Abstract
The novel coronavirus (SARS-CoV-2) binds to Angiotensin II-
Converting-Enzyme (ACE2) on cell membrane, allowing the virus entrance,
replication and host commitment. ACE2 is expressed by different cell
types, which include the enterocytes in the gut. Such cells are highly
active in metabolism, as they internalize molecules to be processed and
used by the organism. ACE2 disruption leads to intestinal inflammation
and impairs tryptophan absorption by enterocytes. Low tryptophan levels
are also associated with intestinal inflammation and decreased synthesis
of serotonin, affecting motility. During postnatal development,
breastfeeding is the first source of nutrition, and tryptophan is milk
component, together with mucin1, growth factors and secretory
immunoglobulin A (sIgA). By reviewing the pathways and effects of
SARS-CoV-2 and the gut responses to early weaning, we suggest that it is
important to evaluate the benefits of maintaining breastfeeding during
SARS-CoV-2 infection, as it might be essential to protect newborns from
gastrointestinal-associated disorders.