The presence of 6′-sialyllactose (6′SL) in milk during exclusive suckling influences gut microbiota composition and improves adult attention and memory functions, which was suggested by Tomasi and colleagues from the Centre for Behavioural Sciences and Mental Health, Italy and the Nestle Research, Switzerland. The findings of their preclinical study were presented at the 52nd Annual Meeting of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) held in Glasgow, Scotland, in June 2019.
Human milk oligosaccharides (HMOs) are the third most abundant components of human milk. HMOs, especially, the sialylated ones, are proposed to be one of the mediators for the beneficial effects of breastfeeding on neurodevelopment and related adult brain functions. However, the mechanisms of action for this effect of sialylated HMOs are not fully understood.
In this study, Tomasi and colleagues evaluated the role of normal levels or absence of 6′SL in modulating composition of gut microbiota and cognitive functions in adult offspring. The study comprised 4 groups of wild type (WT) mice and mutant (MUT) mice that received milk with and also without 6′SL. As opposed to the WT mice, MUT mice (both parents and their offspring) cannot produce 6′SL due to gene mutation. The researchers evaluated spatial and recognition memory and attention, along with gut microbiota composition and function, once the animals reached adulthood.
The study found a reduction in spatial and recognition memory and attention in the WT mice and MUT mice that received milk without 6′SL, as reported by the research team in a previous study. The presence and absence of 6′SL in milk have shown an effect on the abundance of several species of Actinobacteria phylum and Bacteroides genus. However, the preliminary results indicate no effects on the microbiota diversity.
The researchers concluded that the presence of 6′SL in milk during exclusive suckling influences gut microbiota composition and is associated with improved attention and memory functions later in life.
Source: Tomasi F, Battistoni M, Pisa E, Hauser J, Macri S. Presence of 6'SL in pre-weaning milk or mutation of St6gal1 gene modulated microbiota composition and improved cognitive functions in adult offspring. Abstract presented at the 52nd Annual Meeting of ESPGHAN; June 5-8, 2019; Glasgow, Scotland.