IBD

Question 1

Inflammatory bowel disease (IBD)

Answer 1

Inflammatory bowel disease (IBD) = a group of autoimmune conditions of the colon and small intestine. Crohn’s disease (CD) and ulcerative colitis (UC) are the principal types of IBD.

Question 2

IBD: Key symptoms

Answer 2

• Key symptoms (peaks 15‒35 years):

– Abdominal pain and diarrhoea.

– Urgency to pass stools.

– Rectal bleeding (more so in UC).

– Weight loss.

– Fatigue (blood loss and malabsorption).

Question 3

IBD: Key complications

Answer 3

• Key complications:

‒ Colorectal cancer, osteoporosis, anaemia (e.g. iron, folate, B12).

Question 4

IBD scheme

Answer 4

Question 4

IBD aetiology and pathophysiology

Answer 4

• IBD is characterised by the interaction between a genetically-susceptible individual and environmental factors, which have an impact on gut microbiota composition, triggering overly aggressive T-cell responses.
• Genetics — there are at least 163 genes involved in IBD. Many are shared between UC and CD but some are unique to each.
• Damage to the mucosal lining is very much associated with IBD

Question 5

Bacterial patterns commonly seen in IBD

Answer 5

• Very low / missing Akkermansia spp., ↑ R. gnavus and R. torques → mucus degradation.
• Raised gram-negative bacteria (e.g., Fusobacterium nucleatum) create a high LPS load, which in itself ↑ immune response.
• Bacteroides fragilis (enterotoxigenic) has also been associated as a trigger for IBD (its toxins destroy intestinal tight junctions).
• A lack of commensal bacteria diversity (especially the SCFAproducers) — necessary in times of mucosal tissue repair.

Lower numbers of F. prausnitzii, a bacterium that generates anti-inflammatory metabolic by-products, e.g., SCFAs incl. butyrate

Question 6

IBD triggers

Answer 6

Certain environmental factors alter mucosal barrier integrity, the immune response, or GI ecology:

• Medication use: Antibiotics, NSAIDs, oral contraception.
• Smoking (particularly CD).
• Stress.
• Infections (e.g., viral).
• Poor diet (e.g., ↓ fibre = ↓ commensal substrates and ↓ SCFAs; ↓ omega-3’s, ↑ arachidonic acid, ↑ refined sugars). Also, food additives such as carrageenan

Question 7

Dietary strategies for IBD

Answer 7

• Remove inflammatory foods / beverages (e.g., dairy, gluten, refined sugars, coffee, alcohol, damaged oils).
• Consider a low reactive dietary model such as SCD (especially for CD) or low FODMAP.
• Include well-cooked foods (slow-cooked at a low temperature) as well as soups, stews and broths that are easy to digest and nourishing.
• Consider an elimination diet to identify problematic foods.
• Optimise omega-3 to 6 ratio (e.g., skinless oily fish) can also be addressed via supplementation.
• Fresh green juices (chlorophyll rich, anti-inflammatory).
• Vitamin D — stabilises tight junctions, regulates mucosal

inflammation and supports commensal bacterial colonisation. Supports immune function (↓ inflammatory cytokines, e.g., TNF-α).

• Fish oils (4.5 g / day) — DHA and EPA have profound antiinflammatory effects, inhibiting NFκB, TNF-α and IL-6.
• Supporting the mucosal / epithelial barrier:

– Demulcent herbs (marshmallow root, slippery elm).

– Green tea — catechins and epicatechins support the mucosal barrier; inhibits COX-1 and 5-LOX.

– Vitamin A, N-acetyl glucosamine, zinc carnosine, L-glutamine

• Ginger (e.g., fresh or powdered in food; grated ginger steeped in hot water) — inhibits LOX, COX and TNF-α.
• Turmeric (2 g+ daily) — inhibits COX-2 and NF-kB.
• Quercetin — inhibits LOX and COX; down-regulates NF-κB.
• Aloe vera — inhibits COX and supports wound healing.
• Bowellia serrata (frankincense) — inhibits 5-LOX.
• Chamomile (infusion 2 tsp. dried herb) inhibits COX-2 and NF-Κb inhibition).
• Lion’s mane mushroom — promotes regeneration of the intestinal mucosa; acts as a prebiotic; immune-modulating
• Probiotics — species of Lactobacilii (E.g., L. acidophilus, L. casei) and Bifidobacteria have been shown to strengthen the epithelial barrier function and reduce inflammation. Advisable not to use in a flare.
• Prebiotics (e.g., FOS, psyllium) — bacterial fermentation of prebiotics = SCFAs, e.g., butyrate.
• Prioritise nutrient deficiencies in IBD: Vitamin B12 (esp. in CD), folate (depleted by methotrexate), iron (bleeding), zinc (poor absorption and faecal loss), calcium (low absorption, vitamin D deficient), potassium (diarrhoea), magnesium, vitamin A / D / E / K.