Behind the scenes of infectious diarrhea: the role of microbiota

According to the WHO, diarrhea is currently defined as the passage of at least three loose or liquid stools per day. Recognizing that the joint presence of 2 criteria (frequency + consistency) is necessary, the frequent passing of formed stools (that is, of normal consistency) does not constitute diarrhea, nor does the passing of loose stools at a normal frequency, such as with breastfeeding babies.

However, while common in mild forms, diarrhea can be life-threatening. It was responsible for 1.6 million deaths in 2016, mainly among malnourished or immunocompromised children, or people living with HIV. ¹ The main cause of these deaths was severe dehydration associated with fluid loss due to the repeated passing of stools.

Most cases of acute diarrhea are due to infections from pathogenic bacterial, viral or parasitic microorganisms.^1-3