Food and nutrition in IBD

Question 1

Definition of IBD: the two types and similarities and differences

Answer 1

1) ulcerative colitis: affects only the colon, and is characterised by ‘shallow inflammation’ which occurs along long lengths of the colon
2) Crohn’s disease: affects anywhere from the mouth to the anus in trans-mural skip lesions, giving this ‘cobble-stoned’ affect
- they are both chronic relapse and remitting diseases
- they are both characterised by symptoms such as: abdominal cramping, blood loss, weight loss, loss of appetite

Question 2

Incidence of IBD in the UK

Answer 2

• UC: 15.7/100,000
• CD: 10.2/100,000
• IBD: 28.6/100,000
• there has been an increase in incidence in 10-16 year olds of 94%, but a fall in incidence by 38% in those over 40 years

Question 3

Aetiology of IBD: role of western diets, milk protein, saccharin/sucralose, emulsifiers, omega 6/omega 3

Answer 3

• IBD does have a greater prevalence in Western regions, and has been linked to consumption of highly processed foods
• milk protein: in rodent study, only developed colitis if fed milk fat. Theory is that sulphur-rich bile is needed to digest, which provides a good environment for pathogenic bacteria and causes dysbiosis and inflammation of the gut
• saccharin/sucralose: epi studies in the US have showed decreased incidence of IBD when saccharin limited. Theory is that sweeteners cause dysbiosis and lower beneficial bacteria which worsens gut integrity and inflammation
• emulsifiers: such as polysorbate 80 (icecream) or maltodextrin (cereals), in rat models they increase intestinal permeability and predispose to bacterial translocation
• omega 3/6: increased risk of CD and UC according to meta-analyses with greater intakes of omega 6, higher intakes of total fat and meat. high intakes of LA have been linked to 30% increase in UC. Higher intakes of omega 3 have been linked to a 77% lower risk of UC. Recommended to follow Mediterranean diet

Question 4

Impact of IBD on nutritional status: hypercatabolism, nutrient malabsorption, anemia, increased GI losses, reduced nutrient intake, osteopenia/osteoporosis

Answer 4

• hypercatabolism: common in CD and in severe UC, due to increase in inflammatory cytokines
• nutrient malabsorption: more common in CD due to small bowel involvement, but may occur in US with mucosal disease. May be due to strictures, fistuales, resections, extensive disease, SBS
• anaemia: common in both if rectal bleeding
• increased GI losses: only in CD, due to vomiting, diarrhoea
• reduced nutrient intake: only in CD, most likely due to strictures causing obstruction and a lot of nausea and vomiting
• osteopenia/osteoporosis: common in both due to malnutrition and Ca + vitamin D deficiencies

Question 5

Nutrient deficiencies in IBD: weight loss, Fe, folate, B12, Ca, vitamin D, magnesium, zinc- recommendations?

Answer 5

• weight loss: can occur across both, a lot of fear or foods and vomiting/diarrhoea
• Fe: common in both due to blood losses (recommend eating red meats where possible, and pairing non-haem sources with vitamin C and avoiding Ca supplements or tannins around meals)
• folate: common in both due to blood loss, and also long term use of MTX (similar structure to folate- competitive inhibitor)
• B12: common in both, due to poor dietary intake, or could be due to terminal ileum resection
• Ca: may be due to poor dietary intake (avoidance of dairy as a trigger) and use of corticosteroids (recommend 1000 mg/day- ideally through dietary sources)
• vitamin D: greater requirements (due to corticosteroids) and poor intake
• magnesium and zinc: common in both especially if watery diarrhoea, may be due to bacterial overgrowth causing malabsorption or extensive mucosal disease
• recommend routine supplementation as deficiencies do appear to be independent of BMI and disease activity

Question 6

Dietary interventions: exclusive enteral nutrition (including ESPEN guidance)

Answer 6

• EN diet for 6-8 weeks recommended as 1L for children to avoid steroids (not recommended in adults as 1L due to steroids being more efficacious)
• no difference in literature on polymeric/peptide/elemental feeds to any is fine, but there MAY be better remission in lower fat feeds (<3g/1000kcal) but more trials needed
• as high as 60-80% remission rates are seen
• reasons for efficacy may be: removing food ‘antigens’, improving nutritional status, beneficial microbiome, anti-inflammatory effects (i.e. if have omega 3)

Question 7

Dietary interventions: Partial liquid diets

Answer 7

• Idea to have 35-50% of kcals from EN and the rest from food (i.e. 900 kcal + 3 Ensures)
• more UK based research needed

Question 8

Dietary interventions: LOFFLEX diet

Answer 8

• ‘low fat fibre-limited exclusion diet’
• list of foods which cause symptoms in >5% of CD patients after coming of EN diet- these are to be excluded
• examples: wheat, onion, coffee, corn, oats

Question 9

Dietary interventions for functional “IBS” symptoms in IBD

Answer 9

• IBS symptoms experienced by 35-57% of the population
• low FODMAP (fermentable oligosaccharides disaccharides monosaccharides and polyols)- poorly digested CHO may cause luminal distention in the colon as bacteria digest
• studies suggest low-FODMAP reduces symptoms and symptom severity score of IBS, but it can decrease beneficial bacteria in the gut so may need to use a probiotic alongside
• may also want to do low FODMAP for 4-8 weeks, see if symptoms improve, then start reintroducing foods again

Question 10

Dietary interventions: Crohn’s disease exclusion diet

Answer 10

• idea is that this removes all animal fats, dairy, gluten, emulsifiers (‘western’ diet)
• study in children showed that CDED versus EN alone caused remission in 75% versus 59% at 6 weeks, which changed to 75.6% and 45.1% at 12 weeks

Question 11

Dietary interventions: Specific CHO diet

Answer 11

• theory that tricky to digest CHO end up being fermented by gut bacteria and contributing to symptoms
• allows: fruits and vegetables, nuts, fresh meat, honey butter, home made yoghurt
• not allowed complex CHO such as starches, lactose, sucrose
• some very small studies have suggested a reduction in disease activity and remission rates with this diet

Question 12

Dietary interventions: semi-vegetarian diet

Answer 12

• plant-based eating, but much more focussed on the Japanese diet
• meat/fish only allowed once fortnight/once week
• 92% remission at 2 years in very small study versus 33% in omnivores

Question 13

Dietary interventions: CD-TREAT (solid EN)

Answer 13

• food based dietary approach where foods have exactly the same composition as EN
• in healthy adults this form of eating was thought to be more acceptable than liquid EN
• children on CD-TREAT: 60% went into remission
• larger trial in the works