Anholt Heather
School of Population and Public Health, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
PLoS One. 2025 Jul 28;20(7):e0304044. doi: 10.1371/journal.pone.0304044. eCollection 2025.
The hygiene hypothesis proposes that declining exposure to microbial influences early in life is implicated in the rising trend of allergy and asthma in high-income societies. Approximately 8% of Americans have been diagnosed with asthma, representing 25 million people, and understanding how the human microbiome affects asthma could help guide exposure recommendations or microbe-based therapeutics. Toxoplasma gondii is a common gastro-intestinal microorganism that may modulate immune function. We used a cross-sectional study design to examine a public database of U.S. residents aged 6-80 years or older from the 2012-2014 survey cycles of the American National Health and Nutrition Examination Survey (NHANES) to construct an ordinal logistic regression model of the relationship between T. gondii infection and asthma. Of the 12,620 subjects tested for T. gondii infection, 89.2% were seronegative and 10.8% seropositive. No asthma was reported by 83.5% of subjects, while 16.5% reported varying degrees of asthma severity. We detected no significant association between T. gondii infection and asthma. While the unadjusted regression model suggested a small protective effect of T. gondii on asthma (OR = 0.90; 95% CI = 0.83-0.97), no effect was detected when the model was adjusted for key demographic factors (OR = 1.00, 95% CI = 0.91-1.10). While T. gondii may be a marker for the protective effect of exposure to a diversity of microbial organisms early in life, it has no apparent causal effect on asthma, or it may not be significant when considered in isolation.
卫生假说提出，在高收入社会中，人们在生命早期接触微生物影响的机会减少，这与过敏和哮喘发病率的上升趋势有关。约8%的美国人被诊断患有哮喘，患者人数达2500万，了解人类微生物组如何影响哮喘有助于指导暴露建议或基于微生物的治疗方法。弓形虫是一种常见的胃肠道微生物，可能会调节免疫功能。我们采用横断面研究设计，利用美国国家健康与营养检查调查（NHANES）2012 - 2014年调查周期中6至80岁及以上美国居民的公共数据库，构建了弓形虫感染与哮喘关系的有序逻辑回归模型。在12620名接受弓形虫感染检测的受试者中，89.2%为血清阴性，10.8%为血清阳性。83.5%的受试者未报告哮喘，而16.5%的受试者报告了不同程度的哮喘严重程度。我们未检测到弓形虫感染与哮喘之间存在显著关联。虽然未调整的回归模型显示弓形虫对哮喘有轻微的保护作用（OR = 0.90；95% CI = 0.83 - 0.97），但在对关键人口统计学因素进行调整后未检测到该效应（OR = 1.00，95% CI = 0.91 - 1.10）。虽然弓形虫可能是生命早期接触多种微生物产生保护作用的一个标志，但它对哮喘没有明显的因果效应，或者单独考虑时可能并不显著。
