Insular resting state functional connectivity is associated with gut microbiota diversity

Area of Science:

• Neuroscience
• Microbiology
• Psychiatry

Background:

• The gut microbiota is increasingly recognized for its role in modulating brain activity.
• Associations between gut microbiota and neuropsychiatric conditions like depression, autism, and anxiety are reported.
• The insula plays a key role in processing signals from the gut via the vagus nerve.

Purpose of the Study:

• To investigate the relationship between gut microbiota diversity and structure and brain activity.
• To examine insular function using resting state functional connectivity (RSFC) in relation to the gut microbiome.

Main Methods:

• Faecal samples were collected from 30 healthy participants (non-smokers, tobacco smokers, and electronic cigarette users).
• Insular function was assessed using resting state functional connectivity (RSFC).
• Bacterial microbiota diversity and structure were analyzed and correlated with insular connectivity.

Main Results:

• Resting state functional connectivity (RSFC) between the insula and specific brain regions (left frontal pole, right lateral occipital cortex, right lingual gyrus, and cerebellum) correlated with gut microbiota diversity and structure.
• Specific bacterial genera, Prevotella and Bacteroides, differed between tobacco smokers and were associated with insular connectivity.
• The association between insular connectivity and the gut microbiome may be influenced by tobacco smoking.

Conclusions:

• Insular connectivity is associated with gut microbiome diversity, structure, and specific bacterial genera.
• Tobacco smoking may modulate this association, warranting further investigation in larger cohorts.
• The gut microbiota represents a potential therapeutic target for modulating insular connectivity, relevant to anxiety and tobacco use disorders.