This study is conducted to elucidate the effect of differently engineered resistant maltodextrin (RMD) and resistant starch (RS) on human intestinal microbiotal fermentation. Different types of RMD and RS are used as the sole carbon sources for bacteria in feces from healthy volunteers. The cultured samples are analyzed for changes in microbial groups from which the prebiotic index (PI) is calculated. The metabolic activity of the microbiotal communities is monitored by efficiency of carbon utilization and short chain fatty acid (SCFA) profiling. Bifidobacteria and lactobacilli are found to be increased whereas clostridia (histolyticum subgroup) and bacteroides are decreased. RMD is more efficiently utilized than RS showing up to 78% of carbon source consumption. Utilization of RS provides the highest content of propionic and butyric acid while RMD shows a higher content of acetic and lactic acid. RMD and RS show a superior PI compared to that of glucose. Different types of molecular stearic hindrances, configurational hindrance for RMD, and conformational/aggregational hindrance for RS, prevent their hydrolytic utilization, directly influencing the human gut microbiotal composition and/or fermentation capability in different manners. RMD demonstrates the highest acetic acid content while RS3 and RS4 provide the highest butyric acid content.