Studies on Amine Production in the Human Colon: Enumeration of Amine forming Bacteria and Physiological Effects of Carbohydrate and pH

Fecal Trimethylamine, Lactate and Volatile Fatty Acid Concentrations and Their Relationships with Diarrhea in Newborn Dairy Calves

“…Similar to the high trimethylamine level observed in several feces (Fig. 1b) in the present study, a substantial amount (3.5 mM on the average; highest 9.2 mM) was found in the feces of healthy human adults who consumed western-style diets [13].…”

“…However, it has been reported that certain humans [21] and dairy cows [3,5] excrete substantial amounts of trimethylamine in their breath, urine, sweat and milk, resulting in a characteristic fishy odor and in an off-flavor of bovine milk, although the detailed mechanisms remain a matter of debate. In the present study, a definite relationship was not observed between the trimethylamine level and fecal pH or VFA concentrations, although a potential decrease of toxic amine excretions was suggested by increasing the supply of fermentable carbohydrates or dietary fiber in human food [13]. The lack of association between the fecal ammonia and trimethylamine levels may be a reflection of the independent route by which each precursory compound is metabolized.…”

“…Limiting the production of trimethylamine from livestock yards has been declared an urgent task [20], even though the trimethylamine absorbed by animals is mainly oxidized by the liver to odorless and tasteless metabolites that are subsequently excreted in urine [13]. However, it has been reported that certain humans [21] and dairy cows [3,5] excrete substantial amounts of trimethylamine in their breath, urine, sweat and milk, resulting in a characteristic fishy odor and in an off-flavor of bovine milk, although the detailed mechanisms remain a matter of debate.…”

“…The physiological significance of VFAs and lactate in gut health has received considerable attention in humans [7,15,16] and animal nutrition [16,18] during the last few decades. In addition, trimethylamine, which is a degenerative product of intestinal bacteria, is often associated with foul odors in the atmosphere and also has significance in nutritional, clinical and malodor characterization in healthy humans [13,21]. Aside from the air pollution resulting from excess trimethylamine production in the livestock industry [20], little attention has been focused on trimethylamine formation in the gut and its clinical significance in dairy and beef cattle.…”

Acquisition, Evolution and Maintenance of the Normal Gut Microbiota

“…[ risk of large bowel cancer [82] as well as a variety of other maladies resulting from the accumulation of bacterial toxins [83,84] . Furthermore, a marked correlation exists between colonic transit time and bacterial cell mass in the large gut.…”