Daily probiotic yogurt consumption may improve energy metabolism and reduce body fat levels by up to 4%, say results of a placebo-controlled, double-blind cross-over clinical trial in Canada.
Yogurt containing the ‘novel probiotic’ strains Lactobacillus amylovorus or Lactobacillus fermentum for six weeks was associated with significantly reduced body fat mass, with the greatest reduction seen for L. amylovorus, according to findings published in the Journal of Functional Foods .
“Consumption of Lactobacillus amylovorus or Lactobacillus fermentum bacteria as probiotics may assist in reducing the development of obesity, since these bacteria may confer modifications to energy handling within the host,” wrote researchers from the University of Manitoba, McGill University, and Micropharma Limited in Canada.
“This creates a microbiome which favors fat oxidation over fat storage, by populating the gut with protective bacteria and preventing the proliferation of pathogenic bacteria, which may ultimately lead to a reduction in body adiposity and transformation of body composition.”
The strains were provided by Micropharma Limited and the company funded the study.
Gut health and obesity
The study adds to emerging body of science supporting the effects of gut microflora on metabolic factors and obesity.
In 2006, Jeffrey Gordon and his group at Washington University in St. Louis reported in Nature (Vol. 444, pp. 1022-1023, 1027-1031) 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, suggesting that obesity may have a microbial component.
Dr Gordon and his group recently pushed back the scientific boundaries even further in this area. In an ‘elegant’ study, the St Louis-based scientists reported that probiotics in a yogurt did not colonize the gut microflora when studied in identical twins, but additional study in mice revealed that ingestion of probiotic bacteria produced a change in many metabolic pathways, particularly those related to carbohydrate metabolism (Science Translational Medicine, Vol. 3, 106ra106).
According to the FAO/WHO, probiotics are defined as "live microorganisms which when administered in adequate amounts confer a health benefit on the host".
Led by Peter Jones from the University of Manitoba, the researchers recruited 28 healthy but overweight participants for their study. The subjects were randomly assigned to consume yogurt containing either L. amylovorus (1.39 billion colony-forming units, CFU), L. fermentum (1.08 billion CFU) or no additional ingredient (control) for 43 days.
Results showed that total fat mass decreased by 4, 3 and 1% for the L. amylovorus, L. fermentum, and control groups, respectively. These changes were statistically significant compared to baseline values. However, no changes were observed in body weight and composition between the groups.
In addition, changes in the gut microflora were observed in both Lactobacilli groups. L. amylovorus was associated with a decrease in levels of Clostridial cluster IV (Clep).
“The reduction in the gut microbial abundance of Clep in response to L. amylovorus yogurt feeding suggests that fat loss may be facilitated through a decreased gut microbial abundance of Clep, as total fat loss was reduced by the greatest degree with L. amylovorus,” they wrote.
“Present results suggest that both LF and LA probiotic treatments are capable of inducing shifts in body composition.”
Source: Journal of Functional Foods
Published online ahead of print, doi: 10.1016/j.jff.2012.09.001
“Lactobacillus fermentum and Lactobacillus amylovorus as probiotics alter body adiposity and gut microflora in healthy persons”
Authors: J.M. Omar, Y-M. Chan, M.L. Jones, S. Prakash, P.J.H. Jones