It's natural to expect that the water coming out of our taps is safe without worry of gastrointestinal or other infectious disease. Yet every year there are dozens of outbreaks linked to drinking water in the United States alone. In the majority of cases, a failure of proper water treatment is the cause. But there is an increasing theory that the problem may not be caused at the source, but rather in the house by a handful of microbes living in the pipes behind your walls.
While we may all believe that the chemicals used in our water treatment are effective against all germs, there is a different reality. Many waterborne disease-causing bacteria, viruses and parasites are resistant to the low levels of chlorine and other disinfectants used in the treatment process. They live quite happily in the plumbing system of the home and form their own tiny cities -- called biofilms.
When formed, biofilms invite other germs to become part of the community and then, as an added bonus, helps them to hide away from the disinfectants that would normally kill them. Then, due to some type of change in the water flow or other disturbance, pieces of the biofilm will break off, grab the current and find its way into your mouth, into your lungs or onto your skin.
The incidence of waterborne infections from the home water supply is rare but this trend of infection due to biofilm formation in the plumbing is showing up not only in the home but also in our travels and in our healthcare leaving many either infected or worse.
Over the last few years, there has been a theorized approach to keeping our water safe that relies not on chemicals, but natural means. In developing countries, the use of slow flowing sand as a natural filter has helped to keep water safe of pathogens. For developed areas along coastlines, investigations on the natural ability of seawater to purify itself has revealed that plankton are the reason and that culturing them could lead to better treatment options. For landlocked populations, the use of a large number of bacteriophages -- viruses of bacteria -- has revealed the potential for treatment and biofilm prevention. Yet all of these measures are large-scale and are not easily implemented at the residential level.
This week, a new theory to keep water safe at the home emerged from a team at the Virginia Polytechnic Institute and State University. They published a paper that asks whether probiotics are the answer to our plumbing problems. The concept is based on the fact that the pipes in your home are not entirely different from those inside your body.
There is ample evidence to show that humans and water pipes alike can develop biofilms. In humans, biofilms exist in the mouth, the respiratory tract including the sinuses and the intestines. Depending on the nature of these biofilms, the overall result may be improved health or the risk of chronic disease, such as dental cavities and colorectal cancer.
It's not a long stretch, therefore, to believe then that promoting the formation of biofilms of good bacteria in the home will inevitably improve the overall health outcome for those living within it. As a result, to promote these good bacteria, the authors suggest similar approaches to that of human probiotic promotion.
First, there has to be supplementation. This could be accomplished by incorporating at the residential level a series of portals in which good bacteria could be sent into the system. These bacteria would then head into the pipes and compete with the pathogens for nutrients and space. Eventually, the probiotics would take over and form a nice, healthy environment.
In addition to supplementation, there has to be a good diet comprising prebiotics. Rather than using inulin and fructo-oligosaccharides, however, these supplements would increase the likelihood of the formation of pathogen-killing proteins known as bacteriocins.
The final key is to incorporate a sniper that targets only the pathogens and leaves the healthy bacteria alone. In the human body, these are foods that contain chemicals that can kill pathogens, such as garlic, the sugar xylitol, and clove oil. For the pipes, the snipers are bacteriophages although unlike the use of a large number, only a few select strains would be used to target the most problematic pathogens.
The authors of the review suggest that while this theory has value, there is still testing to be done both in the lab and in home-based trials. However, they are hopeful that in a world where there is currently no sure fire way to prevent waterborne infections, this option can provide the hope that in the near future, everyone will have a safe water supply thanks to a healthy and happy plumbing system.