Relief from microbial activity and related by-products
is of high relevance, especially in the small intestine,
because production of VFA counteracts stabilization of
the intestinal pH required for optimum activity of digestive enzymes. In addition, intestinal formation of biogenic amines by microbiota is undesirable not only because of toxicity, but also because of the fact that biogenic amines are produced mainly by decarboxylation of
limiting essential AA (e.g., cadaverine from Lys, scatol
from Trp). Consequently, relief from microbial fermentation in the small intestine may improve the supply
status of limiting essential nutrients (e.g., Roth et
al., 1998).