Do Probiotics Have More Going For Them Than Just a Good Story?

Recognition of the important role of the gut microbiome in digestion and metabolism (and possibly the neuroendocrine pathways involved in regulating ingestive behaviour) have spawned a whole industry of probiotics, enthusiastically marketed with often hyperbolic health claims.

How good a use is this of anyone’s money?

Not much, according to a meta-analysis by Amir Hadi and colleagues, just published in Clinical Nutrition

The researchers summarized data from nine randomised controlled trials that examined the effect of pro-/synbiotics on a wide range of metabolic parameters. Six used probiotics and three used synbiotics (formulated combinations of pre- and probiotics) in their intervention arm.

The studies were rather small (only 344 participants (176, intervention group; 168, control group) were included in the meta-analysis) and notably of short duration (between three weeks and seven months).

Overall, there was no discernible effect on body weight, BMI, waist circumference, fasting glucose, fasting insulin, HOMA index, TG, LDL-C, HDL-C, with only a minor difference in total cholesterol levels in studies of longer duration.

To be fair, there was some heterogeneity in outcomes based on the number of probiotic strains, the intervention duration, and participants’ characteristics, however, even the greatest effects seen in individual studies, were nothing to write home about. 

At this time, the consumption of pro-/syn-biotics to improve metabolism appears to be based more on hope (and a good story) than on any notable evidence.

Berlin, D