Your gut health is strongly influenced by your diet, lifestyle, exercise, medication use and stress levels. And as mentioned in my previous blogs, your gut health is defined by a healthy gut microbiota. A healthy gut microbiota is characterised by a rich number of bacteria, a great diversity in bacterial specie types, as well as gut microbes functioning with vitality. If any of these gut microbiota characteristics are compromised, it could mean you have a dis-balance in good and bad bacteria (dysbiosis), or your gastrointestinal tract (GIT) is damaged. It could also mean that you’ve been exposed to gut irritants.

Both dysbiosis and a damaged GIT has been linked to food intolerances, bloating, abdominal pain, diarrhoea, constipation, excess flatulence, reflux, low energy, malabsorption (nutrient deficiencies) and an array of many other unfortunate conditions.

Maintaining your gut health doesn’t just mean eating healthy foods... it also means limiting/avoiding gut irritants. Below contains a list of some of the major gut irritants you could be exposed to:


Alcohol and its metabolites can overwhelm and damage your GIT, as well as your liver and other organs. It does this by promoting intestinal inflammation via multiple pathways, including: altering your gut microbiota composition and function; increasing the permeability of your gut lining; and affecting your intestinal immune homeostasis.


Particularly when consumed in excess, certain components found in coffee, including caffeine, catechols and chemical-substances called N-alkanoly-5-hydroxtryptamides can stimulate molecular mechanisms that result in stomach acid secretion. This in turn can result in heartburn, reflux and indigestion.


Research shows that the consumption of a high fat diet often leads to alterations in gut microbiota composition (dysbiosis), particularly a decrease in Bacteroidetes and an increase in Firmicutes and Protebacteria. These alterations have been associated with obesity and subsequent development of chronic diseases. Potential mechanisms for this effect include: increased energy harvest (from food); enhanced gut permeability; and enhanced gut inflammation.


Greasy foods are high in unhealthy fats and it is a known fact that fat is the most slowly digested macronutrient. Because of this, greasy foods slow the rate at which your stomach empties, which in turn can cause nausea, bloating, abdominal discomfort and diarrhea. Those who suffer from digestive issues tend to be more severely affected by greasy foods. Further to this, greasy foods have been shown to alter your gut microbiota by increasing unhealthy bacteria and decreasing beneficial bacteria (noted above).


It is well known that the consumption of processed foods, particularly ultra-processed foods (UPF), is strongly associated with the development of chronic disease and related ailments. UPF are defined as “industrial formulations made entirely or mostly from substances extracted from foods (e.g. sugar, oils, fats, starch and proteins), derived from food constituents (e.g. hydrogenated fats and modified starch), or synthesised in laboratories from food substrates or other sources (e.g. flavour enhancers, colours and additives).

Studies show that a diet high in UPFs (typical of Western diets) often results in gut dysbiosis and microbiota encroachment, leading to inflammation and metabolic disturbances. Some reasons for these undesirable consequences include the fact that UPFs are predominantly low in dietary fibre, plus contain varying amounts of emulsifiers. Emulsifiers have been shown to alter the gut microbiota and increase gut inflammation. Furthermore, UPFs can often contain artificial sweeteners, which have also been shown to disrupt gut microbiota health and contribute to inflammation.


Antibiotics are very important medicines that are used to treat infections and diseases caused by bacteria. They work by killing bacteria or by preventing them from multiplying. Over the years, they have saved millions of lives. They definitely have their place in health care, however one of their unfortunate drawbacks is that they don’t discriminate between good and bad bacteria. Therefore, even a single dose can lead to undesirable changes in the composition and diversity of your gut microbiota, potentially resulting in dysbiosis. In relation to this, it is integral to eat for both good gut health and a strong immune system to minimise the need for antibiotics. Please note, antibiotics have their place, however can often be misused and/or overused.


NSAIDs (e.g. aspirin, ibuprofen) are commonly used for the symptomatic treatment of acute pain, and chronic inflammatory and degenerative joint diseases. Research shows that the daily use of high doses of NSAIDs are associated with an increased risk of upper GI complications, including bleeding, inflammation and ulceration in the stomach and small intestine. NSAIDs damage the GIT via irritating the gastric mucosa and reducing the levels of protective prostaglandins. This in turn causes increased gastric acid secretion, decreased bicarbonate and mucus secretion and diminished effects on the epithelial mucosa.


Smoking contributes to many disorders of the digestive system, including GORD (reflux), peptic ulcers and some liver diseases. Smoking also increases the risk for inflammatory bowel disease (Crohn’s disease), colon polyps and pancreatitis. Smoking weakens your oesophageal sphincter, which can result in stomach contents refluxing into your oesophagus, causing heartburn and possibly damaging your oesophageal lining. Furthermore, studies show that smoking increases the risk of H. pylori infection, contributing to peptic ulcers. Smoking also increases the production of other substances that can harm your GI lining, including pepsin, an enzyme made in the stomach that breaks down proteins. Smoking also decreases factors that protect and heal the lining of your gut, including mucus, sodium bicarbonate and blood flow. Smoking is bad. We all know it.