Immune Function, Inflammation & Autoimmune Disease

Citation model. Claims grounded in AllNutrition's trust-scored library carry an inline bracketed reference [n] linking to the References section, which lists each source's evidence level and AllNutrition trust score (0–1). Where an AllNutrition query returned an overall evidence_strength and consensus_level, those labels are surfaced in the Evidence Review so readers can calibrate confidence. Only sources actually returned by the tool are cited; no trust scores are invented.

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1. Introduction

Few areas of clinical nutrition attract more marketing noise than "immune support." Bottles promise to "boost" or "supercharge" immunity; wellness culture treats inflammation as an enemy to be eliminated outright; and patients arrive with elimination diets self-prescribed after an online IgG panel. Underneath this noise sits a genuinely important and rapidly maturing science: nutrients are indispensable substrates and signals for both the cells that fight pathogens and the cells that must be restrained from attacking the host's own tissue. Malnutrition is one of the most common causes of secondary immunodeficiency worldwide, and diet quality measurably shifts the tone of chronic low-grade inflammation that underlies cardiometabolic and autoimmune disease alike.

This module draws a firm line between two related but distinct questions: does nutritional status permit normal immune function, and can diet push immune function above normal in an already-replete person. The first question has strong, actionable evidence — deficiency is real, common in specific subgroups, and correctable. The second question — the "boosting" claim underlying most supplement marketing — has almost no support in people who are not deficient. The module also addresses the growing evidence base on nutrition and autoimmune disease (rheumatoid arthritis, multiple sclerosis, psoriasis), the biology of inflammation resolution via omega-3-derived mediators, the real mechanics and diagnostic pitfalls of food allergy versus intolerance versus self-reported "sensitivity," and the gap between the trendy diagnosis of "leaky gut syndrome" and the legitimate science of intestinal permeability. Cross-reference Module 26 for a deeper treatment of the gut microbiome.

2. Learning Objectives

By the end of this module, the learner will be able to:

1. Describe how specific micronutrients (zinc, vitamin C, vitamin D, selenium, iron) and protein-energy status support innate and adaptive immune function, and identify populations at genuine risk of deficiency-related immunodeficiency.
2. Critically evaluate "immune-boosting" supplement claims, distinguishing correction of deficiency from supraphysiologic enhancement in replete individuals.
3. Explain the biology of chronic low-grade inflammation, the Dietary Inflammatory Index concept, and the role of omega-3-derived specialized pro-resolving mediators (resolvins, protectins, maresins) in actively resolving — not merely suppressing — inflammation.
4. Summarize the evidence for dietary and fasting interventions (Mediterranean diet, omega-3, intermittent fasting, autoimmune protocol) in rheumatoid arthritis, and identify the strength of evidence for diet in multiple sclerosis and psoriasis.
5. Differentiate IgE-mediated food allergy, non-IgE food intolerance, and self-reported food sensitivity by mechanism and diagnostic validity, and apply LEAP-trial evidence on early allergen introduction.
6. Critically appraise elimination diets and "leaky gut" claims, weighing legitimate intestinal-permeability science against unvalidated diagnostic entities.
7. Summarize vitamin D's mechanistic role in immune tolerance (Treg/Th17 balance) and the VITAL trial's autoimmune-disease findings, while communicating appropriate uncertainty.

3. Scientific Foundations

3.1 Nutritional foundations of innate and adaptive immunity

Micronutrients act less like fuel and more like calibration signals across every arm of the immune system. Zinc deficiency produces a recognizable syndrome sometimes called nutritionally acquired immune dysfunction syndrome (NAIDS): impaired T-lymphocyte maturation, reduced macrophage and neutrophil function, lymphoid tissue atrophy, and — through overexpression of the protein CREMα — reduced interleukin-2 production that blunts T-cell signaling; it also degrades epithelial tight-junction proteins (claudin-3, occludin), increasing gut and respiratory permeability [1][2]. Clinically, zinc supplementation robustly shortens pediatric diarrheal disease and reduces its mortality, but shows no consistent benefit for non-measles pneumonia — a reminder that "immune nutrient" effects are infection- and tissue-specific rather than generic [1].

Vitamin C supports leukocyte chemotaxis, phagocytosis, epithelial barrier integrity, and antioxidant defense against reactive oxygen species generated during an immune response [3]. Supplementation does not reduce cold incidence in the general population, but regular intake of ≥1,000 mg/day is associated with modestly shorter, less severe colds, with the largest benefit in those with two or more colds per winter and those under extreme physical stress [3][4].

Selenium, incorporated into selenoproteins such as glutathione peroxidases, protects immune cells from oxidative damage during the "oxidative burst," stabilizes IP3 receptor-mediated calcium signaling required for T-cell activation, and supports interferon production and NK-cell activity; deficiency is linked to increased RNA-virus virulence and worse COVID-19 outcomes, though its therapeutic window is narrow [5][6]. Iron functions as an "immunometabolic signal" — required for hematopoiesis, the oxidative burst, and mitochondrial respiration in activated immune cells — while the body's own inflammatory hypoferremia response ("nutritional immunity") sequesters iron to starve pathogens; both deficiency and overload impair host defense through different mechanisms [7].

3.2 Protein-energy malnutrition and immunodeficiency

Protein-energy malnutrition (PEM) is among the most common causes of secondary immunodeficiency globally. It causes atrophy of the thymus, spleen, and lymph nodes; glucocorticoid-driven redistribution of naïve CD4+ T cells out of lymph nodes into the bone marrow; reduced mucosal IgA and complement activity; and gut barrier disruption with bacterial translocation [8][9]. The result is a self-reinforcing "malnutrition–infection cycle": infection-induced anorexia and catabolism worsen malnutrition, while malnutrition blunts the febrile and localizing signs of infection, delaying diagnosis. Children recovering from severe acute malnutrition remain at elevated risk of severe pneumonia for months, and malnutrition impairs vaccine-induced antibody responses [10][8].

3.3 Chronic low-grade inflammation and immunometabolism

Beyond acute host defense, diet chronically tunes a lower-grade inflammatory tone that is mechanistically distinct from infection response but shares signaling machinery. The Dietary Inflammatory Index (DII) and its food-based variant quantify a diet's aggregate inflammatory potential [11]. Diets high in refined carbohydrate and saturated fat generate advanced glycation end-products that activate NF-κB and downstream TNF-α production, raise insulin-driven arachidonic acid synthesis, and — through emulsifiers, low fiber, and additives typical of ultra-processed foods — disrupt the gut barrier and admit endotoxin into circulation [11][12]. Conversely, fiber-fermenting short-chain fatty acids and polyphenols found in Mediterranean-pattern diets inhibit NF-κB, scavenge reactive oxygen species, and lower CRP, IL-6, and TNF-α; an umbrella review of anti-inflammatory dietary patterns found the Mediterranean diet has the strongest evidence, with Portfolio, Nordic, and DASH patterns sharing common anti-inflammatory mechanisms [13][14].

Immunometabolism — how immune cells rewire their metabolism to execute different functions — provides the mechanistic bridge to omega-3 biology. Obesity illustrates this vividly: hypertrophic, hypoxic adipocytes recruit M1-polarized macrophages that form "crown-like structures" secreting TNF-α, IL-6, and IL-1β; dendritic cells lose their tolerogenic phenotype; Treg differentiation is suppressed via sustained Akt activation while Th1 differentiation is favored; and B cells acquire a pathogenic, mitochondrially dysfunctional phenotype — collectively termed "meta-inflammation" [15][16]. Omega-3 fatty acids (EPA, DHA) counteract this by reprogramming macrophages from glycolysis toward oxidative phosphorylation, favoring an M2-like reparative phenotype via GPR120 and PPARγ signaling [17][18].

The most mechanistically elegant piece of this picture is inflammation resolution. Resolution is not passive fading of inflammation but an active, receptor-mediated program. EPA and DHA are converted via COX/LOX pathways into specialized pro-resolving mediators (SPMs) — E- and D-series resolvins, protectins, and maresins — which bind receptors such as GPR32/ALX-FPR2, ChemR23, and LGR6 to halt neutrophil infiltration, stimulate macrophage efferocytosis (clearance of apoptotic cells and debris), and inhibit NF-κB [19][20]. This SPM pathway is distinct from — and complementary to — the anti-inflammatory mechanism of simply displacing arachidonic acid, and its decline with age ("inflammaging") is an active area of research [19][21].

3.4 Immune tolerance and the microbiome-immune axis

Roughly 70% of the body's immune cells reside in gut-associated lymphoid tissue, making the intestine the primary site of immune "education." Commensal bacteria ferment dietary fiber into short-chain fatty acids (acetate, propionate, butyrate); butyrate in particular acts as a histone-deacetylase inhibitor that drives Foxp3+ regulatory T-cell (Treg) differentiation, the principal cellular brake on autoimmunity [22][23]. A shift away from SCFA-producing taxa (Faecalibacterium, Roseburia) toward pro-inflammatory Th17 skewing recurs across multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease, and type 1 diabetes, though the field cautions that these microbial "signatures" are associative and mechanistic causation in humans remains under investigation [22][24].

4. Clinical Relevance

Physicians will repeatedly face three overlapping clinical scenarios this module prepares them for. First, patients and parents asking whether a supplement can "boost" immunity — the correct, evidence-grounded answer distinguishes correcting a documented deficiency (strong evidence) from enhancing an already-adequate immune system (essentially no evidence, and some risk of harm from megadosing). Second, patients with autoimmune disease (RA, MS, psoriasis) asking whether diet can replace or reduce their medication — here the evidence supports diet as a genuine adjunct with measurable effect sizes, never a substitute for disease-modifying therapy. Third, patients self-diagnosing food sensitivities or "leaky gut" via unvalidated tests and pursuing restrictive elimination diets — here the clinician's job is to distinguish real, testable allergy/intolerance from unvalidated symptom constructs, and to weigh the real risk of nutritional harm from unsupervised restriction.

5. Evidence Review

Established (high confidence):

• Protein-energy malnutrition and specific micronutrient deficiencies (zinc, iron, vitamin A, vitamin D, vitamin C, selenium) cause measurable immunodeficiency and increase infection-related morbidity and mortality, especially in children. AllNutrition evidence_strength: strong/moderate, consensus_level: moderate [8][1][10].
• Zinc supplementation shortens duration and reduces mortality of pediatric diarrheal disease. evidence_strength: strong [1].
• Early, sustained peanut introduction in infancy (LEAP trial) reduces peanut allergy incidence by roughly 81% in high-risk infants, with allergen-specific, durable protection. evidence_strength: strong, consensus_level: moderate [25][26].
• Omega-3 fatty acids are enzymatically converted into specialized pro-resolving mediators (resolvins, protectins, maresins) that actively terminate inflammation via specific GPCR signaling. evidence_strength: moderate, consensus_level: mixed [19][20].

Probable:

• Omega-3 supplementation and Mediterranean-style diets modestly but measurably reduce disease activity and inflammatory markers in RA — the most consistent dietary evidence in this disease. evidence_strength: strong, consensus_level: mixed [27][28][29].
• Weight loss reduces psoriasis severity (PASI) in overweight/obese patients; a Mediterranean-diet RCT (MEDIPSO) achieved PASI75 in nearly half of participants. evidence_strength: strong, consensus_level: mixed [30][31].
• Vitamin D modulates the Treg/Th17 balance and supports thymic architecture — a coherent mechanistic case for its plausibility in autoimmune disease. evidence_strength: strong, consensus_level: moderate [32][33].
• Fiber- and polyphenol-rich, Mediterranean-pattern diets lower the Dietary Inflammatory Index and CRP/IL-6/TNF-α versus Western, refined-carbohydrate patterns. evidence_strength: strong, consensus_level: moderate [13][11].

Emerging:

• Intermittent fasting (16:8) shows short-term DAS28 reductions in RA meta-analysis, but studies are small, adherence-dependent, and confounded by concurrent weight loss; long-term safety is unestablished. evidence_strength: strong (per tool), consensus_level: mixed [34][35].
• Probiotic/synbiotic supplementation shows small-to-moderate improvements across RA, MS, and psoriasis in meta-analyses of >80 RCTs, but strain, dose, and host-microbiome heterogeneity limit firm recommendations. evidence_strength: strong (per tool), consensus_level: moderate [36][37].
• Diet in multiple sclerosis (Mediterranean, low-saturated-fat, ketogenic, fasting-mimicking) shows favorable associations with relapse rate and disability biomarkers, but trials remain too small for disease-modifying claims. evidence_strength: strong (per tool), consensus_level: mixed [38][39].
• VITAL-trial ancillary analyses linking vitamin D to reduced incident autoimmune disease are promising and mechanistically consistent, but need replication; the trial population was largely vitamin D–replete. evidence_strength: strong (per tool), consensus_level: moderate [33].

Controversial:

• Whether intestinal permeability ("leaky gut") is a driver or a consequence of systemic/autoimmune disease is unsettled; the underlying tight-junction/zonulin biology is real, but "leaky gut syndrome" as popularly marketed is not a validated standalone diagnosis. evidence_strength: limited, consensus_level: moderate [40][41].
• Self-reported food "sensitivity" (non-celiac wheat sensitivity, systemic nickel allergy syndrome) lacks validated biomarkers; double-blind challenges find only a minority of self-identified sensitive patients actually react to the implicated trigger. evidence_strength: moderate, consensus_level: mixed [42][43].

Unsupported / overstated:

• That supplements can "boost" immunity above normal in replete, healthy individuals. Evidence supports correcting deficiency, not enhancement; high-dose zinc, selenium, or vitamin C carry documented harms (copper deficiency, GI toxicity, kidney stones) without added benefit [2][44].
• IgG-based "food sensitivity" panels used to guide elimination diets. This session's AllNutrition query on this exact question timed out twice; professional allergy/immunology consensus broadly does not endorse IgG panels for this purpose, but this module flags it as an unverified gap rather than an AllNutrition-sourced claim.

6. Practical Clinical Applications

When nutritional immune support is indicated:

• Confirmed or high-risk zinc, iron, selenium, vitamin A, vitamin C, or vitamin D deficiency (vegetarians/vegans, older adults, chronic kidney/liver/GI disease, malnourished children) — correct via diet first, supplement to physiologic replacement doses with monitoring [1][7].
• Children with persistent diarrhea: zinc supplementation is evidence-based and should be part of standard management [1].
• High-risk infants (moderate-severe eczema, egg allergy) for early, sustained peanut introduction around 4–6 months per LEAP-informed guidelines — under allergist supervision if pre-existing sensitization is suspected [25][26].
• RA patients as an adjunct to (never replacement for) DMARDs: Mediterranean diet and omega-3 supplementation have the most consistent supporting evidence; discuss with rheumatology before high-dose fish oil in patients on anticoagulants [27][29].
• Overweight/obese psoriasis patients: structured weight loss (Mediterranean or medically supervised low-calorie approaches) as adjunct therapy [30][31].

When to avoid or exercise caution:

• Routine high-dose "immune-boosting" supplementation in replete, healthy individuals — no demonstrated benefit and documented risk of copper deficiency (chronic high-dose zinc), kidney stones (high-dose vitamin C), and hypercalcemia (high-dose vitamin D) [2][44].
• Unsupervised elimination diets based on IgG panels or self-diagnosed "leaky gut" — risk of iatrogenic malnutrition, sarcopenia, micronutrient deficiency, and adverse microbiome shifts (e.g., reduced Bifidobacteria on prolonged low-FODMAP diets) without validated diagnostic benefit [42][40].
• Prolonged or intermittent fasting in RA patients with osteoporosis risk, sarcopenia, type 1 diabetes, or disordered eating history without medical supervision — fasting can also interfere with DMARD/biologic pharmacokinetics [34][35].
• High-dose omega-3 in patients on anticoagulant/antiplatelet therapy — bleeding risk from reduced platelet aggregation [19].
• Vitamin D at chronic doses above the tolerable upper intake level in patients with granulomatous disease (sarcoidosis) or chronic kidney disease — hypercalcemia risk [44].

7. Clinical Pearls

• "Boosting" is not a real immunological state in a nutritionally replete person — ask "is this correcting a deficiency, or claiming to exceed normal?" before endorsing a supplement.
• Zinc's clinical benefit is infection-specific: strong for diarrhea, absent for non-measles pneumonia. Nutrient effects rarely generalize across all infections.
• Resolution of inflammation is an active, receptor-mediated process (resolvins, protectins, maresins) — not simply the withdrawal of a pro-inflammatory stimulus.
• In RA, diet is an adjunct with real effect sizes (Mediterranean diet, omega-3) — but it does not replace DMARDs, and patients should never be counseled that diet alone can control erosive disease.
• "Leaky gut syndrome" as a stand-alone diagnosis is not validated; intestinal permeability as a physiological phenomenon and contributor to some diseases is real and mechanistically documented — the clinician's job is to keep these two claims separate.
• Delaying allergen introduction in infancy is now known to increase, not decrease, allergy risk — the LEAP trial reversed decades of avoidance-based guidance.

8. Common Misconceptions

• "Natural immune boosters work because the immune system can always use more support." The immune system requires balance, not maximization; supraphysiologic nutrient status does not improve, and can impair, immune regulation (e.g., excess zinc causing copper deficiency and neutropenia) [2].
• "A positive IgG food panel means I'm allergic." IgG antibodies indicate exposure, not necessarily pathological reaction; these panels are not validated diagnostic tools for food allergy or intolerance (professional consensus, flagged here as a knowledge gap in this session's AllNutrition data — see Evidence Review).
• "Anti-inflammatory diets can replace RA medications." Diet produces modest, adjunctive improvements in inflammatory markers and pain; it does not have disease-modifying, joint-protective evidence comparable to DMARDs or biologics [29][27].
• "Leaky gut causes most chronic disease." Increased intestinal permeability is a real, measurable phenomenon associated with several diseases, but the popular framing of "leaky gut syndrome" as a unifying, self-diagnosable root cause of unrelated symptoms outpaces the evidence [40][41].
• "Multivitamins meaningfully boost immunity in healthy people." Meta-analytic benefit is concentrated in older adults and populations with baseline insufficiency; effect sizes in healthy, replete adults are small [4].

9. Summary

Nutrition and immunity intersect at two levels clinicians must keep separate. At the deficiency level, evidence is strong and actionable: zinc, iron, selenium, vitamins A/C/D, and protein-energy adequacy are required for normal immune function, and correcting documented deficiency — especially in children, older adults, and the malnourished — meaningfully reduces infection morbidity and mortality. At the "enhancement" level, evidence for boosting immunity above normal in replete individuals is essentially absent, and megadosing carries real, documented harms. Chronic low-grade inflammation is measurably shaped by diet — refined carbohydrate and saturated fat drive it via AGE/NF-κB and gut-barrier mechanisms, while fiber, polyphenols, and omega-3-derived specialized pro-resolving mediators actively resolve it via dedicated receptor pathways. In autoimmune disease, diet (Mediterranean pattern, omega-3, weight loss, possibly intermittent fasting) is a genuine, evidence-supported adjunct in rheumatoid arthritis and psoriasis, with more limited evidence in multiple sclerosis — but it never substitutes for disease-modifying pharmacotherapy. Vitamin D's mechanistic role in Treg/Th17 balance is well characterized, and the VITAL trial's autoimmune-disease signal is promising but needs replication. Finally, clinicians must distinguish real, mechanistically distinct entities — IgE allergy, non-IgE intolerance, and validated intestinal permeability — from unvalidated constructs like IgG "sensitivity" panels and "leaky gut syndrome," to protect patients from unnecessary restriction while taking the legitimate science seriously.

10. References

Ordered by evidence strength / relevance. Evidence level and AllNutrition trust score (0–1) as returned by the tool.

1. Understanding the Biological Evidence and Emerging Research Gaps in Nutrition That Impact the Health of School-Aged Children (BOND-KIDS). The Journal of Nutrition (2026). Review — trust 0.925.
2. Between Deficiency and Excess: The Dual Role of Selected Dietary Supplements in Immune Health. Cureus (2026). Review — trust 0.695.
3. Are the UK's vitamin C recommendations evidence-based? A critical comment. British Journal of Nutrition (2025). Review — trust 0.733.
4. Effects of micronutrient supplementation on immune function in older adults: a meta-analysis. Frontiers in Immunology (2026). Systematic review — trust 0.713.
5. Current Advances in the Physiological Roles of the Thioredoxin-Like Family of Selenoproteins. Biological Trace Element Research (2026). Review — trust 0.917.
6. The Role of Diet and Specific Nutrients during the COVID-19 Pandemic: What Have We Learned over the Last Three Years? International Journal of Environmental Research and Public Health (2023). Review — trust 0.725.
7. Iron as an immunometabolic signal in infection and inflammation. Frontiers in Immunology (2026). Review — trust 0.73.
8. Targeted pneumococcal conjugate vaccination strategies for high-risk children. Human Vaccines & Immunotherapeutics (2026). Review — trust 0.867.
9. Glucocorticoids intrinsically redirect naïve CD4+ T cells to the bone marrow for preservation in malnourished mice. Biology Open (2026). Observational — trust 0.74.
10. Insights into the mechanism of intestinal flora imbalance and immune disorder in co-morbidity of pneumonia and diarrhea in children. Frontiers in Pediatrics (2026). Review — trust 0.688.
11. Inflammation and Nutrition: Friend or Foe? Nutrients (2023). Review — trust 0.675.
12. Low polyphenol content is on the pathway between ultra-processed food consumption and low-grade inflammation (Moli-sani Study). Nutrition, Metabolism and Cardiovascular Diseases (2026). Observational — trust 0.767.
13. Dietary Patterns Associated With Anti-inflammatory Effects: An Umbrella Review of Systematic Reviews and Meta-analyses. Nutrition Reviews (2025). Systematic review — trust 0.835.
14. Overview of anti-inflammatory diets and their promising effects on non-communicable diseases. British Journal of Nutrition (2024). Review — trust 0.705.
15. Meta-inflammation in Hidradenitis Suppurativa: from pathogenic evidence to therapeutic approaches. Frontiers in Immunology (2026). Review — trust 0.838.
16. Gut microbiota and immunometabolism in obesity. Gut Microbes (2026). Review — trust 0.677.
17. Fatty Acid Metabolism in Health and Cancer: From Fundamental Mechanisms to Therapeutic Application. MedComm (2026). Review — trust 0.742.
18. Omega-3 modulates macrophage immunometabolic profile without changing Pseudomonas aeruginosa proliferation. Life Sciences (2026). Observational — trust 0.702.
19. Dietary Modulation of Postoperative Inflammation: Molecular Mechanisms and Implications for Tissue Repair and Healing. International Journal of Molecular Sciences (2026). Review — trust 0.775.
20. Bioactive Anti-Inflammatory Compounds and Therapeutic Strategies for Promoting Resolution. Nutrients (2026). Review — trust 0.688.
21. Dietary omega-6 arachidonic acid and omega-3 docosahexaenoic acid supplementation differentially impact skeletal muscle inflammaging in mice. bioRxiv (2026). Observational — trust 0.662.
22. The impact of diet on gut microbiome composition: Implications for immune-mediated diseases. Clinical Immunology Communications (2026). Review — trust 0.677.
23. Influence of Foods and Nutrition on the Gut Microbiome and Implications for Intestinal Health. International Journal of Molecular Sciences (2022). Review — trust 0.692.
24. Microbiome-orchestrated cross-organ immunity in autoimmunity: from metabolites to therapeutic targets. Frontiers in Immunology (2026). Review — trust 0.875.
25. Prevention and Treatment of Peanut Allergy. The New England Journal of Medicine (2026). Review — trust 0.762.
26. Infant Feeding and Allergy Prevention. Australasian Society of Clinical Immunology and Allergy (2020). Guideline — trust 0.83.
27. The Role of Microbiome and Diet on Disease Activity and Immune–Inflammatory Status in Rheumatoid Arthritis. Nutrients (2026). Review — trust 0.833.
28. Comparison of Mediterranean and healthy eating guideline interventions on the dietary inflammatory index in rheumatoid arthritis: RCT. European Journal of Nutrition (2026). RCT — trust 0.835.
29. Impact of Nutritional Diet Therapy on Rheumatoid Arthritis Disease Activity. Nutrients (2026). Review — trust 0.7.
30. Medical Nutrition Therapy in Dermatological Diseases: Joint Consensus Statement. Current Obesity Reports (2025). Review — trust 0.72.
31. A Powerful Way To Improve Psoriasis: The Mediterranean Diet Intervention Of The MEDIPSO Study. Journal of Dermatological Treatment (2026). RCT — trust 0.767.
32. 40 years later: Why do immune cells have vitamin D receptors? Journal of Steroid Biochemistry and Molecular Biology (2026). Review — trust 0.73.
33. Vitamin D in Gut and Systemic Immune Tolerance and in Infections' Risk: An International Evidence-Based Consensus Statement. Reviews in Endocrine and Metabolic Disorders (2026). Review — trust 0.757.
34. Intermittent fasting for rheumatic diseases: a systematic review and meta-analysis of conflicting evidence. PeerJ (2026). Systematic review — trust 0.827.
35. The impact of fasting and caloric restriction on rheumatoid arthritis in humans: A narrative review. Clinical Nutrition (2025). Review — trust 0.672.
36. Effect of Probiotic and Synbiotic Oral Supplementation in Autoimmune Diseases: An Updated Systematic Review and Meta-Analysis. Nutrients (2026). Systematic review — trust 0.825.
37. The Effects of Microbiome Modulating Therapies on Inflammatory Markers in Autoimmune Disease: A Systematic Review and Meta-Analysis. Nutrients (2026). Systematic review — trust 0.827.
38. Anti-aging and Anti-inflammatory Dietary Interventions in Multiple Sclerosis: A Narrative Review. Neurology and Therapy (2026). Review — trust 0.765.
39. Fasting, ketogenic, and anti-inflammatory diets in multiple sclerosis: an RCT with 18-month follow-up. BMC Nutrition (2025). RCT — trust 0.777.
40. Systemic Nickel Allergy Syndrome: A Critical Appraisal of an Unvalidated Diagnostic Entity. Clinical and Translational Allergy (2026). Review — trust 0.673.
41. Gut Microbiota during Dietary Restrictions: New Insights in Non-Communicable Diseases. Microorganisms (2020). Review — trust 0.9.
42. Reframing precision nutrition in irritable bowel syndrome: a mechanism-informed conceptual framework. Frontiers in Immunology (2026). Review — trust 0.95.
43. Recent progress in the effects and mechanisms of non-thermal technologies on alleviating food allergy. Food Chemistry (2026). Review — trust 0.7.
44. Optimizing vitamin D3 efficacy: the role of co-supplementation with Zn, Mg, and K2. Precision Nutrition (2026). Review — trust 0.833.

Supporting sources also surfaced: Vitamin D status, supplementation, and multiple sclerosis systematic review (Frontiers in Immunology 2026, systematic review, trust 0.842); Vitamin D as a cellular endocrine system (iScience 2026, review, trust 0.777); Vitamin D as a central modulator of thyroid diseases (Frontiers in Immunology 2026, review, trust 0.73); Reduced interleukin-2 production and increased CREMα protein expression in vegetarians/vegans due to zinc deficiency (Journal of Nutritional Biochemistry 2026, observational, trust 0.752); Immunometabolic control of cytokine production by micronutrients (Frontiers in Immunology 2026, review, trust 0.748); Altered Lipid Metabolism in Psoriatic Arthritis (Metabolites 2026, review, trust 0.875); Intestinal mucosal barrier injury: insights from interdisciplinary perspectives (Frontiers in Nutrition 2026, review, trust 0.733); The Effect of an Autoimmune Protocol (AIP) Diet in Adults With Rheumatoid Arthritis (Musculoskeletal Care 2026, observational, trust 0.672); Nuts For Babies Study protocol (BMJ Open 2025, RCT, trust 0.777).

Known evidence gaps this session: AllNutrition queries on (a) vitamin D supplementation and acute respiratory tract infection risk and (b) the validity of IgG food-antibody testing both timed out after repeated retries and returned no usable data; these claims are flagged rather than asserted, per the module's sourcing rules.