The microbiologist: “Thanks to the probiotic it increases the absorption of vitamin D”

An underdiagnosed vitamin D deficiency can promote greater susceptibility to infections, including viral ones. Pregnant and postmenopausal women, obese children and adults, and people who abstain from direct sun exposure are the most at risk. However, “the absorption and bioavailability of vitamin D could be increased if the intake of the vitamin is combined with that of a probiotic. However, this is not true for all probiotics: in an in vitro study the cells of Lacticaseibacillus paracasei Dg showed a significantly greater ability, compared to the other strains tested, to solubilize cholecalciferol (one of the forms of vitamin D) in the aqueous phase. Based on the results of this experiment, L. paracasei Dg * was selected for the in vivo vitamin D bioavailability experiment in a mouse model. Administered in association with vitamin D3 once a day for a week, it resulted in an increase of about 50% compared to the control group in the serum concentration of vitamin D “. This was stated by Simone Guglielmetti, professor of Microbiology in the Department of Science for food, nutrition and the environment at the University of Milan and co-author of the Italian study, conducted by the Universities of Padua and Milan and recently published by the journal ‘Annals of Microbiology’. the lack of vitamin D, which “can lead to malfunctioning of the immune system, inducing greater susceptibility to infections, which in the Covid era is particularly relevant. Additionally, vitamin D is vital for maintaining bone health. Supplementing the diet with “fortified” foods and vitamin D supplements appears to be beneficial in several areas including fracture prevention in elderly women, reduction of gestational diabetes, low birth weight and preeclampsia in pregnancy “. The confirmation that the absorption of vitamin D represents a problem comes from the latest Aifa dossier, entitled ‘The use of drugs in the elderly population in Italy’, according to which cholecalciferol is the most used molecule: about 4 out of 10 women received at least one dose during 2019, with a value of 41.7% in the age group between 70 and 74 years. “Hence the idea of ​​the study – underlines Guglielmetti – to improve absorption of vitamin D, starting from the assumption that it is fat-soluble. And given that lactic acid bacteria can have biosurfactant, i.e. surfactant and emulsion-contributing properties, we tested six bacterial strains belonging to the Lactobacillaceae family in vitro to see if they could improve the bioavailability of vitamin D. Working on lactobacilli we focused on lactic bacteria present in probiotic products on the market. In particular, one of the most used species today is called Lacticaseibacillus paracasei which includes various strains: from the probiotic Shirota to L. paracasei Dg *, the latter the protagonist of the research. “During the study, groups of mice were treated with the bacterium probiotic L. paracasei Dg * (which in vitro had shown the greatest ability to solubilize vitamin D3), with vitamin D and vitamin D together with the bacterium, “in two conditions – again Guglielmetti – single dose or with a one week. The result went beyond the rosiest expectations: after a week of daily administration in association with vitamin D3, we recorded a 50% increase compared to the control group in the serum concentration of vitamin D. This result is in agreement with the initial hypothesis according to which the emulsifying capacity of the probiotic bacterium may be such as to favor the absorption and therefore the bioavailability of vitam ina D “. Next step to repeat the same human study. “If the conclusions of the murine study on humans were equally positive, in the future it could be advisable to associate the probiotic L.paracasei Dg * with vitamin D, which also brings benefits to the intestine especially for those categories that need constant integration of the vitamin. It is an already known probiotic bacterium, a food supplement that does not bring with it any negative effects, in accordance with the European Food Safety Authority (EFSA) and with the guidelines of the Ministry of Health on probiotics ” , concludes Guglielmetti.