Probiotic supplements increase the diversity of intestinal bacteria in extremely preterm infants Extremely preterm infants can suffer from a life-threatening inflammation of the gut. A new clinical study has shown that supplements of a lactic acid bacterium may have positive effects by increasing the diversity of intestinal bacteria in these infants. The study has been led by researchers at Linköping University, Sweden, and published in the scientific journal Cell Reports Medicine. A litre of milk weighs a kilogram. Most infants who are born extremely prematurely weigh less than that. An infant who should have developed and grown for three more months in the protective environment of the mother's womb is, of course, extremely vulnerable.