In recent times, nutrition has become one of the main health patterns due to disorders related to sedentary lifestyles and therefore consumers consider functional foods as an attractive solution.1 Among the main ingredients of functional foods are probiotics, food supplements based on live microbes that have beneficial effects on the host organism.2 Probiotic microorganisms include the lactic acid bacteria (LAB) group, which have several scientifically proven effects on human health, such as antimicrobial activity, immune enhancement and anti-cancer activity. Their probiotic activity derives from the molecules they produce, including polysaccharides, which are used not only as ingredients but also especially as food additives. The wide spectrum of applications of microbial polysaccharides is in fact due both to their properties as thickeners or filmogens and, above all, to their immunomodulatory properties, i.e. anti-cancer, anti-inflammatory or antimicrobial.3
Based on the above, the present work focuses on the structural elucidation of polysaccharides produced by Lactiplantibacillus plantarum, a gram-positive, mesophilic bacterium belonging to the LAB group, which colonises the human and animal gastrointestinal tract. L. plantarum possesses probiotic activity and therefore this bacterium is associated with several beneficial effects due to its ability to: produce antimicrobial molecules, modulate the immune system and strengthen the intestinal microflora.4 However, the probiotic activity of this bacterium is not fully associated with molecules whose structure and more general chemical nature is known. This is why the present work was based on the extraction, purification and structural characterisation of a polysaccharide expressed by this bacterium, with the aim of being able to associate a possible probiotic function with it.
