Environmental factors associated with Crohn's disease in India

Associations of Fish and Fish Oil Consumption With Incident Inflammatory Bowel Disease: A Population-Based Prospective Cohort Study

BACKGROUND

We examined the associations of fish and fish oil consumption with inflammatory bowel disease (IBD) incidence.

PATIENTS AND METHODS

We conducted a longitudinal analysis based on the UK Biobank, a population-based prospective cohort. Dietary consumption of fish and fish oil was collected by questionnaire. IBD incident cases were identified through links to National Health Services datasets. Cox proportional hazards regression models were used to assess the associations between oily fish, nonoily fish, and fish oil intake and IBD incidence with adjustment for various confounding factors.

RESULTS

A total of 265 839 participants free of IBD at baseline were included, and 1554 incident IBD cases were identified during an average follow-up of 11.8 years. In fully adjusted models, we found that compared with participants who never ate oily fish, those having <1 serving/wk, 1 serving/wk, and >1 serving/wk had 9% (hazard ratio [HR], 0.91; 95% confidence interval [CI], 0.77-1.08), 19% (HR, 0.81; 95% CI, 0.69-0.96), and 12% (HR, 0.88; 95% CI, 0.73-1.06) lower risks of IBD, respectively, albeit not all statistically significant. A significant association was found between fish oil intake and a reduced risk of IBD (HR, 0.84; 95% CI, 0.75-0.93). We found no significant associations for nonoily fish. In a subsample (n = 105 714) of participants with multiple subsequent dietary reviews, we also found a negative association between the frequency of fish oil intake over time and incident IBD (P trend < .05).

CONCLUSIONS

Our findings indicate that oily fish and fish oil supplements might be protective factors against IBD.

Physical Activity is Associated with a Decreased Risk of Developing Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

Modifiable risk factors in inflammatory bowel disease [IBD], such as physical activity, may be used as prevention strategies. However, the findings of previous studies on the association between physical activity and IBD risk have been inconsistent. We aimed to perform a systematic review and meta-analysis to estimate the effect of physical activity on IBD risk.

METHODS

A search was conducted for relevant studies published before April 2023 that assessed the effect of pre-IBD diagnosis levels of physical activity on IBD incidence. Individual summary statistics [relative risks; RR], and confidence intervals [CI] were extracted with forest plots generated. We used the Grading of Recommendations Assessment, Development and Evaluation [GRADE] approach to assess the quality of evidence.

RESULTS

Ten observational studies were included. For cohort studies, there were 1182 Crohn's disease [CD] and 2361 ulcerative colitis [UC] patients, with 860 992 participants without IBD. For case-control studies, there were 781 CD to 2636 controls, and 1127 UC to 3752 controls. Compared with individuals with low physical activity levels, the RRs of CD in individuals with high physical activity levels for cohort and case-control studies were 0.78 [95% CI 0.68-0.88, p = 0.0001] and 0.87 [95% CI 0.79-0.95, p = 0.003], respectively. For UC, the RRs were 0.62 [95% CI 0.43-0.88, p = 0.008] and 0.74 [95% CI 0.51-1.07, p = 0.11].

CONCLUSION

This meta-analysis suggests that physical activity is inversely associated with the risk of developing IBD, more so in CD than in UC.

Systematic review with meta-analysis: environmental and dietary differences of inflammatory bowel disease in Eastern and Western populations

BACKGROUND

While the incidence of inflammatory bowel disease (IBD) has stabilised in the West, it is still increasing in several newly industrialised countries.

AIMS

To investigate whether the environmental and dietary risk factors for IBD differ between Eastern and Western populations METHODS: We systematically searched PubMed, Embase, and Web of Science for studies published from inception through June 30, 2020. Data were pooled using a random effects model.

RESULTS

Overall, 255 studies were assessed. We identified 25 risk factors for IBD, seven of which were noted in both Eastern and Western populations: family history of Crohn's disease [CD] or ulcerative colitis [UC], former smoking (CD/UC), smoking (CD), appendicectomy (CD), tonsillectomy (CD), meat and meat products (CD), and vitamin D deficiency (UC). The remaining factors, including urban living, current smoking, antibiotics, oral contraceptives, caesarean section, isotretinoin, total energy, fat, cholesterol, fatty acids and their sub-classifications, eggs, and soft drinks, were associated with an increased risk of IBD in Western or Eastern populations only. We identified 21 protective factors for IBD, among which eight were common in the East and West: farm animals (CD/UC), Helicobacter pylori infection (CD/UC), multiple births (CD), physical activity (CD), history of breastfeeding (CD), pets (UC), current smoking (UC), and coffee intake (UC). Ten factors conferred protection against IBD in Western populations only, whereas eight factors conferred protection against IBD in Eastern populations only.

CONCLUSIONS

Numerous environmental and dietary factors influenced the development of IBD in both Western and Eastern populations, whereas certain factors influenced IBD risk differently in these populations.

Habitual Fish Oil Supplementation and Risk of Incident Inflammatory Bowel Diseases: A Prospective Population-Based Study

Background

Inflammatory Bowel Diseases (IBDs) have been emerging in recent years with the advance of global industrialization and diet pattern transformation. Marine n-3 polyunsaturated fatty acids (n-3 PUFAs), enriched in fish oils, have well-known human health promotion. Evidence on the association of fish oil supplementation with the risk of developing IBDs was scarce. This study aimed to examine the association between the use of fish oil supplements and the risk of developing inflammatory bowel diseases (IBDs) among the general population.

Methods

We conducted a prospective cohort study of 447,890 participants aged 40-69 years from the UK Biobank. A touch screen questionnaire was used to get the data about fish oil intake at baseline. Incident diagnoses of IBDs were ascertained by the International Classification of Diseases (ICD-9 and ICD-10) or self-report. Cox proportional hazards model was applied to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of developing IBDs and their subtypes.

Results

We documented 1,646 incident cases of IBDs, including 533 incident cases of Crohn's disease (CD) and 1,185 incident cases of ulcerative colitis (UC) during an average of 8 years of follow-up. After multivariate adjustment, the use of fish oil was associated with a 12% lower risk of IBDs (HR: 0.88, 95% CI: 0.78-0.99, p = 0.03) compared with non-consumers. For subtypes of IBDs, fish oil supplementation was inversely associated with a 15% lower risk of UC (HR: 0.85, 95% CI: 0.75-0.99, p = 0.02) but was not correlated with the risk of CD (p = 0.22). Besides, fish oil supplementation showed a significant inverse correlation with baseline CRP levels (β = -0.021, p < 0.001) and a positive association with baseline albumin levels (β = 0.135, p < 0.001) after adjustment for multiple variates.

Conclusion

Habitual intake of fish oil supplements was associated with a lower risk of IBDs and UC. Fish oil users tended to have lower baseline C-reactive protein levels and higher baseline albumin levels compared with non-users. It was concluded that fish oil supplement use may be recommended for the prevention and control of IBDs.

Inflammatory bowel disease: An Indian perspective

Inflammatory bowel disease (IBD) in recent times is causing a significant healthcare burden as both ulcerative colitis and Crohn's disease (CD) require lifelong therapy and constant monitoring. The current review highlights the concerns in a country like India with special reference to the changing trends of IBD, risk attribution and the financial issues. Indian immigrants behave like residential Indians, whereas their children show IBD prevalence similar to the West, highlighting the role of environmental triggers. However, the environmental and genetic factors in Indians with IBD are not well understood. Men appear to be more frequently affected than women in India. The disease severity is milder in the patients, both males and females, but the risk for colorectal cancer (CRC) is similar to the West. The incidence of paediatric IBD is on the rise. The major burden of IBD in the Indian subcontinent at present is in children, adolescents and teens. Cost towards the management of complications, non-adherence to treatment, differentiating tuberculosis from CD and finally screening for CRC in patients with IBD are the points to ponder in the Indian scenario.

Fish Oil for Inflammatory Bowel Disease: Panacea or Placebo?

Dietary supplements have increasingly gained popularity over the years not only to replete micronutrient deficiencies but for their use in treatment of disease. The popularity of dietary supplements for inflammatory bowel diseases (IBD) arises from their perceived ease of use, potential disease-modifying benefits, and perceived safety. Overall, randomized controlled trials have not consistently shown a benefit of fish oil for the maintenance of remission with Crohn's disease. The inconsistency of these findings highlights the need for more studies that are powered to clarify the context in which omega-3 fatty acids might have a role in the treatment algorithm of IBD.

Crohn's disease in low and lower-middle income countries: A scoping review

BACKGROUND

While Crohn's disease has been studied extensively in high-income countries, its epidemiology and care in low and lower-middle income countries (LLMICs) is not well established due to a lack of disease registries and diagnostic capacity.

AIM

To describe the published burden, diagnostic/treatment capacity, service utilization, challenges/barriers to individuals with Crohn's in LLMICs and their providers.

METHODS

We conducted a scoping review utilizing a full search strategy was developed and conducted in PubMed, Embase and World Health Organization Global Index Medicus. Two independent reviewers screened the titles and abstracts of all of the publications found in this search, reviewed selected publications, and extracted relevant data, which underwent descriptive review and was analyzed in Excel.

RESULTS

The database search yielded 4486 publications, 216 of which were determined to be relevant to the research questions. Of all 79 LLMICs, only 21 (26.6%) have publications describing individuals with Crohn's. Overall, the highest number of studies came from India, followed by Tunisia, and Egypt. The mean number of Crohn's patients reported per study is 57.84 and the median is 22, with a wide range from one to 980.

CONCLUSION

This scoping review has shown that, although there is a severe lack of population-based data about Crohn's in LLMICs, there is a signal of Crohn's in these settings around the world.

Prevalence of past hepatitis A infection among Crohn's patients and controls - An examination of the 'hygiene hypothesis', and the need for hepatitis A vaccination

Our study aimed to determine the prevalence of prior exposure to hepatitis A virus in Crohn's disease patients, whose IgG antibody levels against hepatitis A virus were compared with age and sex-matched controls. All of the 41 cases with Crohn's disease and 43 controls included in the study tested positive for IgG anti-hepatitis A virus antibody, with titres (38.8 IU/ml, 22-63.9; median, IQR) similar to those in controls (40.7 IU/ml, 17.3-66.7; p = 0.75). Environmental sanitation remains poor in India, despite reasonable economic gains as reflected by universal exposure to hepatitis A virus infection. Vaccination against hepatitis A may not be important in patients attending inflammatory bowel disease clinic, owing to natural immunity provided by prior infection. The observed rise in inflammatory bowel disease incidence seems to be increasing despite persistently poor environmental hygiene.

IBD in India: Similar Phenotype but Different Demographics Than the West

BACKGROUND

Inflammatory bowel disease (IBD) is emerging in the developing world but phenotypic data are limited. We aimed to describe the phenotype, clinical presentation, disease behavior, and treatments of IBD in a large cohort in India.

METHODS

All persons presenting to the Asian Institute of Gastroenterology in Hyderabad, India since 2004 with a confirmed diagnosis of IBD were enrolled. The demographic profile at the first visit, family history of IBD, smoking history, time from first symptom onset to diagnosis, use of anti-tuberculousis treatment before IBD-specific treatment, disease phenotype, and medication history were collected by interview and chart review. Disease and family history and treatments used were updated at each follow-up visit.

RESULTS

Of 4006 persons enrolled, 59.9% had ulcerative colitis (UC) and the majority were male (60.3%). The median diagnostic delay in both UC and Crohn's disease (CD) was at least 2 years. At the time of diagnosis only 4.5% of CD were smokers and only 3.8% of UC were ex-smokers. Positive family history was uncommon (2.1%). The phenotype of persons with CD included 22.9% with stricturing disease and 9.4% with fistulizing disease. The most common site of disease was ileocolonic (40.9%) and only 2.5% had perineal fistulas. Among those with UC 18.7% had proctitis and 30.3% had pancolitis.

CONCLUSIONS

This is the largest cohort of persons with IBD reported from Asia. Although there are several demographic differences between persons with IBD from India compared with the West, the phenotypes of the disease are not highly different.

Inflammatory bowel disease in India: challenges and opportunities

Evidence is emerging that inflammatory bowel diseases (IBDs) are becoming increasingly prevalent in developing countries, altering the previously held view that these were diseases of the West. Within this is a substantial increase in the burden of this disease in India, a matter of great importance to the country itself as well as in furthering our understanding of the disease. There is comparatively less data on this, both from the epidemiological standpoint as well as on disease pathogenesis in this particular cohort and is very much a subject matter of evolving understanding and research. This article aims to look at the changing global distribution of the disease and its implications. The Indian disease phenotype, and the aetiology of disease development will also be addressed with particular focus on differing pathogenetic processes in the Indian subpopulation, with consideration of what clues may be offered by the increasing incidence of the disease in this developing nation. Available evidence will be evaluated with the objective of providing a comprehensive overview of the development of IBD in India.

Habitual dietary intake of IBD patients differs from population controls: a case-control study

BACKGROUND

Since evidence-based dietary guidelines are lacking for IBD patients, they tend to follow "unguided" dietary habits; potentially leading to nutritional deficiencies and detrimental effects on disease course. Therefore, we compared dietary intake of IBD patients with controls.

METHODS

Dietary intake of macronutrients and 25 food groups of 493 patients (207 UC, 286 CD), and 1291 controls was obtained via a food frequency questionnaire.

RESULTS

38.6% of patients in remission had protein intakes below the recommended 0.8 g/kg and 86.7% with active disease below the recommended 1.2 g/kg. Multinomial logistic regression, corrected for age, gender and BMI, showed that (compared to controls) UC patients consumed more meat and spreads, but less alcohol, breads, coffee and dairy; CD patients consumed more non-alcoholic drinks, potatoes, savoury snacks and sugar and sweets but less alcohol, dairy, nuts, pasta and prepared meals. Patients with active disease consumed more meat, soup and sugar and sweets but less alcohol, coffee, dairy, prepared meals and rice; patients in remission consumed more potatoes and spreads but less alcohol, breads, dairy, nuts, pasta and prepared meals.

CONCLUSIONS

Patients avoiding potentially favourable foods and gourmandizing potentially unfavourable foods are of concern. Special attention is needed for protein intake in the treatment of these patients.

Inflammatory bowel disease and the South Asian diaspora

Migration is associated with changes in the incidence of diseases, often linked to new environmental exposures or movement away from such exposures. Studies are complicated by the time and length of migration and also by differences in the experience of second‐ and third‐generation migrants. South Asian people have migrated across the world. In this review, the incidence and prevalence of inflammatory bowel disease in these communities is considered, along with their potential role in future investigative studies of the diseases’ etiology.

Urban-rural environmental exposure during childhood and subsequent risk of inflammatory bowel disease: a meta-analysis

BACKGROUND

The relationship between living conditions in urban and rural areas during childhood and subsequent inflammatory bowel disease (IBD) remains controversial.

AIM

To explore the association between environmental exposures early in life and the subsequent risk of IBD.

METHODS

Literature searches were conducted in the following databases: PubMed, EMBASE, and Conference Proceedings Citation Index. Studies were analyzed separately using rate ratios (RRs) or odds ratios (ORs) with 95% confidence intervals.

RESULTS

The search strategy identified 15 studies. Of these, 9 studies explored the association between urban exposure during childhood and ulcerative colitis (UC), and 12 and 4 studies explored this relationship with Crohn's disease (CD) and IBD, respectively. A meta-analysis showed that the pooled ORs estimated for the case-control studies of UC, CD, and IBD were 1.16 (0.83, 1.61), 1.45 (1.45, 1.85), and 1.34 (1.11, 1.62), respectively. The pooled RR estimated for the cohort studies of CD and IBD was 1.48 (1.17, 1.87). The stratified analysis and meta-regression showed significant relationships between CD and living conditions in case-control studies published during 2010-2017 and in non-European countries (P < 0.05).

CONCLUSIONS

Living conditions during childhood are positively associated with the subsequent development of IBD. Urban living environment is more common among those with CD than UC.

Dietary intake of fish, n-3 polyunsaturated fatty acids, and risk of inflammatory bowel disease: a systematic review and meta-analysis of observational studies

PURPOSE

Fish consumption and dietary intake of n-3 polyunsaturated acids (PUFAs) may be associated with inflammatory bowel disease (IBD). We aimed to conduct a systematic review and summarize published articles on the association between fish consumption and dietary intake of n-3 PUFAs with the risk of IBD.

METHODS

PubMed, Scopus, and Web of Science databases were used to conduct a comprehensive search and identify eligible literature published prior to January 2019. Fixed-effects model or random-effects models (DerSimonian-Laird method) were applied to pool the effect sizes. Cochrane Q test was used to trace the potential source of heterogeneity across studies.

RESULTS

12 studies (5 prospective and 7 case-control) were included in the systematic review, which ten of them were eligible for inclusion in the meta-analysis. Studies were included a total sample size of 282610 participants which 2002 of them were cases of IBD [1061 Crohn's disease (CD) and 937 ulcerative colitis (UC)]. A negative association was found between fish consumption and the incidence of CD (pooled effect size: 0.54, 95%CI: 0.31-0.96, P = 0.03). There was no relationship between total dietary n-3 PUFAs intake and IBD (pooled effect size: 1.17, 95%CI: 0.80-1.72, P = 0.41). A significant inverse association was observed between dietary long-chain n-3 PUFAs and the risk of UC (pooled effect size: 0.75, 95%CI: 0.57-0.98, P = 0.03). Moreover, no association was found between α-Linolenic acid (ALA) and IBD (pooled effect size: 1.17, 95%CI: 0.63-2.17, P = 0.62).

CONCLUSIONS

Findings showed a negative association between fish consumption and the risk of CD. Moreover, there was a significant inverse association between dietary long-chain n-3 PUFAs and the risk of UC.

The role of diet in the prevention and treatment of Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBD) - Crohn's disease (CD) and ulcerative colitis (UC) - are chronic conditions characterised by relapsing inflammation of the gastrointestinal tract. They represent an increasing public health concern and an aetiological enigma due to unknown causal factors. The current knowledge on the pathogenesis of IBD is that genetically susceptible individuals develop intolerance to a dysregulated gut microflora (dysbiosis) and chronic inflammation develops as a result of environmental triggers. Among the environmental factors associated with IBD, diet plays an important role in modulating the gut microbiome, and, consequently, it could have a therapeutic impact on the disease course. An overabundance of calories and some macronutrients typical of the Western dietetic pattern increase gut inflammation, whereas several micronutrients characteristic of the Mediterranean Diet have the potential to modulate gut inflammation, according to recent evidence. Immunonutrition has emerged as a new concept putting forward the role of vitamins such as vitamins A, C, E, and D, folic acid, beta carotene and trace elements such as zinc, selenium, manganese and iron. However, when assessed in clinical trials, specific micronutrients showed a limited benefit. Further research is required to evaluate the role of individual food compounds and complex nutritional interventions with the potential to decrease inflammation as a means of prevention and management of IBD. The current dietary recommendations for disease prevention and management are scarce and non evidence-based. This review summarizes the current knowledge on the complex interaction between diet, microbiome and immune-modulation in IBD, with particular focus to the role of the Mediterranean Diet as a tool for prevention and treatment of the disease.

Lipid and Bile Acid Dysmetabolism in Crohn's Disease

Crohn's disease is one of the systemic autoimmune diseases. It commonly affects the small intestine and colon but may involve any portion of the gastrointestinal tract from the mouth to the anus. The most affected area by Crohn's disease is the distal part of the small intestine, in which the bile acid molecules are most efficiently reabsorbed. Bile acids form mixed micelles together with fatty acids, which function as a transport vehicle to deliver fatty acids to the apical membrane of enterocytes for absorption. Therefore, if the terminal ileum is impaired, bile acid malabsorption may occur, which may cause congenital diarrhoea in Crohn's disease. Similarly, the impairment of the terminal ileum also induces fatty acid malabsorption, which may influence the role of fatty acids in Crohn's disease. In contrast, a recent study reported that multidrug resistance protein 1 (MDR1) regulated effector T-cell function in the ileum from bile acid-driven oxidative stress and MDR1 loss of function in a subset of patients with Crohn's disease. However, the role of consumption of fatty acids in Crohn's disease remains to be fully elucidated. This review is aimed at providing an overview of some recent developments in research of Crohn's disease from comprehensive perspective with a focus on the connection between disease location and behaviour, lipid diets, and bile acid malabsorption.

Risk factors for inflammatory bowel disease: A prospective multi-center study

INTRODUCTION

Environmental risk factors have been associated with inflammatory bowel disease (IBD). With rising incidence, it is important to know risk factors associated with IBD in our population. This study was aimed to evaluate risk factors for IBD from western India.

METHODS

This was prospective, multi-center case-control study which included 1054 patients with IBD of which 765 (72.5%) were ulcerative colitis (UC) and 289 (27.4%) Crohn's disease (CD). Asymptomatic individuals without a history of any major illness served as controls. The questionnaire containing risk factors for IBD was given to patients and control group. Odds ratio and 95% confidence interval were calculated for each variable.

RESULT

Significant numbers of patients with CD were from rural area. Rural environment (OR 1.071, 0.82-1.38 and OR 1.441, 1.02-2.02), higher education (OR 1.830, 1.52-2.19 and OR 1.519, 1.16-1.97), professional by occupation (OR 1.754, 1.46-2.09 and OR 1.293, 0.99-1.67), annual family income >100,000 Indian national rupees (OR 2.185, 1.52-3.13 and OR 4.648, 3.10-6.95), history of appendectomy (OR 3.158, 1.71-5.80 and OR 3.158, 1.71-5.80), and family history of IBD (OR 4.510, 2.19-9.25 and OR 3.972, 1.58-9.96) were the risk factors for UC and CD, respectively. Vegetarian diet was protective factor for UC (OR 0.29, 0.27-0.39) and risk for CD (OR 1.179, 0.88-1.57). Smoking and chronic alcoholism were not found to be the risk factors.

CONCLUSION

This study highlights association between socioeconomic, dietary factors, appendectomy, and family history as risk factors for IBD.

Peripartum Antibiotics Promote Gut Dysbiosis, Loss of Immune Tolerance, and Inflammatory Bowel Disease in Genetically Prone Offspring

Factors affecting the developing neonatal gut microbiome and immune networks may increase the risk of developing complex immune disorders such as inflammatory bowel diseases (IBD). In particular, peripartum antibiotics have been suggested as risk factors for human IBD, although direct evidence is lacking. Therefore, we examined the temporal impact of the commonly used antibiotic cefoperazone on both maternal and offspring microbiota when administered to dams during the peripartum period in the IL-10-deficient murine colitis model. By rigorously controlling for cage, gender, generational, and murine pathobiont confounders, we observed that offspring from cefoperazone-exposed dams develop a persistent gut dysbiosis into adulthood associated with skewing of the host immune system and increased susceptibility to spontaneous and chemically dextran sodium sulfate (DSS)-induced colitis. Thus, early life exposure to antibiotic-induced maternal dysbiosis during a critical developmental window for gut microbial assemblage and immune programming elicits a lasting impact of increased IBD risk on genetically susceptible offspring.

Ethnicity Influences Phenotype and Outcomes in Inflammatory Bowel Disease: A Systematic Review and Meta-analysis of Population-based Studies

BACKGROUND & AIMS

Inflammatory bowel diseases (IBDs) (Crohn's disease [CD], ulcerative colitis) are global diseases. Similarities and differences in disease presentation and outcomes across different geographic regions and ethnic groups have not been compared previously.

METHODS

We performed a systematic review and meta-analysis of population-based cohort studies examining the phenotype and outcome of IBD across ethnic groups categorized as Whites, Blacks, Hispanics, and Asians. Further stratification was performed by migration status (native or immigrant). Pooled proportions of disease location, behavior, medication, and surgery use were calculated by using a random-effects model and compared statistically.

RESULTS

Our final analysis included 198 unique studies reporting outcomes on 525,425 IBD patients (Caucasian, 65%; Asian, 30%; Hispanic, 2%; and Black, 1%). CD in Asians but not other ethnicities demonstrated a strong male predominance. Family history of IBD was infrequent in Asian patients. Both Black and Asian CD patients demonstrated perianal involvement more frequently. Surgery for both CD and UC was less common in Asians than Caucasians. Compared with native residents, a family history of IBD was reported more often among immigrant IBD patients, but no significant differences were noted in phenotype.

CONCLUSIONS

We demonstrate significant variation in the demographic distribution, familial predisposition, phenotype, and outcomes of IBD between Caucasians, Blacks, Hispanics, and Asians. There is need for further study to understand the biology behind this variation.

Epidemiology of Inflammatory Bowel Disease in India: The Great Shift East

BACKGROUND

Inflammatory bowel disease (IBD), once considered to be a Western disease, is increasingly being reported from India and other Asian countries. The present review summarizes epidemiology and disease characteristics of IBD in India with reference to other Asian countries and the West.

SUMMARY

India is projected to have one of the highest disease burden of IBD across the globe. The overall genetic risk and microbial signature in Indian IBD patients are similar to those of patients in the West as demonstrated by the similar incidence of IBD in second-generation Indian immigrants and matching perturbations in the structural and functional component of gut microbiota in Indian studies. The concept of the hygiene hypothesis continues to remain controversial with Indian studies demonstrating contradictory findings. The disease characteristics, long-term outcomes including the risk of colorectal cancer, and the effect of pregnancy on IBD and vice versa in Indian patients with IBD are in general similar with few differences. Unlike patients in the West, very few Indian patients have a positive family history.

KEY MESSAGE

The Indian disease pattern is going through a phase of epidemiological transition with a surge in the incidence of IBD. The epidemiology and disease characteristics of IBD mirror the patterns observed in the West.

Systematic review with meta-analysis: breastfeeding and the risk of Crohn's disease and ulcerative colitis

BACKGROUND

Breastfeeding is a modifiable factor that may influence development of inflammatory bowel diseases. However, literature on this has been inconsistent and not accounted for heterogeneity in populations and exposure.

AIM

To conduct a meta-analysis to examine the association between breastfeeding in infancy and risk of Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

A systematic search of Medline/PubMed and Embase was performed for full text, English-language literature through November 2016. Studies were included if they described breastfeeding in infancy in patients with CD or UC, and healthy controls. Data were pooled using a random effects model for analysis.

RESULTS

A total of 35 studies were included in the final analysis, comprising 7536 individuals with CD, 7353 with UC and 330 222 controls. Ever being breastfed was associated with a lower risk of CD (OR 0.71, 95% CI 0.59-0.85) and UC (OR 0.78, 95% CI 0.67-0.91). While this inverse association was observed in all ethnicity groups, the magnitude of protection was significantly greater among Asians (OR 0.31, 95% CI 0.20-0.48) compared to Caucasians (OR 0.78, 95% CI 0.66-0.93; P = .0001) in CD. Breastfeeding duration showed a dose-dependent association, with strongest decrease in risk when breastfed for at least 12 months for CD (OR 0.20, 95% CI 0.08-0.50) and UC (OR 0.21, 95% CI 0.10-0.43) as compared to 3 or 6 months.

CONCLUSION

Breastfeeding in infancy protects against the development of CD and ulcerative colitis.

Understanding the Gut Microbiota in Inflammatory and Functional Gastrointestinal Diseases

OBJECTIVE

During the last decade, experimental and observational studies have shown that patients with inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) may have an altered intestinal microbial composition compared with healthy individuals. However, no uniform microbial signature has as yet been detected for either IBD or IBS. This review summarizes the current knowledge of microbial dysbiosis and its potential relationship to the pathophysiology in IBD and IBS.

METHODS

A selective review was conducted to summarize the current knowledge of gut microbiota in the pathophysiology of IBD and IBS.

RESULTS

Experimental and observational studies provide good evidence for intestinal microbial dysbiosis in subgroups of IBD and IBS. Still, no uniform disease pattern has been detected. This is most likely due to the heterogeneous nature of IBD and IBS, in combination with the effects of intrinsic and extrinsic factors. Such intrinsic factors include genetics, the gastrointestinal environment, and the host immune system, whereas extrinsic factors include early life diet, breastfeeding, and method of infant delivery.

CONCLUSIONS

Recent and ongoing work to define microbial dysbiosis in IBD and IBS shows promise, but future well-designed studies with well-characterized study individuals are needed. It is likely that the microbial dysbiosis in IBD and IBS is dependent on the natural disease course of IBD and symptom pattern in IBS. Therefore, assessment of the entire microbiota along the gastrointestinal tract, in relationship to confounding factors, symptom fluctuations, and other pathophysiological factors, is needed for further understanding of the etiology of these common diseases.

An Examination of Diet for the Maintenance of Remission in Inflammatory Bowel Disease

Diet has been speculated to be a factor in the pathogenesis of inflammatory bowel disease and may be an important factor in managing disease symptoms. Patients manipulate their diet in attempt to control symptoms, often leading to the adoption of inappropriately restrictive diets, which places them at risk for nutritional complications. Health professionals struggle to provide evidence-based nutrition guidance to patients due to an overall lack of uniformity or clarity amongst research studies. Well-designed diet studies are urgently needed to create an enhanced understanding of the role diet plays in the management of inflammatory bowel disease. The aim of this review is to summarize the current data available on dietary management of inflammatory bowel disease and to demonstrate that dietary modulation may be an important consideration in managing disease. By addressing the relevance of diet in inflammatory bowel disease, health professionals are able to better support patients and collaborate with dietitians to improve nutrition therapy.

The gut microbiota and inflammatory bowel diseases

Inflammatory bowel diseases (IBDs) are chronic diseases of unclear etiology that affect over 1 million individuals in the United States and over 2.5 million people in Europe. However, they are also expanding globally, affecting populations in Asia, South America, and the Middle East as they become more industrialized. These diseases are believed to arise from the convergence of genetic, environmental, and microbial factors that trigger aberrant immune and tissue responses, resulting in intestinal inflammation. Advances in cultivation-independent investigations, experimental models, and bioinformatics approaches have improved our understanding of the role of gut microbiota in IBD. However, determining and understanding the functional consequences of gut dysbiosis and altered host-microbiota interactions in IBD remain a challenge due to the limits of current experimental models and difficulty in establishing causal links in human-based investigations. Continued development of new methodologies and improvements in clinical study design are needed to better understand the interplay of genetic, microbial, and immunological factors in IBD. This knowledge can then be applied clinically to improve therapeutic strategies and outcomes for IBD.

Inflammatory bowel disease in India - Past, present and future

There is rising incidence and prevalence of inflammatory bowel disease (IBD) in India topping the Southeast Asian (SEA) countries. The common genes implicated in disease pathogenesis in the West are not causal in Indian patients and the role of "hygiene hypothesis" is unclear. There appears to be a North-South divide with more ulcerative colitis (UC) in north and Crohn's disease (CD) in south India. IBD in second generation Indian migrants to the West takes the early onset and more severe form of the West whereas it retains the nature of its country of origin in migrants to SEA countries. The clinical presentation is much like other SEA countries (similar age and sex profile, low positive family history and effect of smoking, roughly similar disease location, use of aminosalicylates for CD, low use of biologics and similar surgical rates) with some differences (higher incidence of inflammatory CD, lower perianal disease, higher use of aminosalicylates and azathioprine and lower current use of corticosteroids). UC presents more with extensive disease not paralleled in severity clinically or histologically, follows benign course with easy medical control and low incidence of fulminant disease, cancer, complications, and surgery. UC related colorectal cancer develop in an unpredictable manner with respect to disease duration and site questioning the validity of strict screening protocol. About a third of CD patients get antituberculosis drugs and a significant number presents with small intestinal bleed which is predominantly afflicted by aggressive inflammation. Biomarkers have inadequate diagnostic sensitivity and specificity for both. Pediatric IBD tends to be more severe than adult. Population based studies are needed to address the lacunae in epidemiology and definition of etiological factors. Newer biomarkers and advanced diagnostic techniques (in the field of gastrointestinal endoscopy, molecular pathology and genetics) needs to be developed for proper disease definition and treatment.

Fluoride: a risk factor for inflammatory bowel disease?

Although the association between inflammatory bowel disease (IBD) and oral hygiene has been noticed before, there has been little research on prolonged fluoride exposure as a possible risk factor. In the presented cases, exposure to fluoride seems indirectly associated with higher incidence of IBD. Fluoride toxicology and epidemiology documents frequent unspecific chronic gastrointestinal symptoms and intestinal inflammation. Efflux genes that confer resistance to environmental fluoride may select for IBD associated gut microbiota and therefore be involved in the pathogenesis. Together these multidisciplinary results argue for further investigation on the hypothesis of fluoride as a risk factor for IBD.

Environmental Hygiene and Risk of Inflammatory Bowel Diseases: A Systematic Review and Meta-analysis

BACKGROUND

According to the hygiene hypothesis, individuals raised in a sanitary environment have a higher risk of developing inflammatory bowel diseases (IBD). However, results have been inconsistent. We conducted this systematic review of factors related to environmental hygiene and risk of IBD, Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

A systematic search was performed on MEDLINE between 1980 and 2015 to identify studies of the association between IBD and contact with pets and farm animals, number of siblings, bedroom sharing in childhood, and access to personal toilet and hot water. Random- or fixed-effect meta-analyses were performed, and analysis further stratified based on ethnicity of the included cohort.

RESULTS

A total of 29 relevant studies were included. Having a pet (odds ratio [OR], 0.76; 95% confidence interval [CI], 0.63-0.88) and contact with farm animals was inversely associated with risk of IBD (OR, 0.45; 95% CI, 0.31-0.60). However, the strength of association with farm animals was statistically stronger in non-white cohorts (OR, 0.27; 95% CI, 0.02-0.53) than in white cohorts (OR, 0.55; 95% CI, 0.45-0.65) (P = 0.028). Access to toilet (OR, 0.71; 95% CI, 0.56-0.85) and hot water (OR, 0.67; 95% CI, 0.44-0.89) was inversely associated with UC in non-white populations but not whites. Having more than 2 siblings was inversely associated with risk of CD.

CONCLUSIONS

Several factors pertaining to reduced environmental hygiene are inversely associated with risk of IBD. However, underlying ethnicity influences susceptibility to the effect of these factors.

Do We Need Worms to Promote Immune Health?

Many immune-mediated diseases like inflammatory bowel disease, multiple sclerosis, type 1 diabetes, asthma, and food allergy appeared to have increased in frequency in developed countries in the latter part of the twentieth century. Reports from less developed countries suggest that the "epidemic" of immune-mediated diseases now is spreading into these regions as well. The "hygiene hypothesis" was developed to partly explain this phenomenon. It has been proposed that modern-day sanitary living has altered our exposure to organisms that provided protection from these diseases in the past. Alternations in the composition of our intestinal flora and fauna could play a role. Helminths are a group of worm-like parasitic organisms that have adapted to live in various regions of their hosts. Epidemiological and some clinical data suggest that these organisms can protect people from developing immune-mediated diseases. Animal experimentation has shown that helminths stimulate the production of regulatory cytokines, activate regulatory T cells, and induce regulatory dendritic cells and macrophages. This could be the mechanism by which they protect the host from these diseases. Early clinical studies also suggest that helminths may prove useful for treating immunological diseases. More sophisticated clinical studies are underway, testing live helminth agents as therapeutic agents. Also, a strong effort is ongoing to discover the agents produced by helminths that modulate host immune responses with an eye on developing new, highly effective immune modulatory therapeutic agent.

The association between the intake of specific dietary components and lifestyle factors and microscopic colitis

Background/Objectives:

The incidence of microscopic colitis (MC) has increased over the previous decades. In addition to smoking and drugs, currently unidentified environmental factors may have a role. The aim of this study was to determine whether specific dietary or other lifestyle factors were associated with the development of MC.

Subject/Methods:

The population-based cohort Malmö Diet and Cancer Study of 28 095 individuals was examined. Information about dietary habits was collected by a modified diet history method. Data on anthropometry were measured, and socio-economic and lifestyle factors were collected by questionnaires. Cases of MC were identified in medical registers. Associations were estimated using Cox regression analysis.

Results:

During a 22-year period, 135 patients were diagnosed with MC. Intakes of protein, carbohydrates, sucrose, saturated fat, monounsaturated fat, polyunsaturated fat, omega-3 or omega-6 fatty acids, fibre and zinc were not associated with MC. We could verify the previously reported association between MC and smoking (hazard ratio (HR): 2.29; 95% confidence interval (CI): 1.66–3.84) and the female gender (HR: 3.57; 95% CI: 2.22–5.74). High alcohol consumption was associated with an increased risk for MC (HR: 1.89 for the highest quartile; 95% CI: 0.82–4.33, P for trend=0.032). In a post hoc analysis, alcohol intake including all patients independently of consumption seemed to reduce the smoking-related risk.

Conclusions:

Despite a large cohort and a long follow-up period, we could not detect any dietary risk factors for MC. The aetiological mechanisms behind the positive impact of smoking and alcohol on MC risk should be investigated.

Influence of environmental factors on the onset and course of inflammatory bowel disease

Numerous environmental factors have been linked with inflammatory bowel disease. These include smoking, diet, hygiene, drugs, geographical and psychosocial factors. These factors may either increase the risk of or protect against developing this condition and can also affect the course of illness in a positive or negative manner. A number of studies have examined the influence of environmental factors on inflammatory bowel diseases as a whole as well as on ulcerative colitis and Crohn’s disease separately. As there are differences in the pathogenesis of ulcerative colitis and Crohn’s disease, the effect of environmental factors on their onset and course is not always similar. Some factors have shown a consistent association, while reports on others have been conflicting. In this article we discuss the current evidence on the roles of these factors on inflammatory bowel disease, both as causative/protective agents and as modifiers of disease course.

High School Diet and Risk of Crohn's Disease and Ulcerative Colitis

BACKGROUND

Diet may play an important role in the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC); yet, there are few prospective studies of dietary factors. None have examined the association between adolescent diet and risk of inflammatory bowel diseases (CD and UC).

METHODS

This study included women enrolled in Nurses' Health Study II who completed a validated high school dietary questionnaire in 1998. We examined the effect of dietary patterns (prudent or Western diet) and individual components of each patterns. We documented incident cases of CD and UC through 2011 based on physician review of medical records and used Cox proportional hazards models adjusting for confounders to estimate hazard ratios and confidence intervals for CD and UC.

RESULTS

Over 763,229 person-years of follow-up, we identified 70 incident cases of CD and 103 cases of UC. Compared with women in the lowest quartile of a prudent diet score (characterized by greater intake of fruits, vegetables, and fish), women in the highest quartile had a 53% lower risk of CD (hazard ratio, 0.47; 95% confidence interval, 0.23-0.98; P trend = 0.04). Specifically, greater intake of fish (P trend = 0.01) and fiber (P trend = 0.06) were associated with lower risk of CD. In contrast, Western diet score was not associated with risk of CD. Neither dietary patterns nor individual food or nutrient groups was associated with UC.

CONCLUSIONS

Adolescent diet is associated with risk of CD, but not UC, offering insights into disease pathogenesis.

Indian Society of Gastroenterology consensus statements on Crohn's disease in India

In 2012, the Indian Society of Gastroenterology's Task Force on Inflammatory Bowel Diseases undertook an exercise to produce consensus statements on Crohn's disease (CD). This consensus, produced through a modified Delphi process, reflects our current recommendations for the diagnosis and management of CD in India. The consensus statements are intended to serve as a reference point for teaching, clinical practice, and research in India.

The microbial basis of inflammatory bowel diseases

Inflammatory bowel diseases (IBD) are chronic, progressive diseases characterized by aberrant immune responses to environmental and gut microbial triggers in genetically susceptible hosts. Clinical, genetic, and experimental data support the role of gut microbes in causing and sustaining these diseases. Our understanding of IBD has changed dramatically as the result of advances in cultivation-independent approaches and computational platforms for the analysis of large data sets. However, investigations relevant to clinical observations and the natural history of the diseases will be essential for the development of microbial, genetic, and biological metrics that may be used to individualize assessment of risk and improve clinical outcomes in IBD.

Review article: the association of diet with onset and relapse in patients with inflammatory bowel disease

BACKGROUND

The role of diet in inflammatory bowel disease (IBD) is supported by migration studies and increasing incidences in line with Westernisation.

AIM

To give a complete overview of studies associating habitual diet with the onset or relapses in ulcerative colitis (UC) or Crohn's disease (CD).

METHODS

A structured search in Pubmed, the Cochrane Library and EMBASE was performed using defined key words, including only full text papers in English language.

RESULTS

Forty-one studies were identified, investigating onset (n = 35), relapses (n = 5) or both (n = 1). Several studies reported high intake of sugar or sugar-containing foods (n = 7 UC, n = 12 CD), and low intake of fruits and/or vegetables (n = 5 UC, n = 10 CD) to be associated with an increased onset risk. However, these findings could not be confirmed by similar or higher numbers of other studies. A possible protective role was found for grain-derived products in CD onset, but results were inconsistent for dietary fibre in UC and CD and grain-derived products in UC. No definite conclusions could be drawn for unsaturated fatty acids (UFA), protein and energy intake due to limited and/or inconsistent results. Six studies reported on diet and relapse risk, of which only two (n = 1 UC, n = 1 CD) had a prospective follow-up.

CONCLUSIONS

The current evidence is not sufficient to draw firm conclusions on the role of specific food components or nutrients in the aetiology of IBD. Furthermore, large prospective studies into the role of habitual diet as a trigger of relapses are needed, to identify new therapeutic or preventive targets.

Geographical variability and environmental risk factors in inflammatory bowel disease

The changing epidemiology of inflammatory bowel disease (IBD) across time and geography suggests that environmental factors play a major role in modifying disease expression. Disease emergence in developing nations suggests that epidemiological evolution is related to westernisation of lifestyle and industrialisation. The strongest environmental associations identified are cigarette smoking and appendectomy, although neither alone explains the variation in incidence of IBD worldwide. Urbanisation of societies, associated with changes in diet, antibiotic use, hygiene status, microbial exposures and pollution have been implicated as potential environmental risk factors for IBD. Changes in socioeconomic status might occur differently in different geographical areas and populations and, consequently, it is important to consider the heterogeneity of risk factors applicable to the individual patient. Environmental risk factors of individual, familial, community-based, country-based and regionally based origin may all contribute to the pathogenesis of IBD. The geographical variation of IBD provides clues for researchers to investigate possible environmental aetiological factors. The present review aims to provide an update of the literature exploring geographical variability in IBD and to explore the environmental risk factors that may account for this variability.

Survey of inflammatory bowel diseases in India

INTRODUCTION

Inflammatory bowel disease (IBD), both ulcerative colitis (UC) and Crohn's disease (CD), once thought to be uncommon, is now seen commonly in India. The Indian Society of Gastroenterology (ISG) Task Force on IBD decided to collate data on the clinical spectrum of IBD currently prevailing in India.

METHODS

An open call to members of ISG was given through publication of a proforma questionnaire in the Indian Journal of Gastroenterology and the web portal of ISG. The proforma contained questions related with demographic features, family history, risk factors, clinical manifestations and characteristics, course of disease, and pattern of treatment of IBD.

RESULTS

Of 1,255 filled questionnaires received, 96 were rejected and 1,159 (92.3 %) were analyzed. This comprised data on 745 (64.3 %) patients with UC, 409 (35.3 %) with CD, and 5 with indeterminate colitis. The median duration of illness was longer in patients with CD (48 months) compared to those with UC (24 months) (p = 0.002). More than one half of patients (UC 51.6 %, CD 56.9 %) had one or more extraintestinal symptoms. A definite family history of IBD was present in 2.9 % (UC 2.3 % and CD 4.6 %; p = 0.12). The extent of disease in UC was pancolitis 42.8 %, left-sided colitis 38.8 %, and proctitis alone in 18.3 %. The extent of disease involvement in CD was both small and large intestine in 39.6 %, colon alone in 31.4 % and small intestine alone in 28.9 %. Stricturing and fistulizing disease were noted in 18.8 % and 4.4 % of patients with CD respectively. Chronic continuous and intermittent disease course were present in 35.5 % and 47.2 % of UC patients respectively, and in 23.1 % and 68.8 % of CD patients. Four percent of patients with UC had undergone colectomy, while 15.2 % of patients with CD underwent surgical intervention.

CONCLUSIONS

The present survey provides a reasonable picture of the demographic features and clinical manifestations of Indian patients with IBD, their risk factors, course of disease, and the treatment given to them.