| Abstract [eng] |
Diabetes mellitus is a type of metabolic disorder and a major worldwide unresolved health challenge that has been affecting population above 40 - 50 years. It is characterized by persistent high blood glucose levels. It increases the risk of developing other chronic conditions while reducing quality of life and increasing mortality. Modern approach could be used in treatment of diabetes, like functional food by lacto-fermentation. Probiotics have been reported to have a positive impact on the metabolic control of patient’s diabetes. During functional food preparation process by lactobacillus bacteria, generation of new bioactive compounds could play an important role to inhibit key enzymes involved in carbohydrate metabolism and blood glucose levels regulation. These compounds can also provide antioxidant protection against oxidative stress and inflammation. We aimed to evaluate the administration of functional food fermented by probiotics in treatment of diabetes. For preparation of functional food, isolation of different lactic acid bacterias form local fermented Lithuanian food products were procured. For selection of suitable strain for lacto-fermentation in beetroot juice different assay kits like β-Glucosidase activity, total antioxidant activity, DPP-IV, α-Amylase, α-Glucosidase inhibitory ability was used. Fermentation was optimized by changing time and temperature. HPLC-MS was used to identify potential anti-diabetic bioactive compounds. The molecular identification of bacterium was assisted by 16s rRNA and later confirmed by whole genome sequencing. At last, genome analysis was used to ascertain the antimicrobial susceptibility and antimicrobial resistant genes. Lastly, in in vivo studies, STZ-induced diabetic C57BL/6 mice were administered with lacto-fermented beetroot juice to determine how the fermented product works on hyperglycemia reduction. For the selection of probiotics, lactic acid bacteria were isolated from different fermented food sources. Among 160 isolated cultures, 18 strains were able to use beetroot as main source of energy and had great β-Glucosidase activity. In vitro test indicated that while 18 bacterial cultures lack inhibition activity of α-Amylase and α-Glucosidase enzymes, bacteria culture PN39 indicated potential to inhibit DPP-IV and antioxidant ability. Further work confirmed that the finest product optimal temperature and time for fermentation is 45 ᵒC for 72 h. HPLC-MS analysis determined that PN39 fermented sample compound variety is different than raw beetroot and dihydromyricetin has the greatest possibility to give anti-diabetic effect. 16s rRNA analysis and whole genome sequencing identified that culture is closely related to Lacticaseibacillus curvatus while also is safe to use in industry due to the lack of antibiotic resistance plasmid and genes. In vivo STZ- induced diabetic mice blood glucose levels and glucose tolerance test allowed to determine that PN39 fermented beetroot has an influence to reduce hyperglycemia. In conclusions, polyphenolic rich vegetable, red beetroot, has potential to become modern anti-diabetic product after lacto-fermentation. Further studies are however required to ascertain other metabolites in the fermented samples that may have been involved in the antidiabetic potentials displayed. The fermented product could be tested to identify its effects on gut microbiota modulation. Experiment with tissue could help to identify fermented product mechanisms, if it increases pancreas β cells viability, promotes β-cell regeneration, increases sensitivity to glucose or insulin, increases insulin production, reduces ROS formation and inflammation. |
