I’ve mentioned the BBC 4 Food Programme podcasts before… but again: check out their podcasts and maybe start with these ones on gut microbiota:
https://www.bbc.co.uk/programmes/b07ff0hl
https://www.bbc.co.uk/programmes/b07h60lv
The BBC is actually just a great site to do searches for topics you’re interested in. The following podcast looks into Gut Microbiota, too:
https://www.bbc.co.uk/programmes/b03h429g “Adam Hart discovers the role gut microbes play in our health and development, and asks if we should consider ourselves an ecosystem rather than an individual?”