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How does stress affect the body?

  • Healthy Living

  • Wellness

  • By Marie-Christine Robitaille, Products Expert for Bio-K+

    I don’t know about you, but I’ve never heard so much talk about stress. Everyone seems to be worried about stress. We all experience it in this performance-driven world we live in, surrounded by the unknown. We experience stress at work, at home, in our relationships and in our personal lives, all to measure up to society’s standards or even our own. Have you ever wondered what happens to your body when you’re stressed? If so, let me give you a few pointers.

    What is stress?

    Stress is a reaction to a given situation. Of course, it can be useful, but it can also be harmful when poorly managed.

    In stressful situations, a series of reactions take place in the body: catecholamines such as adrenalin are released by the adrenal glands, the heart rate increases, breathing quickens and body temperature rises, all to prepare the body to flee or fight off the stress. Should the situation persist, the adrenal glands release cortisol, or glucocorticoids if you prefer, to raise blood sugar levels so that glucose is available for the muscles, brain, and heart. Then, if things go on for longer, other activating hormones come into play. These hormones could be harmful to long-term health.

    “Corti” what?

    Keeping the notorious cortisol levels in the blood under control is crucial to optimal health. In the event of prolonged stress, cortisol modifies glucose and water storage and reduces muscle mass. It allows fat to be stored in the abdomen, increasing appetite for food rich in sugars and fats.

    What about our gut microbiota?

    You’ve probably already or often heard of our second brain, yes? It’s the two-way link between the brain and the billions of bacteria that live in our intestines. In stressful situations, all the above-mentioned activations modulate the intestinal microbiota and have an impact on the type of bacteria found in our intestines and their effects on our health. On the other hand, these bacteria also have an impact on mental health and stress management.

    In fact, under stress, it’s interesting to note that cortisol leads us to choose foods rich in sugars and fats, which clearly influence the type of bacteria found in our intestines and their effects on our health. Pathogenic bacteria feed mainly on refined sugar, creating an imbalance (dysbiosis) within the microbiota, altering the intestinal barrier formed by the mucosa and leaving it more vulnerable to foreign substances. Research in the healthcare sector is focusing on the development of an intestinal barrier permeable to these foreign substances. In fact, a new pathway mediated by the bone marrow has recently been discovered. Immune cells become the messengers for transmitting psychological stress to intestinal bacteria. The increased inflammation that comes with stress and depression triggers the proliferation of pathogenic bacteria and, once again, produces an imbalance (dysbiosis) in the intestinal microbiota.

    Bacteria and food—the two go hand in hand!

    Conversely, the gut microbiota can also influence eating behavior through mood changes, by releasing neurotransmitters such as serotonin, the so-called happy hormone. Many studies have even suggested that an anti-inflammatory diet, such as the Mediterranean diet, may reduce the risk of stress-related depression, all by being modulated by the intestinal microbiota.

    The Mediterranean diet is rich in polyphenols, polyunsaturated fatty acids, and fiber. Intestinal bacteria feed on these elements to enable the production of certain hormones beneficial to psychological health, as well as enable the secretion of mucus to protect the intestinal barrier and modulate the immune system.

    Stress is certainly complex, but it’s clear from the scientific literature that the gut microbiota can have an impact on it, just as stress can have an impact on the make-up of the bacteria in our intestines. It’s a win-win situation! Stress can’t be completely avoided, but it is necessary in certain situations, and it’s clear that it can be better managed by taking care of ourselves and being more aware of its effects on our overall health.

    Bio-K+ is proud to launch the new “Extra Stress Support” drinkable probiotic with Sensoril®. Sensoril® is in fact an extract of Ashwagandha (Withania somnifera), well clinically studied for promoting the support of occasional sleeplessness, everyday stress and supporting cortisol levels, a marker of occasional stress†. Ashwagandha (Withania somnifera) is a plant that grows in India, the Middle East, and parts of Africa. Sensoril® Ashwagandha extract is formulated using the root and leaves of this plant for maximum efficacy. This promising ingredient, combined with Bio-K+’s three exclusive probiotic strains proven to support digestive and immune health†, is sure to be an ally in our daily routine.


    †These statements have not been evaluated by the Food & Drug Administration.

    This product is not intended to diagnose, treat, cure or prevent any disease



    1. 7 hacks to beat stress | Heart and Stroke Foundation (heartandstroke.ca)
    2. Stress au travail. Effets sur la santé - Risques - INRS (available in French)
    3. Stress and Its Effects on Weight| Articles | Nutritionniste Diététiste | EquipeNutrition
    4. Ashwagandha: Is it helpful for stress, anxiety, or sleep? - Health Professional Fact Sheet (nih.gov)
    5. Madison A, Kiecolt-Glaser JK. Stress, depression, diet, and the gut microbiota: human-bacteria interactions at the core of psychoneuroimmunology and nutrition. Curr Opin Behav Sci. 2019 Aug;28:105-110. doi: 10.1016/j.cobeha.2019.01.011. Epub 2019 Mar 25. PMID: 32395568; PMCID: PMC7213601.
    6. Dinan TG, Stanton C, Long-Smith C, Kennedy P, Cryan JF, Cowan CSM, Cenit MC, van der Kamp JW, Sanz Y. Feeding melancholic microbes: MyNewGut recommendations on diet and mood. Clin Nutr. 2019 Oct;38(5):1995–2001. doi: 10.1016/j.clnu.2018.11.010. Epub 2018 Nov 17. PMID: 30497694.

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    Marie-Christine Robitaille Products Expert for Bio-K+
    About the author
    Dietitian nutritionist graduated from the University of Ottawa, Marie-Christine is passionate about food and intestinal health, she has been actively involved in the development of training within the company Bio-K+ for several years.

    Registered Dietitian (Quebec Province) and member of : The Order of nutritionists dietitians of Quebec
    View all articles by Marie-Christine Robitaille
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