Balancing Safety and Health: Microbial Dynamics in Food Systems

Microorganisms, though invisible to the naked eye, play a fundamental role in the global food system. The research from Prof. Xia Xiaodong, Associate Professor of the Department of Food Science and Nutrition at The Hong Kong Polytechnic University, focuses on these “invisible players” and their dual roles in enhancing food quality and posing risks to human health. His work integrates food safety with gut microbiome science, aiming to balance the control of harmful pathogens with the utilisation of beneficial microbes.

Microbes are present throughout the food chain. Beneficial microorganisms support soil health, plant growth and fermentation processes that produce foods such as yogurt, cheese, and bread. In contrast, harmful microbes—including pathogens such as Salmonella and Escherichia coli—could cause food spoilage and illness, creating significant public health and economic challenges.

A central focus of Prof. Xia’s research is understanding how pathogens survive in complex environments. His laboratory investigates mechanisms such as biofilm formation, quorum sensing, and two-component regulatory systems, which enable microbial adaptation and resistance. Quorum sensing allows bacteria to coordinate collective behaviours through signalling molecules, while two-component systems translate environmental cues into gene regulation via sensor kinases and response regulators. Together, these processes form an integrated multi-component signalling framework that enhances bacterial survival and persistence.

Building on this understanding, his team develops innovative strategies to detect and control harmful microbes. Notably, they have developed a hydroxyl radical water-based decontamination method for pathogens in foods, enabling rapid and eco-friendly food sanitation. 

In parallel, Prof. Xia explores the beneficial roles of microbes in human health. His research on Akkermansia muciniphila demonstrates its potential in alleviating hyperuricemia, highlighting the therapeutic value of gut microbiota and supporting the development of next-generation probiotics.

A key challenge in this field is balancing pathogen control with the preservation of beneficial microbes. Translating microbiome research into practical applications remains difficult due to the complexity of microbial identification and the need for both broad-spectrum and targeted interventions.

Despite these challenges, his work demonstrates strong real-world potential in improving food safety, advancing precision nutrition, and enabling microbiome-based therapies, contributing to safer, healthier and more sustainable food systems.