Fiber and the Risk of Flaring in Patients With Inflammatory Bowel Diseases: Lessons From the Crohn's and Colitis Foundation of America Database

Higher Fiber Intake is Associated with Reduced Risk of Related Surgery among Individuals with Inflammatory Bowel Disease in a Prospective Cohort Study

BACKGROUND

Evidence for the effects of dietary fiber on adverse outcomes in individuals with inflammatory bowel disease (IBD) is insufficient and controversial.

OBJECTIVES

We aimed to prospectively explore the association between dietary fiber intake and the risk of IBD-related surgery.

METHODS

We identified 5580 individuals with diagnosed IBD [Crohn disease (CD, n = 1908) and ulcerative colitis (UC, n = 3672)] at baseline in the UK Biobank via electronic medical records and self-reported information. Dietary fiber intake was estimated by a partial fiber score derived from a valid food frequency questionnaire. IBD-related surgery (enterotomy, perianal surgery, and others) was ascertained via inpatient data. Cox proportional model was applied to estimate hazard ratios with 95% confidence intervals (CIs) of dietary fiber in quartiles for the risk of IBD-related surgery.

RESULTS

During a mean follow-up period of 11.2 y, we documented 624 IBD-related surgery among 5580 individuals with IBD (mean age, 57.3; 52.8% females). Compared with individuals in the lowest quartiles, those with second to fourth quartiles of fiber intake were associated with 23% (95% CI: 5%, 38%, P = 0.015), 29% (95% CI: 11%, 43%, P = 0.003), and 28% (95% CI: 10%, 43%, P = 0.005) reduced risk (P-trend = 0.002) of IBD-related surgery. Similar associations were observed in CD (P-trend = 0.005) but not UC (P-trend = 0.131). We observed inverse associations of fiber in vegetables and fruits (P-trend = 0.017 and 0.007) but positive associations of fiber in bread (P-trend = 0.046) with the risk of IBD-related surgery.

CONCLUSIONS

Higher intake of fiber is associated with reduced IBD-related surgery risk in patients with IBD with CD but not UC.

Sex-Specific Differences in the Gut Microbiome in Response to Dietary Fiber Supplementation in IL-10-Deficient Mice

There is growing interest in studying dietary fiber to stimulate microbiome changes that might prevent or alleviate inflammatory bowel disease (IBD). However, dietary fiber effects have shown varying degrees of efficacy, for reasons that are unclear. This study examined whether the effects of isomaltodextrin on gut microbiota and IBD were dependent on dose or host sex, using an Interleukin (IL)-10 deficient murine colitis model. After 12 weeks, colonic IL-12p70 was depressed in male mice receiving high-dose isomaltodextrin supplementation compared to the control group (p = 0.04). Male mice receiving high-dose isomaltodextrin exhibited changes in microbial alpha-diversity, including enhanced richness and evenness (p = 0.01) and limited reduction in the relative abundance of Coprococcus (q = 0.08), compared to the control group. These microbial compositional changes were negatively associated with IL-12p70 levels in the male group (rs ≤ −0.51, q ≤ 0.08). In contrast, female mice receiving isomaltodextrin displayed a reduction in alpha-diversity and Coprococcus abundance and a high level of IL-12p70, as did the control group. Together, these results indicate that isomaltodextrin altered the gut microbial composition linking specific immune-regulatory cytokine responses, while the interactions among fiber, microbiota and immune response were dose dependent and largely sex specific. The results further indicate that interactions between environmental and host factors can affect microbiome manipulation in the host.

Non-pharmacological therapies for inflammatory bowel disease: Recommendations for self-care and physician guidance

We performed a scoping review on sought-after complementary therapies for patients with inflammatory bowel disease (IBD), specifically diet, physical activity and exercise (PA/E), and psychotherapy. We aim to update patients with IBD on therapies for self-care and provide physicians with guidance on how to direct their patients for the management of IBD. A search of MEDLINE, EMBASE, and PUBMED was completed in Sept 2016. Studies on diet, PA/E, or psychotherapy in patients with IBD were included. Medical Subject Heading terms and Boolean operators were used. The search was limited to full-text English articles describing an adult population. This review included 67 studies: Diet (n = 19); PA/E (n = 19); and psychotherapy (n = 29). We have made the following recommendations: (1) Diet: Consumption of diets rich in vegetables, fruit and soluble fiber may be beneficial in IBD. A trial of a low FODMAP diet can be considered in those patients with functional gastrointestinal symptoms. Restrictive diets are lacking in evidence and should be avoided; (2) PA/E: Regular low-moderate intensity activity, including cardiovascular and resistance exercise, has been shown to improve quality of life (QOL) and may improve inflammation; and (3) psychotherapy: Therapies such as cognitive-behavioural interventions, mindfulness, hypnosis, and stress management have been shown to improve QOL, but evidence is limited on their impact on anxiety, depression, and disease activity. Overall, these complementary therapies are promising and should be used to treat patients with IBD from a more holistic perspective.