Probiotics are defined as live microorganisms that may offer a health benefit when taken in adequate amounts.

Beneficial effects of probiotics on regulating immune system function and preventing diarrhoea are increasingly supported by scientific evidence. A less studied area is the potential effect of probiotics on body weight.

Gut bacteria have been linked to how fat is stored, how glucose levels are regulated and even how hormones involved in making us feel hungry or full are regulated. The wrong mix of microbes could exacerbate problems in a person regulating how much food they eat and controlling their weight.

So the big question is can taking a probiotic supplement help with weight loss?  And the answer appears to be ‘yes’; at least according to a systematic review and meta-analysis of clinical trials. Twenty-five randomised controlled trials involving close to 2,000 people informed the review.

The trials were made up of a mixture of healthy adults, people with type 2 diabetes, people with high cholesterol or hypertension and people with non-alcoholic fatty liver disease. Most of the people were overweight or obese at the start of the studies.

All trials included both a group receiving either one or a combination of several probiotic supplements and another group receiving a placebo. The difference in weight loss between the two groups was in favour of the probiotic supplement with an additional 0.54 kg lost. This may not seem like a lot, but it represented additional weight lost compared to any other diet or physical changes the people were making.

Digging a bit deeper, it seemed that trials using multiple strains of probiotics gave a greater weight loss benefit. Furthermore, the longer the study ran for, the more likely that additional weight loss would be seen.  Because so many different strains of probiotics were used and the length of time they were taken varied, it is not possible to narrow in on which protocol may work best for weight loss.

Implications

A probiotic supplement or food is not some magical panacea for obesity. The findings from this review, however, give some validity to the theory that our gut microbes have some sway in controlling what we eat and how we regulate our weight.

There are just too many over-hyped ineffective weight-loss supplements that fill shelves, but at least for probiotics the case for their use has some validity.

Last Reviewed: 23/11/2019

Norman Swan Medical Communications



References

Zhang Q et al. Effect of probiotics on body weight and body-mass index: a systematic review and meta-analysis of randomized, controlled trials. Epub online May 5, 2016. doi: 10.1080/09637486.2016.1181156.