Food for thought: Functional foods and microbial metabolites in diet-microbiome-brain communication

This scientific review critically examines the burgeoning field of the diet-microbiome-brain axis through the lens of food science, with a focus on the development and evaluation of functional foods. The review proposes dietary components thus, specifically prebiotic fibres, probiotics, fermented foods and polyphenols, as primary modulators of the gut microbiota, which in turn influences brain function via microbial metabolites such as short-chain fatty acids (SCFAs) and neuroactive compounds. Moving beyond mechanistic associations, the following analysis provides a critical appraisal of human clinical evidence, highlighting significant methodological limitations and the pervasive challenge of inter-individual variability. Central to the discussion are the practical implications for food science, including the synergistic design of ‘brain-healthy’ foods, technological hurdles in stabilizing live cultures and sensitive bioactives and the imperative for robust biomarker discovery to substantiate health claims. The review identifies key research gaps, emphasizing the need for longitudinal dietary studies, advanced model systems for establishing causality and a definitive shift toward personalised nutrition. Ultimately, the synthesis underscores the pivotal role of food scientists in translating complex gut-brain axis research into credible, effective and innovative nutritional strategies for cognitive and mental well-being.