The research, published in the Journal of Functional Foods, investigated the potential anti-obesity activity of two strains of lactic acid bacteria (LAB) and their soy milk fermented products – finding that consumption both strains improved measures of obesity in an animal model.
Led by Bao-Hong Lee from the National Taiwan University, the research team tested two fermented soy milk products – containing Lactobacillus paracasei subsp. paracasei NTU 101 and Lactobacillus plantarumNTU 102 – on obesity and fat metabolism using rats fed a high-fat diet to induce obesity.
The results showed that both fermented products (referred to as SM101 and SM102) blocked the differentiation of fat precursor cell in culture models in addition to increasing circulating levels of the appetite supressing hormone leptin in rat models.
“It was demonstrated that SM101 and SM102 in soy-milk both effectively inhibited adipocyte differentiation, up-regulated lipolysis activity, and suppressed HR-LPL activity to decrease free acid accumulation,” explained the researchers.
The team said that both products also improved measures of blood lipids (dyslipidemia) and increased serum levels of serum leptin in rats given a high-fat diet (HFD).
“These effects may be the result of L. paracasei subsp. paracasei NTU 101 and L. plantarum NTU 102 converting isoflavones into daidzein and genistein, thereby attenuating HFD-induced obesity,” suggested Lee and his colleagues.
Research details
Lee and his team noted that lactic acid bacteria in the form of Lactobacillus casei has been previously suggested to have beneficial effects on insulin resistance in high-fat diet induced obese mice. They also noted that several studies have reported that soy milk may also prevent obesity in obese animals.
“However, the anti-obesity and hypolipidemic activities of Lactobacillus fermented soy milk in HFD-induced animals remain unknown,” they said.
As a result, the new study set out to investigate the effect of L. paracasei subsp. paracasei NTU 101- and L. plantarumNTU 102-fermented soy milk on the prevention of obesity related conditions in HFD-induced Wistar rats – and to evaluate the activity of fermented products in inhibiting preadipocyte differentiation.
“Results indicated that the inhibition of 3T3-L1 differentiation and the accumulation of free fatty acids markedly increased in rats treated with SM101 and SM102,” they explained.
“Moreover, the up-regulation and down-regulation of lipolysis and heparin-releasable lipoprotein lipase, respectively, were observed in the 3T3-L1 adipocytes of the SM101 and SM101 groups, and these effects of SM101 and SM102 were greater than unfermented soy milk (USM),” they said.
Lee and his team also said that SM101 and SM102 both improved obesity in the rats fed with a high-fat diet and that this improvement was stronger than that observed for USM.
Source:Journal of Functional Foods
Published online ahead of print, doi: 10.1016/j.jff.2013.01.040
“Anti-obesity activity of Lactobacillus fermented soy milk products”
Authors: Bao-Hong Lee, Yi-Hsuan Lo, Tzu-Ming Pan