Case Study: Rheumatoid Arthritis Remission in a 57-Year-Old Woman Using Gut-Directed Functional Medicine Protocol

Illustrative composite — not a single patient. This case study is a teaching composite synthesised from anonymised patterns in the published clinical literature and Nutri-Link case-history references. It does not describe a specific identifiable patient seen by Codenutri Ltd or any single practitioner. Names, demographic specifics, and quoted dialogue are constructed for educational illustration. Always work with a registered clinician for individual care. Editorial review by Chris Massamba, Dip CNM, FMCHC.

Patient Presentation

Margaret (not her real name), a 57-year-old retired primary school headteacher from Surrey, presented to the clinic in January 2026 after five years of progressively worsening rheumatoid arthritis that had forced her into early retirement.

Her presenting complaint, in her own words: "I was diagnosed with seropositive RA in 2021. The rheumatologist started me on methotrexate, then added sulfasalazine, then a biologic — adalimumab. For a while it helped. Then it didn't. My hands are so stiff in the morning I can't make a cup of tea for two hours. My knees ache going downstairs. I'm exhausted all the time — not normal tired, bone-tired. And my stomach has been a mess for years: bloating, unpredictable bowels, reflux. No one's ever connected the dots between my gut and my joints. I'm not sure anyone's tried."

Margaret's symptom timeline revealed a striking pattern. In 2019, two years before her RA diagnosis, she had completed three consecutive courses of broad-spectrum antibiotics for recurrent urinary tract infections — trimethoprim, then nitrofurantoin, then ciprofloxacin. Within months, she developed new-onset bloating, alternating diarrhoea and constipation, and multiple food intolerances she'd never had before. The joint pain began approximately twelve months after the gastrointestinal symptoms, starting in the small joints of her hands before spreading to wrists, knees, and ankles.

She reported that her joint pain flared noticeably after consuming wheat, dairy, and nightshade vegetables — a pattern she'd observed herself but which her rheumatology team had dismissed as coincidental. She was taking omeprazole daily for reflux, paracetamol for breakthrough pain, and had gained 11 kg since starting adalimumab.

Initial Clinical Assessment

Using the Stewart Nutrition deficiency symptom screening by body system, I systematically assessed Margaret for nutritional insufficiencies that could be driving her inflammatory state:

Musculoskeletal system: Joint pain and stiffness (wrists, MCPs, PIPs, knees, ankles), morning stiffness lasting >2 hours, muscle weakness in quadriceps — suggestive of vitamin D insufficiency, magnesium deficiency, and essential fatty acid imbalance.

Digestive system: Bloating within 30 minutes of eating, erratic bowel habits (constipation alternating with loose stools), reflux despite PPI therapy, multiple food intolerances — pattern consistent with small intestinal bacterial overgrowth (SIBO) and compromised gut barrier integrity.

Nervous system: Brain fog described as "cotton wool thinking," poor short-term memory, tingling in fingertips — suggestive of vitamin B12 insufficiency (possibly compounded by long-term PPI use impairing B12 absorption).

Immune system: Frequent upper respiratory infections (4-5 per year), slow wound healing, history of antibiotic overuse — indicating mucosal immune compromise and likely dysbiosis.

Energy systems: Profound fatigue not relieved by sleep, cold intolerance, unexplained weight gain — suggestive of mitochondrial dysfunction and possible thyroid involvement (despite normal TSH on previous testing).

Skin and mucous membranes: Dry skin, angular cheilitis, brittle nails with longitudinal ridging — classic signs of essential fatty acid deficiency and zinc insufficiency.

The pattern was unmistakable: this was not simply rheumatoid arthritis as an isolated autoimmune condition. This was a gut-driven systemic inflammatory disorder with multiple downstream nutritional and metabolic consequences. The antibiotics in 2019 had likely disrupted Margaret's gut microbiome, triggering intestinal permeability. Partially digested food proteins and bacterial lipopolysaccharides crossing the compromised gut barrier had primed her immune system for the autoimmune attack that manifested in her joints.

Functional Health Matrix Assessment

I scored Margaret across all seven nodes of the Functional Health Matrix, with 1 representing severe dysfunction and 5 representing optimal function:

Total Initial Matrix Score: 9/35 — a severely compromised system with the Assimilation node as the clear therapeutic priority.

Wheel of Life Assessment

Total Initial Wheel of Life Score: 29/80 — significant imbalance across physical health domains, with Movement, Stress Management, and Nutrition as the most dysfunctional dimensions.

Functional Testing Ordered

Based on the clinical presentation and matrix assessment, I ordered the following functional tests:

Comprehensive Stool Analysis (Genova Diagnostics GI Effects):

• Faecal calprotectin: 186 µg/g (elevated, reference <50)
• Pancreatic elastase: 198 µg/g (borderline low, reference >200)
• Zonulin: 142 ng/mL (markedly elevated, reference <107 — confirming intestinal permeability)
• Short-chain fatty acids: butyrate low at 4.2 µmol/g (reference >6.0)
• Commensal bacteria: marked deficiency in Bifidobacterium and Lactobacillus species
• No pathogenic bacteria, ova, or parasites detected

SIBO Lactulose Breath Test:

• Positive for hydrogen-dominant SIBO: baseline hydrogen 18 ppm, peak rise to 86 ppm at 80 minutes
• Methane: negative (peak 8 ppm)

Nutritional Evaluation:

• 25-OH Vitamin D: 28 nmol/L (deficient, optimal >75)
• Red blood cell magnesium: 4.2 mg/dL (borderline low, optimal >5.5)
• Plasma zinc: 10.2 µmol/L (low, optimal 12-18)
• Omega-3 Index: 3.8% (deficient, optimal >8%)
• Homocysteine: 14.2 µmol/L (elevated, optimal <8 — suggesting functional B12/folate insufficiency)
• hs-CRP: 6.8 mg/L (significantly elevated, optimal <1.0)

HPA Axis (DUTCH Complete):

• Flattened cortisol awakening response (CAR): 15% rise (optimal >50%)
• Low total daily free cortisol: 98 nmol (optimal 138-260)
• Cortisol-to-DHEA ratio: suggestive of early-stage adrenal insufficiency secondary to chronic inflammatory stress

Intervention Protocol

The therapeutic strategy followed three phases, addressing the Assimilation node first (as the identified root driver) before targeting downstream systems.

Phase 1: Gut Restoration (Weeks 1-6)

Dietary intervention:

• Modified elimination diet for 6 weeks, removing gluten, dairy, nightshades (tomatoes, peppers, aubergines, potatoes), refined sugar, alcohol, and processed foods
• Emphasis on anti-inflammatory foods: wild-caught salmon (omega-3), bone broth (collagen/glycine for gut barrier repair), turmeric, ginger, fermented vegetables (probiotic re-inoculation)
• Four-week rotation plan for remaining foods to prevent new sensitivities

SIBO eradication protocol:

• Oregano oil (standardised to 70% carvacrol): 200 mg three times daily, weeks 1-4
• Berberine HCl: 500 mg three times daily, weeks 1-4
• Partially hydrolysed guar gum (prebiotic): 5 g daily as tolerated, introduced week 3

Gut barrier support:

• L-glutamine: 5 g twice daily, ongoing
• Zinc carnosine: 75 mg twice daily, weeks 1-8
• Vitamin D3: 5,000 IU daily (loading dose for 8 weeks, then maintenance 2,000 IU)

Digestive support:

• Gradual PPI withdrawal over 3 weeks (rebound management with DGL licorice and slippery elm)
• Betaine HCl with pepsin: titrated up to 650 mg with protein-containing meals
• Digestive enzymes (broad-spectrum): 1-2 capsules with each main meal

Phase 2: Immune Modulation and Metabolic Restoration (Weeks 7-12)

Anti-inflammatory and immune modulation:

• Curcumin (BCM-95): 500 mg twice daily
• Omega-3 fatty acids (EPA/DHA): 3,000 mg daily (aiming for Omega-3 Index >8%)
• Vitamin D3 maintenance: 2,000 IU daily
• Magnesium glycinate: 400 mg at bedtime

Mitochondrial support:

• Coenzyme Q10 (ubiquinol): 200 mg daily (addressing probable methotrexate-induced depletion)
• Acetyl-L-carnitine: 1,000 mg daily
• Alpha-lipoic acid: 300 mg twice daily
• B-complex (activated forms): 1 capsule daily

HPA axis rebalancing:

• Phosphatidylserine: 300 mg at bedtime (cortisol modulation)
• Ashwagandha (KSM-66): 600 mg daily
• Morning sunlight exposure: minimum 15 minutes within 30 minutes of waking

Joint support:

• Collagen peptides (Type II): 10 g daily
• Glucosamine sulphate: 1,500 mg daily
• MSM: 2,000 mg daily

Phase 3: Lifestyle Integration and Maintenance (Weeks 13-16)

Movement programme:

• Week 13-14: daily 10-minute gentle walks, chair-based yoga (15 minutes, 3× weekly)
• Week 15-16: progressed to 20-minute walks, standing yoga sequence, introduction of resistance band exercises for quadriceps and gluteal strengthening

Sleep optimisation:

• Consistent sleep window 22:00-06:30
• Magnesium glycinate 400 mg with glycine 3 g at bedtime
• Blue light restriction from 20:00 (amber glasses)
• Bedroom temperature maintained at 18°C

Stress and identity restoration:

• Guided breathwork (4-7-8 pattern): 5 minutes, twice daily
• Weekly volunteering at local primary school library (re-establishing purpose and community connection)
• Journaling practice: 10 minutes daily, gratitude-focused

Medication management (coordinated with her NHS rheumatologist):

• Adalimumab: dose interval extended from 2 to 3 weeks (week 12), then to 4 weeks (week 16)
• Methotrexate: dose reduced from 15 mg to 10 mg weekly (week 16)
• Plan for further reduction contingent on inflammatory markers

Outcomes at 16 Weeks

Symptom resolution:

• Morning stiffness reduced from >2 hours to <15 minutes
• Joint pain (VAS): reduced from 7/10 to 2/10
• Grip strength: right hand improved from 12 kg to 18 kg, left from 9 kg to 15 kg
• Walking tolerance: from 15 minutes to 45 minutes without pain
• Bloating and bowel irregularity: fully resolved
• Reflux: resolved within 2 weeks of PPI withdrawal
• Fatigue: from 8/10 to 2/10 on fatigue severity scale

Repeat functional testing:

• Faecal calprotectin: 78 µg/g (significant reduction from 186)
• Zonulin: 89 ng/mL (normalised — gut barrier restored, reference <107)
• SIBO breath test: negative (peak hydrogen 22 ppm)
• 25-OH Vitamin D: 82 nmol/L (replete)
• Omega-3 Index: 7.6% (approaching optimal)
• hs-CRP: 2.1 mg/L (significant reduction from 6.8)
• Homocysteine: 8.4 µmol/L (normalised)

Repeat Functional Health Matrix (Week 16):

Repeat Wheel of Life (Week 16):

Patient testimonial: "I can make a cup of tea in the morning now. That probably sounds like a small thing, but for five years it was the thing I couldn't do. My hands work. My knees don't scream going downstairs. I walked my granddaughter to school last week — the whole way, about a mile. When I told my rheumatologist I'd reduced the adalimumab, she was sceptical. Then she saw my CRP. She said 'whatever you're doing, keep doing it.' I told her: I'm healing my gut. She said she'd heard that before. I said, yes, but this time someone actually tested it and treated what they found."

Clinical Pearls

1. The Assimilation node is the autoimmune ignition switch. In this case, antibiotic-induced dysbiosis → SIBO → leaky gut → systemic immune activation → joint-targeted autoimmunity. Rheumatoid arthritis was the manifestation, not the disease. Treating the joints with immunosuppression without addressing the gut was like mopping the floor while the tap was still running.

2. PPI therapy is a hidden driver of autoimmune pathology. Long-term omeprazole impairs protein digestion (through hypochlorhydria), mineral absorption (magnesium, zinc, calcium), B12 status, and the gastric acid barrier against oral bacteria. In an autoimmune patient, PPIs should be considered a modifiable risk factor, not a benign background medication.

3. Medication deprescribing requires biochemical evidence. Margaret's rheumatologist was comfortable reducing immunosuppression because we could show the falling CRP, normalising zonulin, and improving nutritional status. Clinicians respond to data. Generate the data.

4. The patient is the diagnostician when we listen. Margaret had already identified her food triggers (wheat, dairy, nightshades) and suspected a gut-joint connection years before she walked into my clinic. She'd been told it was coincidental. It wasn't. When a patient reports a pattern, believe them — and test it.