Last reviewed: May 12, 2026 Last updated: May 12, 2026

Written by: Jay Hastings , CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance. His work has included scaling healthcare startups, leading CLIA lab integrations, and helping expand consumer access to precision health tools.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

This article is part of the PlexusDx Education Hub — your resource for evidence-based guidance on food, inflammation, and your genes. Browse all Diet & Genetics education

Why does the same meal leave one person feeling fine and another achy and bloated? Part of the answer is genetic. Your DNA shapes how you convert dietary fats, how strongly your immune system mounts an inflammatory response, and how you tolerate specific food components. A genetic test can add real context to that picture — though it is a starting point, not a diagnosis.

How food and inflammation are connected

Inflammation is a normal immune response to injury or infection. Problems arise when it becomes chronic and low-grade, a state linked in research to heart disease, type 2 diabetes, and autoimmune conditions. Diet is one input among many: diets high in refined sugar and certain fats tend to push inflammatory signaling up, while those rich in vegetables, fiber, and omega-3 fatty acids tend to pull it down. Genetics helps explain why the size of that effect differs between people.

FADS1 and FADS2: converting the fats you eat

The FADS1 and FADS2 genes encode desaturase enzymes that convert plant-based omega-3 and omega-6 fatty acids into the longer-chain forms your body uses in inflammatory and anti-inflammatory signaling. A common variant near these genes (rs174537) shifts how efficiently that conversion runs. People with lower-activity versions may derive less benefit from plant omega-3 sources and, in research, show different balances of pro- and anti-inflammatory fatty acids — useful context when choosing between flaxseed and marine omega-3 sources with a provider.

TNF and IL6: your inflammatory set point

Two of the most studied inflammatory signals are tumor necrosis factor and interleukin-6. A variant in the TNF promoter (rs1800629, the -308G/A change) and one in IL6 (rs1800795, -174G/C) are each associated in some studies with differences in how much of these messengers a person tends to produce. Think of them as influencing your baseline inflammatory "set point." They do not determine your health on their own, but they help explain why some people are more reactive to inflammatory dietary triggers than others.

Food-sensitivity genes: lactose and beyond

Some food reactions are less about inflammation genes and more about digestion. The MCM6 region controlling the LCT (lactase) gene — notably rs4988235 — determines whether you keep producing lactase into adulthood. People without lactase persistence often experience digestive symptoms from dairy that can feel inflammatory. Gluten-related risk is shaped by HLA genes, though those require clinical evaluation. Genetic markers flag possibilities to explore; they do not confirm a sensitivity by themselves.

What a genetic test can and cannot tell you

A genetic test offers pathway-level context: it can show that you carry variants associated with fat conversion, inflammatory signaling, or nutrient tolerance. It cannot diagnose an inflammatory condition, confirm a specific food allergy, or replace medical evaluation. The Precision Peptide Genetic Test analyzes 14 pathways, 49 peptides, 150+ genetic insights, including markers within inflammation- and metabolism-related pathways, and reports that biology so you and a qualified provider can decide what to test in real life. For the broader diet-and-DNA picture, see our guide to tailoring your diet to your DNA.

Turning genetic context into dietary experiments

The practical move is a structured elimination-and-reintroduction approach, guided by a provider or dietitian and informed by your genetics. If your markers suggest reduced omega-3 conversion, that is a reason to discuss marine sources; if lactase persistence is unlikely, dairy is a logical variable to test. You confirm what matters through your own response, not the genotype alone. Genetics is a guide, not a guarantee.

Frequently Asked Questions About Genetics and Food Inflammation

Can a genetic test diagnose a food allergy?

No. Genetic testing describes predispositions in pathways like fatty-acid conversion and inflammatory signaling, but it does not diagnose allergies or sensitivities. Confirming a true food allergy or intolerance requires clinical evaluation — which may include supervised elimination diets or specific testing — with a qualified healthcare provider.

Which genes are linked to food-related inflammation?

Commonly studied ones include FADS1 and FADS2, which govern omega-3 and omega-6 conversion, and TNF and IL6, which influence inflammatory signaling. MCM6/LCT variants affect lactose tolerance. These markers add context about tendencies; they work alongside diet, activity, and other factors rather than acting alone.

If I carry these variants, will anti-inflammatory foods still help?

Usually yes. Carrying a variant changes the size or nature of your response, not whether diet matters. Fiber, vegetables, and appropriate omega-3 sources remain broadly supportive. Your genetics simply helps you prioritize which changes to test first with guidance from your provider or dietitian.

Want to see how your own biology maps to these pathways? Take the Precision Peptide Genetic Test to turn guesswork into an informed conversation with your provider.

This article is part of the PlexusDx Education Hub. Browse all Diet & Genetics education

Disclaimer: The Precision Peptide Genetic Test analyzes how your genes influence peptide-related biological pathways. It does not recommend, prescribe, or determine which peptides you should use. Consult a qualified healthcare provider before beginning any peptide protocol.

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance. References are included at the end of the article when scientific, medical, or health-related claims are discussed.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.