Stress affects the stomach – that's not just a saying; it has a scientific basis. More and more studies are showing how closely our gut and our brain are connected. At the heart of this interaction is the intestinal flora , i.e. the totality of microorganisms in our digestive tract. But what exactly happens in our body when we are stressed – and how does this affect our intestinal health? Conversely: Can a healthy intestinal flora help us cope better with stress? In this article, we take a closer look at the fascinating connection between intestinal flora and stress .
What is the intestinal flora?
The intestinal flora, also known as the microbiome , consists of approximately 100 trillion bacteria, viruses, and fungi that live in our digestive tract. They not only aid digestion but are also involved in numerous other processes:
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Production of vitamins (e.g. vitamin K, B vitamins)
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Protection against pathogens
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Building and training the immune system
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Regulation of inflammatory processes
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Influence on the hormonal balance and the nervous system
A healthy gut is therefore crucial for our general well-being – both physical and mental.
The gut-brain axis: two-way communication
The connection between the gut and the brain is called the gut-brain axis . It is based on a complex network of:
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Nerve pathways , especially the vagus nerve
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Hormones
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Immune messengers (cytokines)
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Metabolic products of intestinal bacteria
The gut and brain constantly communicate with each other through these channels. Interestingly, around 90% of the "happy hormone" serotonin is produced in the gut – not in the brain, as is often assumed. This explains why a disturbed gut can affect mood – and vice versa.
How stress affects the intestinal flora
Chronic stress alters the composition of the intestinal flora—a condition known as dysbiosis . The balance between "good" and "harmful" bacteria is disrupted. The consequences:
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More permeable intestinal mucosa (“leaky gut”)
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Pollutants and inflammatory messengers can more easily enter the bloodstream.
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Immune system becomes overactive
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Increased risk of inflammation, autoimmune diseases and infections.
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Impaired digestion
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Bloating, constipation or diarrhea occur more frequently.
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Increased psychological symptoms
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Anxiety, depression and sleep disturbances may worsen.
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How the gut affects stress and emotions
A healthy gut can improve stress tolerance . Certain bacterial species produce short-chain fatty acids (e.g., butyrate), which have an anti-inflammatory effect on the nervous system. Other microbes directly influence the production of neurotransmitters such as GABA or dopamine.
Studies show that a balanced microbiome is associated with a lower tendency toward anxiety and depression. Animal experiments have even identified "psychobiotic" bacteria that can specifically influence behavior.
What you can do yourself: Tips for a stress-resistant intestinal flora
1. High-fiber diet
Fiber from vegetables, fruit, whole grain products and legumes promotes the growth of “good” intestinal bacteria.
2. Practice stress management
Techniques such as meditation, yoga, breathing exercises or progressive muscle relaxation reduce the negative impact of stress on the intestines.
3. Probiotics and prebiotics
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Probiotics (e.g. in fermented foods or as a dietary supplement) provide live “good” bacteria.
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Prebiotics (e.g. inulin, oligofructose) serve as food for these microbes.
4. Movement
Regular exercise promotes intestinal circulation and helps reduce stress.
5. Improve sleep
Chronic sleep deprivation disrupts both hormonal balance and intestinal flora.
Conclusion: Gut and head are a team
Science is increasingly recognizing how crucial the gut flora is for our mental health and our perception of stress. The good news: You can do a lot yourself to positively influence this cycle. A gut-friendly lifestyle is therefore not only good for digestion but also an effective means of combating stress.
Because: A healthy gut often means a relaxed mind.
