I recommend this overview of effect of human diet on the gut microbiome: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6950569/?report=classic https://www.ncbi.n

I recommend this overview of effect of human diet on the gut microbiome: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6950569/?report=classic https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6950569/?report... Tl;dr is that while the gut microbiome varies by diet, it's largely stable after around 3 years of age, and even extreme dietary changes only result in impermanent shifts in relative abundances and function of your bacteria.