHODS

We performed a prospective case-control study, from May-June to November 2017. Glucose/lactulose breath tests, radiopaque markers (multiple capsule techniques) and wireless motility capsule analysis were used to assess colonic and oro-cecal transit time, after excluding small-intestinal bacterial overgrowth condition. Then, we measured 25-hydroxyvitamin D levels in patients with intestinal motility disorders and we further evaluated the influence of intestinal motility disorders on psychological symptoms/quality of life using validated questionnaires, the Irritable Bowel Syndrome Quality of life (IBS-QOL), the Short Form Health Survey 12, and the Hospital Anxiety and Depression Scale 14 (HADS-14 A and HADS-14 D).

RESULTS

We enrolled 86 patients with chronic functional constipation associated to intestinal motility disorders and 86 matched healthy subjects. Patients with intestinal motility disorders had lower 25-hydroxyvitamin D levels (P < 0.001), and they showed a significant impairment of all health-related quality of life and psychological tests (IBS-QOL, Short Form Health Survey 12-Physical Component Summary, Short Form Health Survey 12-Mental Component Summary, HADS-14 A and HADS-14 D), as compared to the control group (P < 0.001), which significantly correlated with low vitamin D levels (r = - 0.57, P < 0.001; r = 0.21, P = 0.01; r = - 0.48, P < 0.001; r = - 0.57, P < 0.001; r = - 0.29, P < 0.001, respectively). At multivariate analysis vitamin D low levels remained a significant independent risk factor for the occurrence of intestinal motility disorder (odds ratio = 1.19; 95% confidence interval: 1.14-1.26, P < 0.001).

CONCLUSION

Vitamin D deficiency, anxiety and depression symptoms are commonly associated with chronic functional constipation induced by intestinal motility disorders. Vitamin D serum levels should be routinely measured in these patients.

Effectiveness of vitamin D for irritable bowel syndrome: A protocol for a systematic review of randomized controlled trial

BACKGROUND

Irritable bowel syndrome (IBS) is a prevalent and debilitating condition for patients who experience this disorder. Clinical researches indicate that vitamin D (VD) can help relief the symptoms of IBS. However, no systematic review has addressed this issue yet. Thus, this systematic review aims to investigate the effectiveness and safety of VD for patients with IBS.

METHODS

We will retrieve the following databases for randomized controlled trials to assess the effectiveness and safety of VD for patients with IBS: Cochrane Library, EMBASE, MEDICINE, Web of Science, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. Each database will be retrieved from its inception to January 31, 2019. Two researchers will independently selection studies, extract data and assess methodological quality. RevMan 5.3 software will be used to pool the data, and carry out the meta-analysis if it is possible.

RESULTS

This systematic review will evaluate the effectiveness and safety of VD for patients with IBS. The primary outcomes include stool frequency and abdominal pain. The secondary outcomes consist of stool status, quality of life, and adverse effects.

CONCLUSIONS

The findings of this systematic review may provide the existing evidence on the effectiveness and safety of VD for patients with IBS.

ETHICS AND DISSEMINATION

This systematic review will not require ethical approval, because all data will be extracted from the published literature. The findings of this study will be disseminated at peer-reviewed journals.PROSPERO registration number: PROSPERO CRD42019122641.

Association of the Vitamin D Level and Quality of School Life in Adolescents with Irritable Bowel Syndrome

There is no treatment of choice for irritable bowel syndrome, which affects up to 20% of school-aged children. This cross-sectional study evaluated the difference in the average vitamin D level between subtypes of irritable bowel syndrome, and the relationship between the vitamin D level as well as the severity of irritable bowel syndrome symptoms. We included 124 adolescents aged 10–17 years (68 boys, 56 girls; mean age 12.29 ± 1.92 years) from 2014 to 2016. Patients with irritable bowel syndrome were diagnosed by Rome III criteria and classified by clinical manifestation: irritable bowel syndrome with constipation (n = 29), irritable bowel syndrome with diarrhea (n = 63), and irritable bowel syndrome with constipation and diarrhea (n = 32). The severity of irritable bowel syndrome symptoms and school absence were evaluated. Vitamin D levels were measured by serum 25-hydroxyvitamin D. The chi-square test and analysis of variance were used. The patients’ average vitamin D level was 16.25 ± 6.58 ng/mL. There was a significant negative association of the 25-hydroxyvitamin D level with symptom severity and school absence (p = 0.022 and p < 0.001, respectively). Vitamin D supplementation could be considered as a choice of therapeutic method.

Vitamin D supplementation in adolescents with irritable bowel syndrome: Is it useful? A randomized controlled trial

BACKGROUND/AIM

Vitamin D deficiency is common in irritable bowel syndrome (IBS). There is growing interest in the role of vitamin D in pediatric IBS. We aimed to evaluate the effect of vitamin D supplementation in adolescents with IBS and vitamin D deficiency.

PATIENTS AND METHODS

One hundred and twelve adolescents with IBS and vitamin D deficiency were randomly divided into two groups of matched age and sex. The first group received oral vitamin D₃ 2000IU/day for 6 months and the second group received placebo for 6 months. Vitamin D status as well as different IBS score systems (IBS-SSS, IBS-QoL, and total score) were evaluated before and 6 months after treatment.

RESULTS

IBS patients who received vitamin D supplementation for 6 months showed significant improvement in IBS-SSS (P < 0.001), IBS-QoL (P < 0.001), and total score (P = 0.02) compared to IBS placebo group. IBS patients treated with vitamin D showed two folds increase in their serum vitamin D levels (from 17.2 ± 1.3 to 39 ± 3.3) ng/ml with P < 0.001. While in the placebo group, their serum vitamin D levels were not significantly changed (P = 0.66). Vitamin D was tolerated well without any recorded adverse effects during the study period.

CONCLUSION

Vitamin D supplementation can be effective in treating adolescents with IBS and vitamin D deficiency.

Gene Expression Profiling and Assessment of Vitamin D and Serotonin Pathway Variations in Patients With Irritable Bowel Syndrome

BACKGROUND/AIMS

Irritable bowel syndrome (IBS) is a multifaceted disorder that afflicts millions of individuals worldwide. IBS is currently diagnosed based on the presence/duration of symptoms and systematic exclusion of other conditions. A more direct manner to identify IBS is needed to reduce healthcare costs and the time required for accurate diagnosis. The overarching objective of this work is to identify gene expression-based biological signatures and biomarkers of IBS.

METHODS

Gene transcripts from 24 tissue biopsy samples were hybridized to microarrays for gene expression profiling. A combination of multiple statistical analyses was utilized to narrow the raw microarray data to the top 200 differentially expressed genes between IBS versus control subjects. In addition, quantitative polymerase chain reaction was employed for validation of the DNA microarray data. Gene ontology/pathway enrichment analysis was performed to investigate gene expression patterns in biochemical pathways. Finally, since vitamin D has been shown to modulate serotonin production in some models, the relationship between serum vitamin D and IBS was investigated via 25-hydroxyvitamin D (25[OH]D) chemiluminescence immunoassay.

RESULTS

A total of 858 genetic features were identified with differential expression levels between IBS and asymptomatic populations. Gene ontology enrichment analysis revealed the serotonergic pathway as most prevalent among the differentially expressed genes. Further analysis via real-time polymerase chain reaction suggested that IBS patient-derived RNA exhibited lower levels of tryptophan hydroxylase-1 expression, the enzyme that catalyzes the rate-limiting step in serotonin biosynthesis. Finally, mean values for 25(OH)D were lower in IBS patients relative to non-IBS controls.

CONCLUSIONS

Values for serum 25(OH)D concentrations exhibited a trend towards lower vitamin D levels within the IBS cohort. In addition, the expression of select IBS genetic biomarkers, including tryptophan hydroxylase 1, was modulated by vitamin D. Strikingly, the direction of gene regulation elicited by vitamin D in colonic cells is "opposite" to the gene expression profile observed in IBS patients, suggesting that vitamin D may help "reverse" the pathological direction of biomarker gene expression in IBS. Thus, our results intimate that IBS pathogenesis and pathophysiology may involve dysregulated serotonin production and/or vitamin D insufficiency.

Vitamin D status in irritable bowel syndrome and the impact of supplementation on symptoms: what do we know and what do we need to know?

BACKGROUND

Low vitamin D status is associated with risk of colorectal cancer and has been implicated in inflammatory bowel disease. Irritable bowel syndrome (IBS) is a chronic, relapsing, functional bowel disorder. A nascent literature suggests a role for vitamin D in IBS, but this has not been collated or critiqued. To date, seven studies have been published: four observational studies and three randomised controlled trials (RCTs). All observational studies reported that a substantial proportion of the IBS population was vitamin D deficient. Two intervention studies reported improvement in IBS symptom severity scores and quality of life (QoL) with vitamin D supplementation. There are limited data around the role of vitamin D in IBS.

CONCLUSIONS

The available evidence suggests that low vitamin D status is common among the IBS population and merits assessment and rectification for general health reasons alone. An inverse correlation between serum vitamin D and IBS symptom severity is suggested and vitamin D interventions may benefit symptoms. However, the available RCTs do not provide strong, generalisable evidence; larger and adequately powered interventions are needed to establish a case for therapeutic application of vitamin D in IBS.

Serum Transaminase Concentrations and the Presence of Irritable Bowel Syndrome Are Associated with Serum 25-Hydroxy Vitamin D Concentrations in Adolescent Girls Who Are Overweight and Obese

Background/Aims: Vitamin D deficiency has become endemic globally and its etiology is complex. Few studies have investigated the determinants of serum 25-hydroxy vitamin D (25-OH D). The aim of this study was to investigate the association between lifestyle patterns, liver functional tests (LFTs), and the presence of irritable bowel syndrome (IBS) with serum 25-OH D in apparently healthy girls. Methods: This cross-sectional study was undertaken in 965 adolescent girls aged 12–18 years. IBS was diagnosed using the Rome III questionnaire. An electrochemiluminescence method was used to measure serum 25-OH D. LFTs were measured using commercial kits and an auto analyzer. Linear regression and univariate analyses were performed to determine the association between continuous and categorical variables with serum 25-OH D respectively. Results: Serum 25-OH D was significantly higher in normal weight subjects compared to either overweight or obese subjects (9.5 ± 7.02 vs. 7.9 ± 5.7 ng/mL, p = 0.03). Physical activity level was positively associated with serum 25-OH D in overweight and obese subjects (β = 0.15, p < 0.05). An inverse relationship was found between the presence of IBS and 25-OH D in both normal (β = –1.95, p < 0.05), overweight and obese subjects (β = –1.83, p < 0.05). Serum alanine transaminase (ALT; β = –0.19, p < 0.05) and aspartate transaminase (β = –0.17, p < 0.05) were inversely associated with serum 25-OH in overweight and obese subjects. Conclusions: Individuals with IBS had significantly lower serum 25-OH D concentrations. In addition, there was an inverse association between serum ALT and 25-OH D. Prospective studies, and perhaps interventional trials, will be required to clarify these associations.

Diagnosis and treatment of irritable bowel syndrome with predominant constipation in the primary-care setting: focus on linaclotide

Irritable bowel syndrome (IBS) is a complex functional gastrointestinal disorder that is exceedingly common in clinical practice. IBS with predominant constipation (IBS-C) is a subtype of IBS that accounts for more than a third of the IBS diagnosed. Diagnosis of IBS requires a careful personalized approach, a comprehensive clinical history, limited but relevant investigations, and continued follow-up. Major IBS societies and guidelines recommend offering a positive diagnosis of IBS based on presenting symptomatology. Abdominal pain that may or may not be relieved by defecation is the cardinal symptom of IBS; distension and bloating are other common symptoms. Careful attention should be paid to alarm symptoms before a diagnosis of IBS is made. Pharmacotherapy with linaclotide is recommended for moderate-severe IBS-C, based on high-quality evidence from randomized controlled trials. Diarrhea is the major side effect of linaclotide, and limited cost-effectiveness data currently exist.

Vitamin D/VDR, Probiotics, and Gastrointestinal Diseases

Vitamin D is an important factor in regulating inflammation, immune responses, and carcinoma inhibition via action of its receptor, vitamin D receptor (VDR). Recent studies have demonstrated the role of vitamin D/VDR in regulating host-bacterial interactions. Probiotics are beneficial bacteria with the power of supporting or favoring life on the host. In the current review, we will discuss the recent progress on the roles of vitamin D/VDR in gut microbiome and inflammation. We will summarize evidence of probiotics in modulating vitamin D/VDR and balancing gut microbiota in health and gastrointestinal diseases. Moreover, we will review the clinical application of probiotics in prevention and therapy of IBD or colon cancer. Despite of the gains, there remain several barriers to advocate broad use of probiotics in clinical therapy. We will also discuss the limits and future direction in scientific understanding of probiotics, vitamin D/VDR, and host responses.

Vitamin D status in pediatric irritable bowel syndrome

Importance

Irritable bowel syndrome (IBS) is associated with significant morbidity in children and adolescents, and the therapeutic efficacy of available treatment options is limited. The role of vitamin D supplementation in pediatric IBS is unclear as the vitamin D status of pediatric patients with IBS is unknown. Equally, the relationship of vitamin D status with psychosomatic symptoms in children and adolescents is unclear.

Aim

To characterize the vitamin D status of pediatric patients with IBS using a case-control study design.

Hypothesis

Serum 25-hydroxyvitamin D [25(OH)D] concentration will be similar between patients with IBS and controls.

Subjects and methods

A retrospective case-controlled study of 116 controls (age 14.6 ± 4.3 y), female (n = 67; 58%) and 55 subjects with IBS (age 16.5 ± 3.1y), female (n = 44; 80%). Overweight was defined as BMI of ≥85^th but <95^th percentile, and obesity as BMI ≥95^th percentile. Vitamin D deficiency was defined as 25(OH)D of <50 nmol/L, while seasons of vitamin D draw were categorized as summer, winter, spring, and fall. Major psychosomatic manifestations included in the analysis were depression, anxiety, and migraine.

Results

More than 50% of IBS subjects had vitamin D deficiency at a cut-off point of <50 nmol/L (53% vs. 27%, p = 0.001); and >90% of IBS subjects had vitamin D deficiency at a cut-off point of <75 nmol/L (93% vs. 75%, p = 0.006). IBS subjects had significantly lower mean 25(OH)D: 53.2 ± 15.8 nmol/L vs. 65.2 ± 28.0 nmol/L, p = 0.003; and albumin: 6.2 ± 0.6 vs. 6.5 ± 0.6 μmol/L, p = 0.0.01. IBS subjects with migraine had significantly lower mean 25(OH)D concentration compared to controls (p = 0.01). BMI z-score was similar between the controls and IBS subjects (0.5 ± 1.4 vs. 1.2 ± 2.9, p = 0.11).

Conclusions

Pediatric patients with IBS had significantly lower 25(OH)D concentration compared to controls despite having similar mean BMI values as controls. Only 7% of the children and adolescents with IBS were vitamin D sufficient, and >50% of the subjects with IBS had vitamin D deficiency. This is a much higher prevalence of vitamin D deficiency compared to IBD and other malabsorption syndromes. Monitoring for vitamin D deficiency should be part of the routine care for patients with IBS. Randomized control trials are warranted to determine the role of adjunctive vitamin D therapy in pediatric IBS.