Do probiotics help with weight loss?

Probiotics such as lactobacilli or bifidobacteria are considered to support weight loss. Are the microorganisms really an effective aid in weight loss?

The tasks of the microbiota include, for example, the fermentation of otherwise indigestible carbohydrates to short-chain fatty acids (SHFAs) such as propionate and butyrate, which are involved in maintaining the barrier function of the intestine, regulating the immune system and in various processes in energy metabolism. In addition, the bacteria of the microbiome compete with pathogenic germs for nutrient supply and binding sites on epithelial cells, thus contributing to pathogen defense.

Changes in the microbiome of diseased compared to healthy individuals have been found in various disease conditions. For example, the abnormality known as dysbiosis has been shown to be associated with irritable bowel syndrome, colon cancer, asthma, multiple sclerosis (MS), and metabolic syndrome. However, it must be qualified that these are mostly observational studies; whether the dysbioses were the cause or consequence of the disease is often unclear. Nevertheless, causal relationships have also been described: For example, transfer of the microbiome from MS patients resulted in MS-like encephalopathy in mice.

Obesity and microbiome

The fact that obesity, together with its cardiovascular and metabolic sequelae, is one of the most pressing health problems in industrialized countries is as well known as the difficulties in combating the excess pounds. Often there is a lack of motivation and stamina for sport and diet; sometimes, however, there is no (long-term) success despite the most intensive efforts. As one of the possible reasons for this – in addition to genetic aspects and environmental factors – connections with the microbiome are being discussed. Initial indications were provided by animal studies: after fecal transplantation, mice that had previously been raised germ-free were more likely to become overweight if they had received the transplant from an obese animal than if it had come from a normal-weight individual.

Indeed, differences in the microbiota of normal-weight and obese individuals have also been shown in observational studies in humans. In this context, it is interesting to note that the type and amount of short-chain fatty acids produced by fermentation depend on the composition of the microbiome; different bacterial species are differentially efficient in this regard. Bacteria systematically assigned to the division Firmicutes (e.g., the genera Enterococcus and Lactobacillus) are better food utilizers than bacteria of the division Bacteroidetes due to a divergent enzyme equipment. Since short-chain fatty acids are a significant energy carrier, consequently the microbiome composition influences the energy yield obtained from a given food portion. Fittingly, increased amounts of short-chain fatty acids have been found in the stool samples of obese individuals. However, data from animal experiments, according to which a high proportion of Firmicutes promotes obesity, while the proportion of Bacteroidetes is higher in normal-weight individuals, were not fully confirmed in humans. If this had been the case, shifting the ratio of Firmicutes to Bacteroidetes toward Bacteroidetes would have represented an interesting approach to obesity prevention and treatment. In fact, the underlying mechanisms seem to be much more complex and it is not yet clear which bacterial genera or species in particular promote or prevent the development of obesity – in some cases even contradictory results have been described for one species in relation to its associated genus.

Firmicutes

Predominantly gram-positive bacteria, some of which can form endospores; are considered to be very good food metabolizers.

Bacteroidetes

Gram-negative bacteria, which do not form endospores, live anaerobically or also aerobically, are considered poor food utilizers; break down dietary fiber.

Actinobacteria

Gram-positive rods. Can grow under different oxygen environments, from strictly aerobic to strictly anaerobic. Some are filamentous and multicellular, many can form endospores. Major producer of folate.

Proteobacteria

Form-rich, gram-negative bacteria. Some possess flagella for locomotion produces acetic acid, lactic acid and succinic acid via mixed acid fermentation.

Another aspect that probably plays a role in the link between obesity and the microbiome is the increased transfer of lipopolysaccharides from the cell membrane of Gram-negative bacteria into the blood when the barrier function of the intestine is disturbed by changes in the microbiota. Lipopolysaccharides, as endotoxins, lead to inflammatory processes associated with metabolic disorders such as insulin resistance and obesity.

Do probiotics help with weight loss?

The use of dietary supplements as an aid to weight loss appears attractive to many sufferers because of the well-known problems associated with losing weight. Accordingly, there is a wide range of products containing, for example, the pregnancy hormone hCG (human chorionic gonadotropin) or preparations of prickly pear, green tea or bitter orange, the effect of which has not been proven in most cases. Increasingly, probiotics are also being touted as “natural helpers” for weight loss. We have incredible probiotic product colon drink, it has 900 trillion good bacteria and 27 strains. Colondrink is dairy-free!

Probiotics are preparations of living microorganisms which, after oral application, are supposed to influence the ratio of intestinal germs in such a way that positive effects for the organism result. Bacterial strains of the genera Lactobacillus, Bifidobacterium and Enterococcus as well as Escherichia coli strains and the yeast Saccharomyces boulardii are mostly used. Probiotics are believed to have various health-promoting properties. While some uses are relatively well documented, in many cases there is a lack of conclusive human studies that can confirm results obtained in cell or animal experiments.

If, as described, the microbiome of normal and overweight individuals differs and, in addition, the microbiome composition can be altered by the use of probiotics, it seems reasonable to assume that properly selected probiotics can aid in weight loss. Animal studies have yielded promising results: With certain strains, body weight as well as body fat percentage and various metabolic parameters could be positively influenced in mice.

The numerous available human studies on the subject are often of inadequate methodological quality. Over 8000 studies were identified for a recent meta-analysis on the association of pre- and probiotics with obesity. However, only 21 studies were randomized and controlled and thus usable for the meta-analysis, fourteen of which dealt with probiotics. Unlike previous systematic reviews that found no effect of probiotics on body weight and fat percentage, the current work shows statistically significant effects of probiotic intake on these parameters in overweight individuals. However, the effects determined by the authors from the synopsis of the very heterogeneous and difficult-to-compare individual studies were small: BMI was reduced by a mean of 0.33 kg/m2 and body weight by 0.65 kg. The best effects were achieved with the intake of various Lactobacillus strains – here the body weight was reduced by an average of 1.25 kg. Whether this is noticeable for those affected in everyday life or even mitigates the health consequences of obesity may be doubted – a fine example of the discrepancy between statistical significance and clinical relevance. Incidentally, many of the included studies did not take into account participants’ dietary habits or physical activity, which severely limits their power. The study duration ranged from two to 24 weeks. The effects of longer-term use are not known. It is also not known whether the changes in the microbiome induced by probiotics would be reversed if previous dietary habits were maintained.

In a recent, methodologically high-quality study over twelve weeks using a Bifidobacterium strain, no difference was found between the placebo and verum arms in terms of body weight, but body fat mass was reduced by an average of 0.6 kg in the verum group compared to placebo.

Microorganisms in probiotic foods

Lactobacillus ssp.:

• Lactobacillus acidophilus group
• Lactobacillus casei group
• Lactobacillus reuteri
• Lactobacillus johnsonii
• Lactobacillus plantarum

Bifidobacterium ssp.

• Bifidobacterium bifidum
• Bifidobacterium breve
• Bifidobacterium infantis
• Bifidobacterium longum

Entercoccus ssp.

• Entercoccus faecalis
• Entercoccus faecium

Conclusion

That there is a relationship between the structure of the microbiota and the occurrence of overweight and obesity is now well established. The use of certain strains of probiotics may possibly reduce body weight and fat percentage. However, the observed effects are minimal, but this could also be due to the fact that both the optimal duration of intake and dosage, as well as the type of “correct” strain, are as yet completely unclear.

Probiotic effects are highly strain-specific, so effects observed on one strain are not readily transferable to closely related strains of the same species. Our probiotics COLONDRINK has 27 strains and 900 trillion CFU. Also, it is vegan!