Health officials are investigating a multistate outbreak of salmonella that may be linked to a Trader Joe’s product, the Department of Public Health announced Friday. The department advised consumers of Trader Joe’s valencia creamy salted peanut butter made with sea salt to consult with their health care provider and to discard the product. Since June 11, 29 cases of Salmonella bredeney have been detected nationally, and some of the people infected were hospitalized, the department said. Three of the diagnosed cases were in Massachusetts, health officials said.