Patients who are severely immunocompromised or immunosuppressed do not have the ability to mount an appropriate response to any microbe that they come in contact with. Specialised cells in the intestine (M Cells & Peyers patches) are continually sampling the intestinal lumen for antigens (food or microbes). Microbes, even those that are normally neutral or considered beneficial, can sometimes cross the gut barrier and grow in the blood or in the internal organs where the nutrients are high and the competition for nutrients is low. Growth in these areas can cause septicaemia, fungemia, abscesses, myo-endocarditis (infection of the heart), or pancreatitis.
There may in fact be a benefit in taking probiotics for patients with severe immunosuppression, but the risk is also thought to be high in many circumstances. Because there is currently insufficient clinical evidence around this area, we would not recommend probiotics for individuals who are severely immunocompromised or immunosuppressed.
For further information about friendly bacteria and immunity, healthcare practitioners might wish to look at Probiotic Professionals.
This FAQ has been answered by Joanna Scott-Lutyens, BA (hons), DipION, Nutritional Therapist.