Abstract
BACKGROUND: The gut microbiota has been extensively studied for its relationship with mental health; however, there is limited systematic synthesis of empirical evidence examining its association with indicators of subjective well-being from an integrative gut–brain axis perspective. OBJECTIVE: To synthesize the available scientific evidence on the relationship between gut microbiota and subjective well-being through a qualitative systematic review. METHOD: A qualitative systematic review was conducted using the Scopus, PubMed, and SciELO databases. Eighteen studies published between 2019 and 2025 were included and analyzed using thematic analysis supported by Atlas.ti software, allowing the identification of narrative patterns and conceptual convergences across studies. RESULTS: Four thematic axes were identified: (1) the association between gut microbiota and subjective well-being; (2) the role of protective and risk factors—such as environmental conditions, lifestyle factors, and stress exposure—in modulating the microbiota; (3) the relationship between intestinal dysbiosis and mental health problems linked to neurochemical dysregulation; and (4) interventions focused on nutritional education, healthy caloric restriction diets, and the use of probiotic, prebiotic, and psychobiotic supplements. CONCLUSION: The findings indicate consistent associations between gut microbiota and subjective well-being, highlighting the relevance of contextual and behavioral factors related to microbial balance and well-being indicators.
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