Inclusion Criteria:

- Age >18; <65 yo

- Previous diagnosis of SARS-CoV-2 infection, documented by nasopharyngeal or
antigenic molecular swab;

- Not currently be in quarantine or isolation;

- No antibiotics treatment in the 30 days prior to the trial;

- Chalder Fatigue Scale (in dichotomous form)>=4 possibly associated with signs and
symptoms of Long COVID-19 syndrome: signs and symptoms that develop during or after
SARS-CoV-2 infection, which persist for more than 4 weeks and are not reasonably
explained otherwise; signs and symptoms include: fatigue, sleep disturbances,
cognitive deficits (i.e. brain fogging, loss of concentration and memory, anxiety,
depression), strength deficits, arthralgias and myalgias, gastroenterological
alterations (reduced appetite, nausea, changes in bowel habits, abdominal pain

Exclusion Criteria:

- Cardiovascular and pulmonary disease with moderately severe organ dysfunction
(NYHA>2, Borg scale>=2);

- Decompensated endocrine and metabolic diseases (child cirrhosis >= B, decompensated
hypo/hyperthyroidism, decompensated hypoadrenalism)

- Diagnosis of FM, CFS/ME, and/or IBS prior to SARS-CoV-2 infection;

- Confirmed diagnoses of neurological pathologies, psychiatric diseases and cognitive
disorders prior to SARS-CoV-2 infection;

- Previous confirmed diagnosis of chronic musculoskeletal pathologies prior to prior
to SARS-CoV-2 infection;

- Refusal to participate in the study / refusal to process personal data;

- Pregnancy or breastfeeding;

- Addiction to alcohol or drugs in previous years;

- Use of other probiotics during the trial;

- Use of antibiotics during the trial and in the previous 30 days;

- Substantial change of diet during the trial;

- Participation in another clinical study in the previous 30 days or previous
participation in this same trial;

- Known intolerance/hypersensitivity to the investigational drug or to the excipients
of the placebo formulation