doi:10.1038/nindia.2016.159 Published online 1 December 2016
Dietary potassium reduces the risk of developing Inflammation Bowel Disease (IBD), a chronic inflammatory disorder of the gastrointestinal tract, a study1 by Indian and US scientists has found.
Crohn’s disease (CD) and Ulcerative Colitis (UC) that constitute IBD are caused by an imbalance between disease promoting immune cells (Th1 and Th17) and disease suppressing ones (Foxp3+ T-regulatory). Normally, these cells maintain a balance, making for a healthy, disease-free bowel. However, due to environmental and gut microbial triggers, the T-cell immune balance may get disrupted, leading to inflammation and bowel injury. Such injury requires lifelong medical therapy.
Why the gut environment is altered in IBD has been the focus of the collaborative study by researchers at Translational Health Science Technology Institute (THSTI) in Faridabad in India and at the Massachusetts General Hospital of Harvard Medical School.
Nearly 170,000 US women, followed up for over 20 years, were screened for potassium content in their urine. Their dietary intake was also monitored every 2-4 years. The diagnosis of CD and UC were confirmed by review of medical records.
"We found that dietary intake of potassium but not sodium was associated with decreased risk of developing CD," says Amit Awasthi, an Assistant Professor at THSTI and co-senior author of the joint study. They found that extracellular potassium modifies the T cell response and promotes the generation of disease preventing T cells. In vitro, potassium was found to suppress the T-cells proliferation and induced the expression of protective Foxp3+ cells, suggesting a possible anti-inflammatory function.
A potassium rich diet has the ability to modulate the immune response via induction of Foxp3-mediated T cell tolerance, the researchers say. Further research is needed to elucidate the precise mechanisms by which dietary potassium regulates the balance between Th17 and T-regulatory cells, they add.
1. Khalili, H et al. Identification and characterization of a novel association between dietary potassium and risk of Crohn’s Disease and Ulcerative Colitis. Front. Immunol. (2016) doi: 10.3389/fimmu.2016.00554