Can probiotics help you lose weight?

A probiotic is a live microorganism that provides health benefits when consumed [1]. Besides supplements, fermented foods also contain them.

In addition to improving immune function, digestive health and heart health, probiotics may also help lose weight and belly fat [23].

Body weight regulation may be affected by gut bacteria

Your digestive system contains hundreds of microorganisms. Several of these bacteria produce vital nutrients, such as vitamin K and certain B vitamins. As well as breaking down fiber, which your body cannot digest, they convert it into beneficial short-chain fatty acids like butyrate [4]. 

Generally, two types of good bacteria live in the gut: bacteroidetes and firmicutes. The balance between these two families of bacteria affects body weight [5]. Human and animal studies have shown that moderate-weight people have different gut bacteria than overweight or obese people [678].

The majority of those studies found that obese people had more firmicutes and less bacteroidetes than moderate-weight individuals. Numerous studies, however, have failed to find a link between the ratio of firmicutes to bacteria [9].

Can probiotics help you lose weight?
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Obese people tend to have less diverse gut bacteria than lean people. Furthermore, obese people with fewer gut bacteria gain more weight than obese people with more [10]. It has also been shown that when gut bacteria from obese mice are transplanted into lean mice, the lean mice become obese [11].

How probiotics affect body weight

It’s still unclear how probiotics affect body weight and belly fat. Short-chain fatty acids like acetate, propionate and butyrate are produced by probiotics and influence appetite and energy consumption [1213].

Certain probiotics may interfere with the absorption of dietary fat, causing more fat to be excreted with wastes [14]. Your body “harvests” fewer calories from what you eat when you consume them. Bacteria from the Lactobacillus family are known to function in this way.

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Other ways in which probiotics may fight obesity include:

  • Probiotics may release appetite-reducing hormones like glucagon-like peptide-1 (GLP-1) and peptide YY (PYY). These hormones may aid in helping burn calories and fat [15].
  • Probiotics may increase levels of the fat-regulating protein angiopoietin-like 4 (ANGPTL4). This may lead to decreased fat storage [16].

Inflammation throughout the body is strongly linked to obesity. Probiotics may reduce systemic inflammation and offer protection against obesity and other diseases by improving the health of the gut lining [171819]. Further research is needed to uncover these mechanisms fully.

Losing belly fat and weight with probiotics may be possible

Several studies have found that probiotics can help people lose weight and reduce body fat in people with overweight and obesity [20]. Certain strains of the Lactobacillus family have been found to help reduce belly fat and weight. One study found that yogurt containing Lactobacillus fermentum or Lactobacillus amylovorus lowered body fat by 3–4% over six weeks.

Another study examined the effects of Lactobacillus rhamnosus supplements on weight loss and maintenance among 125 overweight dieters [21]. The probiotics lead to a 50% weight loss over three months compared with a placebo pill. Additionally, they continued to lose weight during the weight maintenance phase.

One well-designed study tested Lactobacillus sakei against a placebo for 12 weeks in 114 adults with obesity. Here, probiotics significantly decreased both body fat mass and waist circumference [22].

Lactobacillus gasseri

To date, Lactobacillus gasseri has shown some of the most promising weight loss effects out of all the probiotic bacteria studied. Numerous rodent studies have found that it has anti-obesity effects [232425]. Furthermore, studies in adults have shown promising results [2627].

A study of 210 people with substantial amounts of belly fat found that taking Lactobacillus gasseri for 12 weeks significantly decreased body weight, fat around organs, body mass index (BMI), waist size and hip circumference. Additionally, belly fat was reduced by 8.5%. By the end of the study, participants had regained all of their belly fat [28].

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Various strains

It is also possible to reduce belly fat and weight with other strains of probiotics. An eight-week study included obese or overweight women taking either a probiotic containing strains of Lactobacillus and Bifidobacterium or a placebo, along with a dietary intervention. Those taking the probiotic lost considerably more belly fat than those taking a placebo [29].

One study of 135 people with significant amounts of belly fat found that those who took Bifidobacterium animalis subsp. lactis daily for three months lost substantially more belly fat and had a lower BMI and waist circumference, in comparison with those taking a placebo.

The results were particularly pronounced in women [30].

Can probiotics help you lose weight?

Probiotics may prevent weight gain in some cases

The only way to combat obesity is not to lose weight. In order to avoid obesity, it may be even more important to prevent unwanted weight gain.

A probiotic formulation called VSL#3 was found to reduce weight gain and fat gain in people who consumed 1,000 extra calories a day [31]. However, neither insulin sensitivity nor metabolism changed significantly in the probiotic group.

In the context of a high-calorie diet, some probiotic strains may prevent weight gain. However, this needs to be studied further.

Obesity and weight gain are associated with some probiotic strains

Weight loss with probiotics has not been proven in all studies. Certain probiotic strains might contribute to weight gain rather than weight loss, according to some studies.

Depending on the strain and species of probiotics used, probiotics can affect body weight differently. One Lactobacillus gasseri strain reduced weight gain, while another strain promoted it [32].

There are many health benefits associated with probiotics. Depending on the type of probiotic, their effects on weight are mixed.

People with obesity may benefit from Lactobacillus gasseri by losing weight and belly fat. Those on high-calorie diets may also benefit from a probiotic blend called VSL#3.

Probiotics may have minimal effects on your weight, specifically when combined with a healthy, whole-food diet. However, there are many other reasons to take a probiotic supplement. Improve your digestive health, lower your cardiovascular risk factors, reduce inflammation and even fight depression and anxiety with them [33].

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