I have never heard of IgG for gut health, so I had to look it up. Usually, IgG is given IV or subcutaneously. But, in this instance, it is an oral supplement. Even though it has been around for years, it does not seem that there are clear indications of efficacy. I am not sure how it survives digestion. Like probiotics, perhaps it is a mixed bag. Hopefully, someone with some personal experience comes along.
Jan