On February 18, 2003, a metropolitan subway train was set on fire by an arsonist at the Jungangno Station in Daegu, South Korea. One hundred ninety-two people perished and hundreds more were injured. After this tragedy, a substantial number of survivors have struggled to overcome the traumatic memories and to return to their normal lives. Five years after the disaster, most survivors showed significant improvement in posttraumatic stress disorder (PTSD) symptoms, echoing our innate mechanism to promote psychological recovery from a severely traumatic event.

Around the world, fermentation of foods has been adopted over many generations, primarily due to their commercial significance with enriched flavors and high-profile nutrients. The increasing application of fermented foods is further promoted by recent evidence on their health benefits, beyond the traditionally recognized effects on the digestive system. With recent advances in the understanding of gut-brain interactions, there have also been reports suggesting the fermented food's efficacy, particularly for cognitive function improvements. These results are strengthened by the proposed biological effects of fermented foods, including neuroprotection against neurotoxicity and reactive oxygen species. This paper reviews the beneficial health effects of fermented foods with particular emphasis on cognitive enhancement and neuroprotective effects. With an extensive review of fermented foods and their potential cognitive benefits, this paper may promote commercially feasible applications of fermented foods as natural remedies to cognitive problems.

Autism spectrum disorder (ASD) is a common neurodevelopmental disorder with a lifetime prevalence of up to 1 in 100 individuals.^1-4 Autism spectrum disorder is typically diagnosed between 2 and 4 years of age based on delayed and atypical language and communication, impaired social interaction, and a restricted range of interests and is associated with functional and financial impacts throughout the individual's life span, as well as substantial distress to families.^5-7 Empirically validated interventions demonstrate that early intervention can substantially improve the prognosis for many, but not all, children with ASD.^8-10 An enhanced understanding of the neurobiological underpinnings of ASD would promote development of treatments targeting the underlying pathophysiology of this disabling disorder and could extend the benefits of early intervention.^11,12