Blood testing is not reliable for post-treatment H. pylori diagnosis/rediagnosis. Nearly all studies have found that successful treatment is associated with a 40 to 50% decrease in IgG levels by 6 months post-treatment. However, only about 25% of successfully treated patients show a complete disappearance of IgG antibodies, even when measured 3.5 years after treatment.
The only reliable post-treatment blood testing is A combination IgG, IgM, and IgA PLUS a Western blot for antibodies recognizing specific H. Pylori proteins, including cytotoxin-associated gene A (CagA) protein and vacuolating cytotoxin A (VacA) protein.
The best test is still an H. pylori antigen assay, which detects H. pylori antigen present in stool. Unlike antibody assays, this test is positive only in association with active infection. All testing has a margin of error.
If symptoms are still present after H. pylori treatment, wait at least one month and get an H. pylori stool antigen test (most accurate). If negative, test for SIBO using a 3-hour lactulose challenge, which measures both hydrogen and methane gas. If that is negative, go see a functional medicine doctor who can work you-up for what is truly going on. The potential issues can be many. Here is just a few:
- Excess histamine production in the stomach or an inability to enzymatically break-down histamine – lack of the enzyme, diamine oxidase (DAO).
- Leaky gut causes by many sources.
- Lack of HCl and/or pancreatic enzymes production.
- Eating foods, not for your blood type (A, B, O, AB), causing inflammation.
- Inability to break-down simple sugars, especially fructose.
- A deficiency of the enzyme alpha-galactosidase. This deficiency can cause an inability to break-down certain complex carbohydrates found in many foods such as beans, vegetables. and whole grains.
- Blastocystis hominis and other bacterial and parasite infection.
- Excessive Candida albicans overgrowth.