Here, in consultation with Prof Sudipto Das, associate professor and principal investigator at RCSI<\/a>, we look at gut health and signs that all may not be well. Das is one of the contributors to a MyHealth RCSI podcast and video dealing with gut health, to be released this week (Gut Health and You will be available from September 24th. See rcsi.com<\/a>)<\/p>\n What is the gut microbiome?<\/p>\n It is an individualised ecosystem populated by bacterial, viral and fungal species. These species influence different body functions, including the immune, endocrine and nervous systems, as well as digestion. Genes, age, environmental and lifestyle factors all shape the composition of the microbiome. A key to gut health is nurturing the \u201cgood\u201d bacteria \u2013 we feed them and they benefit us \u2013 while also trying to guard against overgrowth of \u201cbad\u201d bacteria.<\/p>\n When the balance goes askew, with beneficial bacteria decreasing and harmful bacteria increasing, it leads to \u201cdysbiosis\u201d, which is linked to various diseases. But the cause and effect of dysbiosis is still under research. For instance, we know chronic stress is bad for gut health, as is the inflammation it causes or exacerbates, but \u201cwe still don\u2019t have proof that stress directly causes bowel cancer\u201d, says Das.<\/p>\n How do we feed the gut well?<\/p>\n Eat plenty of fibre for a start. Adults should aim for 25-35g a day, yet about 80 per cent of people in Ireland fall well short of that. Fibre nourishes the beneficial microbes as food passes through the bowel; it reduces inflammation and supports the immune system.<\/p>\n A mix of soluble fibre and insoluble fibre is recommended. The former, found in foods such as oats, beans, berries, carrots and chia seeds, helps to slow digestion and reduce \u201cbad\u201d cholesterol. Insoluble fibre, contained in foods such as brown rice, leafy greens, cauliflower and fruit with edible skins, adds bulk to the stool and quickens its passage through the system.<\/p>\n Also make sure you are well hydrated. Drinking water helps to keep food-waste toxins moving through the gut, as will exercise.<\/p>\n What about probiotics and prebiotics?<\/p>\n Both are important for gut health. Just to be clear, probiotics are live, \u201cgood\u201d bacteria (also yeast) in fermented foods, which help to counteract the growth of harmful bacteria in the gut. Prebiotics are high-fibre foods, such as vegetables and whole grains, that \u201cfeed\u201d the probiotics, to help them do their work.<\/p>\n [\u00a0Ultraprocessed foods: Do they affect gut health?Opens in new window<\/a>\u00a0]<\/p>\n For healthy people, a \u201cfood-first\u201d approach, getting a variety of probiotics through eating yoghurt, kefir and sauerkraut, for instance, is reasonable, Das suggests. <\/p>\n Are there consumables to avoid? Those with troublesome guts are often advised to limit or avoid fermentable carbohydrates that disrupt the microbiome, collectively known as Fodmap (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols). Think lactose, excess fructose, and sugar alcohols in some artificial sweeteners, for example. Some people are more sensitive than others to fermentation of these substances by the microbes in the large intestine.<\/p>\n Ultra-processed foods tend to contain emulsifiers and additives, which can disrupt the microbiome and gut lining. High alcohol consumption is likely to kill off beneficial bacteria, irritate the gut lining and increase permeability, also known as \u201cleaky gut\u201d.<\/p>\n \u2018Leaky gut\u2019 sounds alarming, what exactly is it?<\/p>\n It is loss of the mucosal barrier function, says Das, which leads to illness. However, the question researchers are trying to answer is does the leaky gut come first, causing damage to the microbes within, or do bacterial changes in the gut weaken the barrier? <\/p>\n There is \u201ccrosstalk\u201d between the host cells and the microbial species, which is really important, he says, to maintain normal microbiome. \u201cWhen the leaky gut happens, this crosstalk gets imbalanced. Because it is a crosstalk, whatever is happening to the bacteria will obviously consequentially have an impact on the host itself.\u201d<\/p>\n What are outward signs of trouble within?<\/p>\n Signs of good gut health include comfortable digestion; regular and easy bowel movements; minimal bloating; no excessive gas. A deviation from those might indicate all is not well. <\/p>\n Any sudden change in bowel movements, which then lasts for a prolonged period, is a concern that should be brought to a GP without delay. Blood in the stool is also a red flag.<\/p>\n [\u00a0Could vagus nerve stimulation be used to treat obesity, Alzheimer\u2019s and bowel disorders?Opens in new window<\/a>\u00a0]<\/p>\n The symptoms could indicate any one of a number of illnesses, including irritable bowel syndrome (IBS), or inflammatory bowel disease (IBD) \u2013 such as Crohn\u2019s disease or colitis, or sometimes cancer.<\/p>\n Are IBS and IBD as similar as their acronyms suggest? No \u2013 they\u2019re two distinct and quite different conditions affecting the gastrointestinal tract, says Dr Orlaith Kelly, consultant gastroenterologist at Connolly Hospital, Dublin, and senior lecturer at the RCSI.<\/p>\n IBS is far more common \u2013 affecting about one in 10 people in Ireland during their lifetime \u2013 and it is a functional digestive disorder. \u201cWhat that means is that it doesn\u2019t limit your life; it doesn\u2019t cause damage to the gut, but can cause quite severe symptoms, which definitely can alter your quality of life if they\u2019re not dealt with,\u201d she says on the RCSI\u2019s new podcast. Symptoms include diarrhoea, cramping and constipation. The treatment is mainly diet, medication, and managing stress and lifestyle. <\/p>\n IBD, in contrast, is a digestive, inflammatory condition with genetic, environmental, and immune components. While onset is often between age 15 to 35, it can happen at any stage in life. <\/p>\n \u201cThis does cause damage to the digestive system,\u201d she says. IBD is an umbrella term for a number of disorders, the most common of which are ulcerative colitis and Crohn\u2019s disease. These certainly alter the quality of life for the approximately 40,000 people living with such conditions in Ireland, which has one of the highest rates of IBD in Europe. They also have a significant impact on health outcomes, says Kelly. <\/p>\n![\"Prof](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/09\/DM6FW7RYH5AZ5PRM773PXADDHY.jpg\")
Prof Sudipto Das, associate professor and principal investigator at RCSI <\/p>\n![\"Dr](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/09\/NJUUPVXEYNENNFAEEQXE6T2INQ.png\")
Dr Orlaith Kelly, consultant gastroenterologist at Connolly Hospital, Dublin. <\/p>\n
![\"The](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/09\/MFJZBOWZNZHU3MDTWC63GUJDSA.jpg\")
The gut has a number of neurons that connect with the brain, which governs functions such as mucus production, digestion and gut movement.