A randomised, double-blind, placebo-controlled trial was performed to investigate the health benefits of probiotic bacteria in infants when delivered in a follow-on infant formula. The study was conducted in Fuyang (Anhui Province, China) during winter and enrolled 192 healthy infants aged six to 12 months. Infants received one of three follow-on formulae daily for 12 weeks: supplemented with 106 cfu/g Bifidobacterium animalis subsp. lactis HN019 (n=64); 106 cfu/g Lacticaseibacillus rhamnosus HN001 (n=64); or without added probiotics (n=64). The primary endpoint was physician-confirmed bacterial or viral infections during the treatment period. Secondary endpoints included parentally reported (confirmed and unconfirmed) infections; antiviral or antibiotic treatments, and hospitalisation; stool frequency and consistency; infant growth; infant temperament; and adverse events. There were 8 cases of confirmed infection, all upper respiratory tract infections (URTIs). Confirmed URTIs were observed in 9.4% of the control group, compared to 3.1% in the HN001 group (P=0.273), and 0.0% in the HN019 group (P=0.028). A similar trend was observed for parentally reported URTIs, with 25.0% in the control group, compared with 14.1% in the HN001 group (P=0.119) and 9.4% in the HN019 group (P=0.019). No infants in the HN019 group were prescribed antibiotics or antivirals, compared with 3 (4.7%) in the HN001 group and 7 (10.9%) in the control group. No infants required hospitalisation. The probiotic-containing formulae were well-tolerated: there were no cases of diarrhoea or differences in stool frequency or characteristics, no differences in infant growth or temperament, and no treatment-related adverse events. This study directly compared the benefits of two different probiotics when added to follow-on infant formula at 106 cfu/g and consumed over a 12-week period. While HN001 showed trends toward reduced infections, HN019 showed better performance in terms of significantly reduced incidence of both physician-confirmed and parentally reported URTIs, and antibiotic/antiviral use compared to a control in Chinese infants.

The trial is registered at ClinicalTrials.gov (NCT01724203).