Comparative Microbiome Profiles of Korean Fermented Foods Based on Production Type and Additive Use

Fermented foods are produced through controlled microbial activity and are valued for their extended shelf life, sensory attributes, and potential health benefits. This study examined the effects of production methods on microbial ecology by comparing microbial community structure, Shannon diversity, and pH changes in traditional and commercially produced Korean fermented foods. Cabbage and radish kimchi were fermented for four weeks to assess microbial succession and physicochemical changes, and additional fermented foods, including soy sauce, soybean paste, pepper paste, fruit vinegar, yogurt, and aged kimchi, were compared according to production method. Microbial communities were analyzed using amplicon sequencing targeting the V3-V4 regions of the bacterial 16S rRNA gene and the fungal internal transcribed spacer (ITS) region. Traditionally produced cabbage kimchi exhibited high microbial diversity at the early fermentation stage, initially dominated by <i>Weissella</i> and <i>Leuconostoc</i>, followed by a gradual shift toward lactic acid bacteria dominance at later stages. In contrast, commercially produced cabbage kimchi maintained a simplified microbial community dominated by a limited number of lactic acid bacteria throughout fermentation. Radish kimchi showed production-method-dependent patterns, with the rapid dominance of lactic acid bacteria during traditional fermentation and partial recovery of microbial diversity during commercial fermentation. Shannon diversity was consistently higher in traditionally produced kimchi during fermentation. In contrast, commercially produced kimchi exhibited more rapid acidification. Across other fermented foods, traditionally produced soy-based products exhibited complex microbial communities dominated by <i>Bacillus</i> spp., whereas commercially produced products were characterized by yeast-dominant profiles. Fruit vinegar and yogurt showed low microbial diversity regardless of the production method. These findings demonstrate the importance of production strategies in shaping microbial ecology, fermentation dynamics, and resulting product characteristics across various Korean fermented foods.