In a study, Rose et al. [5] compared the microbiota and immune responses in children with ASD with and without gastrointestinal (GI) symptoms and showed that, following the stimulation of toll-like receptors, the autism group with GI symptoms have higher levels of cytokines such as interleukin-5 (IL-5) and interleukin-17 (IL-17) compared to the group without GI symptoms [5]. Here, IL17A is linked to autism.