- taking probiotic supplements at enrollment; - taking antibiotics for a reason other than covid-19 at enrollment; - allergies to soy, lactose, yeast, maltodextrin, vitamin c, potato starch, magnesium stearate, hypromellose or titanium dioxide; - has a chronically weakened immune system (aids, lymphoma, chemo-radio- corticosteroid therapy, immunosuppressive pathology); - was treated with chemo-radio-corticosteroid therapy in the last 6 months; - has active cancer; - taking immunosuppressive drugs (e.g. anti-rejection treatment after organ transplant); - already participating in another clinical trial; - is pregnant, expects to become pregnant in the next few months or is breastfeeding; - has any other condition that would prevent safe participation in the study.

- taking probiotic supplements at enrollment; - taking antibiotics for a reason other than covid-19 at enrollment; - allergies to soy, lactose, yeast, maltodextrin, vitamin c, potato starch, magnesium stearate, hypromellose or titanium dioxide; - has a chronically weakened immune system (aids, lymphoma, chemo-radio- corticosteroid therapy, immunosuppressive pathology); - was treated with chemo-radio-corticosteroid therapy in the last 6 months; - has active cancer; - taking immunosuppressive drugs (e.g. anti-rejection treatment after organ transplant); - already participating in another clinical trial; - is pregnant, expects to become pregnant in the next few months or is breastfeeding; - has any other condition that would prevent safe participation in the study.