The Correlations among Dietary Lifestyle, Microecology, and Mind-Altering Toxoplasmosis on the Health of People, Place, and the Planet

Being one of the most common foodborne protozoa worldwide, chronic toxoplasmosis caused by Toxoplasma gondii (T. gondii) could contribute significantly to the etiology of several mental disorders. The neurotropic parasite can directly influence the gut microbiota, causing inflammation with subsequent degradation of tryptophan required for parasite growth. Research in humans and animals shows that the gut microbiome is involved in the regulation of brain serotonergic pathways through the microbiota–gut–brain axis. Since the serotonin system is extensively interconnected with the body’s master clock through neuronal networks, the microbiota has been suggested as a potential mediator, fine-tuning circadian misalignment, following a reciprocal relationship with human eating patterns. Furthermore, adherence to an intermittent fasting diet can improve the serotonin biosynthesis pathway in the intestines and improve cognitive function. This review aims to explain the role of fasting in parasite-driven gut microbiome perturbation and the mechanisms by which Toxoplasma infection alters brain function. Due to its significant impact on social–economic status, diet patterns, microbiota disruption, circadian rhythm, chronic inflammation, and mental disorders, toxoplasmosis is an underestimated threat that could be prevented by simple lifestyle changes through educational actions. Furthermore, there are few research studies that address toxoplasmosis-induced mental disorders from a holistic perspective. Thus, a planetary health lens is needed to understand these correlations that directly relate to the promotion of a resilient and empathic civilization, crucial to enabling a flourishing healthy society on all scales.