One study in 2013 observed that Dandruff is associated with a ratio of bacteria to funghi that is out of balance on the scalp.
In addition, a 2018 paper described how microbial dysbiosis was found on the scalp microbiome of people with dandruff. Interestlingly, they found that the unbalanced bacterial and fungal communities were not just found on the affected areas, but were present across the whole skin microbiome.
They suggested that:
A 2021 systematic review also noted that an out of balance scalp microbiome is apparent for those with dandruff and seborrheic dermatitis.
These findings suggest that re-balancing the scalp, and the microbiome as a whole, could provide future treatment for Dandruff, as well as a whole host of other diseases associated with a dysbiotic and non-diverse microbiome.