Gut Microbiota, Nutraceuticals, and Human Physiology: Scientific Evidence, Consumer Protection Laws, and Regulatory Perspectives: A Narrative Review

The human intestinal microbiota is a diverse community of microorganisms that has established itself as being crucial for human health and the course of various diseases. Growing evidence indicates that microorganisms in the human gut contribute to host physiological processes, including digestion, metabolism and immune responses as well as neurophysiological processes. Meanwhile, nutraceuticals are of great interest due to their demonstrated ability to influence and promote health through interaction with the intestinal microbiota. Nutraceuticals such as prebiotics, probiotics, synbiotics and postbiotics, as well as functional foods, have become a burgeoning product sector in the recent decade, and increased attention on product quality, security, potency and marketing claims has been attracted, as well as regulatory control and consumer protection laws. This narrative review seeks to discuss interactions between gut microbiota, nutraceuticals and human physiology, and evaluate scientific evidence and application of nutraceuticals along with their consumer protection legislation and regulatory structure in different countries.