I had to Google this one (had no idea what was being discussed). So what is being said is to eat foods that have shown lower IgG or IGA concentrations when testing against a sample of your blood?
I am sure i do not have POTS (just Neuro) but eating is still tough. Some will focus on IBS diet just because of the symptoms (like me) I never considered a delayed food reaction causing inflammation (have had similar symptoms with this as well) and being a suspected driver behind a number of issues ( Irritable bowel syndrome (IBS), migraines, rashes, asthma, and chronic fatigue)
IgA and IgG reactions are known as delayed response reactions, that include food sensitivities, where IgE responses are immediate and are considered a true food allergy. IgA and IgG reactions may not happen immediately, but can take hours to days to show up in your skin or intestines, and cause symptoms related to inflammation like headaches, fatigue, brain fog, or joint pain. People with food intolerance may experience digestive upset like nausea, constipation, or diarrhea, or skin itching and rashes including conditions like eczema and psoriasis.
IgA Reactions
IgA immunoglobulins are present in our mucus membranes and helps us fight bacteria and viruses. IgA increases in response to foods when the foods we eat cause inflammation, and in response to stress, disease, or alcohol.
IgG Reactions
An IgG reaction to food proteins suggests tolerance related to immune cell reaction. Repeated exposure, inflammation, and immune reactivity contribute to sensitivity and high IgG in response to food proteins.