Early Exposure to Certain Antibiotics Might Promote Autism Spectrum Disorders (ASDs)—Related Dysbiosis in European Countries, Supporting Experimental Observations

Autism spectrum disorders (ASDs) are complex illnesses of largely unknown etiology with lifelong neurodevelopmental consequences. The global prevalence of au-tism has increased twentyfold to thirtyfold since the earliest epidemiologic observa-tions were reported in the late 1960s and early D1970s. Recent reports agree on the as-sociation of ASD with the modification of the microbiome (dysbiosis), which raises the possible role of external factors. Our study aimed to identify antibiotic classes that might be associated with the prevalence of ASD in 30 European countries through the possible modification of the intestinal microbiome. Statistical comparison was made between the average yearly consumption of different antibiotic classes (1997-2020) and the number of individuals living with ASD estimated for 2023/100000 population in 30 European countries, and the results were statistically analyzed. Tetracycline (J01A) showed significant positive (promoting) association with the prevalence of ASD (Pearson r: 0.373, p: 0.043. OR: 1.312, CI95%: 0.995-1.791, p: 0.065) and nar-row-spectrum, beta-lactamase resistant penicillin (J01CF) (Pearson r: 0.524, p: 0.003, OR: 3.240, CI95%: 1.710-8.853, p: 0.004, Kruskal-Wallis p: 0.032, post hoc test p: 0.027). Mild, negative (inhibitory) association was observed with broad-spectrum, be-ta-lactamase sensitive penicillin (J01CA) (Pearson r: -0.278, p: 0.157, OR: 0.808, CI95%: 0.649-0.957, p: 0.028) and narrow-spectrum, beta-lactamase-sensitive penicillin (J01CE) (OR: 0.725, CI95%: 0.543-0.885, p: 0,009). Our findings strongly support the animal experiments when penicillin V-exposed newborn mice developed "autism-like" behavior.