Kidney stones are a common health problem that affects almost 10% of the world's human population. However, recent research has shown that dolphins are also prone to kidney stones. These tiny painful objects can block urine and cause urinary infections, leading to significant health problems. Traditionally, kidney stones have been removed using small telescopes and instruments, which can cause blood in the urine and bruising on the back or abdomen. Therefore, there is a need for alternative treatments that can prevent or reduce the occurrence of kidney stones.

Did you know that dolphins also suffer from kidney stones? The well-known health problem torments not only humans but dolphins. Those tiny painful objects hiding in the urinal tract of the body can easily block the urine and cause urinary infections. This condition affects almost 10% of the world's human population.

Fortunately, there could be a breakthrough in the treatment of kidney stones –  a dietary change. With the help of the  U.S. Navy, scientists conducted research on a managed collection of dolphins being fed on a diet of high-quality, frozen–thawed fish, including mackerel, herring, capelin, and squid (New York Times, 2023). By giving them foods with different concentrations of protein, fat, ash, and alkali content, the scientists aimed at examining the influence of diet on urinary citrate concentrations.

In another control study, Smith et al. (2013) who has been riding the waves of dolphin research discovered a significant fact in wild dolphins — bottlenose dolphins, not commonly affected by kidney stones, possibly because of their diet (St. Leger, 2018). They consume foods rich in urinary citrate which inhibits stone formation by complexing with calcium in the urine, inhibiting spontaneous nucleation, and preventing the growth and agglomeration of crystals. That is a great step into the blueprint of solutions to this kidney problem.

Traditionally, medical practitioners have removed kidney stones using small telescopes and instruments inserted through a small incision in the back. However, such procedures cause blood in the urine and bruising on the back or abdomen. Therefore, the impact of the study is profound.

When evaluating potential reasons why managed collection dolphins are prone to kidney stones, may low citrate level was attributed to this phenomenon, scientists felt that it is unlikely that dolphins from managed collections absorb citrate less well than their wild population's counterparts, given that the presence of citrate in dolphin diets is likely to be low (Le-Bert et al.2018 & Ardete et al. 2017). Further, there is a potential, though unlikely, for a genetic mutation that has been passed within managed collections associated with citrate malabsorption.

Scientists have also found out that crystal growth of ammonium urate can be controlled by manipulating isomers of urate called tautomers  (Le-Bert et al. 2018 & Ardete et al. 2017). This process can control the rate at which crystals grow to the point they can completely block crystallisation. The scientists think it is possible to mimic this procedure by diet control to get the concentration in the kidney in that range. Significantly humans and dolphins are affected by kidney stones alike — this finding is exclusively meaningful and crucial.

Pharmaceuticals are critical in our daily life. Health problems are very normal and hospitals are necessary facilities in the community. However, dietary change to mimic bottlenose can mean a great step toward the elimination of kidney stones. Even though the research on similarities between humans and dolphins is ongoing, dietary changes lift the veil of the mysterious mechanisms of our bodies.

Reference

Smith CR, Venn-Watson S, Wells RS, Johnson SP, Maffeo N, Balmer BC, Jensen ED, Townsend FI, Sakhaee K. Comparison of nephrolithiasis prevalence in two bottlenose dolphin (Tursiops trun- catus) populations. Front Endocrinol (Lausanne) 4: 145, 2013. doi:10.3389/fendo.2013.00145.

St. Leger J, Raverty S, Mena A. Cetacea. In: Pathology of Wildlife and Zoo Animals, edited by Terio KA, McAloose D, St. Leger J. London, UK: Academic Press, 2018, p. 533–568. dx.doi.org/ 10.1016%2FB978-0-12-805306-5.00022-5.

Le-Bert CR, Smith CR, Poindexter J, Ardente A, Meegan J, Wells RS, Venn-Watson S, Jensen ED, Sakhaee K. Comparison of poten- tial dietary and urinary risk factors for ammonium urate nephrolithia- sis in two bottlenose dolphin (Tursiops truncatus) populations. Am J Physiol Renal Physiol 315: F231–F237, 2018. doi:10.1152/ ajprenal.00606.2017.

Ardente AJ, Wells RS, Smith CR, Walsh MT, Jensen ED, Schmitt TL, Colee J, Vagt BJ, Hill RC. Dietary cation-anion difference may explain why ammonium urate nephrolithiasis occurs more fre- quently in common bottlenose dolphins (Tursiops truncatus) under human care than in free-ranging common bottlenose dol- phins. J Anim Sci 95: 1396–1406, 2017. doi:10.2527/jas.2016. 1113.