Definition: Antiprotosal refers to a cell type found within certain types of bacteria, particularly in the gut flora. This term signifies a kind of amoeba-like organism with no clear-cut boundary between its cells and those that are not directly connected. In essence, it describes a diverse group of microorganisms, including E. coli (Lactobacillus acidophilus) but also other types like Bacillus subtilis or Trichoderma species.