The manipulation of the gut microbiota is complex and may cause bacteria-host interactions. Though<unk> s are considered safe, some have concerns about their safety in certain cases. Some people, such as those with immunodeficiency, short bowel syndrome, central venous catheters, and cardiac valve disease, and premature infants, may be at higher risk for adverse events. In severely ill people with inflammatory bowel disease, a risk exists for the passage of viable bacteria from the gastrointestinal tract to the internal organs (bacterial translocation) as a consequence of bacteremia, which can cause adverse health consequences. Rarely, consumption of<unk> s by children with lowered immune system function or who are already critically ill may result in bacteremia or fungemia (i.e., bacteria or fungi in the blood), which can lead to sepsis, a potentially fatal disease. Lactobacillus spp. have been suggested to contribute to obesity in humans, but no evidence of this relationship has been found.
Probiotic
Postbiotic
Prebiotic 
Anthelmintic
Cathartic
Antiparasitic
Toxoid
Antiseptic