Ultra-Processed Foods Harm Gut Health
A BBC Future feature explores how ultra-processed foods can negatively affect the gut microbiome, with additives used to preserve freshness potentially disrupting healthy gut bacteria. The research has implications for digestion, immunity, and overall well-being.
- Ultra-processed foods (UPFs) are industrial formulations containing ingredients not typically found in a home kitchen, such as emulsifiers, artificial sweeteners, and preservatives. Common examples include instant soups, packaged snacks, sugary drinks, and reconstituted meats like hot dogs. - The term originates from the NOVA classification system, which categorizes food based on its degree of processing, from unprocessed (like fresh fruit) to ultra-processed. Breads made only with flour, water, salt, and yeast are considered processed, but they become ultra-processed when ingredients like emulsifiers are added. - On average, 55% of total calories in the U.S. diet come from ultra-processed foods. For youth aged 1-18, that number is higher, at 61.9% of their daily calories. - Research shows that high consumption of UPFs can reduce gut microbial diversity by as much as 40%. This includes a decrease in beneficial bacteria like *Lactobacillus* and *Bifidobacterium*. - Specific additives, such as the emulsifiers carboxymethylcellulose and polysorbate-80, have been shown in studies to disrupt the intestinal mucus layer, potentially leading to inflammation and increased gut permeability. - The gut-brain axis, which is the communication link between the gut and the brain, can be altered by UPFs. The gut produces around 90% of the body's serotonin, and disruptions in the microbiome are associated with a higher risk of depression. - In response to growing evidence, the 2025-2030 U.S. Dietary Guidelines for Americans specifically advise a significant reduction in the consumption of "highly processed foods."
