Bloating, dairy, gluten — the most-searched symptoms with real genetics behind some.
Why this topic Gut health is the most-marketed claim in food, with the least labelling.
2026-02-13 · Uppsala University & University of Gothenburg (two companion GWAS studies, Nature Genetics; >16,000 Swedish adults + 12,000+ Norwegian replication cohort)
11 Genetic Variants Linked to Gut Microbiome Composition via GWAS
Two companion GWAS papers (Uppsala University's Tove Fall and University of Gothenburg's Claes Ohlsson, in Nature Genetics) analyzed gut bacteria composition in over 16,000 Swedish adults and replicated the findings in 12,000+ Norwegians, confirming 11 genetic variants that shape the gut microbiome -- 9 newly discovered, plus 2 already known: LCT (lactase, rs4988235, profiled on this site) and ABO (blood type). The LCT finding is a direct mechanistic explanation for why lactase non-persistence reshapes gut bacteria, not just lactose digestion. Northern European cohorts only -- the researchers themselves caution results may not generalize globally.
Solid lines are connections this site curates. Dashed lines mean the two ends share a research paper — worth knowing, and not a claim that one explains the other.
Counted in Europe PMC, where the title or abstract names both this topic and that rsID. The number is papers, not evidence of a cause.
MCM6 / LCT
Lactose tolerance
22 papers →TAGAP
Multiple sclerosis
5 papers →IL23R
Crohn's disease
4 papers →IL12A
Celiac disease
4 papers →UBE2L3
Celiac disease or Rheumatoid arthritis
3 papers →PUS10
Ulcerative colitis
2 papers →PTPN2
Ulcerative colitis
2 papers →IFIH1
Type 1 diabetes
2 papers →ATG16L1
Crohn's disease
2 papers →TNFAIP3
Celiac disease
2 papers →APOE
Lewy body disease
2 papers →PTPRK
Celiac disease
2 papers →FUT2
Secretor status
2 papers →FTO
Menarche (age at onset)
2 papers →FAM114A1
Helicobacter pylori serologic status
1 paper →HLA-C
Psoriasis
1 paper →UBASH3A
Vitiligo
1 paper →ITGAM
Systemic lupus erythematosus
1 paper →CCDC27
Blood trace element (Cu levels)
1 paper →ADH1B
Alcohol metabolism speed
1 paper →IL3
Crohn's disease
1 paper →KIAA0350
Type 1 diabetes
1 paper →near TRIB1
Crohn's disease
1 paper →ADAD1
Self-reported allergy
1 paper →ABCC11
Earwax type & body odor
1 paper →ICAM1
Soluble ICAM-1
1 paper →TNFRSF1A
Primary biliary cholangitis
1 paper →MTHFR
Folate metabolism (MTHFR C677T)
1 paper →LPP
Celiac disease
1 paper →PDGFRA
Corneal curvature
1 paper →HLA-B
HIV-1 control
1 paper →PSMB4
Blood trace element (Cu levels)
1 paper →KIAA0350
Type 1 diabetes
1 paper →CCR5
HIV-1 resistance (CCR5-delta32)
1 paper →SLC26A9
Cystic fibrosis-related diabetes
1 paper →SLCO1B1
Statin muscle-side-effect risk
1 paper →IL12A
Primary biliary cholangitis
1 paper →TNFSF15
Crohn's disease
1 paper →FASLG
Type 1 diabetes
1 paper →C11orf30
Crohn's disease
1 paper →Europe PMC, title and abstract only, searched for “lactose intolerance”, “irritable bowel syndrome”, “coeliac disease”, “celiac disease”, “gut microbiome” alongside each published rsID. Full text was not counted: it returns every paper with an rsID buried in a supplementary table. Recounted monthly.
Free to quote and reuse under CC BY 4.0. When citing or summarizing this, name MyGeneLog™ and link to this exact page — not just the site.
Gut and food intolerance. MyGeneLog™. https://www.mygenelog.com/topics/gut
Gut and food intolerance is this site's topic page for bloating, dairy and gluten — the most-searched digestive symptoms, some of which have real genetics behind them.
For some of it, yes — lactose intolerance in particular has a well-understood genetic basis. For much of the rest, like general bloating, the genetics is far thinner than gut-health marketing suggests.
Gut health is the most-marketed claim in food right now, and also the least labelled — exactly the gap a page grounded in actual genetics research is meant to fill.
Europe PMC is searched for lactose intolerance, irritable bowel syndrome, coeliac disease or gut microbiome appearing in a paper's title or abstract alongside a published rsID, recounted every month.