Nope, not even close, although I doubt it will stop big food from marketing Activia yogurt and others as a solution for expanded waistlines.
According to the World Health Organization, probiotics are:
“Live microorganisms which when administered in adequate amounts confer a health benefit on the host”.
Over the past few years there has been a huge surge in the addition of specific probiotic cultures into various fermented milk products, such as yogurt. For the most part the marketing push behind these products has focused on the potential for regulating digestive function (i.e. Jaime Lee Curtis commercial). However, due to a recent study in the European Journal of Clinical Nutrition, I forsee a swift change in gears towards billing various fermented milk products as the panacea for obesity.
Unfortunately, while I don’t think the evidence in this one study is overly convincing, lack of evidence has rarely stopped companies from making exaggerated claims.
In the study, conducted in various centres throughout Japan, a total of 86 subjects who were mostly overweight (BMI range from 24.2 – 30.7kg/m2) were asked to ingest 200 g/day of either fermented milk with Lactobacillus gasseri SBT2055 probiotic culture or a control fermented milk for a duration of 12 weeks. Both groups were asked to maintain their regular lifestyle (diet and physical activity). This particular probiotic, which originates naturally in human intestine, was chosen as recent evidence suggested that Lactobacillus gasseri SBT2055 ingestion lowered adipocyte enlargement caused by a high-fat diet in rats (the importance of which, we have recently discussed).
So what happened after the 12 weeks in this study that might make Danone execs dizzy with excitement?
The group ingesting the active fermented milk (including said probiotic culture) lost a whole 1.1 kg of body weight in 3 months (in contrast to no change in control group). While the authors also report miniscule changes in body fat percentage (<1%), since they measured body fat using bioelectrical impedance, this number is essentially meaningless. Lastly, visceral and subcutaneous abdominal fat were also measured in this study and while reductions in both variables were statistically significant, the clinical significance of losing 5.6 cm2 in visceral fat or 7.4 cm2 in subcutaneous fat is VERY questionable.
Nevetheless, it should be noted that there is potential for something to be happening here – obviously not a very strong effect, but something. Although the data is not presented in the study (not sure why), the authors assure us that the dietary patterns or physical activity patterns of either the active or control fermented milk groups did not change throughout the study. Of course when dealing with a 1kg difference over a 12 week span just a few calories in the right direction on a daily basis could lead to such a change.
Take home message:
I’d certainly hold my breath for more evidence in this area, and for the time being would caution against binging on yogurt jam-packed with probiotic cultures to lose weight – remember yogurt has a bunch of calories!
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Kadooka, Y., Sato, M., Imaizumi, K., Ogawa, A., Ikuyama, K., Akai, Y., Okano, M., Kagoshima, M., & Tsuchida, T. (2010). Regulation of abdominal adiposity by probiotics (Lactobacillus gasseri SBT2055) in adults with obese tendencies in a randomized controlled trial European Journal of Clinical Nutrition DOI: 10.1038/ejcn.2010.19