Probiotics and alkalizing minerals against kidney stones

Kidney stones are hard crystals, most often composed of calcium oxalate, which form in the kidneys and can lead to renal colic, which is particularly painful. However, the presence of crystals in the urine, or crystalluria, is an important indicator of the recurrence of kidney stones.

The conditions under which these crystals form are not fully understood, and researchers are showing increasing interest in the intestinal flora for its contribution to maintaining the balance of urinary solutes.

Read: How to Prevent Kidney Stones (Subscribers)

Probiotics to improve intestinal flora

A study carried out at a hospital in Rome included 23 patients who suffered from calcium oxalate stones, a form of stones that develops in an acidic urinary environment.

The patients received a daily dietary supplement of 1 billion for 20 days. Lactobacillus paracasei LPC09, 1 billion Lactobacillus plantarum LP01, 1 billion Bifidobacterium breve BR03. They also received potassium (520 mg) with citrate (1,400 mg) and magnesium (80 mg). Potassium citrate alkalizes urine.

Results: One month after taking oral supplements, no patients reported crystalluria; at 3 months, of the 20 participants available for reassessment, none reported crystalluria. On the other hand, crystalluria was reported in 3 patients (15%) at 6 months and in 5 patients (25%) at 12 months of follow-up.

The researchers conclude that oral supplementation with lactobacilli and bifidobacteria, combined with alkalizing minerals, is able to reduce the prevalence of crystalluria.

The role of acid-base balance

The management of kidney stones depends on their nature. In the event of oxalate stones, the nephrologist may prescribe potassium citrate, which makes the urine less acidic. More concentrated in the urine, citrate binds to calcium and potassium to oxalates, which prevents the crystallization of oxalate with calcium in the urine.

The kidney plays a vital role in maintaining the body’s acid-base balance. Urinary pH reflects the amount of acidic compounds the body gets rid of. It should be around 6. If it is lower than 6, the urine is acidic. It is therefore important to alkalize your diet, as explained by Sandra Gressard, dietician-nutritionist specializing in nephrology, in her book Bye Bye kidney stones : “The body’s acid-base balance depends largely on diet, and in particular on the mineral composition of the foods we ingest. »

To know the acid load of a food, you must refer to its PRAL index. “This index measures the quantity of acidic minerals and basic minerals provided by 100 g of a food taking into account its intestinal absorption coefficient”, said Sandra Gressard. “The PRAL index also takes into account the quantity of proteins and sulfur-containing amino acids in this same food. »

• Examples of acidifying foods, with a positive PRAL index : meat, fish, eggs, cold meats, shellfish, dairy products, cereal products.
• Examples of alkalizing foods, with a negative PRAL index : vegetables and aromatic herbs, starchy foods such as tubers (potatoes), certain legumes, fresh and dried fruits, and certain oilseeds.

To find out more: Bye Bye kidney stones