Safe gut cleanse while pregnant?

Hi ladies! Any safe gut cleanses to do while pregnant? Just thinking of adding a fruit smoothie to my day and doing a miralax cap in them.

I am 28 weeks now and feeling incredibly bogged down and sluggish, pretty constipated, yadda yadda. Previously when I’ve felt this way I’ve done some short term cleanses just to restart my digestive health so that I can regain that energy and feel a little less blah. But some of those things I know are unsafe during pregnancy, and I’m really just trying to clean my system out, not reduce weight or anything.

Tips and tricks to help me through this third trimester stretch would be appreciated! 💕