Scientists from Duksung Women’s University and Mediogen Co., Ltd, in Korea report that mice fed a high fat diet and supplemented with Weissella cibaria MG5285 for eight weeks experienced significant improvements in a range of health measures, including benefits for body weight and liver health.
Writing in Food & Nutrition Research, the researchers also found that other lactic acid bacteria (LAB) produced significant benefits, notably Lacticaseibacillus rhamnosus MG4502, Lactobacillus gasseri MG4524, and Limosilactobacillus reuteri MG514, but the most effective strain was W. cibaria MG5285.
“This study demonstrated that the oral administration of LAB (L. rhamnosus MG4502, L. gasseri MG4524, L. reuteri MG5149, and W. cibaria MG5285) prevented body weight gain, improved glucose tolerance, and lipid metabolism, thereby preventing fatty liver disease in obese mice,” wrote the researchers.
“Among the four LAB strains, W. cibaria showed the most effective inhibition of obesity […] Hence, the study results offer significant insights into the anti-obesity effect of W. cibaria as a functional food source.”
Gut microbiota and obesity
The link between the gut microbiota and obesity was first reported in 2006 by Jeffrey Gordon and his group at Washington University in St. Louis, who found that microbial populations in the gut are different between obese and lean people, and that when the obese people lost weight their microflora reverted back to that observed in a lean person. This suggested that obesity has a microbial component (Nature, Vol. 444, pp. 1022-1023, 1027-1031).
A 2013 paper in Science (Vol. 341, Issue 6150), also led by Prof Gordon, found that transplanting gut bacteria from obese humans into germ-free mice leads to greater weight gain and fat accumulation than mice that were given bacteria from the guts of lean humans.
The findings showed that weight and fat gain is influenced by communities of microbes in the gut and their effect on the physical and metabolic traits of the host, leading to metabolic changes in the rodents that are associated with obesity in humans. However, the vast majority of bacteria linked to obesity (positively or negatively) have never been cultured.
This has led many research groups to explore if probiotics may help manage weight. A probiotic is defined as a “live microorganisms which when administered in adequate amounts confer a health benefit on the host” – FAO/WHO.
Study details
The Korea-based researchers fed mice a high fat diet (HFD) to induce obesity, and divided them into five groups: No supplements (control), or four groups with each separately receiving L. rhamnosus MG4502, L. gasseri MG4524, L. reuteri MG5149, or W. cibaria MG5285. A six group of animals were fed a normal (non-high fat) diet and acted as a second control group.
After eight weeks, the data showed that all four strains led to lower body weight, liver and adipose tissue weights, while glucose tolerance also improved, compared to the high-fat diet-only mice.
“In this study, glucose intolerance was confirmed in HFD-induced obese mice,” wrote the researchers. “However, four LAB strains significantly reduced blood glucose levels, especially in the W. cibaria-administered group, which substantially improved glucose metabolism.”
In addition, improvements in triglyceride, total cholesterol, and LDL cholesterol levels were recorded for all four probiotic groups. Pro-inflammatory cytokines also improved, said the researchers.
Improvements in liver health, and less fat accumulation in the liver were also reported for the probiotic-fed animals, they said. “These results indicate that all LAB strains used in this study have a beneficial effect on HFD-induced NAFLD [non-alcoholic fatty liver disease].”
In select tissue samples, the researchers found that mice receiving L. reuteri MG5149 or W. cibaria MG5285 had significantly expression of proteins linked to production of fat (lipogenic proteins).
“Among the Weissella genus, W. cibaria is the most prevalent species in kimchi and has been reported to have potential functional effects, such as antioxidant and anti-inflammatory effects,” wrote the researchers. “Despite the various benefits of W. cibaria, there are relatively few reports on its anti-obesity and hepato-protective roles. Therefore, this study suggests that W. cibaria may be a potential candidate for developing an anti-obesity functional food source.”
Source: Food & Nutrition Research
2021, 65: 8087, doi: 10.29219/fnr.v65.8087
“Weissella cibaria MG5285 and Lactobacillus reuteri MG5149 attenuated fat accumulation in adipose and hepatic steatosis in high-fat diet-induced C57BL/6J obese mice”
Authors: S-I. Choi et al.