Although starch with natural B-type crystal structure is a typical type 2 resistant starch， most of them have to undergo varying degrees of thermal processing before consumption， resulting in a significant decrease in enzymatic resistance. Under certain conditions， even the digestible starch could escape digestion in the small intestine and enter the colon to be utilized by microbiota， which， however， has rarely been reported. The present study prepared a series of potato starch samples with different gelatinization degrees (DG) and investigated the fermentability by human fecal microbiota in an in vitro batch system. Gas production increased from 9.8 mL of gelatinized starch with low DG (DG 16) to 14 mL of gelatinized starch with high DG (DG100) during the first half of fermentation (0-12 h)， and the acetate and propionate production also gradually increased with increasing DG. For instance， the yields of acetate (67.26 mmol/L) and propionate (61.19 mmol/L) of high gelatinized starch sample(DG100) were significantly higher than those of low gelatinized starch sample (DG16， 41.29 mmol/L of acetate， 21.27 mmol/L of propionate). Compared with other groups， gelatinized starch groups with low and medium DG (DG16， DG49) exhibited the higher butyrate yields at the end of fermentation. Moreover， Roseburia， Lachnospiraceae and Blautia were promoted by gelatinized starches with low and medium DG. Compared with other groups， gelatinized starch groups with medium and high DG (DG49， DG65 and DG76) promoted the proliferation of Megamonas， and generated higher levels of acetate and propionate. The proliferation of butyrate-producing bacterial and higher production of butyrate by gelatinized potato starch with low and medium DG (DG 16 and DG49) suggested that these starches could potentially improve the colon health function.