The use of continuous flow systems for studying the metabolic activity of the hindgut microflora In vitro

The use of rats associated with a human faecal flora as a model for studying the effects of diet on the human gut microflora

“…In addition, the use of rodent hosts associated with human faecal bacteria may be of use in toxicology for investigating the in uizw microbial metabolism of potentially toxic compounds. The modification of bacterial enzyme activities by dietary factors is well documented for the rat flora (Rowland et al 1986), but comparable evidence for the human is not available.…”

“…The gut flora has an extensive metabolic capacity, and a large variety of compounds that enter the intestinal tract undergo bacterial biotransformation, with subsequent changes in their toxicological activity in oivo (Rowland & Walker 1983;Rowland et al 1986). The four bacterial enzymes reported in this particular study are representative of hydrolytic and reductive functions associated with the flora reported to influence the toxicity of chemicals.…”

“…The metabolic activity of the gastrointestinal microflora is an important factor in influencing the disposition of chemicals in the gut, and can result in their activation to toxic, mutagenic or carcinogenic products (Rowland & Walker 1983;Rowland et a/. 1986).…”

“…1986). A number of these bacterial functions may be influenced by dietary factors (Rowland et al 1986) and plant cell wall components exhibit particularly interesting properties in this respect (Wise et a/. 1982;DeBethizy et a/.…”

“…Various methods have been described for the study of bacterial metabolism of xenobiotic compounds in uitro and have yielded important information on the importance of microbial transformation to the expression of toxicity in the whole animal. Such studies may be adversely influenced, however, by the simple transfer of bacteria from the gut ecosystem to an in virro incubation system, with subsequent exposure to oxygen and changes in pH and redox potential adversely affecting the obligately anaerobic members of the intestinal flora (Rowland et al 1986). One means of circumventing such constraints is the use of continuous flow methods to maintain a stable, mixed bacterial flora ex oiuo over extended periods of time (Veilleux & Rowland 1981: Mallett er al.…”