FIG. 2.

Gastrointestinal phage transit in human volunteers. Fifteen adult volunteers received the lower phage T4 dose (squares), the higher phage T4 dose (diamonds), and no phage (triangles) in their drinking water for 2 days (the treatment period is marked by a horizontal bar). The stool samples were tested for the presence of phages starting 1 day preceding the intervention. (a) The prevalence (in percent) of phage-positive stool samples; (b) the time development of the mean phage titer in the feces of the volunteers (expressed as PFU/g stool). Each datum point represents the results from all 15 volunteers. The mean titers for the recipients of the lower phage dose were 17 and 68 at days 2 and 3, respectively; they are too small to be visible at the chosen scale.