Expert reaction: Could probiotics be an exciting answer to childhood obesity?

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A study which suggests probiotics may enhance weight loss in obese children has been scrutinised by experts who say despite its limitations the results are 'exciting'.

The findings of the study "Effect of Probiotics intake on obese children", presented last week at the 58th Annual European Society for Paediatric Endocrinology Meeting in Austria, state that a cocktail of Bifidobacterium longum, Lactobacillus bulgaricus and Streptococcus thermophilus may help obese children lose weight and reduce their risk of future metabolic conditions, including type 2 diabetes and heart disease.

In the study, Professor Rui-Min Chen and colleagues at Fuzhou Children's Hospital of Fujian, China, conducted a randomised, double-blind trial of probiotic effects on the health of obese children, aged 6-14 years old. All 54 study participants were following a reduced-calorie diet combined with an exercise regime.

The children's body weight and markers of metabolic health (blood lipid, blood glucose, insulin and inflammatory markers) were measured before and at the end of the 12 week study.

Delegates at the meeting were told children treated with probiotic supplements lost "significantly more weight" and had lower levels of markers that indicate poor metabolic health.

Prof Chen said: "Our findings suggest that probiotic supplementation may help with weight loss and improve metabolic health in obese children, and that this may be an effective strategy for the prevention and treatment of obesity in the future."

He admitted that more work was needed to confirm these findings as the number of participants was small and limited to the Fuijan area, therefore the team plans to conduct larger trials examining the effect of probiotics on the metabolic health of obese children.

Expert response

Dr Harriët Schellekens, a molecular and behavioural pharmacologist investigating the diet-microbiota-gut-brain axis at the University College Cork, says: “The fact that this was shown in obese children is exciting, as childhood obesity is a serious concern which needs early intervention to prevent long-term health problems.

"It is very promising that only 12 weeks of supplementation of the probiotic cocktail was able to reduce Body Mass Index (BMI) and also led to the improvement of other metabolic markers of obesity, including a reduction in fasting glucose levels.

“This reinforces the concept of the link between the gut microbiome and metabolic disease, which is a growing area of obesity research."

However, she points out that the study does not investigate if the probiotic on its own has any benefits and it is likely only enhancing the effect of caloric restriction and increased exercise thus the probiotic does not cure obesity. 

"It will also be interesting to see if the probiotic effect size is independent of the amount of caloric restriction and/or amount of exercise."

Prof Kim Barrett, Distinguished Professor of Medicine at the University of California San Diego, and Editor-in-Chief of The Journal of Physiology, points out that the treatment and control groups were well-matched but points out that statistical significance doesn’t necessarily mean biologically significance, so the numbers need to be seen.

“The authors propose that the length of treatment may account for the fact that they saw a beneficial effect when other such trials have failed, but again we need to know what the size of the effect is, which isn’t given in the abstract. 

"I look forward to seeing the results of this work in the peer-reviewed literature as well as attempts to replicate it in larger cohorts of children and in other settings.”

Prof Glenn Gibson, Professor of Food & Nutritional Sciences, University of Reading, says the probiotics used are not well described and two of the three bacteria used are not usually considered to be probiotics - S. thermopilus and L. bulgaricus are yoghurt starter cultures.  Therefore he argues that if there is any probiotic effect then it must be due to B. longum.

He also points out a number of limitation including that no faecal microbiology seems to have been done, which is essential if the authors wish to claim probiotic effects.

He also worries whether EU legislation will ever allow these sorts of important health messages to ever reach consumers.

“One wonders, however, whether legislation to allow these important health messages on the gut microbiome will ever be unravelled to the extent that consumers can actually be made aware of realistic benefits?  This is the main conundrum in the field – the science is progressing extremely well but communication paths to the people who can benefit from good science is poor and needs addressing.”