This undated inverted image shows powder transferred following a handshake, to illustrate the possible transfer of bacteria at Prifysgol Aberystwyth University in Aberystwyth, Wales. According to results published online Monday, July 28, 2014, in the American Journal of Infection Control researchers found that the knocking of knuckles, fist bump, spreads only one-twentieth the amount of bacteria that a handshake does. (AP Photo/Prifysgol Aberystwyth University)

Fist bumps less germy than handshakes

NEW YORK (AP) — When it comes to preventing the spread of germs, maybe the president is on to something with his fondness for fist bumps.