Are there studies showing the increased cancer rate is caused (or at least correlated with) reduced fiber intake? Or is this just a guess of yours?

Low fiber intake is very heavily correlated with an increase in all cause mortality.

Every 10g per day is correlated with a 10% reduction in all cause mortality (up to 30g). Mostly from a reduction in cardiac and cancer deaths.

There’s an enormous amount of data on this topic. So much I’ll just tell you to do a web search rather than pointing to some papers in is response: it’s just so pervasive and going back for decades.

Use a conventional search not an ai-generated summary as that will have influencer slop mixed in. Though oddly, I’ve never seen an anti-fibre influencer, but have seen lots of pro-fibre influencer posts!