According to a study by scientists at the University of Aberdeen (UK), the bacterium Heliobacter pylori related to gastritis, intestinal ulcer or cancer reproduces quietly in the water pipe. In developed countries half of those over the age of 50 have this bacteria, but so far no one knew where it came from.
According to the researchers, Heliobacter pyloria would form biological biolayers and thus colonize water pipes. These types of layers are common in water distribution networks. According to laboratory studies, biolayers remain there after 192 hours of water passage. Chlorine treatments consider that they only affect the surface of the biolayer and thus the bacteria also face treated waters.