Dose-related effects of early-life intake of sn-2 palmitate, a specific positionally distributed human milk fatty acid, on the composition and metabolism of the intestinal microbiota

sn2 Palmitate in human milk plays an important role in the physiological health of infants by reducing mineral loss, improving stool hardness, and relieving constipation. Also, sn-2 palmitate modulates intestinal microbiota. However, it remains unclear whether the effects of sn-2 palmitate on infant gut microbiota are dose-dependent. In this study, we investigated the effects of low, medium, and high doses (600, 1,800, and 5,400 mg/kg body weight, respectively) of sn-2 palmitate on the structure, composition, and metabolic function of intestinal microbes in mice. Our results showed that high doses of sn-2 palmitate significantly modulated α- and β-diversity of the intestinal microbiota. The relative abundance of Lachnospiraceae_NK4A136_group decreased with increasing doses of sn-2 palmitate. In contrast, the abundances of Bacteroidetes phylum, Bacteroides, uncultured_Lachnospiraceae, and uncultured_Muribaculaceae were positively correlated with sn-2 palmitate doses. The number of genes predicted encoding autophagy-yeast, phospholipase D signaling pathway, and pentose and glucuronate interconversion metabolic functions of intestinal microbiota increased with increasing doses of sn-2 palmitate. In addition, low and medium doses of sn-2 palmitate significantly upregulated the arginine and proline metabolic pathways, and high doses of sn-2 palmitate significantly increased purine metabolism. Our results revealed that the effects of sn-2 palmitate intake early in life on the composition and metabolism of the intestinal microbiota of mice showed dose-related differences. The study is expected to provide a scientific basis for the development of infant formulas.

Absorption of 1,3-dioleyl-2-palmitoylglycerol and intestinal flora profiles changes in mice

The purpose of this study was to investigate the digestion and absorption of 1,3-dioleyl-2-palmitoylglycerol (OPO) and its effects on mineral absorption and intestinal flora in vivo. Fatty acids and mineral faeces were measured using gas chromatography-mass spectrometry and inductively coupled plasma mass spectrometry, respectively. The intestinal flora composition was assessed using high-throughput 16S rRNA sequencing. After 4-week feeding experiment, the apparent absorption rate of calcium in O group (mice fed with OPO) was 48.54 ± 0.21%, which was significantly higher than that in Z group (mice fed with mixed vegetable oil), the percentage of palmitic acid in serum of the O group mice was significantly higher. Compared with Z group, the mean relative abundance of Bifidobacteriaceae and Lactobacillaceae in the O group mice was higher. These results show that OPO can promote the absorption of fat and calcium, promote the growth of beneficial bacteria.