Kombucha is one of the most intensively researched fermented beverages in recent years. Modern microbiological, nutritional, and clinical studies show that the drink possesses an exceptionally complex biochemical composition. During fermentation, numerous bioactive compounds are formed, including organic acids, polyphenols, enzymes, vitamins, and various microorganisms.
Current scientific literature shows several key effects and properties of kombucha:
- a high diversity of microorganisms, including bacteria and yeasts
- the formation of numerous bioactive metabolites during fermentation
- a high content of antioxidant polyphenols
- a potential modulation of the gut microbiome
- metabolic effects related to lipid metabolism and metabolic parameters
- a role of fermented acids in digestive processes and microbial balance
These properties make kombucha, from a scientific perspective, a particularly complex functional fermented food.
Fermentation: The Biochemical Origin of its Effects
Kombucha is produced by fermenting sweetened tea with a so-called SCOBY culture (Symbiotic Culture of Bacteria and Yeast). This symbiotic community of bacteria and yeasts forms a variety of bioactive metabolites during fermentation.
A comprehensive review describes kombucha as a dynamic microbial ecosystem in which yeasts convert sugar into ethanol and carbon dioxide, while acetic acid bacteria further metabolize this alcohol into organic acids (Jayabalan et al., 2014).
Among the most important substances formed during fermentation are:
- Acetic acid
- Gluconic acid
- Glucuronic acid
- Lactic acid
- Polyphenol metabolites
- Bacterial enzymes
This biochemical transformation means that kombucha has a significantly different composition than the original tea.
Recent microbiological analyses show that more than 200 different microbial species from over 30 genera can be identified in kombucha (Nutritional Metagenomics Analysis, 2021). Acetic acid bacteria such as Acetobacter and Komagataeibacter are particularly dominant and are responsible for the production of organic acids.
Polyphenols and Antioxidant Effect
An important part of the scientific research on kombucha concerns its antioxidant properties.
Tea – the basis of kombucha – already contains a high concentration of polyphenols, especially catechins, flavonoids, and phenolic acids. During fermentation, these compounds are partially enzymatically converted, making them more bioavailable.
A comprehensive analysis of the ingredients describes kombucha as rich in antioxidant compounds that are formed or enhanced during fermentation (Martínez Leal et al., 2018).
Polyphenols are particularly interesting scientifically because they:
- can reduce oxidative stress
- interact with metabolic processes
- influence microbial growth in the gut
In a clinical study with regular kombucha consumption, 145 different phenolic compounds were identified in the beverage, including flavonoids and phenolic acids (Costa et al., 2025).
These compounds play an important role in antioxidant protection mechanisms in the body.
The Microbiological Diversity of Kombucha
The microbiological composition of kombucha is one of the most important factors for its properties.
A genetic analysis of several kombucha samples showed that the beverage contains a stable community of bacteria and yeasts (Marsh et al., 2014). The most common microorganisms include:
Bacteria
- Komagataeibacter
- Acetobacter
- Gluconobacter
- Lactobacillus
Yeasts
- Saccharomyces
- Brettanomyces
- Zygosaccharomyces
- Pichia
These microorganisms form complex metabolic networks during fermentation and produce numerous bioactive metabolites.
The microbiological diversity is considered one of the reasons why kombucha is frequently studied in scientific research in connection with the gut microbiome.
Influence on the Gut Microbiome
The gut microbiome is one of the central research topics in modern nutritional science. Fermented foods are particularly in focus here.
A controlled clinical study from 2024 investigated the effects of kombucha consumption on the gut microbiome of adults. The analysis was based on high-resolution shotgun sequencing of stool samples (Ecklu-Mensah et al., 2024).
The results showed:
- Changes in the composition of the gut microbiota
- An increased presence of certain microbial species from fermented foods
- Adjustments in microbial metabolic pathways
Among other things, an increased relative abundance of Weizmannia coagulans and changes in metabolic pathways for vitamin and nucleotide biosynthesis were observed.
Further studies confirm these effects.
Intervention studies with regular kombucha consumption showed changes in the gut flora, including:
- an increase in Bacteroidota
- an increased presence of Akkermansiaceae
- an increase in Subdoligranulum, a known butyrate-producing gut bacterium (Costa et al., 2025).
Butyrate is one of the most important short-chain fatty acids in the gut and plays a significant role in gut health.
Another clinical study also showed that kombucha can increase the proportion of Bifidobacterium, a bacterial genus closely associated with gut health and immunological processes.
Effects on Digestion and Gut Function
Several clinical studies report on the effects of kombucha on digestive function.
A systematic analysis of clinical studies found that kombucha consumption was associated with improvements in certain gastrointestinal symptoms, including:
- improved stool consistency
- reduced discomfort with incomplete bowel emptying
- improved gut motility
The researchers attribute these effects to the organic acids contained in the beverage.
Organic acids such as acetic acid, citric acid, or malic acid can influence physiological processes in the gut. Studies show that these acids can increase gut motility by stimulating the production of prostaglandin E₂, which binds to receptors on smooth intestinal muscles and supports peristaltic movements.
Influence on Metabolism and Metabolic Parameters
Another area of research concerns the possible metabolic effects of kombucha.
A randomized intervention study with 60 participants investigated the effects of daily kombucha consumption over six weeks. Both metabolic parameters and changes in the gut microbiome were analyzed.
The results showed:
- Changes in lipid metabolism
- a reduction in triglyceride levels
- changes in the gut microbiota favoring certain bacterial groups
In parallel, a systematic review on kombucha and metabolic health showed that the beverage is associated with a reduction in oxidative stress, an improvement in metabolic processes, and a reduction in intestinal dysbiosis.
Antimicrobial Properties
In addition to its microbial effects on the gut microbiome, kombucha also possesses antimicrobial properties.
These are mainly caused by several factors:
- Acetic acid
- Gluconic acid
- low pH value
- phenolic compounds
Laboratory studies show that kombucha can have inhibitory effects against various pathogenic microorganisms. These properties are often attributed to the combination of organic acids and phenolic plant compounds.
Vitamins and Minerals
In addition to fermentation-related metabolites, kombucha also contains various micronutrients.
An analysis of the nutrient content showed the presence of several water-soluble vitamins and minerals in the beverage (Bauer & Petrusevska-Tozi, 2001).
These include, among others:
- B vitamins
- Vitamin C
- Potassium
- Magnesium
- Iron
These micronutrients partly originate from the tea and are partly formed during fermentation.
Kombucha as a Complex Functional Food
Modern scientific reviews increasingly describe kombucha as a functional fermented beverage, whose properties arise from the interaction of several factors:
- Fermentation of tea
- Microbial ecosystem of bacteria and yeasts
- Formation of organic acids
- High concentration of plant polyphenols
- Production of microbial metabolites
This combination leads to an exceptionally complex biochemical structure, which is increasingly being investigated in nutritional science.
A current review therefore describes kombucha as a beverage with "therapeutic potential due to its microbial diversity, bioactive metabolites, and antioxidant properties" (Prajapati et al., 2024).
Kombucha and Holistic Well-being
In addition to its biochemical properties, researchers are also investigating kombucha's role in the context of holistic nutrition.
A recent scientific analysis describes kombucha as a functional fermented beverage associated with various aspects of physical and mental health due to its microbial diversity, antioxidant compounds, and fermentation products (Batista et al., 2023).
The following areas, among others, are discussed:
- Metabolic processes
- Oxidative stress
- Gut microbiome
- General well-being
Popular science summaries of the research also highlight that kombucha contains a variety of bioactive ingredients that are produced through fermentation (Leech, 2023; Herzig, 2025).
Conclusion: Kombucha – A Versatile Fermented Beverage with Great Potential
Scientific research clearly shows that kombucha is far more than a fermented refreshing drink. Through the fermentation of tea, a complex mixture of bacteria, yeasts, organic acids, polyphenols, enzymes, as well as vitamins and minerals is created (Jayabalan et al., 2014; Martínez Leal et al., 2018; Bauer & Petrusevska-Tozi, 2001).
The microbiological diversity, in particular, makes kombucha interesting: Acetic acid and lactic acid bacteria, as well as various yeasts, produce bioactive substances that influence the gut microbiome and support physiological processes in the body (Marsh et al., 2014; Ecklu-Mensah et al., 2024). At the same time, the fermented ingredients provide antioxidant polyphenols, organic acids, and micronutrients that positively accompany metabolism, digestion, and general well-being.
Research also shows that kombucha not only supports the gut but can potentially have a holistic effect on the human organism. The interaction of fermented microflora, bioactive metabolites, and tea polyphenols creates a beverage that goes far beyond mere refreshment and provides insights into how fermentation can contribute to promoting health and well-being (Batista et al., 2023).
In short: kombucha is a functional, versatile beverage with an exceptionally complex composition that can naturally support the gut, metabolism, and general well-being.
Study Overview
Kombucha: Refreshing and healing through fermentation
Herzig, K. (2025). Kombucha: Refreshing and healing through fermentation. G. Dorschner (Exam.). You can find the complete article here.
7 Evidence-Based Health Benefits of Kombucha
Leech, J. (2023). 7 Evidence-Based Health Benefits of Kombucha. Healthline.
You can find the complete article here.
The health benefits of kombucha's ingredients and metabolites
Martinez Leala, J., Valenzuela Suárez, L., Jayabalan, R., Huerta Oros, J., & Escalante-Aburto, A. (2018). A review on health benefits of kombucha nutritional compounds and metabolites. CyTA - Journal of Food, 16(1), 390-399. You can find the complete article here.
Minerals and vitamins in kombucha
Bauer, B., & Petrusevska Tozi, L. (2001). Mineral and water soluble vitamin content in the Kombucha drink. International Journal of Food Science & Technology, 35(2), 201-205. You can find the complete article here.
An Overview of Kombucha – Microbiology, Composition, Fermentation & Health Benefits
Jayabalan, R., Malba, R. V., Lonar, E. S., Vitas, J. S., & Sathishkumar, M. (2014). A review on Kombucha tea—Microbiology, composition, fermentation, beneficial effects, toxicity, and tea fungus. Comprehensive Reviews in Food Science and Food Safety, 13(4), 538-550. You can find the complete article here.
Influence of Kombucha on the human gut microbiome and key health markers
Ecklu-Mensah, G., Miller, R., Maseng, M. G., Hawes, V., Hinz, D., Kim, C., & Gilbert, J. A. (2024). Modulating the human gut microbiome and health markers through kombucha consumption: A controlled clinical study. Scientific Reports, 14(1), 31647. You can find the complete article here.
Microbiological study on kombucha alchemy: Analysis of bacterial compositions
Marsh, A. J., O'Sullivan, O., Hill, C., Ross, R. P., & Cotter, P. D. (2014). Sequence-based analysis of the bacterial and fungal compositions of multiple kombucha (tea fungus) samples. Food Microbiology, 38, 171-178. You can find the complete article here.
The effect of kombucha on physical and mental health
Batista, P., Rodrigues Penas, M., Vila-Real, C., Pintado, M., & Oliveira-Silva, P. (2023). Kombucha: Challenges for health and mental health. Foods (Basel, Switzerland), 12(18), 3378. You can find the complete article here.
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