Habitual dietary fibre and prebiotic intake is inadequate in patients with inflammatory bowel disease: findings from a multicentre cross‐sectional study

Dietary Fiber in Inflammatory Bowel Disease: Are We Ready to Change the Paradigm?

Accumulating evidence from pre-clinical and clinical studies demonstrate the benefit of dietary fibers for inflammatory bowel disease (IBD). However, the majority of patients avoid or limit their consumption to manage their symptoms during the active and remission phases, although limited research supports these long-term dietary habits. Although recent evidence-based dietary guidelines highlight the importance of promoting an adequate intake of dietary fiber in IBD patients, intervention trials have not yet clearly clarified the quality and quantity of dietary fiber that should be consumed to be equally tolerated by and provide benefit for patients with IBD. This narrative review describes dietary fibers and their characteristics, analyzes the real-word studies on the impact of dietary fiber consumption in IBD in different clinical settings, and concludes with potential future directions in fiber research, focusing on the real-world needs of characterizing the consumption of fiber-rich foods and promoting their adequate intake.

Risk of avoidant/restrictive food intake disorder in patients with inflammatory bowel disease: predictive value of disease phenotype, disease activity and food literacy

BACKGROUND

Avoidant/Restrictive Food Intake Disorder (ARFID) is a newly described eating disorder. Adequate levels of food literacy allow individuals to have adequate food choices. This study aimed to assess the prevalence of ARFID and the level of food literacy in patients with inflammatory bowel disease (IBD) and to analyse the correlation between ARFID and food literacy.

METHOD

This cross-sectional study screened for ARFID and assessed food literacy levels in patients with IBD attending four tertiary hospitals in China. ARFID risk was measured using the Nine Item Avoidant/Restrictive Food Intake Disorder Screen (NIAS). Food literacy was assessed using the Food Literacy Evaluation Questionnaire (Chinese version, FLEQ-Ch).The relationship between individual NIAS scores and food literacy variables was analysed to assess which food literacy aspect is positively or negatively associated with NIAS scores. Stepwise linear regression analysis was performed to identify the possible predictors of NIAS scores in patients with IBD.

RESULT

A total of 372 IBD subjects completed the NIAS and FLEQ-Ch. The overall mean NIAS scores for the IBD cohort was 28.16 ± 8.03 (p < 0.01), and of the 372 participants, 123 (32.5%) had positive ARFID risk scores (≥ 10 NIAS-picky eating, ≥ 9 NIAS-poor appetite, and ≥ 10 NIAS-fear of negative consequences).The NIAS scores were inversely associated with food literacy levels (β =  - 0.299; p < 0.01).Disease phenotype, disease activity, and food literacy in patients with IBD provided valuable predictive insights for avoiding positive outcomes in ARFID.

CONCLUSION

This study shows that the risk of ARFID in the cohort of patients with IBD is associated with their inadequate food literacy levels. Therefore, this study supports the notion that patients with IBD should be assessed for food literacy regardless of whether they are currently diagnosed with ARFID. Specifically, for early identification of those at risk for ARFID in IBD, disease phenotype, disease activity, and food literacy should be routinely considered in clinical practice.The food literacy awareness of patients must be investigated and improved to predict the risk occurrence of ARFID and encourage healthy eating behaviour.

Pea Starch-Lauric Acid Complex Alleviates Dextran Sulfate Sodium-Induced Colitis in C57BL/6J Mice

The previous documentation has shown the role of resistant starch in promoting intestinal health, while the effect of starch-lipid complex (RS5) on colitis remains unclear. This study aimed to investigate the effect and potential mechanism of RS5 in colitis. We prepared RS5 complexes by combining pea starch with lauric acid. Mice with dextran sulfate sodium-induced colitis were treated with either RS5 (3.25 g/kg) or normal saline (10 mL/kg) for seven days, and the effects of pea starch-lauric acid complex on mice were observed. The RS5 treatment significantly attenuated weight loss, splenomegaly, colon shortening, and pathological damage in mice with colitis. Compare with the DSS group, cytokines levels, such as tumor necrosis factor-α and interleukin-6 in both serum and colon tissue was significantly decreased in RS5 treatment group, while the gene expression of interleukin-10 and the expression of mucin 2, zonula occludens-1, Occludin, and claudin-1 in the colon was significantly upregulated in RS5 treatment group. In addition, RS5 treatment altered the gut microbiota structure of colitis mice by increasing the abundance of Bacteroides and decreasing Turicibacter, Oscillospira, Odoribacter, and Akkermansia. The dietary composition could be exploited to manage colitis by attenuating inflammation, restoring the intestinal barrier, and regulating gut microbiota.

To Fiber or Not to Fiber: The Swinging Pendulum of Fiber Supplementation in Patients with Inflammatory Bowel Disease

Evidence-based dietary guidance around dietary fiber in inflammatory bowel disease (IBD) has been limited owing to insufficient reproducibility in intervention trials. However, the pendulum has swung because of our increased understanding of the importance of fibers in maintaining a health-associated microbiome. Preliminary evidence suggests that dietary fiber can alter the gut microbiome, improve IBD symptoms, balance inflammation, and enhance health-related quality of life. Therefore, it is now more vital than ever to examine how fiber could be used as a therapeutic strategy to manage and prevent disease relapse. At present, there is limited knowledge about which fibers are optimal and in what form and quantity they should be consumed to benefit patients with IBD. Additionally, individual microbiomes play a strong role in determining the outcomes and necessitate a more personalized nutritional approach to implementing dietary changes, as dietary fiber may not be as benign as once thought in a dysbiotic microbiome. This review describes dietary fibers and their mechanism of action within the microbiome, details novel fiber sources, including resistant starches and polyphenols, and concludes with potential future directions in fiber research, including the move toward precision nutrition.

Unfermented β-fructan Fibers Fuel Inflammation in Select Inflammatory Bowel Disease Patients

BACKGROUND & AIMS

Inflammatory bowel diseases (IBD) are affected by dietary factors, including nondigestible carbohydrates (fibers), which are fermented by colonic microbes. Fibers are overall beneficial, but not all fibers are alike, and some patients with IBD report intolerance to fiber consumption. Given reproducible evidence of reduced fiber-fermenting microbes in patients with IBD, we hypothesized that fibers remain intact in select patients with reduced fiber-fermenting microbes and can then bind host cell receptors, subsequently promoting gut inflammation.

METHODS

Colonic biopsies cultured ex vivo and cell lines in vitro were incubated with oligofructose (5 g/L), or fermentation supernatants (24-hour anaerobic fermentation) and immune responses (cytokine secretion [enzyme-linked immunosorbent assay/meso scale discovery] and expression [quantitative polymerase chain reaction]) were assessed. Influence of microbiota in mediating host response was examined and taxonomic classification of microbiota was conducted with Kraken2 and metabolic profiling by HUMAnN2, using R software.

RESULTS

Unfermented dietary β-fructan fibers induced proinflammatory cytokines in a subset of IBD intestinal biopsies cultured ex vivo, and immune cells (including peripheral blood mononuclear cells). Results were validated in an adult IBD randomized controlled trial examining β-fructan supplementation. The proinflammatory response to intact β-fructan required activation of the NLRP3 and TLR2 pathways. Fermentation of β-fructans by human gut whole microbiota cultures reduced the proinflammatory response, but only when microbes were collected from patients without IBD or patients with inactive IBD. Fiber-induced immune responses correlated with microbe functions, luminal metabolites, and dietary fiber avoidance.

CONCLUSION

Although fibers are typically beneficial in individuals with normal microbial fermentative potential, some dietary fibers have detrimental effects in select patients with active IBD who lack fermentative microbe activities. The study is publicly accessible at the U.S. National Institutes of Health database (clinicaltrials.gov identification number NCT02865707).

Low-Grade Inflammation and Role of Anti-Inflammatory Diet in Childhood Obesity

At present, pediatric obesity is a significant public health concern. We have seen a surge of disorders that are obesity-related, e.g., insulin resistance (IR), type 2 diabetes mellitus (T2DM), high blood pressure, heart disease, stroke, cancer, non-alcoholic fatty liver disease (NAFLD), autoimmune disorders and many more. The mechanisms linking these diseases to excess body weight are related to low-grade inflammation (LGI). Although there is a limited number of studies assessing this immune process in childhood obesity, they indicate its significant importance for the health of future generations. There is a need for more research into the prevention and treatment of low-grade inflammation in childhood. The aim of this review is to present and discuss the process of "cold" inflammation, and its impact on health and anti-inflammation nutrition. A diet rich in anti-inflammatory nutrients may be the key to maintaining health, as well as recovery.

Effectiveness of diet, psychological, and exercise therapies for the management of bile acid diarrhoea in adults: A systematic review

BACKGROUND

Bile acid diarrhoea (BAD) causes chronic diarrhoea and is primarily treated pharmacologically. This systematic review aimed to evaluate the effectiveness of non-pharmacological therapies for evidence-based management of BAD in adults.

METHODS

A systematic review of the medical literature was performed from 1975 to 13 July 2021 to identify studies on diet, psychological, and exercise therapies that met diagnostic criteria for BAD in adults with diarrhoea. Effectiveness was judged by responder or improvement in diarrhoea at study endpoint according to each study's definition of diarrhoea. Therapeutic effect on abdominal pain and flatulence was also measured. Risk of bias was assessed using the Risk Of Bias In Non-Randomised Studies of Interventions tool. A narrative review was conducted using 'Synthesis Without Meta-analysis' guidance. Certainty of the evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation.

RESULTS

Eight prospective cohort studies were identified on diet therapies from 2 weeks to over 2 years involving 192 patients. No psychological or exercise therapies were found. Carbohydrate modification (one study, n = 2) in primary BAD, and dietary fat intake reductions (five studies, n = 181) and an exclusive elemental diet therapy (two studies, n = 9) in secondary BAD, showed beneficial directions of effect on diarrhoea, abdominal pain, and flatulence. Risks of bias for each study and across studies for each therapy type were serious. Certainty of the evidence was very low for all outcomes.

CONCLUSIONS

No conclusions could be drawn on the effectiveness of diet, psychological, or exercise therapies on diarrhoea, abdominal pain, and flatulence for the management of BAD in adults. High-quality randomised controlled trials are needed.

Nutrient, Fibre, and FODMAP Intakes and Food-related Quality of Life in Patients with Inflammatory Bowel Disease, and Their Relationship with Gastrointestinal Symptoms of Differing Aetiologies

BACKGROUND AND AIMS

Certain foods are reported as gut symptom triggers in inflammatory bowel disease [IBD], and fructans are shown to worsen non-inflammatory symptoms in inactive IBD, which may result in self-imposed dietary restrictions. The aim of this study was to investigate nutrient and FODMAP intakes, and the relationship between gut symptoms and dietary intake, in IBD.

METHODS

Nutrient, fibre, and FODMAP intakes were estimated using 7-day food records in patients with active IBD [Active IBD], inactive IBD with non-inflammatory gut symptoms [Inactive IBD-GI], inactive IBD without gut symptoms [Inactive IBD], and healthy controls. Nutrient intakes, numbers of participants achieving national recommendations, and food-related quality of life [FR-QoL] were compared across study groups.

RESULTS

Food diaries were obtained from 232 patients with IBD [65 Active IBD, 86 Inactive IBD-GI, 81 Inactive IBD] and 84 healthy controls. Patients with Active IBD had significantly lower intakes of numerous micronutrients, including iron, folate, and vitamin C, compared with controls. All IBD groups consumed less total fibre [4.5 to 5.8 g/day] than controls [p = 0.001], and total FODMAP and fructan intakes were lower in Active IBD compared with controls. Strikingly, FR-QoL was significantly lower in all IBD groups compared with controls [all p = 0.001].

CONCLUSIONS

This study revealed lower intakes of fibre, FODMAPs, and micronutrients, in addition to poorer FR-QoL, in Active IBD and Inactive IBD-GI with gut symptoms compared with healthy controls. Future research should address dietary restrictions responsible for these differences.

Can dietary intake protect against low-grade inflammation in children and adolescents?

In children and adolescents, chronic low-grade inflammation has been implicated in the pathogenesis of co- and multi-morbid conditions to mental health disorders. Diet quality is a potential mechanism of action that can exacerbate or ameliorate low-grade inflammation; however, the exact way dietary intake can regulate the immune response in children and adolescents is still to be fully understood. In this review, I discuss the current observational and interventional evidence that supports a potential therapeutic role for dietary intake in the amelioration of low-grade inflammation and highlight the need to develop a better understanding of the biological mechanisms underlying and attenuating the associations between dietary intake and low-grade inflammation in children and adolescents.

Daily Vegetables Intake and Response to COPD Rehabilitation. The Role of Oxidative Stress, Inflammation and DNA Damage

Chronic obstructive pulmonary disease (COPD) is a respiratory disease associated with airways inflammation and lung parenchyma fibrosis. The primary goals of COPD treatment are to reduce symptoms and risk of exacerbations, therefore pulmonary rehabilitation is considered the key component of managing COPD patients. Oxidative airway damage, inflammation and reduction of endogenous antioxidant enzymes are known to play a crucial role in the pathogenesis of COPD. Recently, also natural antioxidants have been considered as they play an important role in metabolism, DNA repair and fighting the effects of oxidative stress. In this paper we evaluated the response of 105 elderly COPD patients to pulmonary rehabilitation (PR), based on high or low vegetable consumption, by analyzing clinical parameters and biological measurements at baseline and after completion of the three weeks PR. We found that daily vegetable intake in normal diet, without any specific intervention, can increase the probability to successfully respond to rehabilitation (65.4% of responders ate vegetables daily vs. 40.0% of non-responders, p = 0.033). The association was especially evident in subjects ≥ 80 year of age (OR = 17.0; p < 0.019). Three weeks of pulmonary rehabilitation are probably too short to reveal a reduction of the oxidative stress and DNA damage, but are enough to show an improvement in the patient’s inflammatory state.

Food-related quality of life in adults with inflammatory bowel disease is associated with restrictive eating behaviour, disease activity and surgery: A prospective multicentre observational study

BACKGROUND

Measuring food-related quality of life (FRQoL) quantifies the psychosocial impact of eating and drinking. FRQoL and associated factors are not well explored in people with inflammatory bowel disease (IBD), despite IBD being a chronic disease affecting the digestive tract. The present study aimed to characterise and identify any patient or disease-related predictors of FRQoL in individuals with IBD.

METHODS

Adults with a formal diagnosis of IBD were recruited to a prospective multicentre cross-sectional study between April 2018 and December 2019. Participants completed questionnaires measuring FRQoL (FRQoL-29), clinical disease activity (Harvey Bradshaw Index and Simple Clinical Colitis Activity Index), restrictive eating behaviour (Nine-Item Avoidant/Restrictive Food Intake Disorder Screen), mental health (Depression Anxiety Stress Scale-21) and other patient and disease-related variables. A multivariable regression was performed to identify factors associated with FRQoL.

RESULTS

One hundred and eight participants completed the questionnaires (n = 39, Crohn's disease; n = 69, ulcerative colitis). The mean FRQoL was 79 (95% confidence interval = 75-84) (poor, 0; superior, 145). Poorer FRQoL was observed in those with restrictive eating behaviour associated with fear of a negative consequence from eating (p < 0.0001) and reduced appetite (p < 0.030). Greater FRQoL was observed in those with lower disease activity (p < 0.0001) and previous IBD surgery (p = 0.024). FRQoL was not associated either way by IBD phenotype, duration, or gender. The majority of participants obtained their dietary information from the internet (60%) or gastroenterologist (46%).

CONCLUSIONS

FRQoL in people with IBD is poorer in those with restrictive eating behaviours and clinically active disease. Interestingly, it was greater in those with previous IBD surgery. Further research is required to validate these associations and explore longitudinal effects of poor FRQoL on patient outcomes and potential strategies for prevention or management of impaired FRQoL in IBD.

Dietary Intakes of Recipients of Faecal Microbiota Transplantation: An Observational Pilot Study

This study reports on the dietary intake of recipients of faecal microbiota transplantation (FMT), comparing this with dietary guidelines, and investigates the relationship between dietary intake and clinical outcomes. Males and females aged ≥ 16 years with irritable bowel syndrome or inflammatory bowel disease undergoing FMT were invited to complete validated symptom and quality of life (QOL) questionnaires and three-day weighed food diaries. Descriptive statistics were calculated for symptom scores, QOL scores, nutrients, and food group servings, and compared to Australian population norms, nutrient reference values, and dietary guidelines. The relationship between dietary intake, symptoms, and QOL was assessed. Participants (n = 18) reported baseline symptoms of urgency, abdominal pain, nausea, and bloating and reduced QOL. Of the participants who completed food diaries, 8/14 met the recommended 30 g of fibre when including supplements. Participants met the recommendations for micronutrients and food groups except calcium, fruit, and dairy/dairy alternatives. There was a non-significant trend towards lower symptom severity scores in participants who met the fibre target. The high degree of variability in participant fibre intakes highlights diet as a key variable that has not been previously controlled for in FMT intervention studies. Future studies examining FMT should include dietary analysis of habitual intake of the recipients and donors.

Associations of Dietary Intake on Biological Markers of Inflammation in Children and Adolescents: A Systematic Review

BACKGROUND

In children and adolescents, chronic low-grade inflammation has been implicated in the pathogenesis of co- and multi-morbid conditions to mental health disorders. Diet quality is a potential mechanism of action that can exacerbate or ameliorate low-grade inflammation; however, the exact way dietary intake can regulate the immune response in children and adolescents is still to be fully understood.

METHODS

Studies that measured dietary intake (patterns of diet, indices, food groups, nutrients) and any inflammatory biomarkers in children and adolescents aged 2 to19 years and published until November 2020 were included in this systematic review, and were selected in line with PRISMA guidelines through the following databases: Academic Search Complete, CINAHL, Global Health, Medline COMPLETE and Web of Science-Core Collection. A total of 53 articles were identified.

RESULTS

Results show that adequate adherence to healthful dietary patterns such as the Mediterranean diet, or food groups such as vegetables and fruit, or macro/micro nutrients such as fibre or vitamin C and E, are associated with decreased levels of pro-inflammatory biomarkers, mainly c-reactive protein (CRP), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α), whereas adherence to a Western dietary pattern, as well as intake of food groups such as added sugars, macro-nutrients such as saturated fatty acids or ultra-processed foods, is associated with higher levels of the same pro-inflammatory biomarkers.

CONCLUSIONS

This is the first systematic review examining dietary intake and biological markers of inflammation in both children and adolescents. A good quality diet, high in vegetable and fruit intake, wholegrains, fibre and healthy fats ameliorates low-grade inflammation, and therefore represents a promising therapeutic approach, as well as an important element for disease prevention in both children and adolescents.

The Adequacy of Habitual Dietary Fiber Intake in Individuals With Inflammatory Bowel Disease: A Systematic Review

BACKGROUND

Dietary fiber may influence disease course in individuals with inflammatory bowel disease (IBD), yet there is a paucity of understanding of habitual fiber intakes.

OBJECTIVES

To identify studies measuring fiber intakes of individuals with IBD, compare the adequacy of fiber intakes with that of control groups or respective national dietary guidelines, and examine factors associated with fiber consumption.

METHODS

Five electronic databases-MEDLINE, CINAHL, SCOPUS, PROQUEST, and COCHRANE LIBRARY-were systematically searched, using search terms inflammatory bowel disease, Crohn's disease, ulcerative colitis, dietary intake, and fiber, until December 2019, with hand searching of reference lists. Primary studies were included if fiber intakes were measured in participants 18 years of age or older, with confirmed IBD, with or without comparison to a control.

RESULTS

A total of 2105 publications were identified, and 26 met inclusion criteria. Total fiber intake of 4164 participants with IBD ranged broadly (9.9 ± 7.8 g/day to 21.0 ± 10.5 g/day). Most (18/26) used cross-sectional study design, with a large degree of heterogeneity in tools measuring fiber intake. Sixty-six percent of studies comparing participants with IBD with control groups found that participants with IBD consumed significantly less fiber than control subjects. Four studies reported that less than 10% to 21% of IBD participants met their national fiber recommendations. Data conflicted regarding an association between disease type, disease activity, or rate of relapse and fiber intake.

CONCLUSIONS

Individuals with IBD consume less fiber than healthy populations. Fiber intakes are inadequate compared with respective national fiber guidelines. Interpretation of factors associated with fiber intakes were limited by data quality and conflicting results. Future research is required into factors associated with fiber intake and whether increasing fiber intakes can influence disease course and behavior.