# Unlocking Wellness: Probiotics as Key Drivers in Functional Food Innovation and Health Promotion
## 1 Introduction  
With continuous improvements in quality of life and increasing attention being paid to healthy living and nutrition, probiotics have gained popularity owing to their unique prebiotic properties and health benefits [1]. By the joint expert committees of the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO), probiotics are defined as \"live microorganisms that benefit the health of their hosts when taken in moderation\" [2]. Probiotics, alternatively termed live bacterial preparations, microecological regulators, ecological products, or biotin promoters [3]. They colonize the intestinal microecological system and, through multiple interactions, collectively maintain homeostasis in the body.  
Functional foods are foods that have potential health benefits beyond their basic nutritional value [4]. The health benefits of functional foods stem from their bioactive compound composition, which may be naturally occurring, formed during industrial processing, or extracted and added from other sources [5]. Probiotics, as essential functional ingredients, play a pivotal role in functional food manufacturing [6]. In recent years, the development and application of probiotics in functional foods have emerged as a significant focus in functional food research, while the global probiotic functional food market has undergone rapid expansion. According to Blue Weave data, the global market size was USD 60.23 billion in 2022, while China, as the second-largest market, had a market size of CNV 109.38 billion in the same year [7]. In the post-pandemic era, consumer demand for immune health has surged, further driving market expansion. For example, global sales of respiratory immuneprobiotics experienced a 45% surge in 2024 [8]. Furthermore, the global probiotic functional food market is projected to exceed USD 80 billion by 2025, exhibiting a compound annual growth rate of 8.5% during the forecast period [9]. With the increasing global burden of metabolic disorders and immune-related diseases [10], probiotics, as a scientifically validated natural intervention, have demonstrated their potential as an adjunctive strategy. Probiotics have demonstrated a positive impact on type 2 diabetes mellitus (T2 DM) through mechanisms such as improving insulin sensitivity and modulating glucose metabolism [11]. The application scope of probiotics in functional foods is gradually expanding, extending from traditional fermented dairy products to diverse sectors, including fruit and vegetable products and meat products. Concurrently, the development of innovative technologies such as microencapsulation [12] and biofilm delivery systems [13] has effectively addressed probiotic stability challenges in practical applications, thereby expanding the potential applications of probiotics in functional foods.  
This review comprehensively summarizes the latest developments in probiotic mechanisms and technological innovations in strain stabilization and provides a detailed introduction to the widespread application of probiotics in the field of functional foods. Furthermore, it comprehensively analyzes the safety assessment framework and regulatory discrepancies to achieve standardization in probiotic development for functional foods. With the continuous advancement of science and technology and the increasing market demand, the potential applications of probiotics in the field of functional foods are expected to expand, thereby bringing more benefits to human health.