Digestion supports the healthy function of other body systems and pathways?
Gut health is becoming a hot topic at the moment with the likes of nutrition experts such as Tim Spectre, Rhiannon Lambert and Madeleine Shaw all talking about its importance. However digestion is more than ‘gut health’ or simply addressing symptoms like bloating, constipation or IBS. After all, these are just signs that your digestion system is not functioning properly.
The digestion system is made up of different organs that work together to support the breakdown of food, turning it into energy that the body needs for important functions. The digestion system then helps to eliminate anything remaining that is not needed.
Discover how digestion impacts specific body systems (or pathways) and how.
Digestion and endocrine
Your endocrine system is made up of glands that produce and release hormones - chemical messengers that influence your periods, mood, energy and even stress response.
Digestion is deeply connected with hormone health, helping to keep them balanced. One study found that 73% of women experience at least one common digestive symptom before or during their period, such as stomach pain or diarrhoea (3).
Nutrients from food fuel the production of hormones. For example healthy fats, protein and certain vitamins and minerals help to make hormones.
If there is inflammation within the digestion system, then it’s likely you won’t be able to absorb nutrients efficiently and may affect the health of your menstrual cycle (8). For example, the mineral magnesium supports relaxing the uterine muscles, calming the nervous system, supporting blood sugar and helping the liver process hormones. So even if you are eating enough magnesium, poor absorption could show up as a deficiency with symptoms like pre-menstrual syndrome (PMS), such as moods or even cravings and period cramps.
The digestive system plays an important role in breaking down carbohydrates into glucose, which your body uses for energy. Quality carbohydrates are an essential part of a balanced diet. However, when meals are heavily carbohydrate-dominant, especially without adequate protein, fats, or fibre and can place extra pressure on the pancreas and liver. This can create blood sugar spikes and crashes.
These fluctuations can increase inflammation and activate the body’s stress response (“fight or flight”), shifting energy away from digestion and toward managing the ‘perceived stress’. Over time, repeated blood sugar imbalances may contribute to insulin resistance, which is a driving factor in some cases of polycystic ovarian syndrome (PCOS).
Unstable blood sugar levels are common, though not normal, in the second half of the menstrual cycle (the luteal phase), when the body requires more energy and appetite naturally increases. If these increased energy needs aren’t met with balanced meals, it can lead to irritability, low mood, cravings or that ‘hangry’ feeling
Digestion and immune
Did you know around 70% of the immune system resides in the gut? The digestive system is the body’s largest interface with the outside world. (12)
Strengthening the gut barrier: A healthy digestive system maintains a strong gut lining, preventing any unwanted particles from entering the bloodstream. This is compromised if there is a gut microbiome imbalance. For example from poor diet, antibiotics use or stress and we see more of the bad bacteria than the good bacteria in the gut.
This can weaken the gut barrier and cause inflammation, leading to digestive issues or even autoimmune conditions.
Training immune cells: You gut microbes teach your immune cells to distinguish and react appropriately to harmful invaders, food particles and beneficial bacteria. This supports the immune system to fight any infections and regulate inflammatory responses.
Research shows that the immune response can become more active due to the oestrogen rising in the first half of the cycle (the follicular) before ovulation. Although this does not always happen, it can increase inflammation. Whereas in the second half of the cycle (luteal), research shows that the immune system may be less active due to the rise in the hormone progesterone. Further research indicates that may be due to the body encouraging potential pregnancy and now wanting to ‘attack’ a fertilized egg and preventing it from implanting into the uterine lining. (2, 6 10, 11)
Whereas in the late luteal phase and menstruation, chemical like hormones are released to contract the uterine for your period. The immune system works alongside them to manage the inflammation and tissue breakdown. This is why a nutrient-dense diet and supporting the digestive system is important during this time to make sure the prostaglandins aren’t overreacting and prevent period-related symptoms like bloating and diarrohea.
Producing beneficial bacteria: Building good bacteria in the gut is important, and more so, if you have had to take a round of antibiotics. Eating a diverse range of fibre-rich foods can help - such as fruits, vegetables, whole grains and legumes, to feed the good bacteria and help them flourish. (4)
Digestion and cardiovascular health
Digestion plays a much bigger role in heart health than most people realise. When your digestive system is working well, your body can break down food and absorb the nutrients that protect your heart.
These nutrients help keep your blood pressure in a healthy range, support balanced cholesterol levels and reduce inflammation in the body.
For example, minerals like magnesium and potassium help regulate blood pressure and support a steady heartbeat. Healthy fats also essentially, especially getting the right balance between omega-3 (for example (chia seeds, sardines, salmon) and omega-6 fatty acids (for example sunflower seeds, walnuts, some meats) to support inflammation.
Second, your gut is home to trillions of bacteria that play a big role in heart health. When you eat fibre, these beneficial bacteria produce substances called short-chain fatty acids. These compounds help to lower inflammation, support healthy blood vessels and maintain balanced cholesterol levels. (5) Research shows that eating foods with probiotics, like yoghurt or fermented foods, help to populate the gut with good bacteria which can support healthy blood pressure. (7)
However when the gut bacteria are out of balance, it can have the opposite effect and increase inflammation in the body. Even low-level, ongoing inflammation can damage blood vessels over time and make it easier for plaque to build up and puts extra strain on the heart, raising the risk of heart problems. Some gut bacteria can also turn highly processed foods into compounds linked to heart disease. This is particularly important to highlight due to the strong positive relationship between women experiencing menstrual and hormone issues and gut microbiome imbalances.(1)
Research shows that people who experience heart failure have fewer beneficial bacteria and more harmful ones compared to healthy individuals. This imbalance is linked to poorer heart function and increased cardiovascular risk.
Digestion and detoxification
Digestion plays a central role in detoxification, with your body removing waste and toxins largely through the digestive system. It’s a coordinated process involving the whole system of the digestive system from the liver, gallbladder, intestines and bowel movements.
For example, the liver helps to recycle oestrogen at the right level and encourage regular bowel movements. If your digestion is inflamed or your gut microbiome is out of balance or the flow is sluggish, then there may be inadequate hormone elimination and may even be reabsorbed into circulation, increasing the body's toxic load and placing extra strain on the liver. Symptoms we may see with oestrogen dominance are heavy periods, acne, tender or swollen breasts or pre-menstrual syndrome (PMS), to name just a few.
The liver may pack toxins for removal, but the digestive system is the exit pathway. Healthy digestion ensures toxins are properly processed, bound and eliminated, supporting the body’s natural detoxification system that happens every day.
Digestion and nervous system
Digestion has a powerful and direct impact on the nervous system, with the gut and brain constantly communicating. The digestive system has its own network of nerves and is often referred to as the ‘second brain’. It sends messages to the brain and the brain sends messages to the gut, like a 2-way highway.
Many chemicals that influence mood and mental clarity are produced in the gut. For example serotonin, which impacts mood, sleep and appetite is mostly made in the gut. Therefore a healthy digestion and good gut microbiome can help to regulate the production of these brain chemicals. If digestion is disrupted, this can lead to pre-menstrual syndrome or disorder, anxiety, depression or even sleep issues.
The gut also plays a key role in calming or activating the nervous system. For example if there is inflammation in the digestion system, these inflammatory chemicals travel through ‘highway’ to the brain. These signals can interfere with normal brain function, creating symptoms like brain fog, low moods and irritability. (9)
Additionally, if there are unbalanced blood sugars, this can lead to rapid spikes and crashes. This can activate stress hormones such as adrenaline and cortisol and can leave you feeling anxious, wired or even fatigued. Over time, unbalanced blood sugars can affect hormones, potentially disrupting or delaying ovulation and contributing to conditions like Polycystic Ovary Syndrome (PCOS).
So there we have it - how digestion has a huge role in all the other systems and pathways of the body. If you have any questions, please reach out - and if you want to leave a comment or review, please do so on Spotify.
References
1 Akshay A, Gasim R, Ali TE, Kumar YS, Hassan A. (2003) Unlocking the Gut-Cardiac Axis: A Paradigm Shift in Cardiovascular Health. Cureus. doi: 10.7759/cureus.51039. PMID: 38264397; PMCID: PMC10805229.
2 Alvergne A, Tabor VH. (2017) Is Female Health Cyclical? Evolutionary Perspectives on Menstruation. arXiv preprint arXiv:1704.08590.
3 Bernstein MT, Graff LA, Avery L, Palatnick C, Parnerowski K, Targownik LE. (2014) Gastrointestinal symptoms before and during menses in healthy women. BMC Womens Health. doi: 10.1186/1472-6874-14-14. PMID: 24450290; PMCID: PMC3901893.
4 Doral Health and Wellness (2026) https://doralhw.org/microbiome-basics-how-gut-health-affects-immunity/ [Online]
5 Hopkins Medicine [Online] https://www.hopkinsmedicine.org/health/wellness-and-prevention/can-your-gut-health-affect-your-heart
6 Lorenz TK, Heiman JR, Demas GE. (2017) Testosterone and immune-reproductive tradeoffs in healthy women. Hormones and behavior.
7 Hopkins Medicine (2026) https://www.hopkinsmedicine.org/health/wellness-and-prevention/the-power-of-gut-bacteria-and-probiotics-for-heart-health [Online]
8 Nutritional Therapy Association (2020). Basics of Nutrition Student Guide. [PDF Document]
9 Nutritional Therapy Association (2020). Immune System Student Guide. [PDF Document]
10 Reed BG, Carr BR. The Normal Menstrual Cycle and the Control of Ovulation. In: De Groot LJ, Chrousos G, Dungan K, et al., (2000; 2015) editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.
11 Siddiqui R, Makhlouf Z, Alharbi AM, Alfahemi H, Khan NA. The Gut Microbiome and Female Health. Biology (Basel). (2022) 11(11):1683. doi: 10.3390/biology11111683. PMID: 36421397; PMCID: PMC9687867.
12 Wiertsema SP, van Bergenhenegouwen J, Garssen J, Knippels LMJ. (2021) The Interplay between the Gut Microbiome and the Immune System in the Context of Infectious Diseases throughout Life and the Role of Nutrition in Optimizing Treatment Strategies. Nutrients. 9;13(3):886. doi: 10.3390/nu13030886. PMID: 33803407; PMCID: PMC8001875.