[Changes in fecal composition, intestinal transit, bile acid metabolism and intestinal fermentation in long-term nutrition with high molecular weight formula diet].

Treatment with formula diets becomes more and more popular in many patients. The influence of those diets on gut functions is as yet poorly known. We studied in ten healthy volunteers the effects of a high molecular liquid diet. Despite of a sufficient energy supply the volunteers lost significantly weight which may be related to an acceleration of small bowel transit (60 +/- 9 min vs. 31 +/- 5 min; control vs. diet period). Whole gut transit did not change significantly (52 +/- 3 h vs. 56 +/- 3 h). The fecal excretion of bile acids decreased significantly (293 +/- 35 mg/24 h vs. 151 +/- 10 mg/24 h) which was particularly due to a decrease of primary bile acids. The serum bile acid concentrations behaved in a similar way (total bile acids: 3.19 +/- 0.66 mumol/l vs. 1.71 +/- 0.21 mumol/l). Neither the determination of unconjugated serum bile acids nor hydrogen breath testing did indicate increase of bacterial growth. In conclusion, chronic nutrition with formula diets causes significant changes of gut functions.