2,500 years ago, Hippocrates ‘the father of medicine’ stated that “All disease begins in the gut”.¹ This statement is unsurprising, if you consider that your gut is the first line of defence between the outside world and your internal body. In fact, it houses the majority of the immune system, with 70-80% of active immune cells being present in the digestive tract. These cells are in constant communication with our gut microbes, which play an essential role in supporting our immune system and overall health. They provide this support through inhibiting invading microbes and maintaining the integrity of the intestinal lining and mucous layer.²

Our gut microbiota can also help regulate immune function throughout the body, such as reducing systemic inflammation.² However, in individuals with poor gut health, we are likely to see a loss of function within the intestinal barrier (leaky gut), which may then allow toxins, damaging metabolites and undigested food particles to cross over into the bloodstream and interact with the immune system. Research has shown that leaky gut is implicated in a variety of chronic inflammatory conditions, including autoimmune and metabolic diseases.¹

The gut microbiota also has multidirectional communication axes between the organs of the body, such as the gut-brain, gut-lung and gut-skin axes.³ Numerous studies have reported changes in the gut microbiota in many conditions, such as obesity, diabetes, liver diseases, and neurodegenerative diseases (such as Alzheimer’s and Parkinson’s Disease).⁴

So, what are some of the signs that your gut may not be working effectively, and therefore potentially having an impact on your overall wellbeing.

Digestive symptoms – these are often the most obvious signs that your digestive system is not working as well as it should be, and can include symptoms such as constipation, diarrhoea, abdominal bloating and gas. There are numerous factors which could be contributing, including diet, lack of physical activity and high stress levels.
Food sensitivities – some individuals with gut issues, may find it difficult to tolerate certain foods or food groups. This may be due to damage to the gut lining, where many enzymes needed to break down food are produced. If digestion is compromised, undigested proteins and endotoxins can enter the bloodstream and activate a pro-inflammatory immune response. This becomes a vicious cycle, causing further inflammation and damage to the gut wall, less efficient digestion and a greater risk of food intolerances.
Nutrient deficiencies – digestive symptoms (like those mentioned above) plus others, like greasy or floaty stools, as well as weight loss could suggest malabsorption of nutrients. Nutrient insufficiencies in those with digestive issues could potentially develop for two main reasons; either due to poor digestive function or through avoidance of certain nutritious foods (sometimes by following overly restrictive diets to control food sensitivity symptoms).⁵ In addition, small intestinal bacterial overgrowth (SIBO) can potentially increase competition for nutrients, reducing the amount of nutrients available for absorption.⁶

Susceptibility to infections – Given the crucial role that the gut plays in modulating the immune system, recurrent issues such as colds, chest infections, tonsillitis, ear infections, urinary tract infections, stomach bugs and thrush could be a sign that your gut needs some TLC.
Anxiety or low mood –A wide range of hormones, neurotransmitters and immunological factors involved in mood regulation are released from the gut and sent as signals to the brain. These messengers may become dysregulated when there is an imbalance in the concentration or representation of species within the gut. There are a few different theories of causality related to low mood and anxiety, one of which is the presence of systemic inflammation. Maintaining a diverse range of beneficial gut bacteria may prevent this imbalance of microbes and therefore reduce the likelihood of inflammation becoming a problem and consequently, influence our mood for the better.

However, the good news is that there’s lots we can do to get our gut health back on track, such as:

Eat a wide variety of different plant foods. Recent research shows the more plant foods you eat (ideally over 30 different types a week), the greater the diversity in the gut, regardless of other dietary factors.⁷

Consume plenty of foods high in prebiotic fibres. Foods such as garlic, onions, shallots, leeks, slightly under ripe bananas, Jerusalem artichokes, asparagus and dandelion greens, are a particularly favourite food source for beneficial species in the gut.⁸

Regularly consume traditionally fermented foods. These include kefir, live yoghurt, kimchi, sauerkraut, kombucha and miso,⁹ all of which tend to be particularly high in beneficial Lactobacilli and Streptococcus species.⁹

Increase your intake of polyphenol rich foods. Berries, green tea, raw cacao, cloves, star anise and other herbs and spices are packed with antioxidants and associated with numerous potential health benefits, including increasing beneficial species of bacteria in the gut and inhibiting pathogens.¹⁰

Regularly spend time outdoors and near animals. Taking country walks, signing up to an exercise class in the park, visiting farms and animal sanctuaries or walking a neighbour’s dog can all be great for the gut.¹¹^,¹²

Reduce your exposure to environmental toxins. Eating home-grown or organic where possible,¹³ filtering your water,¹⁴ and using natural skin care and home cleaning products,¹⁵ are a good place to start.

Take steps to reduce stress. Sign up to a mediation or mindfulness course, cognitive behavioural therapy, or restorative exercise such as yoga.¹⁶ Prioritise carving out time for yourself, even if just for 15 minutes a day to take a bath or a walk, read a book or do some deep breathing exercises.

Introduce a regular bedtime routine,¹⁷ by getting up and going to bed at the same time each day. Ensure your bedroom is dark and cool enough and practice good sleep hygiene by avoiding screen use for at least an hour before bed and keeping electronic devices out of the bedroom.¹⁸

Take a live bacteria supplement. Bio-Kult Everyday (RRP £10.48, available to buy from www.bio-kult.com) and Bio-Kult Boosted (RRP £24.98, available to buy from www.bio-kult.com), contain 14 clinically-researched strains of live bacteria to help support the resident gut microbiome.

By Liz Cooper, Nutritionist at Bio-Kult

- KHJ PROMOTION -

1 Fasano A. All disease begins in the (leaky) gut: role of zonulin-mediated gut permeability in the pathogenesis of some chronic inflammatory diseases. F1000Res. 2020; 9. DOI:10.12688/f1000research.20510.1.

2 Wiertsema SP, van Bergenhenegouwen J, Garssen J, Knippels LMJ. 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 2021; 13: 1–14.

3 Ahlawat S, Asha, Sharma KK. Gut-organ axis: a microbial outreach and networking. Lett Appl Microbiol 2021; 72: 636–68.

4 Cani PD. Human gut microbiome: hopes, threats and promises. Gut 2018; 67: 1716–25.

5 Torres MJ, Sabate JM, Bouchoucha M, Buscail C, Hercberg S, Julia C. Food consumption and dietary intakes in 36,448 adults and their association with irritable bowel syndrome: Nutrinet-Santé study. Therap Adv Gastroenterol 2018; 11. DOI:10.1177/1756283X17746625.

6 Zaidel O, Lin HC. Uninvited Guests: The Impact of Small Intestinal Bacterial Overgrowth on Nutritional Status. Pract Gastroenterol 2003; 27: 27–30.

7 McDonald D, Hyde E, Debelius JW, et al. American Gut: an Open Platform for Citizen Science Microbiome Research. mSystems 2018; 3. DOI:10.1128/mSystems.00031-18.

8 Gibson GR, Probert HM, Loo J Van, Rastall RA, Roberfroid MB. Dietary modulation of the human colonic microbiota: updating the concept of prebiotics. Nutrition Research Reviews 2004; 17: 259.

9 Rezac S, Kok CR, Heermann M, Hutkins R. Fermented Foods as a Dietary Source of Live Organisms. Frontiers in microbiology 2018; 9: 1785.

10 Cardona F, Andrés-Lacueva C, Tulipani S, Tinahones FJ, Queipo-Ortuño MI. Benefits of polyphenols on gut microbiota and implications in human health. The Journal of Nutritional Biochemistry 2013; 24: 1415–22.

11 Hanski I, von Hertzen L, Fyhrquist N, et al. Environmental biodiversity, human microbiota, and allergy are interrelated. Proceedings of the National Academy of Sciences 2012; 109: 8334–9.

12 Tun HM, Konya T, Takaro TK, et al. Exposure to household furry pets influences the gut microbiota of infants at 3–4 months following various birth scenarios. Microbiome 2017; 5: 40.

13 Center for ecogenetics & Environmental health. Health Risks of Pesticides in Food What Fruits and Vegetables have the most. 2013.

14 Carrasco-Turigas G, Villanueva CM, Goñi F, Rantakokko P, Nieuwenhuijsen MJ. The effect of different boiling and filtering devices on the concentration of disinfection by-products in tap water. J Environ Public Health 2013; 2013: 959480.

15 Zota AR, Singla V, Adamkiewicz G, Mitro SD, Dodson RE. Reducing chemical exposures at home: opportunities for action. J Epidemiol Community Health (1978) 2017; 71: 937.

16 Househam AM, Peterson CT, Mills PJ, Chopra D. The Effects of Stress and Meditation on the Immune System, Human Microbiota, and Epigenetics. Adv Mind Body Med; 31: 10–25.

17 Anderson JR, Carroll I, Azcarate-Peril MA, et al. A preliminary examination of gut microbiota, sleep, and cognitive flexibility in healthy older adults. Sleep Med 2017; 38: 104–7.

18 Fuller C, Lehman E, Hicks S, Novick MB. Bedtime Use of Technology and Associated Sleep Problems in Children. Glob Pediatr Health 2017; 4: 2333794X17736972.