Excessive salt intake wipes out levels of good bacteria in the gut and this can cause blood pressure to rise, a German study has found. The findings have raised hope a simple probiotic could be used as a tool to help reduce the risk of heart attack and stroke caused by hypertension. "This exciting research is the first to suggest that gut bacteria might act as the middle-man between salt and heart health, and provides a new therapeutic target to counteract salt-sensitive diseases," said Dr Hannah Wardill, postdoctoral researcher in Gastrointestinal Neuroimmune Interactions at the South Australian Health & Medical Research Institute and University of Adelaide. Researchers at Berlin's Max Delbruck Center and Charite wanted to study the impact of a salty diet on the immune system. Their research, published in the journal Nature, found that a high-salt diet reduced the levels of Lactobacillus bacteria in mice and increased production of immune cells linked to high blood pressure. When the mice had their guts replenished with the lost bacteria the effects were reversed. A pilot study in humans found similar results.