In recent years, many studies have reported the harmful effects of plastic debris both on the environment and on human health. Therefore, the attempt has increased for the replacement of conventional plastics with bioplastics. On the other hand, not only the studies on the effects of bioplastics and conventional plastics in the field of micro-, submicron- and nano-sized are still very limited, but also knowledge of their relationship with clinically important bacteria. In this study, the effect of two end products made from bioplastics and their equivalent end products from conventional plastics were evaluated using clinically important gram-positive and gram-negative bacteria. To evaluate the effect of the submicron-sized bioplastics and conventional plastics on the bacteria, their viability and activation and/or inhibition mechanism were performed towards the main biochemical (protein, carbohydrate, lipid and antioxidant) and physicochemical (particle size, zeta potential, chemical composition, and surface chemistry) phenomenon. This work highlights the similarities and discrepancies between bio-based and conventional submicron-sized plastics in relation to bacteria.