How ultra-processed foods affect our gut microbiome The additives added to processed food to keep it fresher for longer might be having an unexpected effect on the health of the microbes in our guts. The additives added to processed food to keep it fresher for longer might be having an unexpected effect on the health of the microbes in our guts. Inside all of us there's a bustling community of trillions of cells that influences numerous aspects of our health. We call it our "microbiome". "You can think of gut diversity as like a forest. The more microbes that you have and the different types of microbes in your forest, the greater resilience you have to any perturbations," says Melissa Lane, a nutritional epidemiologist at Deakin University."It's this whole ecosystem. It's like an extra organ that we have in our body," explains Sarah Berry, a professor of nutrition from Kings College London. But some of the foods we commonly eat could be harming this ecosystem, evidence suggests. Ultra-processed foods in particular And one of the reasons is increasingly being attributed to the numerous additives in our food. It made me wonder what these additives do to our gut.Look at any ingredient list as you next browse the supermarket and you'll quickly note just how many dietary emulsifiers, artificial sweeteners and food colourings are added to our food. They do everything from making food tastier or increasing its crunch, to changing texture and extending shelf life.It included several emulsifiers, substances which allow oils and water to mix, which are commonly found in UPFs. The texture of your favourite melt-in-the mouth ice cream?.) Emulsifiers help supermarket bread stays spongy for so long and are also why a shop-bought cake will stay moist for longer than a homemade one.Evidence suggests these additives may negatively affect our gut microbiomecaused gut bacteria to move closer to the gut wall, which helps prevent inflammation. It's when bacteria erode into our protective mucus layer that can trigger chronic inflammatory diseases, Chassaing says.The emulsifiers used in many ultra-processed foods are linked to potential health problems such as inflammatory bowel disease While these were correlations, by collecting intestinal samples Chassaing and colleagues have also shown in a small trial on humans that whenon individuals with Crohn's disease. The trial found those on a restricted emulsifier diet were three times more likely to experience reduced symptoms, compared to those who ate a regular intake of emulsifiers as part of their diet.Despite the health concerns over their use, there is no public guidance over whether we should avoid emulsifiers. One reason is because there are simply so many additives in our food and scientists don't definitely know how many are toxic, or whether it's the combination of them that's harmful, Whelan says. The emulsifiers we eat have all been approved by the food industry, explains Chassaing. "They are only tested for the toxicity effect or for the ability to induce DNA damage. And for those two aspects, they are perfectly fine. But they were never tested in the past for the direct effect on the microbiome," he says.: "In the European Union all food additives are identified by an E number, and their safety is evaluated before they can be permitted for use in food." Similarly in the US"a food additive must be authorised by the FDA before it can be used in food on the market".In addition, how food is processed could also matter for gut health, beyond nutrient content alone, a recent study has shown.The team compared two groups over three weeks; both ate low calorie diets, and the diets contained comparable nutrients. Crucially, one group consumed a diet based mainly on highly processed meal-replacement products like shakes, soups and bars, and the other followed a low-UPF diet made up of minimally processed, freshly prepared food. While the two groups experienced similar weight loss levels, the gut bacteria in each group dramatically differed. Those on the low-UPF diet had a more diverse gut microbiome whilst those on the high-UPF diet had lower diversity, as well as more constipation. Participants whose gut diversity decreased also tended to report less favourable changes in bloating and abdominal pain. Although the team couldn't pinpoint exactly why, Lane says it could be due to the fact that the types of fibre differed. "The higher ultra-processed food diet had mixtures of additives and, very low amounts of minimally processed ingredients, whilst the low-UPF diet had many different types of fibre coming from whole foods, and far fewer additives," she said.The additives in food have been proven not to damage to our DNA, but there has been relatively little study into their effects on our gut biome Another important point to consider is that many UPFs are low in the nutrients we need, which could also affect the gut. It's already well understood that aWith the evidence mounting up, I asked those I spoke to what the public should to look out for to minimise some of these harmful effects of emulsifiers.The best thing, says Berry, is to cook from scratch using fresh ingredients as much as possible. It's unrealistic to avoid ultra-processed foods altogether, she says. Whelan agrees: "I wouldn't want to be saying to the general public, 'never eat anything that has a food additive in it', I certainly don't do that and I'm not recommending people do it." What we can all do, he says, is think about eating more healthily. "Food is a really precious thing in our lives and we should celebrate it." Clearly, moderation is key and rather than only focussing on what to take away, we can also consider what to add to our diet, Berry says, especially when it comes to snacks, as they Ultimately, a good rule of thumb is to eat much fresh produce as possible. When we do so, our health – and our microbes – only benefit.The truth about the most physically active generation Gen Z may lead the way when it comes to a healthy lifestyle, but is Gen Z the healthiest generation overall?Is it possible to 'hack' your own immune system?How one woman's 'immortal' cells changed the worldWhy you're washing your hands wrongJapan's forest of healingWhy are people in the USA living shorter lives?The prime minister says the NHS could lose 1,000 extra training places if resident doctors go ahead with a six-day strike next week.Parents say cancer care delays cost daughter time'Something wasn't right': Wrong sperm given to UK families by IVF clinics in northern Cyprus