H. Pylori, IgG Abs is used to diagnose a Helicobacter Pylori infection. Helicobacter Pylori is a bacteria which is most primarily found in the gut.

Hydrogen is produced when certain bacteria in the small intestine consume sugars and produce hydrogen gas as a byproduct.

Hydrogen levels are considered abnormal when they rise greater than ≥20 ppm (parts per million) from the baseline within 90 minutes.

In healthy humans, hydrogen gas is exclusively produced by intestinal bacteria - primarily a result of carbohydrate fermentation by anaerobic bacteria in the colon. In SIBO, fermentation of the malabsorbed lactulose substrate by bacteria residing in the small intestine results in elevated concentration of exhaled hydrogen (H2).