My attitude toward breastfeeding is: "Depends who's breastfeeding" :D

There are other ways to take probiotics. For example if he eats salads, he can add naturally fermented apple cider vinegar (regular vinegars are sometimes sterile). He could also just take probiotics in pill form (the Good Gut authors basically recommend buying random probiotics and trying them on for size! but they need to be safe, obviously, but that's not an issue in Europe - in the US they're unregulated). Also fermented sauerkraut and gherkins etc., but availability depends on where you live. And just eating lots and lots of veggies (and legumes). I regularly make a salad where I just cut up 1 cucumber, 1 tomato, 2 lettuce leaves, 2 spinach leaves, 1 big leaf of swiss chard, a couple of rocket leaves (all these with stem), 2 tbsp apple cider, 4 tbsp olive oil, salt. You can vary what exactly you put in it, and the quantities, but the overall feel is like a fresh Greek salad without the feta.

You probly already know all that, but saying it just in case!

The Good Gut companion cookbook (written by a woman who is a bonafide science journalist) has 'phase 1' meals for those who have digestive issues. But I'm in the process of reading it now, and I haven't tried any recipes, so I don't know.

Btw if you - um - cannot find some of the books online (it looks like they aren't being seeded), there's a place I can recommend where they can be downloaded :D

Does he take a multivitamin btw? It can work wonders sometimes.

The exercise I do is lifting! I have a gym rack at home, as I quit real gyms after about 3 months, can't stand them. ... I don't trust cardio much. Lifting builds muscle, that muscle requires upkeep 24/7, so the heart works to supply it, and so it benefits even without cardio. Cardio is a bit overrated. You eat a doughnut and you gain everything back. It's also time-wasting, whereas with lifting is intense, almost like a burpee (which is probably bad for most people's knees). If you follow a good program like Starting Strength, you can do everything safely. You can also do lower weights with more repetitions, throughout the day.

A good bodyweight program is You are your own gym, no equipment necessary. Movement can sometimes help digestive issues.

I haven't found exactly what works for me, other than following the general dietary prescriptions, as laid out for example here. I have lowered my anti-inflammatory pills significantly since I started taking them, and it was all diet and exercise. All I know for sure is that more than half a cup of milk causes me digestive disturbances. Other than that I just try to eat healthy, but I haven't really noticed something like "if I eat x, then I suffer y", at least not to the point of certainty. I'm still on the road of discovery myself.

But definitely no yoga. Avoid at all costs :D