Altering the gut microbiome to potentially modulate behavioral manifestations in autism spectrum disorders: A systematic review.

There is a potential association between gastrointestinal (GI) symptoms and the severity of autism spectrum disorder (ASD). Given this correlation, the possible impact of probiotics and prebiotics have been explored in research studies to modify the gut microbiome and ameliorate behavioral manifestations of ASD via modulating the gut-brain-microbiome axis. This systematic review focuses on the interplay between these factors in altering the behavioral manifestations of ASD. Probiotic supplementation tended to mitigate some of the behavioral manifestations of ASD, with less of a discernible trend on the microbiome level. Studies supplementing multiple probiotic species, such as microbiota transfer therapy, or including prebiotics performed better than single strain supplementation. Our analysis suggests that gut dysbiosis may increase intestinal permeability, leading to more severe GI symptoms and a systemic inflammatory response, which can alter permeability across the blood-brain barrier and synaptogenesis in the brain. Future studies are warranted to understand the precise contribution of altering gut microbiome on clinical manifestations of ASD that will open up avenues to develop preventive and treatment modalities.

Evaluating the Efficacy of L-N-acetylcysteine and Dexamethasone in Combination to Provide Otoprotection for Electrode Insertion Trauma.

BACKGROUND: Electrode insertion trauma (EIT) during cochlear implantation (CI) can cause loss of residual hearing. L-N-acetylcysteine (L-NAC) and dexamethasone (Dex) have been individually shown to provide otoprotection albeit at higher concentrations that may be associated with adverse effects. Objective/Aims: The aim of this study is to determine whether L-NAC and Dex could be combined to decrease their effective dosage. MATERIALS AND METHODS: The organ of Corti (OC) explants were divided into various groups: 1) control; 2) EIT; 3) EIT treated with different concentrations of Dex; 4) EIT treated with different concentrations of L-NAC; 5) EIT treated with L-NAC and Dex in combination. Hair cell (HC) density, levels of oxidative stress, proinflammatory cytokines and nitric oxide (NO) was determined. RESULTS: There was a significant loss of HCs in explants subjected to EIT compared to the control group. L-NAC and Dex in combination was able to provide significant otoprotection at lower concentrations compared to individual drugs. CONCLUSIONS AND SIGNIFICANCE: A combination containing L-NAC and Dex is effective in protecting sensory cells at lower protective doses than each compound separately. These compounds can be combined allowing a decrease of potential side effects of each compound and providing significant otoprotection for EIT.