The GtfD 4,6-α-glucanotransferase enzyme of Paenibacillus beijingensis is a member of the glycoside hydrolase family 70. In the presence of amylose V the enzyme generates two reuteran-like polymers distributions: a high-molecular-mass polymer (HMMP) and a low-molecular-mass polymer (LMMP) containing both long linear α(1→4) chains. The HMM polymer with an average length of 27 MDa contains 71 % α(1→4) and 29 % α(1→6)linkages. While the LMM polymer of 19 KDa consists of 77 % α(1→4) and 23 % α(1→6) linkages. Indicating the HMM has a slightly higher amount of α(1→6) linkages. The polymers may be suitable as a biocatalyst to reduce the glycemic index of starch-containing food.