You could also try not combining it with lots of palmitic acid. I'm assuming you're eating it with fattier cuts of meat. Fatty meat high in palmitic acid paired with starch is notorious for causing a sluggish feeling. You'd be better of eating it alongside some very lean meat like chicken breast and cooking it in olive oil because it's low in palmitate.
EDIT - This is a very good probiotic supplement and I'd recommend it. Try taking 2 of these with a good sized sweet potato (minus the skin). Feel free to chase it with a glass of kefir. It should help. It may take months or years to rebuild damaged gut cultures.