Question:
I’m reasonably nutrition-conscious because of an ongoing health condition. I’m particularly interested in gut health and eating in a way that promotes good health. What are the best practical things I can do from a diet perspective for gut health, and what should I avoid?
Answer:
Your interest in gut health is well placed. Research has revealed myriad ways the gut microbiome affects everything from emotional wellbeing to your risk of chronic diseases such as cancer, cardiovascular disease and type 2 diabetes.
Maintaining a balanced gut microbiome – the community of trillions of bacteria and other micro-organisms living in our digestive system – can support immunity, mental health, digestion and even inflammation control, thereby reducing the risk of chronic disease. But where do we start?
Diet has an indisputable role in altering our gut microbiome, notes a 2019 review in Nature Reviews: Microbiology. Specifically, eating a diet low in animal fat and protein but high in plant fibre is linked to a healthier, more diverse microbiome and better metabolic health. On the other hand, eating a diet high in animal fat and protein and low in plant fibre is associated with an irregular microbiome linked to metabolic diseases.
But how do we shape our diet practically to achieve gut health? Start by including plenty of fibre-rich foods in your diet. Fibre serves as food for beneficial gut bacteria, helping them to thrive and produce short-chain fatty acids that promote a healthy gut lining, reduce inflammation, help with the balance of the microbiome, regulate gut motility (preventing constipation) and promote colon health. Beneficial gut bacteria also support metabolic health by helping to balance blood glucose levels and modulate the gut-brain axis, which affects our mood.
Key fibre-rich foods to include in your daily diet include five or more servings of fruits and vegetables, plus wholegrains such as oats, quinoa, brown rice or wholegrain bread, legumes such as lentils, chickpeas and black beans, and a regular snack of nuts and seeds.
You can boost the impact of your fibre efforts by including foods rich in prebiotics – a fermentable fibre that feeds the good bacteria. Foods rich in prebiotics include garlic, onions, asparagus, leeks, Jerusalem artichokes, bananas (particularly slightly green ones) and oats.
Modifying the type of fat in your diet will also affect your microbiome, a 2019 review published in Clinical Nutrition says. In particular, high-fat diets and diets high in saturated fat can cause unfavourable changes to the gut microbiome, whereas polyunsaturated fats have a neutral impact on the gut microbiome. So, opt for healthy fats in olive oil, avocados, nuts, seeds, and fatty fish (eg, salmon and sardines) to optimise your gut health. And limit your animal fat intake by cutting visible fat off meat and choosing leaner meat cuts.
Rather than buying probiotic supplements – which may or may not have any impact – choose natural food sources of probiotics (beneficial bacteria). Popular options that are readily available in many supermarkets include yoghurt with live, active cultures (check the label), kefir (a fermented milk drink), sauerkraut and kimchi (fermented vegetables packed with flavour and gut-friendly microbes), and kombucha (a tangy fermented tea).
Conversely, large amounts of sugar, artificial sweeteners and ultra-processed foods can harm the microbiome, as can too much alcohol. Sticking to the doctor’s prescribing guidelines for antibiotics and pain medications (particularly anti-inflammatory drugs such as aspirin and ibuprofen) is essential, as these can affect gut health, too.
Remember that our lifestyle also has a tremendous impact. Chronic stress can disrupt the immune system, which is interconnected with our gut microbiome, noted a 2024 review in Frontiers in Immunology.
Research is only beginning to piece together the dangers of stress in the context of our gut microbiome, the gut-brain axis and our mental health. So managing stress is crucial, as is exercising regularly and getting enough sleep.
In other words, consider your gut health as a journey best approached holistically. Any specific health concerns should be addressed with a health professional.
