Researchers have shown that when you flush your toilet, an invisible cloud of spray rises from the bowl, filling the bathroom with fecal contamination. This material can be deposited on toothbrushes, countertops and any other objects in the room. Even when the fecal detritus has been flushed, subsequent flushing can also produce a contaminated spray.

While most worry about the infectious contamination, of equal concern (or maybe even more) is the effect of inhaling lipopolysaccharides (LPS) from the fecal spray. Lipopolysaccharides are the lipid coating on colon organisms such as E. coli. This extensively studied substance has been shown to trigger intense widespread immune activation when injected.

When inhaled, it can be absorbed into the olfactory nerves, where it will be transported to brain areas critical to memory and learning. Within the brain, the LPS will trigger an intense activation of microglia, resulting in a very destructive immunoexcitotoxic reaction — which can lead to neurodegenerative diseases such a Parkinson’s disease, Alzheimer’s dementia, and other neurological disorders.

As far as I know, not one has looked into this possible hazard, but it should be examined. It is important to close the lid on the toilet before flushing and quickly leave the room.