By eliminating retinoic acid-inducible gene I (RIG-I) polyubiquitination in the brain and inhibiting the TLR4 and RIG-I-mediated NF-κB signaling pathways and inflammatory responses, Probiotic-4 improves the gut-brain axis and ultimately plays a neuroprotective role associated with cognitive impairment (Yang et al., 2020). The gene discussed is RIGI; the disease is Cognitive impairment.