Chemical Changes in the Large Intestine and Detoxication
CHEMICAL CHANGES IN THE LARGE INTESTINE AND DETOXICATION
• After digestion and absorption in the small intestines, the semi liquid residue is passed into the large intestines. • There are no enzymes to act on the residues in the large intestines. • Only a very small amount of viscous, slightly alkaline fluid containing large amount of mucin is contributed by the mucosal cells of the colon. • There are normal intestinal microorganisms which disintegrate the organic residues into simpler fragments. • Some products are: • Amines and phenols (potentially harmful) • Vitamins (beneficial) • Stercobilinogen (innocuous) • The products are produced through metabolic activity of the bacteria, involving such processes as oxidation, reduction, hydrolysis, deamination and decarboxylation.
CARBOHYDRATES AND LIPIDS
Fermentation – bacterial degradation of carbohydrates under anaerobic condition – occurs in the intestinal tract
Products:
• organic acids (formic, acetic, lactic, propionic, succinic acids) • gaes (methane, carbon dioxide, hydrogen)
PROTEINS
Putrefaction – bacterial decomposition of proteins under anaerobic condition • aromatic amino acids are transformed into phenol, cresol, indole and skatole • sulfur containing amino acids yield hydrogen sulfide, mercaptans and methane • some simple amino acids undergo deamination (removal of amine group) • others undergo decarboxylation (removal of carboxyl group)
Examples:
Tryptophan deamination
Tryptophan -----> Indole propionic acid -----> Indole acetic acid -----> Skatole ----> Indole • Skatole and indole – responsible for the characteristic foul odor of the feces
Tryptophan decarboxylation
Tryptophan -----> Tryptamine • Tryptamine – when absorbed, causes a rise of blood pressure
Tyrosine deamination, oxidation and decarboxylation
Tyrosine -----> Cresol
Tyrosine decarboxylation alone
Tyrosine -----> Tyramine /
• After digestion and absorption in the small intestines, the semi liquid residue is passed into the large intestines. • There are no enzymes to act on the residues in the large intestines. • Only a very small amount of viscous, slightly alkaline fluid containing large amount of mucin is contributed by the mucosal cells of the colon. • There are normal intestinal microorganisms which disintegrate the organic residues into simpler fragments. • Some products are: • Amines and phenols (potentially harmful) • Vitamins (beneficial) • Stercobilinogen (innocuous) • The products are produced through metabolic activity of the bacteria, involving such processes as oxidation, reduction, hydrolysis, deamination and decarboxylation.
CARBOHYDRATES AND LIPIDS
Fermentation – bacterial degradation of carbohydrates under anaerobic condition – occurs in the intestinal tract
Products:
• organic acids (formic, acetic, lactic, propionic, succinic acids) • gaes (methane, carbon dioxide, hydrogen)
PROTEINS
Putrefaction – bacterial decomposition of proteins under anaerobic condition • aromatic amino acids are transformed into phenol, cresol, indole and skatole • sulfur containing amino acids yield hydrogen sulfide, mercaptans and methane • some simple amino acids undergo deamination (removal of amine group) • others undergo decarboxylation (removal of carboxyl group)
Examples:
Tryptophan deamination
Tryptophan -----> Indole propionic acid -----> Indole acetic acid -----> Skatole ----> Indole • Skatole and indole – responsible for the characteristic foul odor of the feces
Tryptophan decarboxylation
Tryptophan -----> Tryptamine • Tryptamine – when absorbed, causes a rise of blood pressure
Tyrosine deamination, oxidation and decarboxylation
Tyrosine -----> Cresol
Tyrosine decarboxylation alone
Tyrosine -----> Tyramine /