Impact of formate supplementation on body weight and plasma amino acids

Current nutritional recommendations are focused on energy, fat, carbohydrate, protein and vitamins. Less attention has been paid to the nutritional demand of one-carbon units for nucleotide and methionine synthesis. Here we investigate the impact of sodium formate supplementation as a nutritional intervention to increase the dietary intake of one-carbon units. A cohort of six female and six male mice received 125 mM sodium formate in the drinking water for three months. A control group of another six female and six male mice was also followed up for the same period of time. Tail vein blood samples were collected once a month and profiled with a haematology Analyser. At the end of the study blood and tissues were collected for metabolomics analysis and immune cell sorting. Formate supplementation has no significant physiological effect on male mice. Formate supplementation has no significant effect on the immune cell counts during the intervention or at the end of the study in either gender. In female mice however, the body weight and spleen wet-weight were significantly increased by formate supplementation, while the blood plasma levels of amino acids were decreased. Formate supplementation also increased the frequency of probiotic bacteria in the stools of female mice. We conclude that formate supplementation induces physiological changes in female mice.