The type of fibre that can reduce blood cholesterol levels is primarily:

Soluble fibre plays a crucial role in reducing blood cholesterol levels. This type of fibre dissolves in water to form a gel-like substance in the digestive tract, which helps to trap cholesterol and prevent its absorption into the bloodstream. By binding with bile acids, soluble fibre promotes the excretion of cholesterol from the body, leading to lower levels of low-density lipoprotein (LDL), often referred to as "bad" cholesterol.

In contrast, insoluble fibre does not have the same impact on cholesterol levels; it primarily aids in digestion and helps prevent constipation by adding bulk to stool. Simple sugars and sugar alcohols are types of carbohydrates that, while they may have various health implications, do not possess the properties necessary to lower cholesterol levels in the way soluble fibre does. Thus, focusing on soluble fibre is key for individuals looking to manage their cholesterol levels effectively.