Side effects from eating Splenda sweetener include reduced effectiveness of therapeutic drugs for cancer; altered blood glucose levels and insulin responses; and released toxic compounds, according to Prevention Magazine. Studies show drinking the amount of Splenda in less than one diet soda daily reduces beneficial gut bacteria by 50 percent.
Sucralose, the active ingredient in Splenda, substantially changes the quality and quantity of good bacteria in the digestive system, explains Prevention Magazine. These types of bacterial alterations may cause obesity and weight gain. The sugar substitute decomposes, and it releases toxic materials known as chloroproanols when people use it for baking. Splenda curtails the body's ability to absorb drugs that treat heart disease and other disorders.