Bacterial overgrowth of H. pylori can suppress stomach acid which enables it to survive the very low pH environment in a healthy stomach. This creates a vicious cycle where bacterial overgrowth and low stomach acid reinforce each other in a continuous decline of digestive function.
H. pylori is the type species of the genus Helicobacter. Helicobacters belong to the family Helicobacteraceae which are all members of the subdivision Proteobacteria.
A high carbohydrate diet promotes bacterial overgrowth. A low-carb (LC) diet would reduce bacterial overgrowth.