Complex sentence: In 1876, Dr. John Harvey Kellogg became the medical superintendent, his brother W. K. Kellogg worked at the sanitarium for twenty-six years before leaving to establish the Battle Creek Toasted Corn Flakes Company.
Split into simpler sentences: In 1876, Dr. John Harvey Kellogg became the medical superintendent at the sanitarium. Kellogg's brother W. K. Kellogg worked at the sanitarium for twenty-six years before leaving to establish the Battle Creek Toasted Corn Flakes Company.