I take a probiotic daily (PB 8 brand) and did so through my RT. I can’t say it made a difference, but I had very few side effects during and after RT (now at 6 months past). My bowel movements are a little more urgent these days, but far from the point of causing me a problem. As heavyphil said, stay hydrated (I drank at least 64 oz of water per day, and still do). Nap when you’re fatigued, or at least slow down. Keep up with exercise. Listen to your body, adjust accordingly, and keep your care team informed of any changes or anything bothersome.

I continued to eat nuts (mostly walnuts and pistachios) but I cut out beans and legumes during treatment (gas control). And, like you, no cruciferous veggies. Allowed myself a morning cup of coffee, and drank 1-2 cups of green tea daily. Daily cup of tomato juice as well.

Best wishes for successful treatment with minimal side effects.

Mel