I’m relieved for you that you don’t have C-Diff. That’s scourge I wouldn’t wish on anyone! Keeping my little gut-bugs happy is my goal. 😃
Antibitoics are godsends for helping us fend off certain bacteria. Unfortunately they are not discriminatory and kill off the good bacteria in our guts as well. So we need to replenish, feed and nurture the good guys!
There are some great articles online about keeping our gut biome healthy. I gave you a couple links yesterday and with the addition of some of those foods, the yogurt you bought and the addition of fiber will help.

I wanted to caution you though! Add fiber daily in small amounts! Too much will cause their own level of gastric disturbances. ☺️ If you end up with more bloating or gas, just back off for a day or so again. For the yogurt, aim for 8 oz daily. You can divide that into smaller portions of 4 oz morning and then evening after dinner. If you’re introducing fiber like ground flax seed, then only mix 1 teaspoon in with your morning oatmeal. And also, if you’re not used to oatmeal, work your way up to larger portions of that as well. I think a serving is 1/2 cup of raw oats (before cooking). That’s a lot if you’re not used to it! So try 1/4 cup and cook in the microwave with either milk or water added.
Same thing for the muffins! They sound healthy but if you’re not used to a lot of fiber, slow and steady gains is the way to introduce them.

Another staple food I add to my diet daily is raw sauerkraut. Fermented foods such as raw sauerkraut or kimchi are super healthy for our guts. The kraut should be fresh, not canned. You can make it at home, or grocery stores carry it in refrigerator case! I eat about 2 tablespoons of kraut daily on a salad or sandwich.
You might also consider having a consultation with a registered dietician to help you find a happy balance with getting enough fiber, nutrition and protein. Weighing only 70 pounds you definitely can’t afford to lose any more weight. Let’s get that gut healthy so you can put some meat on your bones again. It takes time to heal a gut, so don’t rush it!

Best wishes for success in treating your MAC. That’s out of my wheelhouse but I would like you to let me know how you’re doing with your intestinal issues.