Fermented foods and the microbiome

Fermentierte Lebensmittel spielen aus ernährungsphysiologischer Sicht eine besondere Rolle, da sie durch mikrobielle Prozesse bereits vor dem Verzehr biologisch verändert werden. Während der Fermentation bauen Mikroorganismen Bestandteile wie Kohlenhydrate oder Eiweiße teilweise ab und bilden neue Stoffwechselprodukte, die Struktur, Sensorik und funktionelle Eigenschaften der Lebensmittel verändern. Diese Vorverarbeitung kann die Verdauung erleichtern und die Verfügbarkeit bestimmter Nährstoffe verbessern, ohne den Nährstoffgehalt selbst zu erhöhen. Fermentierte Lebensmittel interagieren zudem mit dem Darmmikrobiom, indem sie dessen Aktivität und Milieu modulieren, ohne gezielt oder vorhersehbar in die Zusammensetzung der Darmflora einzugreifen. Ihre Wirkung ist individuell unterschiedlich und stets im Kontext der gesamten Ernährung zu betrachten. Auch bei empfindlichem Darm oder enddarmbezogenen Beschwerden können fermentierte Produkte unterstützend wirken, jedoch ausschließlich im Rahmen einer angepassten, darmfreundlichen Ernährungsweise. Insgesamt sind fermentierte Lebensmittel kein therapeutisches Instrument, sondern ein traditioneller Bestandteil einer ausgewogenen Ernährung mit funktioneller Bedeutung für Verdauung und Darmgesundheit.
Philip Schmiedhofer, MSc

Autor

Philip Schmiedhofer, MSc

Inhaltsverzeichnis

What does fermentation mean from a nutritional perspective?

From a nutritional physiology perspective, fermentation refers to a biological transformation process in which microorganisms such as bacteria or yeasts enzymatically break down and alter the natural components of food.

Difference between fermented and non-fermented foods

The key difference between fermented and non-fermented foods lies in the microbial processing of the raw materials.

How fermented foods affect the gut microbiome

Fermented foods can interact with the gut microbiome in different ways, with effects that are not always predictable.

Probiotic and prebiotic effects of fermented food

Fermented foods can have probiotic and prebiotic effects. It is important to note that these two effects are clearly distinguishable from each other.

Fermentation and Digestion: Improved Nutrient Availability

Fermentation can positively influence digestion and nutrient availability of foods, as it leads to microbial pre-processing of the food before consumption.

Impact of Fermented Foods on Inflammation in the Gut

Fermented foods can indirectly influence the inflammatory status in the gut by affecting the microbial environment and the function of the intestinal mucosa.

Fermented diet for sensitive intestines

A fermented diet can be beneficial but also challenging for people with sensitive intestines.

The Importance of Fermented Products for Rectal Health

Fermented products can have a positive impact on rectal health, as they indirectly affect stool quality, the gut environment, and mucosal integrity.

Fermentation as a Component of a Gut-Friendly Diet

Fermentation is an important part of a gut-friendly diet. It can additionally support the intestinal environment.

Integrating fermented products into everyday life

Fermentation is an important part of a gut-friendly diet.

What does fermentation mean from a nutritional perspective?

From a nutritional perspective, fermentation refers to a biological transformation process in which microorganisms such as bacteria or yeasts enzymatically break down and alter natural components of foods. This process takes place under controlled conditions and occurs either with or without oxygen supply. Originally, it was developed to preserve foods.

 

During the fermentation process, carbohydrates, proteins, and other nutrients are partially broken down by the activity of microorganisms. New metabolic products, such as organic acids, are formed, which stabilize the food and change its properties. From a nutritional perspective, fermentation is not an additive but a microbial-level preprocessing of foods. A key feature of fermentation is the change in the food’s structure. Certain hard-to-digest components are reduced, while other ingredients become more available. At the same time, new taste, sensory, and functional properties arise, clearly distinguishing fermented foods from their non-fermented originals.

Fermentation is therefore not to be understood as a medical or therapeutic measure, but as a traditional nutritional process that biologically alters food. This process forms the basis for many classic foods and still plays an important role in a balanced, varied diet today.

Difference between fermented and non-fermented foods

The key difference between fermented and non-fermented foods lies in the microbial processing of the raw materials. Non-fermented foods are consumed in their original or only physically processed form. Fermented foods, however, undergo a controlled biological transformation process by microorganisms. In non-fermented foods, the structure and composition of the ingredients remain largely unchanged. Carbohydrates, proteins, and other components are present in their natural form and must be fully broken down by human digestion.

Fermented foods, on the other hand, undergo microbial preprocessing before consumption. During this process, the structure, composition, and properties of the food change. Certain components are broken down, others transformed or newly formed. This can lead to altered sensory properties such as taste, acidity, and texture, and influence the utilization of the food.

Characteristic

Fermented foods

Non-fermented foods

Processing method

Biological transformation by microorganisms

No microbial transformation

Structure of ingredients

Partially pre-digested

Largely unchanged

Sensory characteristics

Sour, aromatic, complex

Natural inherent flavor

Shelf life

Often extended

Depends on freshness and storage

Microbial activity

Partially active or inactive presence

No targeted microbial activity

Nutritional classification

Preprocessed food

Original food


This comparison illustrates that fermented and non-fermented foods mainly differ in their processing method and properties, but not fundamentally in their role within a balanced diet. An objective classification is crucial in this context.

Fermented foods are not inherently "better" or "healthier." Rather, they differ functionally from non-fermented products due to the prior microbial process.

How fermented foods affect the gut microbiome

Fermented foods can interact with the gut microbiome in different ways, with effects that are not always predictable. From a nutritional perspective, they mainly influence the microbial environment in the gut and its activity, but not in terms of a direct or guaranteed change in the gut flora.

 

A key aspect is that fermented foods contain microbial metabolic products that are formed during fermentation. These substances enter the gut and can serve as signals or substrates for existing gut bacteria. Fermented foods thus promote the functional activity of the existing microbiome rather than causing its complete renewal. Furthermore, fermented foods can indirectly influence microbial diversity by altering the gut environment. Due to their specific acidity and composition, they promote conditions under which certain microorganisms are encouraged or inhibited. However, the effects that occur vary individually and depend heavily on the initial composition of the microbiome. It is crucial to make a clear distinction: fermented foods are not a substitute for targeted medical therapy and should not be used as medicine. Their effect on the gut microbiome is modulatory, not controlling or deterministic. Studies show that the effects of fermented diets are very individual.

 

In summary, fermented foods influence the gut microbiome by supporting or altering its activity, environmental conditions, and metabolic processes. They are part of an overall nutrition concept and exert their effects not in isolation but in interaction with the rest of the diet and the individual gut environment.

Probiotic and prebiotic effects of fermented food

Fermented foods can have both probiotic and prebiotic effects. It is important to distinguish clearly between these two effects. From a nutritional physiological perspective, they describe different mechanisms of action that can complement each other but do not necessarily occur together.

A probiotic effect occurs when fermented foods contain live microorganisms that reach the gut in an active form. These microorganisms can temporarily interact with the existing gut flora. It should be noted that not every fermented food automatically contains live cultures. Even when microorganisms are present, their survival in the digestive tract varies individually. The prebiotic effect describes the action of certain food components that serve as a food source for already existing gut bacteria. Fermented foods can have a prebiotic effect because complex structures are broken down during the fermentation process, leading to more easily utilizable substrates. These can be used by the existing gut flora without the need to introduce new microorganisms.

Term

Significance

Classification of fermented foods

Probiotic effect

Effect of live microorganisms that reach the gut

Possible if live cultures are present; not given in all fermented foods

Prebiotic effect

Promotion of existing gut bacteria through utilizable food components

Often indirectly present through altered substrate structure

Depends on the individual

Effect varies depending on gut flora

Reactions to fermented food vary individually

Duration of effect

Usually temporary

No permanent change in gut flora guaranteed

Nutritional Physiological Role

Support of the gut environment

Part of a balanced, gut-friendly diet

It is crucial to understand that fermented foods are not automatically classified as probiotics. Their nutritional significance lies rather in their ability to influence the functional environment in the gut. Probiotic effects are possible but not guaranteed. Prebiotic effects are often indirect and depend on the individual composition of the gut microbiome.

In summary, fermented foods can have both probiotic and prebiotic properties. However, it is important to understand that their effect is supportive and modulatory. They do not replace targeted medical intervention but can contribute to the functional stability of the gut microbiome as part of a balanced diet.

Fermentation and digestion: better nutrient availability

Fermentation can positively influence digestion and nutrient availability of foods because it leads to microbial pre-processing of the food before consumption. From a nutritional physiology perspective, this means that certain components of the food become more accessible to the human body.

During the fermentation process, complex structures are broken down by microorganisms. The components include, among others, hard-to-digest carbohydrates and plant cell components. This process relieves the digestive work of the intestines, as certain nutrients no longer need to be fully broken down by the body itself. Another effect of fermentation is the reduction of inhibitory substances. Plant-based foods can contain natural compounds that impair mineral absorption. Fermentative processes can partially break down these substances, making minerals more available. Additionally, biologically active metabolic products are produced during fermentation that can support nutrient utilization in the gut. These changes do not affect the amount of nutrients contained but their physiological accessibility to the body.

An objective assessment is also crucial in this case.

Fermentation does not automatically lead to a higher nutrient density in foods. However, it can help make existing nutrients more efficiently utilized. The effect depends on the starting product, the fermentation process, and the individual digestive situation.

In summary, fermentation has a positive effect on digestion and nutrient availability. This is due to changes in food structure and better accessibility of nutrients for the human body.

Impact of fermented foods on inflammation in the gut

Fermented foods can indirectly influence the inflammatory status in the gut by affecting the microbial environment and the function of the gut mucosa. It is not about targeted treatment of inflammation but about modulating conditions important for a low-irritation gut environment.

A central mechanism lies in the metabolic products formed during fermentation. These enter the gut with food and can affect immune cells and mucosal cells there. A balanced microbial environment supports regulatory processes that help prevent excessive activation of the immune system in the gut. Furthermore, fermented foods help stabilize the ecological balance of the gut flora. A diverse and functionally active microbiome is associated with a controlled immune response. Disruption of this balance can lead to increased sensitivity or inflammatory readiness of the gut mucosa.

 

It is crucial to establish a clear distinction:

Fermented foods do not have medically anti-inflammatory effects and cannot replace medical treatment for inflammatory bowel diseases. Their influence should be understood as supportive and preventive and depends heavily on individual factors such as the initial state of the gut flora, overall diet, and lifestyle.

In summary, fermented foods can help promote a low-inflammatory gut environment by supporting microbial balance and positively influencing the interaction between gut flora and the immune system. Their effect always unfolds within the context of an overall balanced diet.

Fermented diet for sensitive intestines

A fermented diet can be beneficial but also challenging for people with sensitive intestines. The key factor is not the fermentation itself, but the individual tolerance of the respective foods and the composition of the gut flora.

Aspect

Importance for sensitive intestines

Preprocessing of food

Can aid digestion

Acidity

Can be perceived as irritating individually

Serving size

Small amounts are usually better tolerated

Individual reaction

Highly variable from person to person

Integration into the diet

Recommended slowly and gradually

Fermented foods already contain pre-processed components, which can ease digestion. At the same time, they may contain acids or biogenic substances that sensitive individuals might react to. For this reason, a gradual and individualized approach is essential for sensitive intestinal function. It is recommended that affected individuals integrate fermented foods in small amounts and well-distributed throughout daily life. This allows the intestine to gradually adapt to new stimuli. Careful selection of products is crucial. Mildly fermented foods are generally better tolerated than strongly fermented varieties.

An objective assessment is crucial in this context.

A fermented diet is not a universal solution for sensitive intestinal complaints. It is advisable to always consider it in the context of the overall diet and adapt it to personal tolerance.

Importance of fermented products for rectal health

Fermented products can have a positive effect on rectal health as they indirectly influence stool quality, the intestinal environment, and mucosal integrity. It is crucial to understand their role as functional rather than therapeutic. Fermented foods are not intended to treat rectal diseases but can influence the conditions important for the sensitive rectal area.

A central connection exists through stool regulation. Fermented products, combined with a high-fiber diet, can contribute to a more consistent stool texture. A soft, well-formed stool reduces mechanical stress during bowel movements and thus relieves the rectum. This is especially important regarding sensitive mucous membranes or existing irritation.

Medical indication

Connection with rectal health

Role of fermented diet (complementary)

Hemorrhoidal conditions (Grade I–II)

Increased pressure load, mucosal irritation

Support of stool regulation to reduce straining

Proctitis 

Inflammatory irritation of the rectal mucosa

Contribution to a stable, low-irritation intestinal environment

Anal fissure 

Pain-related stool withholding, hard stool

Accompanying promotion of soft stool consistency

Anal canal irritations / proctalgia (functional)

Hypersensitivity of the mucosa

Indirect relief through regulated digestion

Anal thrombosis

Pressure and tension sensation in the end-rectal area

Support for regular bowel emptying

Anal burning / anal itching (functional)

Irritations caused by stool, moisture, mucosal stress

Stabilization of the gut environment through diet

Marisken (symptomatic)

Mechanical irritation during bowel movements

Reduction of mechanical stress through stool quality

Chronic constipation with end-rectal strain

Persistent pressure and straining stress

Central nutritional accompaniment measure

Irritable bowel with proctological symptoms

Functional complaints in the end-rectal area

Individually tailored, cautious integration

Furthermore, fermented foods influence the microbial environment of the gut, which extends to the end-rectal area. A balanced gut environment can help support the mucosal barrier and reduce local irritations. The immunological balance in the end-rectal area also benefits from stable microbial conditions.

 

Fermented products can support end-rectal health as part of a gut-friendly diet by indirectly influencing stool quality, gut environment, and mucosal integrity. A consistent, well-tolerated stool consistency reduces mechanical stress during bowel movements, thereby relieving the sensitive end-rectal area. In addition to nutritional measures, local conventional therapy can be useful for existing end-rectal complaints. In this context, CANNEFF® SUP suppositories with CBD and hyaluronic acid are used to specifically moisturize, protect, and regenerate the mucosa in the end-rectal area. The combination of a tailored diet with fermented foods and locally effective mucosal care pursues a holistic yet medically clearly defined approach, where nutrition and medical products play different, complementary roles.

For an informed assessment, a clear medical classification is essential: fermented products are not a treatment method for anorectal diseases such as hemorrhoids or anal fissures. Their significance lies solely in supporting a gut-friendly diet that can functionally relieve the rectum.

Fermentation as part of a gut-friendly diet

Fermentation is an important part of a gut-friendly diet. It can support the intestinal environment complementarily. Due to their microbially pre-processed structures, they can be well integrated into a balanced, fiber-rich diet. They do not act in isolation but in interaction with other nutritional factors. A crucial aspect is an individual, moderate selection that considers personal tolerance.

Integration of fermented products into everyday life

Fermentation is an important part of a gut-friendly diet. It can support the intestinal environment complementarily. Due to their microbially pre-processed structures, they can be well integrated into a balanced, fiber-rich diet. They do not act in isolation but in interaction with other nutritional factors. A crucial aspect is an individual, moderate selection that considers personal tolerance.

Types of fermented foods

Examples

Typical integration in everyday life

Fermented fruits

Fermented berries, citrus fruits (e.g., lime, orange, pomelo), dried fruits (e.g., fig)

Small portions as a supplement to breakfast or snacks

Fermented roots and tubers

Ginger, turmeric, carrots, beetroot

Side dish to main meals or as a mild addition to dishes

Fermented vegetables

Sauerkraut, kimchi, fermented garlic, fermented cucumbers

Classic side dish to warm meals in moderate amounts

Fermented legumes

Tempeh, miso

Protein source in main dishes

Fermented beverages

Kombucha, water kefir, syrup, herbal essences

In small amounts, preferably with meals, pure or dissolved

Sources

Wastyk, H. C., Fragiadakis, G. K., Perelman, D., Dahan, D., Merrill, B. D., Yu, F. B., Topf, M., Gonzalez, C. G., Van Treuren, W., Han, S., Robinson, J. L., Elias, J. E., Sonnenburg, E. D., Gardner, C. D., & Sonnenburg, J. L. (2021). Gut-microbiota-targeted diets modulate human immune status. Cell, 184(16), 4137–4153.e14. https://doi.org/10.1016/j.cell.2021.06.019

Hooper, L. V., Littman, D. R., & Macpherson, A. J. (2012). Interactions between the microbiota and the immune system. Science (New York, N.Y.), 336(6086), 1268–1273. https://doi.org/10.1126/science.1223490

de Vos, W. M., Tilg, H., Van Hul, M., & Cani, P. D. (2022). Gut microbiome and health: mechanistic insights.Gut, 71(5), 1020–1032. https://doi.org/10.1136/gutjnl-2021-326789

David, L. A., Maurice, C. F., Carmody, R. N., Gootenberg, D. B., Button, J. E., Wolfe, B. E., Ling, A. V., Devlin, A. S., Varma, Y., Fischbach, M. A., Biddinger, S. B., Dutton, R. J., & Turnbaugh, P. J. (2014). Diet rapidly and reproducibly alters the human gut microbiome.Nature, 505(7484), 559–563. https://doi.org/10.1038/nature12820

Sonnenburg, E. D., Smits, S. A., Tikhonov, M., Higginbottom, S. K., Wingreen, N. S., & Sonnenburg, J. L. (2016). Diet-induced extinctions in the gut microbiota compound over generations.Nature, 529(7585), 212–215. https://doi.org/10.1038/nature16504

Cryan, J. F., & Dinan, T. G. (2012). Mind-altering microorganisms: the impact of the gut microbiota on brain and behaviour.Nature reviews. Neuroscience, 13(10), 701–712. https://doi.org/10.1038/nrn3346

Foster, J. A., Rinaman, L., & Cryan, J. F. (2017). Stress & the gut-brain axis: Regulation by the microbiome.Neurobiology of stress, 7, 124–136. https://doi.org/10.1016/j.ynstr.2017.03.001

Palm, N. W., de Zoete, M. R., & Flavell, R. A. (2015). Immune-microbiota interactions in health and disease.Clinical immunology (Orlando, Fla.), 159(2), 122–127. https://doi.org/10.1016/j.clim.2015.05.014

Zmora, N., Zilberman-Schapira, G., Suez, J., Mor, U., Dori-Bachash, M., Bashiardes, S., Kotler, E., Zur, M., Regev-Lehavi, D., Brik, R. B., Federici, S., Cohen, Y., Linevsky, R., Rothschild, D., Moor, A. E., Ben-Moshe, S., Harmelin, A., Itzkovitz, S., Maharshak, N., Shibolet, O., … Elinav, E. (2018). Personalized Gut Mucosal Colonization Resistance to Empiric Probiotics Is Associated with Unique Host and Microbiome Features.Cell, 174(6), 1388–1405.e21. https://doi.org/10.1016/j.cell.2018.08.041

Sharkey, K. A., & Wiley, J. W. (2016). The Role of the Endocannabinoid System in the Brain-Gut Axis.Gastroenterology, 151(2), 252–266. https://doi.org/10.1053/j.gastro.2016.04.015

Minichino, A., Jackson, M. A., Francesconi, M., Steves, C. J., Menni, C., Burnet, P. W. J., & Lennox, B. R. (2021). Endocannabinoid system mediates the association between gut-microbial diversity and anhedonia/amotivation in a general population cohort.Molecular psychiatry, 26(11), 6269–6276. https://doi.org/10.1038/s41380-021-01147-5

Srivastava, R. K., Lutz, B., & Ruiz de Azua, I. (2022). The Microbiome and Gut Endocannabinoid System in the Regulation of Stress Responses and Metabolism. Frontiers in cellular neuroscience, 16, 867267.https://doi.org/10.3389/fncel.2022.867267

Philip Schmiedhofer, MSc

Philip Schmiedhofer, MSc

Philip is the CEO and co-founder of cannhelp GmbH. With a degree in medical engineering and molecular biology, specializing in neuroscience and focusing on cannabinoids, he is recognized as an expert in the medical application of cannabinoids. As a medical device consultant, he also leads the sales of cannmedic and provides specialized advice to medical professionals. His expertise includes the development and sales of cannabinoid-based products. In research, he participates in significant basic research at the Center for Brain Research at the Medical University of Vienna. As co-founder and current CEO of cannmedic GmbH, a pioneer in the CBD medical products market, he has many years of entrepreneurial experience. Additionally, he maintains an extensive network in the industry and advises internationally operating companies in the field of medical cannabinoids.