Effects of Lactation Lactoferrin Deficiency on Intestinal Microbiota in Different Mice Models.

Background/objectives: The establishment of early gut microbiota is crucial for host health. Lactoferrin (LF), which is present in breast milk, positively impacts gut microbiota composition. However, the effect of lactation LF on the establishment and composition of early gut microbiota in different disease models in adulthood remains unclear.

Methods: Lactation-LF-deficient mice were established using systemically LF-knocked-out maternal mice. This study assessed the maturity of the gut microbiota in LF feeding-deficient mice in relation to age and changes in the gut microbiota in adult high-fat diet (HFD)-induced obesity, dextran sodium sulfate (DSS)-induced acute colitis, and chronic unpredictable mild stress (CUMS)-induced depression models.

Results: Compared to LF intake during lactation, LF deficiency during lactation increased the abundance of potentially pathogenic bacteria in the gut, resulting in abnormal microbial maturation. LF intake during lactation aggravated gut microbiota dysbiosis induced via HFD, DSS, and CUMS in adulthood and may change the function of , , , , , and . Comparing the different models revealed that bacteria that were jointly upregulated via HFD and DSS exhibited increased levels of inflammation and oxidation. LF deficiency during lactation may weaken the association between an HFD and inflammatory bowel disease (IBD). The changing trends in many gut microbes caused by DSS and HFD were opposite to those that changed with age.

Conclusions: Lactoferrin deficiency increases the abundance of potential pathogens and disrupts microbial maturation. This lack of LF exacerbates dysbiosis in models of obesity, colitis, and depression. Regulating the gut microbiota according to the rules of microbial succession during the maturation process of gut microbiota may improve gut microbiota dysbiosis in patients with obesity and IBD.