Dr. Marty Makary's resignation from his post atop the Food and Drug Administration is widening a leadership gap that already existed at the U.S.

Makary’s exit ends a turbulent run marred by leadership upheaval, mass layoffs, political pressure and public spats with drugmakers.

Marty Makary is resigning as President Donald Trump's Food and Drug Administration chief. The surgeon and health researcher's tenure had drawn complaints from pharmaceutical…