Lactoferrin stimulates the expression of vitamin D receptor in vitamin D deficient mice

Vitamin D deficiency, a growing public health problem, is associated with elevated serum pro-inflammatory cytokines and gut microbial dysbiosis. Lactoferrin (LF), a strongly cationic glycoprotein, is an multifunctional components of milk. We explored the effects of oral administratation with LF (100 mg/kg and 1000 mg/kg) on intestine of vitamin D deficient mice. Our results showed that LF reduced the abundance of Oscillibacter, increased the proportion of Lachnospiraceae, Faecalibaculum and Lactobacillus. In addition, LF alleviated the elevated serum LBP, TNF-alpha, IL-6 and TGF-beta induced by vitamin D deficiency. Notably, we found the expression of vitamin D receptor significantly increased after LF supplement in colon of vitamin D deficient mice. At the same time, LF reduced the expression of TLR-4, inhibited the activity of NF-kappa B P65 and enhanced the expression of intestinal barrier proteins, including ZO-1, occludin, claudin-1 as well as E-cadherin in the colon of vitamin D deficient mice.