I started out walking my first few Caminos using vaseline, but have since found choosing the right socks, shoes and different preventative measures to be best at keeping me blister free.
I've made a video on blister prevention, which may help some of you -
Fermented foods contain live bacteria, which when consumed can increase healthy bacteria in gut, improving your body's response to unfriendly bacteria and other such delights
I've never had food poisoning on the Camino, but do find the change in diet and the sugary breakfast can be challenging. What works for me is taking OptiBack tablets, which help my tum and staves off acid reflux
I swear by these - https://www.thermarest.com/ie/pillows/foam-pillows/compressible-pillow/compressible-pillow.html
Some of the albergue pillows are like sandbags, so having a therma rest pillow can be a life saver, or should I say neck saver. They fold up, so they don't take up too much space...