Yoghurt story 'hard to swallow'

"A headline in today’s Daily Mail stated: 'Yoghurt drinks could beat bugs that pile the weight on.' It said scientists have shown that 'bugs that live in our stomachs could be causing us to get fat.' The newspaper said the research could lead to probiotic yoghurts that can combat weight gain.

The newspaper’s claim about probiotic yoghurts is misleading. In fact, the study examined the effect of a change in diet on gut flora (micro organisms found in the gut) and weight in mice...

A Western diet caused mice to gain weight and changed the microbes in their gut. Transplanting the gut flora from these mice to healthy mice led to significant weight gain compared with mice that received gut flora from mice on a non-Western diet, even though there was no increase in food consumption...

The study did not examine the effects of yoghurt or other probiotics on weight, as some news reports imply. Nor does it suggest that a probiotic yoghurt will soon be available that can aid weight loss. This extrapolation of the results is likely to have been based on the finding that a Western diet alters the microbial constituents of the gut. Researchers found that when the mice’s diet was changed from a low-fat diet to a Western-style high-fat, high-sugar diet, the component bacteria in their gut changed quickly and considerably. Stating that a probiotic yoghurt could 'combat weight gain', (sic) and including a picture of a normal yoghurt drink next to the article, could mislead people."