I don't think Antibiotics can damage the parietal cells but they create a dysbiosis. Dysbiosis is linked to immune suppression and ovegrowth of pathogenic organisms. For any reason, when people are immune suppressed they don't produce stomach acid. An example is people with HIV. Science doesn't know the reason but there is a link between them. I am more convinced than ever candida isn't alone in this problem but a bacterial overgrowth is too. These intestinal problems are very difficult to resolve and bring under control.