A Study of Healthy Microbiome, Healthy Mind

Inclusion Criteria: \- patients who have survived critical illness, including severe COVID, and are at risk for mental health morbidity/long COVID (spent \>48 hours in the ICU or had COVID requiring ICU stay) who have a smartphone, are enrolled into the Mayo PICS clinic, and have at least one PICS-related impairment. Cognitive impairment, if present, has to be in the mild range to ensure patient can provide consent and follow study instructions Exclusion Criteria: \- History of dementia, mental retardation, psychotic disorders such as schizophrenia, patients not expected to survive the hospital stay or non-English speaking, participants not able to tolerate foods by mouth or those with potential contraindications to such diet (chronically immunosuppressed including organ transplant recipients; those with neutropenia or currently undergoing chemotherapy, those taking Monoamine oxidase inhibitors).