Probiotics
Probiotics are preparations of live microorganisms, usually lactobacilli and bifidobacteria, taken by mouth. They transiently populate the gut, compete with less desirable organisms, and support the barrier and immune functions of the intestinal lining. They are used over the counter for general digestive comfort and as immune support, particularly around courses of antibiotics.
They are taken with food, which buffers stomach acid and improves the chance that the organisms reach the intestine alive. Antibiotics kill the bacteria in the capsule as readily as those in the gut, so the two are separated by about two hours when both are being taken. Mild gas or bloating in the first days is common and usually settles. Refrigeration is required for some products; the label decides.
Persistent diarrhoea, fever, or abdominal pain that does not settle should be assessed rather than treated with more probiotics. Anyone with a seriously weakened immune system, a central venous line, or recent major gut surgery should see a doctor before using live-organism products at all.
Reference information, not medical advice. Discuss any change with your doctor.