Creatine is used by bodybuilders and exercisers. Our body makes our own Creatine, but when we exercise we lose creatine from muscles which means we lose endurance to carry out our exercises for prolonged periods and harder.
Creatine supplements apparently enable the body to go on for longer, enhancing athletic performance and reduces recovery time. However, taking too much Creatine has been known to damage the Liver.
Regarding Protein, our bodies can only digest a certain amount of protein, but as there is a mass trend for protein shakes and other supplements, many people consume much more than they need and yes it does cause really smelly wind. The free weights area of the gym I work at, always has the heady aroma of fart.