Effects of gut microbiota on neurodegenerative diseases

Abstract

A progressive degradation of the brain’s structure and function, which results in a reduction in cognitive and motor skills, characterizes neurodegenerative diseases (NDs) such as Alzheimer’s disease (AD), Parkinson’s disease (PD), Amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD). The morbidity linked to NDs is growing, which poses a severe threat to human being’s mental and physical ability to live well. The gut-brain axis (GBA) is now known to have a crucial role in the emergence of NDs. The gut microbiota is a conduit for the GBA, a two-way communication system between the gut and the brain. The myriad microorganisms that make up the gut microbiota can affect brain physiology by transmitting numerous microbial chemicals from the gut to the brain via the GBA or neurological system. The synthesis of neurotransmitters, the immunological response, and the metabolism of lipids and glucose have all been demonstrated to be impacted by alterations in the gut microbiota, such as an imbalance of helpful and harmful bacteria. In order to develop innovative interventions and clinical therapies for NDs, it is crucial to comprehend the participation of the gut microbiota in these conditions. In addition to using antibiotics and other drugs to target particular bacterial species that may be a factor in NDs, this also includes using probiotics and other fecal microbiota transplantation to maintain a healthy gut microbiota. In conclusion, the examination of the GBA can aid in understanding the etiology and development of NDs, which may benefit the improvement of clinical treatments for these disorders and ND interventions. This review indicates existing knowledge about the involvement of microbiota present in the gut in NDs and potential treatment options.

The role of neuroinflammation in neurodegenerative diseases: current understanding and future therapeutic targets

“…An imbalance in gut microbiota, particularly a surge in detrimental bacteria and a decline in helpful bacteria has been connected to NDs like AD, PD, and HD (Kandpal et al, 2022). It is essential to understand the role of gut microbiota in these diseases to develop novel treatments, including antibiotics, probiotics, and fecal microbiota transplantation, aimed at maintaining healthy gut microbiota and potentially improving outcomes for NDs (Khatoon et al, 2023). Research indicates that changes in the gut microbial composition can result in changes in gut permeability, chronic systemic inflammation, and increased production of amyloid and tau proteins, which are hallmark features of AD, leading to neuroinflammation and neurodegeneration (Kowalski and Mulak, 2019).…”

Psychobiotics and the Microbiota–Gut–Brain Axis: Where Do We Go from Here?

“…Similarly, the link between specific pathogens and the onset of NDDs seems to be multifactorial and involves the activation of chronic inflammatory pathways [44], as it was recently highlighted between AD and the presence of Helicobacter pylori in the gut, which is no longer only associated with gut disorders but also with mental health [49]. Specific profile of gut microbiota alterations in humans suffering from the different NDDs were gathered in a recent review by Khatoon et al [50].…”

Emerging Paradigms in Inflammatory Disease Management: Exploring Bioactive Compounds and the Gut Microbiota

“…These substances primarily affect the biological functions of the GBA. Specifically, compounds such as tyrosine, IPA, 2-hydroxyphenylacetic acid, 3-hydroxyphenylacetic acid, and 4-hydroxyphenylacetic acid can lead to dysbiosis of the GBA by diet and BCs, while 5-HT, tyrosine, and these acids and hydroxyphenyl acetic acids can cause intestinal permeability [ 132 , 133 ]. Consequently, it is apparent that GM plays a role in maintaining both brain physiology and gut flora, and this has received particular attention from the scientific community.…”