TLDR  Malassezia yeast might be linked to more hair shedding.   
  Between 1999 and 2003, a study involving 300 medical students explored the potential link between hair shedding and the presence of Malassezia yeast, formerly known as Pityrosporum ovale. The participants were split into two groups based on their hair condition—normal or shedding. After analyzing scalp scrapings under a microscope, researchers found that 76% of the students carried Malassezia, with a significantly higher occurrence in the hair shedding group (89.92%) compared to the normal hair group (9.52%, p < 0.001). Those with positive smears for Malassezia also reported more hair loss and had positive results on hair-pull tests. These findings indicate a possible connection between Malassezia yeast and increased hair shedding, suggesting the need for further studies with larger populations to confirm the relationship.
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