The SARS-CoV-2 virus, which caused the COVID-19 pandemic, has produced a variety of clinical symptoms, with anosmia (loss of smell) emerging as a notable one. This narrative review aims to explore the incidence and severity of anosmia in COVID-19 patients compared to other respiratory infections. We analyze existing literature to highlight the pathophysiological mechanisms underlying olfactory dysfunction in COVID-19, its prevalence among different patient populations, and the implications for diagnosis and management. The review also discusses the potential long-term effects of anosmia on quality of life and the importance of olfactory training and therapeutic interventions. In order to improve patient outcomes, this paper advocates for the inclusion of anosmia in screening methods and additional research by summarizing current knowledge and highlighting the need for increased awareness of this important clinical characteristic of COVID-19.

A typical gastrointestinal and behavioral symptoms are hallmarks of autism spectrum disorder (ASD), a neuropsychiatric condition that affects children and adolescents. An important factor in the pathophysiology of ASD is the gut microbiome. The intensity of symptoms associated with autism spectrum disorder is thought to be influenced by neurodevelopmental impairment and gastrointestinal symptoms in people with ASD, which are thought to be caused by dysbiosis, or imbalance. In addition to discussing potential therapeutic approaches for treating autism spectrum disorders by modulating the gut-brain axis - which influences brain function through various mechanisms like neuroendocrine signaling, neuro-immune signaling, and bacterial metabolites—this review summarizes the current knowledge regarding the role of the gut microbial community in autism spectrum disorders.