Lactobacillus bulgaricus: From Bulgarian Tradition to Global Probiotic Hero
- NPSelection
- Sep 5
- 4 min read
Lactobacillus delbrueckii subsp. bulgaricus, commonly known as L. bulgaricus, is more than just a yogurt bacterium. Its story connects ancient culinary traditions with cutting-edge microbiome science, offering surprising health benefits while bridging the gap between local heritage and global health trends. From humble beginnings in Bulgarian villages to starring on Japanese breakfast tables, this remarkable microbe has become a probiotic superstar.
Discovery and Historical Significance
In 1905, Bulgarian physician Stamen Grigorov discovered the lactic acid bacterium responsible for fermenting 'kiselo mlyako'—Bulgaria’s traditional yogurt. His identification of the rod-shaped Lactobacillus bulgaricus marked a milestone in microbiology. Grigorov’s discovery caught the attention of Nobel Prize-winning scientist Ilya Mechnikov, who associated the longevity of Bulgarian villagers with their daily yogurt consumption. Mechnikov suggested that L. bulgaricus might help combat ageing by suppressing harmful bacteria in the colon, a theory that boosted yoghurt’s reputation as a health food worldwide.
Fun Fact: During this period, stories of Bulgarian centenarians credited their long lives to daily yogurt consumption, captivating both the scientific community and the media.
Taxonomy and Renaming: A Living Fossil in Microbiology
Initially named Lactobacillus bulgaricus in honour of Dr S. Grogorov, this bacterium underwent taxonomic refinement in 1984, becoming Lactobacillus delbrueckii subsp. bulgaricus. Despite the name change, its association with Bulgarian yogurt culture remains strong. In 2020, the entire Lactobacillus genus was reclassified based on genomic data. Remarkably, L. delbrueckii and its bulgaricus subspecies retained their original placement, considered a 'genomic fossil'—an ancient lineage of lactic acid bacteria that survived centuries of dairy fermentation.
Geographic Origins and Japan's Love Affair with Bulgarian Yogurt
Native to the Balkan Peninsula and the mountains of Bulgaria, L. bulgaricus found global fame thanks to industrial dairy production.
A remarkable example is Japan’s long-standing relationship with Bulgarian yogurt. In the 1970s, Meiji Dairy collaborated with the Bulgarian government, securing authentic L. bulgaricus strains for their iconic “Meiji Bulgaria Yogurt.” This partnership continues today, with LB Bulgaricum, a Bulgarian state-owned company, managing the export of starter cultures. In Japan, Bulgarian yogurt is so revered that a “Day of Bulgarian Yogurt” is celebrated annually, reflecting its cultural and health significance. (Meiji Holdings, 2024; LB Bulgaricum, 2024). (Meiji Holdings, 2024).
Evolutionary Importance: A Survivor from the Ice Age?
Genomic studies suggest that L. bulgaricus evolved from wild lactic acid bacteria associated with grasses consumed by herbivores. Over millennia, it adapted to milk fermentation, losing genes needed to colonise the human gut permanently. This high level of specialisation makes L. bulgaricus an evolutionary relic, ideally suited for dairy but unable to survive long-term in the human intestine. Its role is not colonisation but to exert potent, immediate benefits during and shortly after consumption.
Health Benefits for the Microbiome
Although L. bulgaricus is a temporary visitor to the gut, it provides several highly effective benefits:
1. Helps digest lactose, aiding those with lactose intolerance. (He et al., 2008)
Lowers intestinal pH through lactic acid production, inhibiting harmful microbes (Tomas et al., 2014)
Enhances gut barrier function and mucin production. (Liu et al., 2021)
Modulates immune responses via interaction with gut-associated lymphoid tissue.(Bottari et al., 2022)
Produces metabolites that may reduce allergic inflammation and promote gut homeostasis.(Sun et al., 2022)
Recent studies also explore its role in synbiotics, postbiotic metabolites, and gut-brain axis modulation.
L. bulgaricus in Functional Foods and Therapeutics
Beyond yogurt, L. bulgaricus is now included in functional dairy drinks, probiotic cheeses, topical skincare formulations, and livestock feed to improve digestion and reduce infections. Its anti-inflammatory potential makes it an attractive candidate for mild inflammatory bowel conditions and immune modulation strategies.
Economic and Cultural Impact
For Bulgaria, L. bulgaricus symbolises national pride. The state-owned LB Bulgaricum holds patents and trademarks related to original strains. The yogurt itself is considered a protected geographical indication, much like Champagne or Parma Ham.
The Japanese import contracts are regarded as strategic cultural exports, reflecting economic value and a deep cultural connection.
L. bulgaricus in Yogurt Production: More Than Flavour
In yogurt production, L. bulgaricus is indispensable. It ferments lactose into lactic acid, giving yogurt its tangy taste and creamy texture. Working in synergy with Streptococcus thermophilus, it ensures proper fermentation, texture development, and probiotic properties. Traditional Bulgarian yogurts still use wild strains of L. bulgaricus, offering unique sensory profiles and potential health benefits distinct from industrialised versions.
From ancient dairy traditions to modern scientific research, Lactobacillus bulgaricus remains a symbol of the enduring power of fermented foods. Its unique role as a probiotic workhorse in yogurt production, coupled with emerging health benefits, ensures its continued relevance in global health and nutrition. Whether as a daily dietary habit or a subject of microbiome research, L. bulgaricus connects history, science, and health in a truly remarkable way.
What makes bulgaricus unique
Lactobacillus delbrueckii subsp. bulgaricus is unique for its long-documented role in supporting gut health through yogurt fermentation, backed by over a century of research linking it to improved digestion and a balanced microbiome.
References
- Bottari, B. et al. (2022). Potential Probiotic Properties of Lactobacillus delbrueckii subsp. bulgaricus: A Review. Foods, 11(5), 706.- Grigorov, S. (1905). Research on Bulgarian yogurt and lactic acid bacteria. Bulgarian Academy of Sciences.
- He, T. et al. (2008). Effects of yogurt and Lactobacillus strains on lactose malabsorption. Journal of Dairy Science, 91(3), 582–590.
- Gueimonde, M. et al. (2007). Competitive exclusion of enteropathogens by lactic acid bacteria. Journal of Applied Microbiology, 103(6), 2132-2141.
- Liu, F. et al. (2021). Lactobacillus bulgaricus enhances mucin expression and modulates gut microbiota in DSS-induced colitis. Nutrients, 13(1), 209.
- Marco, M.L. et al. (2017). Health benefits of fermented foods: microbiota and beyond. Current Opinion in Biotechnology, 44, 94-102.
- Mechnikov, I. (1908). The Prolongation of Life: Optimistic Studies.
- Sun, Z. et al. (2015). Genomics of Lactobacillus delbrueckii subsp. bulgaricus reveals dairy adaptation. Applied and Environmental Microbiology, 81(17), 6050-6059.
- Sun, J. et al. (2022). Anti-allergic effects of L. bulgaricus-derived metabolites. Frontiers in Immunology, 13, 900847.
- Tomas, J. et al. (2014). Lactic acid bacteria and gut microbiota modulation. Clinical Microbiology and Infection, 20(9), 1046-1051.
- Zhou, Y. et al. (2021). Lactobacillus delbrueckii subsp. bulgaricus alleviates colitis. Frontiers in Microbiology, 12, 705388.
- Zheng, J. et al. (2020). A taxonomic note on the genus Lactobacillus. International Journal of Systematic and Evolutionary Microbiology, 70(4), 2782-2858.
- LB Bulgaricum (2024). Official Website.- Meiji Holdings (2024). History of Meiji Bulgaria Yogurt.
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