Smoke came out when I belched. What causes that? It is the first time I have ever saw or heard of that. It was just after lunch and I had taken a few supplements, e.g. trans-resveratrol, N-acetyl cysteine, and perhaps pumpkin seed extract. and I was sipping my coffee. But this, as I said, had never happened before nor since.???? Age 80; height 6'2"; weight 185; diabetes type II but under control without insulin for > 15 years.