No, enzymes in the small intestine do not need an acidic environment to work. In fact, they work best in a slightly alkaline environment.

Here's why:

* Stomach acid: The stomach is highly acidic (pH 1-3) and this acidity is crucial for the digestion of proteins by pepsin. However, the acidic chyme (partially digested food) from the stomach enters the small intestine.

* Neutralization: The pancreas secretes bicarbonate into the small intestine, which neutralizes the acidity of the chyme, raising the pH to about 7-8 (slightly alkaline).

* Optimal pH for enzymes: Most of the digestive enzymes in the small intestine, such as pancreatic amylase, lipase, and proteases, have optimal activity in this slightly alkaline environment.

So, while the stomach's acidity is crucial for protein digestion, the small intestine needs a more neutral or slightly alkaline environment for the majority of its digestive enzymes to function efficiently.