Probiotics and Weight Loss
Probiotics are microorganisms which are beneficial to the human host. These benefits can include improved digestion, increased immunity, enhanced energy levels, benefits to skin health, and, as new research suggests, perhaps even weight loss.
Do Probiotics Help You Lose Weight?
Although evidence remains preliminary, the small studies on the topic look relatively promising. As covered on the site last year, a Japanese study  published in 2010 showed a Lactobacillus probiotic to reduce abdominal fat by 4.6%, and subcutaneous fat by 3.3%. The trial recruited 87 overweight participants and randomly assigned participants a daily dose of fermented milk either with or without the probiotics, for a period of 12 weeks. The probiotic group given milk containing Lactobacillus gasseri SBT2055, showed significant decreases in body weight BMI, in waist circumference, and in the hips. Furthermore, the study seems to be fairly reliable – this was a multi-centre, double-blind, randomized, placebo controlled trial. Previous findings  from Kyushu University researchers showed the same Lactobacillus probiotic to reduce fat levels in animals.
In December 2010 scientists in Ireland found that another probiotic of the Lactobacillus genus could seemingly influence the fat composition of the host . Researchers engineered a specific strain of Lactobacillus to produce a specific kind of fatty acid, t10, c12 CLA. Mice fed the probiotic showed significant alterations to their fat tissues. This t10, c12 CLA molecule has already been associated with decreased body fat in humans and other animals, as well as having demonstrated ability to inhibit the growth of colon cancer cells.
Other previous studies include research into obesity following pregnancy where women were less likely to become obese after giving birth had they taken probiotics (Lactobacillus & Bifidobacterium strains) during pregnancy. A small study in 2008 found administration of acidophilus in rats to result in weight loss – the rats given the probiotic acidophilus showed increased levels of leptin, a protein found to decrease the appetite and increase the metabolism. And let us not forget the publication in 2006 which reported a clear difference in gut microbial populations between obese and lean people, suggesting a link between types of bacteria in the gut and obesity.
Prebiotics and Weight Loss
It is also worth noting that prebiotics, the food source for probiotics, have seen preliminary studies examining their role in weight management. Some studies suggest that prebiotics have a capacity to promote satiety, by increasing levels of the satiety hormone, glucagon-like peptide (GLP-1), or by reducing the production of ghrelin, a peptide which triggers the appetite.
Studies into probiotics and prebiotics are relatively small-scale for now, but the results so far look promising, and certainly exciting for our world today. The World Health Organisation states that ‘Rates of overweight and obesity are projected to increase in almost all countries, reaching 1.5 billion people who are overweight by 2015.- Supplements which could help to tackle this obesity epidemic in a natural way could therefore play a fundamental role in the future.
What’s the Verdict?
At the end of the day, evidence remains too sparse for firm conclusions to be made on the role of probiotics in weight loss. Taking a holistic approach and also looking at diet, fitness and exercise is certainly to be encouraged. If you want to try a high quality probiotic supplement, there is no harm in doing so; increasing research stresses the importance of topping up your body’s levels of friendly bacteria, for weight loss or not.
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*This article was a guest post by Soraya Janmohamed from Wren Labs.
Y. Kadooka et al., ‘Regulation of abdominal adiposity by probiotics (Lactobacillus gasseri SBT2055) in adults with obese tendencies in a randomized controlled trial’. European Journal of Clinical Nutrition, 2010, Vol. 64, No. 6, pp 636 – 643.
 Hamad, M., et al., ‘Milk fermented by Lactobacillus gasseri SBT2055 influences adipocyte size via inhibition of dietary fat absorption in Zucker rats’. British Journal of Nutrition, 2009, Vol. 101, pp. 716-724.
 Rosberg-Cody, E., ‘Recombinant Lactobacilli expressing linoleic acid isomerise can modulate the fatty acid composition of host adipose tissue in mice’. Microbiology, Dec 22, 2010 DOI: 10. 1099/mic.0.043406-0