Struvite Kidney Stones: The Bacteria-Based Stone
On the spectrum of kidney stones, Struvite kidney stones represent around 4% of the stones formed. Struvite kidney stones are not the most rare kidney stone type in humans. But, they are unique in the fact that the kidney stone former has almost no control over their formation.
Struvite kidney stones form primarily as a result of an individual consuming specific ammonia-producing bacteria found in soil. To give you an idea of how this might occur, here is a brief outline of how it all is connected to our environment:
- Animals deposit urea all over the planet when they urinate.
- As animals urinate on the soil, their urea brings nitrogen to plant roots. However, plants cannot use it in the form of urea.
- Plants need the nitrogen from the urea, so they employ special ammonia-producing bacteria that contain an enzyme called urease. These special bacteria are also responsible for the formation of Struvite kidney stones.
- The enzyme urease releases the nitrogen from urea for the plants to use. Thus, these soil bacteria with urease maintain the nitrogen cycle of the earth and are found almost everywhere around the globe.
Since the bacteria that form Struvite kidney stones are so prevalent in the natural world, we can often unknowingly consume them through foods that are not cooked. Once inside our digestive system, the bacteria can integrate with our existing gut micro-flora and become part of our intestinal bacterial population from an early age. Outside of consumption, Struvite promoting bacteria can also enter the urinary tract through the urethra if contact is made. This is especially true in women, whose shorter urethra makes entry easier for the bacteria.
Other sources of bacteria that can contribute to Struvite kidney stones are Staphylococcus, Haemophilus species, Klebsiella species, and Pseudomonas, to name a few. Yeast can also cause Struvite kidney stones. In particular, Cryptococcus species, Rhodotorula species, Sporobolomyces species, and Candida humicola are among the yeast that can lead to the formation of stones.
In order for Struvite kidney stones to form, the urine of the host needs to be alkaline. Unfortunately, the bacteria in question can create an alkaline environment for themselves through a process that they control where urea is hydrolyzed to ammonia. Ammonia raises the pH of urine to akaline values (pH of ~8+). Additionally, individuals suffering from urinary tract infections produce alkaline urine, increasing the risk of Struvite kidney stones. This is why a majority of Struvite kidney stones are seen in women.
Struvite kidney stones form in alkaline urine because of the body’s inability to dissolve the array of minerals found in urine. Since the minerals are not being dissolved and passed, they accumulate into crystals and begin to stack on top of each other to form kidney stones. Struvite kidney stones predominantly consist of ammonium, magnesium, and phosphate minerals.
When most people hear bacteria, they immediately think antibiotics as the cure. Unfortunately, since the bacteria that create Struvite kidney stones live among molds and fungi for most of their existence, they easily mount resistance to antibiotics. Often, antibiotics given for a urinary tract infection will tend to kill sensitive bacteria and select out those that can resist them.
This soil bacteria can produce Struvite kidney stones independent of any other input. Or, they can also infect calcium stones to produce mixed stones. Unfortunately for the host, Struvite kidney stones can become huge. Their bacteria can also injure the kidneys and even enter the bloodstream and cause sepsis.
Treatment is not entirely clear-cut and is a mix of thoughtful surgery and selection of antibiotics after surgery to try and kill any remaining bacteria. If the stones that form are a mix of calcium and Struvite crystals, the new calcium stones need to be prevented first and foremost to make any kind of an impact.
The term “Staghorn” kidney stone is also used to reference roughly 75% of the Struvite kidney stones that form. Staghorn kidney stones are different from all of the others, as they typically fill up and into the calyxes of the kidney (see below) making them almost impossible to pass without the assistance of surgery (PNL or SWL).
After removal of the stones and the administration of antibiotics, care should be taken to help reduce the risk of future stone creation. This can be accomplished by creating an inhospitable environment for future kidney stone formation. A few examples include:
- Freshly squeezed lemon juice (for the citrates and urine acidifying qualities)
- Potassium Citrate or other citrate supplements (for the citrates)
- Products like Stone Relief that contain citrate boosting components like Chanca Piedra and fresh lemon