Development of new food products with components active against Helicobacter pylori - with purpose to improve gastric health in humans

Abstract: Gastric and intestinal disorders are common and costly human health problems worldwide. Helicobacter pylori are a gram-negative, pathogen bacteria and the most common cause of duodenal and gastric ulcer in the stomach the intestinal mucosa. Prolonged infection and colonization can lead to chronic gastritis and stomach cancer. H. pylori are present in the gastric and intestinal mucosa of half of the world population and a relation between infection and low socioeconomic status has been shown. Today the bacterial infection is treated with antibiotics and a proton pump inhibitor (e.g. Losec®). The interest in finding an alternative way of treating these bacteria is increasing, due to the risk of developing antibiotic resistance and high costs for medical drug treatments. Within Swedish research, a natural plant substrate, PYLOS, has been developed, which in laboratory tests and a clinical study, has been observed to inhibit adhesion and growth of H. pylori in the gastric and intestinal mucosa. The intention is to add the components of PYLOS to an existing food product in order to produce a functional food product effective against H. pylori infection. This master thesis is based on a collaboration project between four Swedish actors; University of Gothenburg, Food & Health Concept Centre (FHCC), Skånemejerier and the Swedish University of Agriculture Science. The purpose has been to produce a product originating from Skånemejerier, but with addition of raw material and extracts of the plant substrate PYLOS. Two types of food products were used; juices and fermented milks. The activity in the product against H. pylori has been verified with microbiological analyses as hemagglutination-inhibition, where anti-adhesion of bacterial lectins to sialic acid-glycosylated conjugates on the cell surface was tested, as well as analyses of inhibited bacterial growth. The effect of the plant substrate was also tested after product heat treatment. The results showed that PYLOS effectively inhibits H. pylori in juice products containing different fruit mixtures. Juice E, with its unique fruit composition, turned out to be the most effective product. Juice E (250 ml) totally inhibited the bacterial adhesion to erythrocytes diluted in a volume of 16-32 L and partially (about 50%) diluted in a volume of 32-256 L, depending on the bacterial strain tested. The analysis of bacterial anti-growth gave confirming results. However, PYLOS had lower inhibition capacity when added to fermented milk products. It is known that milk contains free sialylated oligosaccharides and sialylated glycoproteins. Theoretically, these can interfere with hemagglutination-inhibition tests. It is possible that sialylated milk compounds competed with sialylated saccharides present on erythrocytes resulting in a weaker inhibition of hemagglutination.