Effects of race distance and probiotics intervention on kidney, muscle, and gut injury and inflammation biomarker responses during running

Abstract

Introduction: Prolonged intense physical activity, such as long-distance running, may lead to systemic inflammation and cause organ injury, particularly to the kidneys. This study aimed to assess the impact of trail race running on kidney and muscle injury and gut inflammation biomarkers, and the potential mitigating effects of Lactiplantibacillus plantarum 299v (Lp299v) supplementation. Methods: This randomized, double-blind, placebo-controlled study included 34 participants who completed 42 races, ranging from 20 to 164 km. Participants were divided into two groups, receiving either 40 bn CFU Lp299v or a placebo for 4 weeks before the race. Urine and fecal samples were collected pre- and post-race (immediately after, morning after and 24 h after the race) to measure biomarkers of muscle and kidney injury, and gut inflammation. Principal component analysis was used to create a single tubular kidney injury biomarker component variable (TKIBC1) positively associated with five separate tubular kidney injury biomarkers (MCP-1, KIM-1, GST-π, clusterin, and calbindin) at the three post-race time points. Results: Running led to increased tubular and glomerular kidney injury markers, increased levels of fecal calprotectin, and, in some cases, elevated urine myoglobin levels. These effects were more pronounced in races ≥107 km (ultradistance). While Lp299v supplementation did not significantly influence TKIBC1, it was associated with a protective effect against gut inflammation. Conclusion: These findings suggest that prolonged intense exercise induces kidney and muscle injury as well as gut inflammation, with more severe effects observed in ultra-distance running. Lp299v may have some protective effects, particularly against gut inflammation, but further studies are needed to confirm these findings and explore the underlying mechanisms linking gut health and kidney injury during extreme physical exertion.