A tragic case report has shed light on the potential dangers of probiotics, highlighting a rare instance where a man died from a bloodstream infection triggered by a probiotic supplement. This type of infection, known as probiotic-related bacteremia, is a known risk associated with the use of probiotics, which are live microorganisms intended to benefit the body by replenishing the gut microbiome.
While probiotic-related infections are uncommon, individuals with weakened immune systems or gastrointestinal abnormalities may be at an increased risk. Previous case reports have documented instances where hospitalized patients developed bacteremia after receiving probiotics. Moreover, more detailed studies, including one published in 2019, have identified genetic evidence linking specific bacteria within a probiotic to patient infections.
In the recent case, a genetic analysis confirmed that bacteria from a probiotic supplement were responsible for the fatal infection in a 70-year-old man residing in Japan. The man had a complex medical history, which likely increased his susceptibility to this rare occurrence. He was initially admitted to the emergency room after collapsing at home, presenting with severe metabolic acidosis, a condition where acid builds up in the blood. This condition was attributed to a lung infection, kidney injury, and potentially heavy drinking due to his history of alcohol dependence.
Further testing revealed the man was infected with SARS-CoV-2, the virus responsible for COVID-19. He was subsequently transferred to an intensive care unit and received various treatments, including breathing support, blood thinners, steroids to combat inflammation, and tocilizumab, which blocks an inflammatory protein. Additionally, antibiotics were administered to address a suspected bacterial infection, which was later confirmed.
However, the antibiotics caused diarrhea, leading to the prescription of a probiotic containing a strain of Clostridium butyricum, a widely used and generally considered safe probiotic. Studies suggest that C. butyricum is found in the intestines of approximately 20% of healthy individuals. As a supplement, it is believed to create an unfavorable environment for pathogens in the gut while promoting the growth of beneficial bacteria that aid in digestion and reduce inflammation.
Despite its generally safe profile, in this case, the probiotic turned detrimental. The man, after a month in the hospital and subsequent rehabilitation, developed fatigue, swelling, and severe abdominal pain. Imaging revealed a dangerous lack of blood flow to his intestines. Upon investigating these symptoms, a blood sample was taken, and it was discovered that C. butyricum bacteria were present. Blood is typically sterile, indicating a bloodstream infection.
A thorough genetic analysis of the bacteria confirmed that it was identical to the strain found in the probiotic supplement. Unfortunately, the man rapidly developed multi-organ failure, and surgery was deemed impossible due to his unstable condition. He eventually succumbed to the infection and passed away on the 60th day of hospitalization.
This case report and others like it raise concerns about the safety of widely accepted probiotic products, particularly in individuals with underlying medical conditions. It is important to note that probiotic-related bacteremia is more commonly observed in older patients with weakened immune systems, chronic illnesses, or specific conditions like chronic kidney disease, rheumatoid arthritis, or gastric cancer. In this case, the patient’s age and medical history, including smoking, colon cancer, high blood pressure, heart disease, and the administration of a steroid to treat his COVID-19 infection, likely contributed to his susceptibility to the infection.
While probiotics are frequently prescribed for various gastrointestinal symptoms and conditions, this case highlights the potential for severe adverse events, albeit rare, and emphasizes the need for careful consideration and individual risk assessment before using these products.
