We know a lot about the live microorganisms that reside within us all, but we don't know everything – yet! There have certainly been plenty of studies over the years, and there continues to be more research. It's an exciting time that's for sure. Now we're hearing a lot about how gut bacteria may even be able to help with weight loss and weight management. This piece looks further into this to see how much truth there is in these claims.
When it comes to weight loss, it seems like every man and his blog has something to say on the issue. It's important therefore to be careful what you read. In this case, the probiotics for weight loss was taken from a study published by the British Journal of Nutrition. A team of researchers headed by Université Laval Professor, Angelo Tremblay, conducted the trial. Here’s what they found in a sentence:
Certain probiotics could help women lose weight and keep it off.
Not All Intestinal Flora Is Equal
Your intestinal flora is the interdependent bacteria which occur naturally in the gut. We all have it and we all need it for digestive health in particular. Not all intestinal floras are equal though. According to studies, it's different in obese individuals than that of thin people, which may be due to diet. A diet that is high in fat and low in fiber will encourage certain bacteria at the expense of other types. Professor Tremblay and his team wanted to look into this and see if probiotics could help to redress this imbalance in overweight or obese people. Here's a breakdown of that trial:
- Trial consisted of 125 overweight men and women
- Subjects underwent a 12-week weight-loss diet
- The diet was followed by a 12-week period aimed at weight maintenance
- Half the participants took two probiotics pills daily (Lactobacillus rhamnosus family)
- Second half of participants received a placebo
The researchers observed the weight loss totals after the 12-week diet period was over. Here are the results of that, which may surprise you:
- Women (probiotic group): average weight loss of 4.4 kg
- Women( placebo group): 2.6 kg
- Men (both groups) No change in weight loss were observed
The researchers can't explain why the probiotics had no effect on the men. One theory is that it might have been related to the dosage, or that the study period was just too short for results to materialize.
The researchers look at the groups again after the 12-week maintenance period.
- Women (both groups): continued to lose weight, avg. 5.2 kg per person
- Women (placebo group): lost twice as much weight over the 24-week study period.
Researchers also noted there was a drop in the appetite-regulating hormone leptin in the probiotic group of women. Even more interesting was the lower concentrations of the intestinal bacteria associated with obesity. Head researcher, Angelo Tremblay, thinks that probiotics alter the permeability of the intestinal wall. One idea is that this helps to keep certain proinflammatory molecules from getting into the bloodstream. This is what could help prevent the chain reaction that leads to glucose intolerance, type-2 diabetes and obesity .
There is more science out there that suggests certain bacterium strains seem to reduce fat mass more so than others . These are, in no particular order:
- Lactobacillus gasseri SBT 2055,
- Lactobacillus rhamnosus ATCC 53103,
- rhamnosus ATCC 53102
- Bifidobacterium lactis
Another scientific review paper assessed 82 previously published probiotic studies. What they concluded was that certain probiotics strains used as food supplements produced a definite anti-obesity effect . These strains include:
- (Lactobacillus) gasseri
- (Lactobacillus) plantarum
Perhaps the most recent trail on humans is the one published in December 2015. Like the others, this too looked encouraging, but also like the others was pretty small-scale.
This study involved 20 volunteers. They were all male and none of them was obese. The trial involved giving the men a strict high-calorie diet (avg. extra 1,000 calories daily). This went on for a four week period and the goal was to get the volunteers to gain body fat.
The scientists selected the participants at random and gave them either a probiotic supplement (VSL#3) or placebo each day to compare the effects. It seemed that probiotic supplementation provided some protection from body mass gain and fat mass gain.
The problem with this latest trial is that it was also small scale and for a short duration. The probiotic supplement maker also funded the study .
All the studies above are interesting, and they certainly look promising. However, none of them are conclusive evidence at this point, at least not from a true scientific perspective. To start with, they're all too short, and also leave some unanswered questions. As far as clinical trials go, the numbers of volunteers and the duration of these trials make them borderline irrelevant. The results that the probiotics have shown are undeniable, just not large scale enough to satisfy science at large. It doesn't help when other researchers disagree with, and debate the evidence either.
In healthy adults, taking probiotic supplements is considered safe. We also know that they are beneficial to human health in many different ways. Probiotics for weight loss, appetite suppression, and weight management also look promising. Whatever the science says, or doesn't say, people can still experiment on themselves. Anyone with weight problems might want to at least try taking certain probiotic supplements to see how they work with them and their condition.