Interesting thought. I cannot say for sure that it is true, but several lectins (including apple and banana I beleive) are known to bind with and either enhance or inhibit gastric H2 receptors. These receptors play a role in histamine synthesis, and in the old days histamine injections were often used to stimulate acid production.

What I do know is that lectin testing of common foods is dreadfully undereported in the literature. Most lectins identified have been with the purpose of developing their use as molecular probes. The more prosaic day to day reactions are not well studied, the last report I have seen are two articles by Nachbar in the 1970's. Many of the food lectin reactions reported in ER4YT were done by myself in the late 1980's on enzyme or albumin treated banks of reagent RBCs after purification via immunodiffusion electrophoresis.