# Effect of Bifidobacterium longum on cognition and microbiota in post-stroke patients: a single-blinded, controlled trial

## TL;DR

This study found that a probiotic, Bifidobacterium longum OLP-01, improved cognitive function and altered gut microbiota in post-stroke patients over 12 weeks.

## Contribution

The novel finding is that Bifidobacterium longum OLP-01 improves cognition and modifies gut microbiota in post-stroke patients.

## Key findings

- The OLP-01 group showed improved Montreal Cognitive Assessment (MoCA) scores.
- The probiotic group had faster Trail-Making Test completion times and better Stroop test accuracy.
- Gut microbiota composition differed between the probiotic and placebo groups.

## Abstract

Stroke is the major leading cause of death globally, and has a high disability rate. Malnutrition, cognitive dysfunction, motor impairment, and gut dysbiosis are observed in stroke patients. Our study explored the effects of Bifidobacterium longum OLP-01, a probiotic from an Olympics gold medalist, on cognitive function and gut microbiota as the primary outcomes, and on nutritional status and physical performance as the secondary outcomes in post-stroke patients. The study was a single-blinded, randomized, placebo-controlled trial. We recruited 22 post-stroke patients. Participants received either placebo (placebo group, n = 10) or 2 × 1010 colony-forming units (CFU) of Bifidobacterium longum OLP-01 powder (OLP-01 group, n = 12) daily for 12 weeks. Nutritional status was assessed using Mini Nutritional Assessment (MNA). Cognitive function was evaluated by Montreal Cognitive Assessment (MoCA), Trail-Making Tests, and Stroop Color Naming Test. Physical performance was measured using Timed Up and Go Test and 6-Minute Walk Test. Blood and stool samples were collected for biochemical and gut microbiota analyses. The OLP-01 group increased MoCA scores, decreased time to completion of Trail-Making Tests, and had greater accuracy on incongruent in Stroop Color Naming Test, but decreased MNA scores within the normal ranges. The cognitive-related gut microbiota strain showed differences between the two groups. Supplementation of Bifidobacterium longum OLP-01 at a dose of 2 × 1010 CFU daily for 12 weeks improved cognitive function and changes gut microbiota, but did not alter physical performance in post-stroke patients.