A compound called oxalate, which is naturally found in foods like spinach, almonds, and sweet potatoes, may contribute to the worsening of chronic inflammatory intestinal diseases, according to a study published in the journal Cellular and Molecular Gastroenterology and Hepatology. The research, led by scientists from the University of North Carolina at Chapel Hill, Texas A&M University, and Duke University, suggests that individuals with conditions such as Crohn's disease or ulcerative colitis may have lower activity of genes that help transport oxalate through the intestines. The study examined the activity of three genes—SLC26A2, SLC26A3, and SLC26A6—that are responsible for transporting oxalate in the intestines. These genes were found to be less active in patients with inflammatory bowel disease (IBD) compared to healthy individuals. The activity of these genes was even lower in the inflamed parts of the intestines of those with ulcerative colitis. This reduced activity could lead to higher levels of oxalate in the intestine, as less of it is absorbed into the bloodstream. In experiments with mice, researchers discovered that a diet containing 1% oxalate made colitis worse and decreased the survival rate of mice exposed to a chemical that induces colitis. Oxalate also caused the disease to develop more quickly in two genetically susceptible mouse strains. In laboratory cell cultures, oxalate increased the inflammatory response of immune cells like macrophages and dendritic cells, although it did not directly harm the cells that make up the intestinal wall. The researchers warn against completely avoiding plant-based foods, as their findings suggest that even moderate oxalate intake might be harmful to some individuals. They suggest that measuring the activity of oxalate transporters could help identify those most at risk or predict how the disease might progress, allowing for more personalized dietary advice. However, the researchers note that their findings are preliminary and based on small human sample sizes and higher-than-normal oxalate levels in mice. The role of gut bacteria in oxalate metabolism is also being studied. While the human body cannot break down oxalate, certain bacteria such as Oxalobacter formigenes can. This bacterium is less common in people with IBD. Increasing its presence in the gut could offer an alternative to restrictive diets, potentially reducing the strain on the kidneys.