A Fungal World: Could the Gut Mycobiome Be Involved in Neurological Disease?

Abstract

The human microbiome has received decades of attention from scientific and medical research communities. The human gastrointestinal tract is host to immense populations of microorganisms including bacteria, viruses, archaea, and fungi (the gut microbiota). High-throughput sequencing and computational advancements provide unprecedented ability to investigate the structure and function of microbial communities associated with the human body in health and disease. Most research to date has largely focused on elucidating the bacterial component of the human gut microbiota. Study of the gut “mycobiota,” which refers to the diverse array of fungal species, is a relatively new and rapidly progressing field. Though omnipresent, the number and abundance of fungi occupying the human gut is orders of magnitude smaller than that of bacteria. Recent insights however, have suggested that the gut mycobiota may be intricately linked to health and disease. Evaluation of the gut mycobiota has shown that not only are the fungal communities altered in disease, but they also play a role in maintaining intestinal homeostasis and influencing systemic immunity. In addition, it is now widely accepted that host-fungi and bacteria-fungi associations are critical to host health. While research of the gut mycobiota in health and disease is on the rise, little research has been performed in the context of neuroimmune and neurodegenerative conditions. Gut microbiota dysbiosis (specifically bacteria and archaea) have been reported in neurological diseases such as multiple sclerosis, amyotrophic lateral sclerosis, and Alzheimer's, among others. Given the widely accepted bacteria-fungi associations and paucity of mycobiota-specific studies in neurological disease, this review discusses the potential role fungi may play in multiple sclerosis and other neurological diseases. Herein, we provide an overview of recent advances in gut mycobiome research and discuss the plausible role of both intestinal and non-intestinal fungi in the context of neuroimmune and neurodegenerative conditions.

Mycobiome in the Gut: A Multiperspective Review

“…Subsequently, the authors showed that supplementation with a probiotic Lactobacillus rhamnosus and Bifidobacterium animalis greatly improved psychiatric symptoms and normalized blood levels of C. albicans antibodies in schizophrenia [138]. A recent review by Forbes et al also describes the recent advancement in knowledge regarding gut mycobiome and the plausible role of gut mycobiota in neurological disorders [139].…”

Parkinson's Disease: A Comprehensive Analysis of Fungi and Bacteria in Brain Tissue

“…In the context of PD, the gut microbiota differs from control individuals and can influence α-synuclein aggregation [37,39,40]. Accordingly, the gut microbiota in each PD patient may contribute to disease pathogenesis [36,41]. With respect to fungal infection, a connection between the mycobiota and neurodegeneration has been recently reviewed [41].…”

Beyond Just Bacteria: Functional Biomes in the Gut Ecosystem Including Virome, Mycobiome, Archaeome and Helminths

“…Although bacteria dominate microbial communities, viruses, archaea, and fungi may also play pivotal roles in maintaining the gut homeostasis [9], as evidenced by a more recent steep increase in studies assessing the role of viral and fungal components of the microbiome. However, the viral and fungal biomes remain relatively uncharacterized thus far, due to their lower abundance as well as lack of optimized tools and curated reference databases for their identification and classification [10,11].…”