The Gut-Brain Connection: Advancing Health Through Nutrition

Recent scientific discoveries have unveiled a profound link between gut health and brain function, positioning dietary choices and gastrointestinal well-being at the forefront of overall health.[1] This connection is particularly significant in two areas: the use of probiotics for digestive health[2] and the application of neuronutrition in stroke recovery[3].

Probiotics and the Aryl Hydrocarbon Receptor

A groundbreaking study published in Foods has shed light on how probiotics influence gut health through the Aryl Hydrocarbon Receptor (AhR) pathway.[4] This cytoplasmic receptor and transcription factor plays a crucial role in various physiological functions, including:

• Immune tolerance
• Gut barrier function
• Maintenance of intestinal homeostasis

Probiotics, especially strains like Lactobacillus and Bifidobacterium, have long been recognised for their benefits in gut health, such as improving the intestinal barrier and reducing inflammation. However, this study elucidates how probiotics interact at a cellular level by binding to AhR. The activation of AhR by probiotic metabolites, particularly those derived from tryptophan, is critical in modulating gut immunity [5]and enhancing intestinal integrity.

The Role of Tryptophan

Tryptophan, an essential amino acid found in protein-rich foods (e.g., poultry, eggs, dairy, nuts, and legumes), is metabolised in the gut by both host enzymes and resident microbiota. Bacteria play a crucial role in converting tryptophan into various bioactive metabolites, including:

• Indole derivatives (e.g., indole-3-acetic acid)
• Tryptamine
• Kynurenine pathway intermediates

AhR Activation and Its Effects

AhR can be activated by both external ligands (such as pollutants) and internal ligands (like bilirubin, biliverdin, and tryptamine). Dietary ligands that stimulate the AhR pathway include:

• 3,3′-diindolylmethane (DIM)
• Indole-3-carbinol (I3C)
• Curcumin
• Diosmin
• Urolithin A

By harnessing the AhR pathway, probiotics offer a promising avenue for maintaining gut health and mitigating gastrointestinal diseases.

Neuronutrition in Stroke Recovery

A study published in Nutrients introduces neuronutrition as a crucial element in post-stroke recovery, emphasising the brain’s capacity for neuroplasticity[6]. This emerging field of nutrition science advocates for targeted dietary interventions designed to optimise neural recovery and enhance rehabilitative outcomes[7].

Key Nutrients for Brain Recovery

Neuronutrition focuses on providing nutrients that support the brain’s functional restructuring post-stroke, including:

• Omega-3 fatty acids
• Choline
• Methyl folate
• Polyphenols
• Vitamins D, B12, and E
• Minerals such as zinc and magnesium

These nutrients are instrumental in promoting antioxidant defences, reducing oxidative stress, and balancing inflammation—all essential for neuroplasticity and brain recovery.

The Gut-Brain Axis: A Common Thread

Both studies highlight the importance of a well-functioning gut-brain axis, revealing how a balanced gut microbiota and strong intestinal barrier can reduce systemic inflammation, benefiting both gastrointestinal and neurological health.

Nutritional Synergies

Certain nutrients and bioactive compounds demonstrate dual benefits for gut and brain health:

• Omega-3 fatty acids improve cell membrane fluidity and support healthy microbiota composition.
• Polyphenols and vitamins E and C act as antioxidants, reducing inflammation and oxidative stress across bodily systems.

Recommended Supplements and Ingredients

Based on these studies, the following supplements and ingredients may support both gastrointestinal and neurological health:

By incorporating these nutrients and probiotics into one’s diet, individuals may support both gut and brain health, potentially improving overall well-being and recovery outcomes.[8]

References

[1] Sasso JM, Ammar RM, Tenchov R, Lemmel S, Kelber O, Grieswelle M, Zhou QA. Gut Microbiome-Brain Alliance: A Landscape View into Mental and Gastrointestinal Health and Disorders. ACS Chem Neurosci. 2023 May 17;14(10):1717-1763.

[2]  Nogueira-de-Almeida CA, Zotarelli-Filho IJ, Nogueirade-Almeida ME, Souza CG, Kemp VL, Ramos WS. Neuronutrients and Central Nervous System: A Systematic Review. Cent Nerv Syst Agents Med Chem. 2023;23(1):1-

[3]  12Badaeva AV, Danilov AB, Clayton P, Moskalev AA, Karasev AV, Tarasevich AF, Vorobyeva YD, Novikov VN. Perspectives on Neuronutrition in Prevention and Treatment of Neurological Disorders. Nutrients. 2023 May 28;15(11):2505

[4] De la Rosa González A, Guerra-Ojeda S, Camacho-Villa MA, Valls A, Alegre E, Quintero-Bernal R, Martorell P, Chenoll E, Serna-García M, Mauricio MD, et al. Effect of Probiotics on Gastrointestinal Health Through the Aryl Hydrocarbon Receptor Pathway: A Systematic Review. Foods. 2024; 13(21):3479.

[5]  Larigot L, Juricek L, Dairou J, Coumoul X. AhR signaling pathways and regulatory functions. Biochim Open. 2018 Jun 11;7:1-9. doi: 10.1016/j.biopen.2018.05.001. PMID: 30003042; PMCID: PMC6039966.

[6]  Ciancarelli, I.; Morone, G.; Iosa, M.; Cerasa, A.; Calabrò, R.S.; Tozzi Ciancarelli, M.G. Neuronutrition and Its Impact on Post-Stroke Neurorehabilitation: Modulating Plasticity Through Diet. Nutrients 2024, 16, 3705. https://doi.org/10.3390/nu16213705

[7] Berding K, Vlckova K, Marx W, Schellekens H, Stanton C, Clarke G, Jacka F, Dinan TG, Cryan JF. Diet and the Microbiota-Gut-Brain Axis: Sowing the Seeds of Good Mental Health. Adv Nutr. 2021 Jul 30;12(4):1239-1285. doi: 10.1093/advances/nmaa181. PMID: 33693453; PMCID: PMC8321864.