Can Probiotics Help You Lose Weight?

by Rakib Sarwar, RPh
Published on October 23, 2019

The problems associated with overweight and obesity couple with poor response and outcomes from already existing weight-loss therapies has led to more scientific research on this subject. The findings from these researches have led to the use of novel therapies for weight loss. One of these novel therapies includes the use of probiotics to stimulate weight loss in overweight and obese.

Probiotics are bacteriological strains with a number of health benefits, and their potential to causing weight loss in the overweight and obese has recently led to a significant escalation in research interest in their use to maintain/modify the gut microflora and making them useful in stimulating weight loss. With research, the role of probiotics has been explored particularly with respect to the homeostasis of body weight, energy control and modulation of inflammation.

What Are Probiotics?

Probiotics are living organisms which when ingested produce health benefits mostly by restoring, maintaining or improving the flora of the intestinal tract. Flora is microorganisms that are normal residents of particular areas in the body whose function remains beneficial to health so long they remain their natural environment. But if for any reason, they can’t carry out their normal function or are diminished in their ideal number, health problems such as overweight and obesity can set in. In this case, probiotics are needed to restore them in numbers and function (1).

The word ‘probiotic’ is a Greek word which means ‘for life’, a term first conceived by Ferdinand Vergin in 1954. The modern conceptual knowledge of probiotics is attributed to Russian scientist and Nobel laureate Élie Metchnikoff whose postulation was that Bulgarian peasant who consumes yogurt (a natural source of probiotics) lives longer and healthier because of such routines.

At the same time, fermented milk with lactic-acid bacteria was recognized as inhibitors of proteolytic bacteria growth due to the acidic pH created by the fermentation process (1, 2).

Overweight and obesity have been associated with abnormal gut microflora that is deranged in function and numbers which in part explains how useful probiotics will be in this set of individuals (3).

There are known natural sources and foods (including fermented foods) that contain probiotics as well as synthetic sources in form of drug formulations. In the setting of overweight and obesity, the number of probiotics may not be able to keep up with the amount needed for weight loss. Hence, the probiotic drug is used to achieve faster results (1, 2, 3).

The known food sources include kefir, kombucha, sauerkraut, pickled vegetable, natto, coconut kefir, yogurt, kvass, raw cheese, brine-cured olives, salted gherkin pickles, apple cider vinegar, miso, tempeh, traditional buttermilk, water Kefir, raw cattle milk, kimchi. There are also several known probiotic drugs which are generally considered safe for humans with few side-effects (4).

Probiotics are mainly isolated from the following genera: Bifidobacterium, Lactobacillus, Saccharomyces, Streptococcus, Enterococcus, Leuconostoc, Bacillus, Pediococcus, Escherichia coli.

Some specific examples include Lactobacillus gasseri, Bifidobacterium bifidum, Lactobacillus amylovorous, Lactobacillus acidophilus, Lactobacillus fermentum, Lactobacillus rhamnosus, Lactobacillus bulgaricus and Bifidobacterium longum amongst others. Other potentially useful probiotics strain comprises bacterial genera Bacillus, Propionibacterium and Escherichia, and some yeast genera, like Saccharomyces (2).

Effects of Probiotics on Overweight and Obesity

Several studies have noted a range of health benefits from probiotics which also includes weight reduction especially in overweight and obese individuals and this is due to their influence on the microflora of the intestinal tract.

There are different populations of microflora in the intestinal tract which are mainly bacteria from 2 phylums- bacteroidetes and firmicutes normally present in fairly equal proportions however in the obese individuals, the firmicutes are much more than the bacteroidete explaining the reason for the alter function of the microflora.

In a literature review in 2015, it was stated that in humans and animals a change in the diet pattern, particularly if there’s too much consumption of high-calorie diet, fatty diet, usage of artificial sweeteners, and disruption of the daily routine and sleep pattern will cause a change the pattern of microflora from the type seen in lean individuals to the pattern seen in obese individuals (10).

They naturally function to breakdown dietary fibers and short-chain fatty acids, aid in vitamins B and K synthesis, and in the body’s defense prevent the growth of disease-causing organisms in the intestinal tract (2).

One key factor that determines the occurrence of overweight or obesity is the nature of the intestinal microflora. Overweight and obese individuals have been noted to have low levels of the gene of fecal bacterial abundance with tendencies towards overall dyslipidemia and adiposity, increased incidence of low- grade inflammation and impaired glucose metabolism (5).

Since probiotics mainly work by restoring the functions and population of intestinal microflora, it will be expedient to know the mechanisms by which these microflora cause overweight and obesity. These mechanisms include (5):

  • Obese individuals have intestinal flora that is very much efficient in taking out energy and any form of sugar from a diet for absorption than the intestinal flora of lean individuals
  • The intestinal flora of obese individuals rapidly induce energy storage and adiposity compared to lean individuals’ intestinal flora
  • Another mechanism is by rapid metabolism is the production of short chain fatty acids (such as acetate, propionate, and butyrate) from indigestible polysaccharides and the serve as energy substrates.
  • Apart from serving as energy substrates, these short-chain fatty acids produced by bacterial fermentation in the obese causes delay in gut motility and prolongs intestinal transit time thereby allowing longer time for absorptions of sugars
  • In affluent societies, the increased use of antibiotics depopulates the microflora leading to overweight and obesity

Convincing preclinical evidence has proven that probiotic administration may cause a drop, the extent of weight added after ingestion of a high-fat diet. Probiotic supplementation with Lactobacillus curvatus HY7601and/or Lactobacillus curvatus HY7601 or when combined with Lactobacillus plantarum KY1032 efficiently suppressed body weight gain and caused a drop in the weight adipose tissue in mice fed with large amount high-cholesterol and high-fat diets for 9 weeks (5).

In another study, similar results were obtained when Bifidobacterium spp. (B. longum SPM 1205, B. pseudocatenulatum SPM 1204, and/or B. adolescents) was added to a high-fat diet fed to rats (5).

Several studies have shown that probiotics can cause weight loss. In a multicentre, double-blind, placebo-controlled, randomized study by Kadooka et al, 87 overweight to obese individuals who also had abdominal obesity where either fermented milk containing LG2055 (n=43) or fermented milk without LG2055 (n=44). Each subject was asked to consume 200 grams per day of fermented milk for 12 weeks (6).

The group that took fermented milk with LG2055 had a significant reduction in the abdominal fat compared to the group that took fermented milk without LG2055 following assessment with computerized tomography scan. More importantly, there was a significant reduction in the weight, body mass index, and waist circumference in the group that ingested fermented milk with LG2055 compared to the group that ingested fermented milk without LG2055 (6).

It was also noted that there was a lesser increase in serum adiponectin in the group in the group that consumed fermented milk with LG2055 compared to the group that consumed fermented milk without LG2055(6). In a systematic review by Crovesy et al, it was noted in nine studies that probiotic lactobacillus causes a drop body fat and/or body weight (7).

Another multi-center, parallel-group, double-blind, randomized control trial was carried-out where 210 healthy Japanese adults were divided into three groups. Subjects in one group were consumed fermented milk containing Lactobacillus gasseri SBT2055 at 108 colony-forming units per gram. Subjects in the second group consumed fermented milk containing Lactobacillus gasseri SBT2055 at 106 colony-forming units per gram, and subjects in the second group consumed fermented milk without Lactobacillus gasseri SBT2055. They all consumed 200g of the fermented milk per day for 12 weeks (9).

The result showed a significant decrease in abdominal adiposity, body mass index, body fat mass, waist and hip circumference in subjects that consumed fermented milk containing Lactobacillus gasseri SBT2055 at 108 colony-forming units per gram, followed by subjects that consumed fermented milk containing Lactobacillus gasseri SBT2055 at 106 colony-forming units per gram, and much lesser in subjects that consumed fermented milk without Lactobacillus gasseri SBT2055 (9).

Mechanism of action of probiotics in stimulating weight loss

It has been shown that there are probiotic effector molecules in Bifidobacterium and Lactobacillus strains which are mainly cell wall-associated components such as exopolysaccharides, muropeptides, and S-layer proteins.

Additionally, the valuable role of some metabolites produced extensively such as histamine-related and tryptophan-related metabolites, CpG-related DNA, and some enzymes such as bile salt hydrolases and lactase have also been considered at the molecular level. Some molecules have been noted to play a vital role in the bacteria-bacteria and host-microbe interaction of Bifidobacterium and Lactobacillus strains.

Numerous attributes that are seen as positive effects of probiotic strains include the capacity to replicate while in the host and carry-on for a suitable period to convey effects, ability to produce antimicrobial substances and those that inhibit pathogen adherence abilities and virulence, the capacity to improve host immunity and promote epithelial barrier function.

The molecular mechanisms may be strain-specific, or they might be common to members of a larger taxonomic assembly, making room for in-common benefits

Other health benefits of probiotics

Antibiotic-associated diarrhea

Several meta-analyses have shown that probiotics hold strong promise in the treatment of antibiotic-associated diarrhea

Bacterial vaginosis

In 2013, investigators found that administration of hydrogen peroxide-producing strains, like Lactobacillus acidophilus and Lactobacillus rhamnosus, controlled and regulated vaginal pH, and also restored the vaginal microbiota, thereby deterring and treating bacterial vaginosis


Some authorities suggested probiotics as a promising treatment for different forms of gastroenteritis. A Cochrane meta-analysis on the usage of probiotics to treat severe infectious diarrhea centered on a broad review of medical literature through 2010 and it was reported that use the various tested probiotic formulations reduced the duration of diarrhea.

Immune function and infections

Certain strains of Lactobacillus may distort activities of pathogens through competitive inhibition (i.e., by contending for growth and survival) and there are indications that they may promote immune function by growing the quantity of IgA-producing plasma cells and increasing the proportion of T lymphocytes as well as improving phagocytosis, and causing a surge in the population of natural killer cells.

Lactobacillus products may aid in the management of travelers’ diarrhea in adults, and possibly treat rotavirus infections in children. A study proved that probiotics may reduce the occurrence of dental caries in children. Two reviews documented a reduction of the occurrence and prevalence of respiratory tract infections.

Its use has been documented in the treatment of lactose intolerance, inflammatory bowel disease, prevention of necrotizing enterocolitis amongst others

Administration of Probiotics

Probiotics are available as fermented dairy products like fermented milk, yogurt or as a supplement in formulations like powders, capsules, tablets. The efficacy depends on their ability to survive to go through the stomach and intestinal tract to get to the target area for colonization. They may be coated with acid- and/or alkaline-resistant coat to prevent destruction by gastric acid and duodenal bile salts, or they may be microencapsulated preparations (8).

The dosing depends on the specific indication and the product. So far, no consensus exists regarding the minimum number of microorganisms that must be ingested to get the needed beneficial outcome. Because of this, the preparations are made to contain several billion microorganisms to ensure adequate colonization of their targets area in the gut once ingested (8).

The recommended dose for various Lactobacillus strains used for weight loss is (2.7 × 1010 CFU/day of probiotic for 2–3 months (3).

Probiotics have few side effects mainly flatulence and bloating in which case the dose can be reduced for resolution of the side effect (1, 8).


The not so favorable outcome of previous strategies and medical therapies for the treatment of overweight and obesity has led to more research on his subject with the outcome of novel therapies one of which is the highlight of the article in order to answer the question ‘Can Probiotics help you lose weight?’

The function of the intestinal microflora and this function become distorted to worsen weight gain in the setting of overweight and obesity was highlighted, so also was the influence of probiotics on intestinal microflora and its mechanisms to induce weight loss.

Sufficient scientific evidence has been provided proving that probiotics are useful in producing weight loss in overweight and obese individuals along with other numerous health benefits.
It has however been suggested that to achieve better result, the use of probiotics as therapy for weight loss in overweight and obese individuals, it should be used in combination with other therapies rather than being the sole therapy in the weight reduction program.



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