Immune Gut Health Link

What’s The Link Between Gut Health And Immune Health?

Written by: Victoria Hanlon
Senior Writer

Let’s face it, your gut is pretty amazing. As well as being responsible for your digestive wellbeing, it also plays a role in women’s health, mood and even helps support immunity health.

How does the gut support immune health?

How does it achieve all this? Well, your gut is full of probiotics, or “good” bacteria – it’s estimated that about 10 trillion microorganisms live in your intestines[1]. These probiotics perform several jobs, one of which is crowding out harmful bacteria before it has a chance to develop into an illness.

In fact, about 70% of the immune system is believed to live in your gut[2], which is why it’s important to support your gut bacteria as part of your immune system maintenance. Consuming probiotics as part of your dietary intake helps maintain the number of good bacteria in your intestine, which in turn can strengthen your immune system.

What can you do to boost the immune system?

Look out for foods rich in probiotics, such as fermented foods and some dairy products. In particular, yoghurt is high in the lactobacillus bacteria strain, which is good for supporting immune health[3]. You can also consider taking a probiotic supplement to maintain the immune system and help fight illness.

The importance of gut health

There’s growing recognition of the amazing impact the gut has on overall health, and the role that diet and other environmental factors can have in influencing digestive health. It’s important to have a healthy intestinal lining, as this helps prevent harmful bacteria from entering the tissues and blood stream. Gut bacteria can also produce important vitamins, such as vitamin B12, vitamin K and thiamine.

How to improve gut health

You can improve gut health by eating a varied diet that is low in processed foods. The best food for gut health includes fruit, vegetables and legumes[4] (particularly ones high in fibre, such as bananas, chickpeas and broccoli[5]), and fermented foods, such as kombucha, kefir and some yoghurts[4]. It can also be a good idea to take a regular gut health supplement, such as a daily prebiotic and probiotic, to help increase and feed the good bacteria in your gut.

How to boost the immune system

As well as incorporating immune-boosting foods into your diet, you can also support immune health by drinking sufficient water, exercising regularly, getting enough sleep and minimising stress.

What is gut health?

Good gut health is when there is a balance between the ‘good’ bacteria and potentially harmful bacteria in your gut, in that more good bacteria is present than bad.

Which foods boost the immune system?

Foods which boost the immune system are ones rich in nutrients that have been identified as critical for the growth and function of immune cells – such as vitamin C, vitamin D, zinc, selenium, iron, and protein (including the amino acid, glutamine)[6]. Overall, it’s important to eat a balanced diet which includes whole fruits, vegetables, lean proteins, whole grains, and plenty of water – a Mediterranean diet is one option that includes these  food groups[6]. And, as mentioned above, probiotic-rich foods are important for supporting immune health. 

What is good for gut health?

The question of what is helps improve gut health could be a whole report in itself. Topline, gut health care comes in the form of:

  • Eating a healthy diet rich in fibre, probiotics and prebiotics.
  • Regular exercise.
  • Limited alcohol intake.
  • Managing stress levels[7]

What are the signs of poor gut health?

Signs of poor gut health tend to arise from an imbalance in the gut bacteria composition. This can present with symptoms like bloating, abdominal pain, and diarrhoea[8].

What are 3 signs of a healthy gut?

The three main sings of a healthy gut are:

  • Regular bowel movements that are easy to pass[9].
  • No excessive bloating[10].
  • A ‘healthy gut transit time’ (the time it takes for ingested food to travel through the whole eight meters of your gut)[11], which is generally between 24-48 hours from when food was consumed[12].

As well as looking after your gut health, you can also support your immune system by exercising regularly, getting adequate sleep, eating a diet rich in fruit and vegetables, and maintaining a healthy weight[13]. Hello wellness, goodbye cold!



  1. Björkstén B, Sepp E, Julge K, Voor T, Mikelsaar M. Allergy development and the intestinal microflora during the first year of life. J Allergy Clin Immunol. 2001;108(4):516-520. doi:10.1067/mai.2001.118130
  2. Purchiaroni F, Tortora A, Gabrielli M, et al. The role of intestinal microbiota and the immune system. Eur Rev Med Pharmacol Sci. 2013;17(3):323-333.
  3. Simin Nikbin Meydani , Woel-Kyu Ha, Immunologic effects of yogurt, The American Journal of Clinical Nutrition, Volume 71, Issue 4, April 2000, Pages 861–872,
  4. Victoria State Government Department of Health. Better Health Channel. Gut Health. Sourced 24 August 2023
  5. Centers for Disease Control and Prevention. Fiber: The Carb That Helps You Manage Diabetes. Sourced 24 August 2023
  6. Harvard School of Public Health. The Nutrition Source: Nutrition and Immunity. Sourced 11 August 2023
  7. Forbes Helath. How To Improve Your Gut Health. Sourced 11 August 2023
  8. Zhang YJ, Li S, Gan RY, Zhou T, Xu DP, Li HB. Impacts of gut bacteria on human health and diseases. Int J Mol Sci. 2015;16(4):7493-7519. Published 2015 Apr 2. doi:10.3390/ijms16047493
  9. Colombia University Irving Medical Centre. How do you know your colon is healthy. Published 15 March 2023
  10. Harvard Health Publishing. Taking the air out of bloating. 1 June 2022
  11. Roager, Henrik Munch & Hansen, Lea & Bahl, Martin & Frandsen, Henrik & Carvalho, Vera & Gøbel, Rikke & Dalgaard, Marlene & Plichta, Damian & Sparholt, Morten & Vestergaard, Henrik & Hansen, Torben & Sicheritz-Ponten, Thomas & Nielsen, Henrik & Pedersen, Oluf & Lauritzen, Lotte & Kristensen, Mette & Gupta, Ramneek & Licht, Tine. (2016). Colonic transit time is related to bacterial metabolism and mucosal turnover in the gut. Nature Microbiology. 1. 16093. 10.1038/nmicrobiol.2016.93.
  12. Keendjele TPT, Eelu HH, Nashihanga TE, Rennie TW, Hunter CJ. Corn? When did I eat corn? Gastrointestinal transit time in health science students. Adv Physiol Educ. 2021;45(1):103-108. doi:10.1152/advan.00192.2020
  13. Harvard Medical School. How to boost your immune system. Published 15 February 2021.

Victoria Hanlon - Senior Writer