Effects of probiotic supplementation on disease progression in patients with moderate to severe chronic kidney disease: a randomized controlled trial.

The short version

This double-blind randomised trial with 72 people who have moderate to severe chronic kidney disease explored whether a daily Lactobacillus plantarum probiotic could slow the decline of kidney function. Chronic kidney disease affects about 10% of people worldwide, and in moderate stages (3 and 4) there are few ways to slow it. The gut-kidney axis is the idea that waste molecules produced by gut bacteria, such as indoxyl sulfate, can burden the kidneys, so changing the gut bacteria with a probiotic might help. The main yardstick was eGFR (estimated glomerular filtration rate), a blood-test estimate of how much blood the kidneys filter each minute. The study ran at a nephrology centre in Mansoura, Egypt, between May and November 2025. Participants were adults with eGFR between 15 and 59, mostly men around 60 years old, and many also had hypertension or diabetes. They were randomly assigned to a daily capsule of 10 billion L. plantarum bacteria (37 people) or an identical dummy capsule (35 people) for six months, while all continued standard kidney care. Neither patients nor staff knew who received which capsule. Kidney function moved in opposite directions. eGFR rose by a median of 4.85 in the probiotic group (30.8 to 36.1) and fell by 1.5 in the placebo group (31.7 to 29.7); after adjusting for starting values the probiotic group's eGFR was 7.72 higher (95% CI 5.63 to 9.82, p < 0.001). Serum creatinine fell by 0.3 mg/dL with the probiotic and rose by 0.1 with placebo, and measured creatinine clearance rose by 7.8 mL/min versus a 4.9 fall. The result held in stage 3 and 4 and in people with and without diabetes. Urine indoxyl sulfate did not differ between groups, and protein in the urine rose in both. Nobody in the probiotic group had disease progression versus three people on placebo (8.6%, p = 0.11), and no side effects were reported. The authors conclude that the probiotic may improve eGFR and that its effect did not appear to work by lowering indoxyl sulfate. Limits include a single centre, only six months, no measurement of gut bacteria or inflammation, a urine rather than blood toxin test, kidney function estimated from creatinine rather than measured directly, and several analyses done after the fact, so the results are preliminary and need confirmation in larger, multi-centre trials with longer follow-up.

Key findings

• In this double-blind trial, 72 adults with stage 3 or 4 chronic kidney disease (moderately reduced kidney filtering) took a daily Lactobacillus plantarum probiotic (10 billion bacteria) or a placebo for six months.
• eGFR (estimated glomerular filtration rate, a blood-test estimate of kidney filtering) rose by a median 4.85 in the probiotic group and fell by 1.5 with placebo; the adjusted difference was 7.72 mL/min/1.73 m² (95% CI 5.63 to 9.82, p < 0.001).
• Serum creatinine and measured creatinine clearance moved in the same favourable direction, and the effect appeared in stage 3 and 4 and in people with and without diabetes.
• Urinary indoxyl sulfate (a gut-derived waste toxin) did not differ between groups, so the authors suggest the benefit may work through other routes; proteinuria rose in both groups.
• No side effects were reported, but the trial was at a single centre, lasted six months, estimated kidney function from creatinine, and relied on some post hoc analyses.

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