The composition of the oral microbiota was associated with nutrition and oral hygiene habits at the OTU level as well as taxonomic levels from genus to phylum, with significant associations with basal IL-8 levels, gender, body mass index (BMI), allergies, flossing habits, chewing gum use, and consumption of tea, meat, beer, white wine, and sweets (perMANOVA; p < 0.05, Table 4). This evidence concerns the gene CXCL8 and allergic disease.