Exploring the relationship between microbiome, immune system and cognitive health
The new review, partially conducted by employees of Danone SN Indonesia, concludes: “Disruption in the gut microbiota may lead to changes in the immune system’s effectiveness.”
The authors note: “Considering the intricate relationship between gut microbiota, immunity, and cognition, it can be assumed that disruption in the gut microbiota may lead to changes in the immune system’s effectiveness that will cause impairment in the central nervous system and cognitive functions.”
Significance
Research is increasingly focusing on the complex relationship between the central nervous system (CNS), gut, brain immune cells, and gut microbiota.
Maintaining a balanced interaction among these systems is vital for preserving homeostasis and preventing complications in the gut-brain and gut-immune axes.
The CNS relies on immune regulation governed by the blood-brain barrier, microglia, astrocytes, and oligodendrocytes.
Microglia, which help maintain brain homeostasis, can be activated by microbial and immune pathways.
One previous mouse study revealed short-chain fatty acids (SCFAs) produced by gut microbiota can trigger microglial activation.
Astrocytes, another group of brain support cells, can also be activated by gut microbiota metabolites, leading to an anti-inflammatory response.
Interactions among gut microbiota, the immune system, and the brain can occur during infection, neurogenesis, or medical treatments.
For example, certain bacteria induce autoimmune symptoms or promote the production of specific regulatory cells.
Dysbiosis in the gut-brain axis has been linked to anxiety and depression, and chemotherapy-induced dysbiosis can lead to long-term complications, including alterations in cognitive functions and increased inflammation.
The authors note that understanding these complex relationships is crucial for developing strategies to maintain gut-brain and gut-immune axis homeostasis and mitigate associated complications.
The review
A comprehensive literature search was conducted in March 2022 across databases including Google Scholar, PubMed, EMBASE, and Cochrane.
The authors of the review concluded that a healthy gut microbiota is vital for maintaining gut homeostasis, and the review highlights how disruptions in the gut microbiota can contribute to the development of gastrointestinal diseases.
Studies show that colonisation of the gut during infancy plays a crucial role in long-term health outcomes, with abnormal development of gut microbiota during this period linked to conditions such as allergies, asthma, atopic eczema, and metabolic disorders.
Certain bacteria, like Staphylococcus and S. aureus, can affect peripheral metabolism and potentially contribute to obesity.
These gastrointestinal disturbances not only impact health outcomes but also can lead to a decline in quality of life and socioeconomic burden, as seen in irritable bowel syndrome (IBS).
The authors note that dietary interventions, such as the use of prebiotics, synbiotics, probiotics, and polyunsaturated fatty acids (PUFAs), can help mitigate the effects of early-life insults on gut microbiota.
Probiotics promote healthy gut microbiota, improve gut integrity, and enhance immune function, while PUFAs, especially omega-3 fatty acids, have anti-inflammatory properties and influence the composition of the gut microbiota.
The authors recommend that implementing nationwide programs to supplement nutrient sources, including synbiotics, prebiotics, probiotics, and fibre, could support the development of healthy gut microbiota and potentially prevent the progression of pathological conditions.
Although the cost of gastrointestinal pathologies associated with gut microbiota disturbances in Indonesia has not been quantified directly, studies have shown a correlation between low socioeconomic status and the prevalence of potentially pathogenic bacteria among Indonesian children.
The authors note these findings suggest the potential benefits of implementing nationwide programs to supplement nutrients and support gut microbiota development, thereby inhibiting the progression of pathological conditions.
Next steps
To gain deeper insights, the authors advocate for further primary research involving a larger sample size specifically within the paediatric population, suggesting that this could help elucidate precise factors shaping gut microbiota development and the consequences of its disruption.
Additionally, they note that exploring the potential for a nationwide nutrition supplementation program to foster healthy gut microbiota could provide valuable solutions for current paediatric nutritional challenges.
https://www.mdpi.com/2072-6643/15/12/2642
“Defining the Relationship of Gut Microbiota, Immunity, and Cognition in Early Life—A Narrative Review”
Authors: Melissa Stephanie Kartjito, Mikhael Yosia, Erika Wasito, Garry Soloan, Achmad Furqan Agussalim, and Ray Wagiu Basrowi.