Scientific Opinion on the substantiation of health claims related to Lactobacillus rhamnosus LB21 NCIMB 40564 and decreasing potentially pathogenic intestinal microorganisms (ID 1064), digestive health (ID 1064), and reduction of mutans streptococci in the oral cavity (ID 1064) pursuant to Article 13(1) of Regulation (EC) No 1924/2006