Prevalence of irritable bowel syndrome in a Brazilian Amazon community

IRRITABLE BOWEL SYNDROME, FOOD INTOLERANCE AND NON- CELIAC GLUTEN SENSITIVITY. A NEW CLINICAL CHALLENGE

Approximately 80% of irritable bowel syndrome (IBS) patients report that their symptoms are triggered after ingesting one or specific food groups. Gluten, wheat and related proteins (e.g., amylase-trypsin inhibitors, and fermentable oligo-di-mono-saccharides and polyols (FODMAPs) are the most relevant IBS symptom triggers, although the true 'culprit(s)' is/are still not well established. The concept of causal relationship between gluten intake and the occurrence of symptoms in the absence of celiac disease and wheat allergy was termed non-celiac gluten sensitivity (NCGS). The borderline between celiac disease, wheat allergy, IBS and NCGS is not always clearly distinguishable, and the frequency and clinical identity of NGCS are still unclear. An overlap between IBS and NCGS has been detected. The incomplete knowledge of the etiopathogenesis of these clinical conditions, lack of data on their real epidemiology, as well as the absence of a gold standard for their diagnosis, make the overall picture difficult to understand "It is crucial to well define the interaction between IBS, food intolerance and NGCS, since the role of diet in IBS and its dietary management is an essential tool in the treatment of a large number of these patients". The objective of the present review is to provide an overview highlighting the interaction between IBS, food intolerance and NCGS in order to unravel whether gluten/wheat/FODMAP sensitivity represents 'facts' and not 'fiction' in IBS symptoms.

The global prevalence of IBS in adults remains elusive due to the heterogeneity of studies: a Rome Foundation working team literature review

OBJECTIVES

The global prevalence of IBS is difficult to ascertain, particularly in light of the heterogeneity of published epidemiological studies. The aim was to conduct a literature review, by experts from around the world, of community-based studies on IBS prevalence.

DESIGN

Searches were conducted using predetermined search terms and eligibility criteria, including papers in all languages. Pooled prevalence rates were calculated by combining separate population survey prevalence estimates to generate an overall combined meta-prevalence estimate. The heterogeneity of studies was assessed.

RESULTS

1451 papers were returned and 83, including 288 103 participants in 41 countries, met inclusion criteria. The mean prevalence among individual countries ranged from 1.1% in France and Iran to 35.5% in Mexico. There was significant variance in pooled regional prevalence rates ranging from 17.5% (95% CI 16.9% to 18.2%) in Latin America, 9.6% (9.5% to 9.8%) in Asia, 7.1% (8.0% to 8.3%) in North America/Europe/Australia/New Zealand, to 5.8% (5.6% to 6.0%) in the Middle East and Africa. There was a significant degree of heterogeneity with the percentage of residual variation due to heterogeneity at 99.9%.

CONCLUSIONS

The main finding is the extent of methodological variance in the studies reviewed and the degree of heterogeneity among them. Based on this, we concluded that publication of a single pooled global prevalence rate, which is easily calculated, would not be appropriate or contributory. Furthermore, we believe that future studies should focus on regional and cross-cultural differences that are more likely to shed light on pathophysiology.

Visceral hypersensitive rats share common dysbiosis features with irritable bowel syndrome patients

AIM

To evaluate gut microbial dysbiosis in two visceral hypersensitive models in comparison with irritable bowel syndrome (IBS) patients and to explore the extent to which these models capture the dysbiosis of IBS patients.

METHODS

Visceral hypersensitivity was developed using the maternal separation (MS) rat model and post-inflammatory rat model. The visceral sensitivity of the model groups and control group was evaluated using the abdominal withdraw reflex score and electromyography in response to graded colorectal distention. The 16S ribosomal RNA gene from fecal samples was pyrosequenced and analyzed. The correlation between dysbiosis in the microbiota and visceral hypersensitivity was calculated. Positive findings were compared to sequencing data from a published human IBS cohort.

RESULTS

Dysbiosis triggered by neonatal maternal separation was lasting but not static. Both MS and post-inflammatory rat fecal microbiota deviated from that of the control rats to an extent that was larger than the co-housing effect. Two short chain fatty acid producing genera, Fusobacterium and Clostridium XI, were shared by the human IBS cohort and by the maternal separation rats and post-inflammatory rats, respectively, to different extents. Fusobacterium was significantly increased in the MS group, and its abundance positively correlated with the degree of visceral hypersensitivity. Porphyromonadaceae was a protective biomarker for both the rat control group and healthy human controls.

CONCLUSION

The dysbiosis MS rat model and the post-inflammatory rat model captured some of the dysbiosis features of IBS patients. Fusobacterium, Clostridium XI and Porphyromonadaceae were identified as targets for future mechanistic research.

Increase in Mexican and Latin American scientific articles on irritable bowel syndrome

BACKGROUND

There is an implied perception that little scientific information on irritable bowel syndrome (IBS) comes out of Mexico and Latin America in the international medical literature, but the number and tendencies of articles from the region on IBS are not known.

AIMS

To determine the number and type of Mexican and Latin American articles on IBS published between 1990-2015.

METHODS

A systematic search of Medline was carried out employing the terms « Irritable Bowel Syndrome » or its abbreviation (IBS). Mexico and every other Latin American country were added to specify the search. The articles were selected if they were published in Mexico and/or the rest of Latin America, if they were international papers on IBS in the region, or if they were written by Mexican and/or Latin American authors. In addition, the articles were classified into the following categories: Reviews/Editorials/Letters to the Editor (REV/ED), Epidemiology/Quality of Life/Psychosocial Factors (EPI/QOL), Diagnostic (DX), Treatment (TX), and Translational/Pathophysiologic (TRANS) studies.

RESULTS

A total of 66 articles from Mexico and 47 from Latin America were identified, but only 87.7 and 48.9%, respectively, fit the selection criteria. Category distribution was: EPI/QOL: 36.2%, REV/ED: 27.5%, TRANS: 18.8, TX: 10%, and DX: 7.5% and was similar between Mexico and Latin America (p=0.33). The year 2005 saw an increase in the number of articles in Mexico, with a peak in 2010. The figures for Latin American articles remained stable over the years, with a peak in 2012.

CONCLUSIONS

A noticeable increase has been observed over the last decade in the research conducted on IBS in Mexico and Latin America. Even though the EPI/QOL studies predominate, the sophistication of research is reflected in the TRANS studies that are in third place of frequency. The information referred to herein demonstrates maturity in the field, making it possible to carry out consensuses based on local data.

The epidemiology of irritable bowel syndrome

Irritable bowel syndrome (IBS) is a functional condition of the bowel that is diagnosed using clinical criteria. This paper discusses the nature of the diagnostic process for IBS and how this impacts epidemiological measurements. Depending on the diagnostic criteria employed, IBS affects around 11% of the population globally. Around 30% of people who experience the symptoms of IBS will consult physicians for their IBS symptoms. These people do not have significantly different abdominal symptoms to those who do not consult, but they do have greater levels of anxiety and lower quality of life. Internationally, there is a female predominance in the prevalence of IBS. There is 25% less IBS diagnosed in those over 50 years and there is no association with socioeconomic status. IBS aggregates within families and the genetic and sociological factors potentially underlying this are reviewed. Patients diagnosed with IBS are highly likely to have other functional disease and have more surgery than the general population. There is no evidence that IBS is associated with an increased mortality risk. The epidemiological evidence surrounding these aspects of the natural history is discussed.

The prevalence and clinical characteristics of primary headache in irritable bowel syndrome: a subgroup of the functional somatic syndromes

CONTEXT

The irritable bowel syndrome and primary headache are two chronic diseases characterized by symptoms of recurring pain and affect approximately 10%-20% of the general population.

OBJECTIVES

To study the prevalence of primary headache in volunteers with irritable bowel syndrome in a Brazilian urban community.

METHODS

It was evaluated the prevalence of primary headache associated with irritable bowel syndrome in adult volunteers 330 no patients.The protocol included the Rome III criteria, international classification of Headaches, later divided into four groups: I- Irritable bowel syndrome (n = 52), II- Primary headache (n = 45), III-Irritable bowel syndrome (n = 26) and headache, and IV- Controls (207).

RESULTS

We not found significant difference in the average age of the four groups and the diagnosis of irritable bowel syndrome, primary headache and their association was more frequent in females. The frequent use of analgesics was greater in groups II and III.

CONCLUSION

Our results suggest that irritable bowel syndrome and primary headache are also common in third world countries. The frequency in use of analgesics in association between the two entities was relevant. The identification of irritable bowel syndrome patients with different clinical sub-types could improve the therapeutics options and the prevention strategies.

Global prevalence of and risk factors for irritable bowel syndrome: a meta-analysis

BACKGROUND & AIMS

Many cross-sectional surveys have reported the prevalence of irritable bowel syndrome (IBS), but there have been no recent systematic review of data from all studies to determine its global prevalence and risk factors.

METHODS

MEDLINE, EMBASE, and EMBASE Classic were searched (until October 2011) to identify population-based studies that reported the prevalence of IBS in adults (≥15 years old); IBS was defined by using specific symptom-based criteria or questionnaires. The prevalence of IBS was extracted for all studies and based on the criteria used to define it. Pooled prevalence, according to study location and certain other characteristics, odds ratios (ORs), and 95% confidence intervals (CIs) were calculated.

RESULTS

Of the 390 citations evaluated, 81 reported the prevalence of IBS in 80 separate study populations containing 260,960 subjects. Pooled prevalence in all studies was 11.2% (95% CI, 9.8%-12.8%). The prevalence varied according to country (from 1.1% to 45.0%) and criteria used to define IBS. The greatest prevalence values were calculated when ≥3 Manning criteria were used (14%; 95% CI, 10.0%-17.0%); by using the Rome I and Rome II criteria, prevalence values were 8.8% (95% CI, 6.8%-11.2%) and 9.4% (95% CI, 7.8%-11.1%), respectively. The prevalence was higher for women than men (OR, 1.67; 95% CI, 1.53-1.82) and lower for individuals older than 50 years, compared with those younger than 50 (OR, 0.75; 95% CI, 0.62-0.92). There was no effect of socioeconomic status, but only 4 studies reported these data.

CONCLUSIONS

The prevalence of IBS varies among countries, as well as criteria used to define its presence. Women are at slightly higher risk for IBS than men. The effects of socioeconomic status have not been well described.

Effect of gender on prevalence of irritable bowel syndrome in the community: systematic review and meta-analysis

OBJECTIVES

Irritable bowel syndrome (IBS) is thought to be commoner in women. However, no systematic review has confirmed whether this is the case, or assessed whether any proposed female preponderance remains stable according to geography and criteria used to define IBS. Nor has effect of gender on subtype of IBS been examined systematically.

METHODS

MEDLINE, EMBASE, and EMBASE Classic were searched (up to October 2011) to identify population-based studies reporting prevalence of IBS in adults (≥15 years) according to gender, and defined using symptom-based criteria, or questionnaire. The prevalence of IBS in women and men was extracted for all studies, and according to study location and diagnostic criteria used, and compared using odds ratios (ORs) with 95% confidence intervals (CIs). Prevalence of each subtype of IBS, according to predominant stool pattern, was compared in women and men with IBS.

RESULTS

Of the 390 papers evaluated, 56 studies containing 188,229 subjects were eligible. The OR for IBS in women, compared with men, in all studies was 1.67 (95% CI: 1.53-1.82). Prevalence of IBS was not significantly higher in women, compared with men, in South Asian, South American, or African studies. The OR was highest with the Rome I criteria (1.99; 95% CI: 1.76-2.25), and lowest with the Rome II criteria (1.40; 95% CI: 1.24-1.59). Women with IBS were more likely to exhibit the constipation-predominant subtype (OR: 2.38; 95% CI: 1.45-3.92), and less likely to meet criteria for the diarrhea-predominant subtype (OR: 0.45; 95% CI: 0.32-0.65) than men with IBS.

CONCLUSIONS

Prevalence of IBS appeared modestly higher in women, and this remained relatively stable according to geography and criteria used to define its presence. However, among individuals with IBS, subtypes varied according to gender.

Discrepancies between the responses to skin prick test to food and respiratory antigens in two subtypes of patients with irritable bowel syndrome

AIM

To compare the response to skin prick tests (SPTs) to food antigens (FAs) and inhalant allergens (IAs) in patients with two subtypes of irritable bowel syndrome (IBS) and healthy controls.

METHODS

We compared the results of SPTs for IAs and FAs in 87 volunteers divided into three groups: diarrhea predominant IBS (D-IBS) Group I (n = 19), constipation predominant IBS (C-IBS) Group II (n = 17), and normal controls Group III (n = 51).

RESULTS

Of the 285 tests (171 for FAs and 114 for IAs) performed in Group I we obtained 45 (26.3%) positive responses for FA and 23 (20.1%) for IA. Of the 153 tests for FA in Group II, we obtained 66 (20.1%) positive responses, and of the 102 tests for IA, we obtained 20 (19.6%) positive responses. Of the 459 tests for FA performed in Group III, we obtained 39 (84%) positive responses, and of the 306 for IA, we obtained 52 (16.9%) positive responses. The numbers of positive responses were not significantly different between the three groups, but in the D-IBS group, the number of SPT FA responses differed significantly from those for the other two groups (P > 0.01).

CONCLUSION

Despite the small number of cases studied, the higher reactivity to FAs in Group I compared to Groups II and III adds new information, and suggests the presence of a possible alteration in intestinal epithelial function.