Long-term use of Lacticaseibacillus paracasei N1115 from early life alleviates high-fat-diet-induced obesity and dysmetabolism in mice.

Obesity has become one of the most serious public health problems worldwide, and an increasing number of studies indicate that the gut microbiota can affect host metabolism. Therefore, the present study was conducted to evaluate whether long-term use of probiotics can alleviate host obesity and metabolism by altering gut microbiota. The high-fat diet (HFD) starting from weaned period led to higher levels of visceral fat and a significantly heavier liver in male mice. Moreover, HFD resulted in disorders of glucose and lipid metabolism, changes in insulin-resistance indices (IR), and an increase in serum insulin and leptin in mice. Of note, 15 weeks use of Lacticaseibacillus paracasei N1115 decreased visceral fat, liver weight, serum levels of insulin and leptin, and IR and alleviated lipid dysmetabolism. HFD resulted in a significant increase in the relative abundance of Bilophila, Lachnoclostridium, and Blautia and may decrease the faecal short-chain fatty acid (SCFA) levels in mice; in turn, treatment with the potential probiotic strain L. paracasei N1115 protected mice from these negative effects. HFD significant impaired the physiology of the host especially in male mice and dramatically changed the composition of host gut microbiota. However, the use of potential probiotic strain, such as L. paracasei N1115, may prevent these impairments due to HFD via effecting the host gut microbiota and SCFA.