When it comes to the formatting of text, there are a couple of different aspects to consider.
The most visually distinct aspect is the actual font used for the text, and there are some good information from organisations that provide support for dyslexic people due to their reduced ability to process text. The style guides suggested generally are design to improve the ability for everyone to process text better. Here is an example of a Dyslexia friendly style guide.
Another important aspect is the structure of the paragraph, which consists of a coherence and harmonious balance between the font size, line width and line-height so that the optimal amount of text is displayed and easily processed (for a given display window or space - e.g. desktop screen versus mobile phone).
In summary, these are the areas you should look into further:
- font style
- clear heading and structure of page content
- optimal structure and spacing of paragraphs / density per line of text
- colour of text and background
- writing style (not related to the formatting but still important)