Background

The human gut has historically been referred to as the ‘second brain’ because of the intimate and complicated pathways linking the enteric (gut) system to the central nervous system. This pathway is known simply as the gut-brain axis. The human gut is host to trillions of micro-organisms that include bacteria, viruses, archae (evolutionarily ancient microbes) and protozoa that collectively constitutes around 50-100 more genes than the human genome. This community of micro-organisms is known as the gut microbiome (MB) and is mostly thought to be beneficial to the host.

The pathways and mechanisms of gut-brain interaction are well understood but the contribution of the MB to the gut-brain axis is an area of active investigation.  The axis forms a two-way communication system in perpetual crosstalk. It is now thought that the MB modulates the gut-brain axis through its metabolites, by influence on the enteric system (a branch of autonomic nervous system governing gastrointestinal functions), and through the vagal nerve. Recent evidence from animal and laboratory-based studies suggests a potential role of an unbalanced MB to neuropathological conditions via the gut-brain axis.

Parkinson’s Disease (PD) is a neurodegenerative condition that primarily affects motor function but also comprises a range of non-motor deficits. The disease is characterized by early dysbiosis (gut problems) that may occur for several decades prior to the neurological problems, suggesting a potential causative role of the MB in the genesis of the condition.

Our study

We conducted a 12-week feasibility study with PD patients randomly allocated to either: (i), probiotic arm (Symprove) or (ii), placebo arm. Behavioral (mood, sleep, cognition, symptoms, quality of life measures) and microbiome data (extracted and sequenced using 16s), were collected at baseline and 12 weeks for both groups. We have presented findings at many conferences (list conferences) and worked with several other groups at Prodigest, UCL, SiTRAN, University of Sheffield investigating the microbiome (https://pubmed.ncbi.nlm.nih.gov/34977556/) in Parkinson’s disease and possible role of microbiome in Motor Neurone Disorder https://eprints.whiterose.ac.uk/170916/

Future Directions

Presently, we have several other studies about to start including an investigation of the microbiome in Multiple Sclerosis with Anouska Carter https://www.shu.ac.uk/about-us/our-people/staff-profiles/anouska-carter#firstSection and the AWRC (link), and also Long Covid and microbiome with Caroline Dalton https://www.shu.ac.uk/about-us/our-people/staff-profiles/caroline-dalton. Our external company collaborator is Symprove for these projects.

Findings might provide new ways of diagnosing and treating neurological conditions that currently have no cure and provide new directions for research combining expertise from Biosciences, Neuroscience, Dietitians, and exercise science.

Media

Conversation Articles

https://theconversation.com/long-term-antibiotic-use-by-middle-aged-women-may-affect-cognitive-function-new-study-179805

https://theconversation.com/your-gut-microbiome-may-be-linked-to-dementia-parkinsons-disease-and-ms-144367

Telegraph article

https://www.telegraph.co.uk/health-fitness/body/key-healthy-brain-may-lie-gut/