Although a variety of probiotics have demonstrated abundance of Lactobacillus (i.e. Lactobacillus GG), a recent study showed that Lactobacillus reuteri, a commensal Lactobacillus strain, drove autoimmunity in a Toll-like receptor 7-dependent mouse model of lupus [42]. This evidence concerns the gene TLR7 and systemic lupus erythematosus.