Often people coming from a primarily meat-based diet will find challenges as they transition to a plant-based one. They may feel bloated, have more wind and other symptoms. There is a reason for this. It is about the bacteria inside your gut biome.
According to nature.com/articles/nature1... the animal-based diet increased the abundance of bile-tolerant microorganisms (Alistipes,Bilophila andBacteroides) and decreased the levels of Firmicutes that metabolize dietary plant polysaccharides (Roseburia, Eubacterium rectale and Ruminococcus bromii).
To put a more tangible way of understanding this, the study took a look at bile acid in stools (see image). This indicated that bile acid increased with animal based diet, whereas with plant-based there was no significant change.
Changes to your gut can take a few days, or for some people a few weeks. But whatever timescale those changes will happen and you will feel better as a result.