Probiotics and weight-loss
Date: 2018-02-07
Author: Ravinder Lilly
Access: Public

Did you know that up to 2kg of your weight is made up of microorganisms? These are the trillions of organisms that make up your unique gut microbiome. Budding in vitro research is revealing the relationship between the microorganisms that live in your gut with both physical and mental health. These microorganisms affect digestive health, contribute to immune health, produce vitamins and amino acids and also affect blood pressure and mental health. Plus, preliminary studies link the microorganisms that live in the gut with body weight - and even with belly fat.

Belly fat, which is also known as visceral fat, lies deep inside the body coating vital organs. People with less visceral (belly) fat tend to have fewer long-term health conditions related to heart, pancreas and hormone health. In laboratory studies, probiotics have been shown to help reduce belly fat.

There are two main types of bacteria in the gut: Bacteroidetes and Firmicutes. Body weight may be related to the balance of these two bacterial families.1,2 In fact, in vitro research has shown that subjects who are of normal weight tend to have different gut bacteria compared to those who are categorised as either overweight or obese. Maintaining a normal healthy weight in this instance can be due to a microbiome containing more Bacteroidetes than Firmicutes.

So how might probiotics affect weight?
Different microorganisms behave in different ways. While some breakdown indigestible fibre into beneficial fatty acids, others can reduce absorption of fat and increase the amount of fat excreted in faeces (such as bacteria from the Lactobacillus family).3,4 Reducing fat absorption is a mechanism of action that's exerted by certain weight-loss products that can be prescribed or bought over the counter in pharmacies.

More research is needed, but probiotics may also fight obesity in other ways:

They may:
Aid the release of the satiety hormone: Raised levels of this hormone may help the body burn both calories and fat.5
Increase specific proteins: Some of which may contribute to reduced fat storage.6
Reduce inflammation: many chronic (long-term) conditions are associated with inflammation. By improving gut health, probiotics may reduce systemic inflammation protecting against obesity and other conditions.7
Reduce absorption of calories: some probiotics may do this by reducing the amount of fat absorbed from the intestines.

In one study, 125 women supplemented with probiotics containing Lactobacillus rhamnosus over a three-month period. Results showed that they lost 50% more weight when compared to the group taking a placebo during the weight-loss period of the study. The women using probiotics also continued to lose weight during the weight-maintenance phase of the study.8

Of all the strains in the Lactobacillus species, L. gasseri seems to show the greatest effects when it comes to weight-loss. One study of over 200 participants in Japan9 with significant belly fat (8.5%) found that supplementing with L. gasseri for 12 weeks reduced body fat, BMI, waist size and hip circumference. The study also highlighted the importance of regular and consistent probiotic consumption to maintain these results in the long term.10,11

What's important to know, though, is that although some probiotics can have a small effect on body weight, a healthy and varied diet (plus regular exercise, healthy lifestyle factors and stress reduction) are vital aspects of good health.

For example, one of the healthiest option is a Mediterranean style of eating - lots of vegetables, seasonal fruits, nuts, seeds, grains, olive oil and fish. These foods provide the body with important prebiotics (foods that feed your microbiome).

Great foods for your microbiome include:

  • Apples
  • Artichokes
  • Asparagus
  • Bananas
  • Barley
  • Capsicum
  • Coffee
  • Dark chocolate
  • Extra virgin olive oil
  • Fermented foods and drinks such as sauerkraut, kimchi, kefir and kombucha
  • Flaxseeds
  • Garlic
  • Green tea
  • Leeks
  • Oats
  • Onions
  • Red wine (but not too much!).

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  1. Eckburg PB1, Bik EM, Bernstein CN, Purdom E, Dethlefsen L, Sargent M, Gill SR, Nelson KE, Relman DA.Diversity of the human intestinal microbial flora. Science. 2005 Jun 10;308(5728):1635-8. Epub 2005 Apr 14.
  2. Ley RE1, Bäckhed F, Turnbaugh P, Lozupone CA, Knight RD, Gordon JI Obesity alters gut microbial ecology.Proc Natl Acad Sci U S A. 2005 Aug 2;102(31):11070-5. Epub 2005 Jul 20..
  3. Ogawa A1, Kobayashi T2, Sakai F3, Kadooka Y4, Kawasaki Y5. Lactobacillus gasseri SBT2055 suppresses fatty acid release through enlargement of fat emulsion size in vitro and promotes fecal fat excretion in healthy Japanese subjects. Lipids Health Dis. 2015 Mar 20;14:20. doi: 10.1186/s12944-015-0019-0.
  4. Hamad EM1, Sato M, Uzu K, Yoshida T, Higashi S, Kawakami H, Kadooka Y, Matsuyama H, Abd El-Gawad IA, Imaizumi K Milk fermented by Lactobacillus gasseri SBT2055 influences adipocyte size via inhibition of dietary fat absorption in Zucker rats. Br J Nutr. 2009 Mar;101(5):716-24. doi: 10.1017/S0007114508043808. Epub 2008 Aug 7 .
  5. Pannacciulli N1, Bunt JC, Koska J, Bogardus C, Krakoff J Higher fasting plasma concentrations of glucagon-like peptide 1 are associated with higher resting energy expenditure and fat oxidation rates in humans. Am J Clin Nutr. 2006 Sep;84(3):556-60..
  6. Aronsson L1, Huang Y, Parini P, Korach-André M, Håkansson J, Gustafsson JÅ, Pettersson S, Arulampalam V, Rafter J.Decreased fat storage by Lactobacillus paracasei is associated with increased levels of angiopoietin-like 4 protein (ANGPTL4). PLoS One. 2010 Sep 30;5(9). pii: e13087. doi: 10.1371/journal.pone.0013087.
  7. David W. Lescheid Probiotics as regulators of inflammation: A review. Probiotics as regulators of inflammation: A review. Functional Foods in Health & Disease
  8. Certain probiotics could help women lose weight, study finds. Université Laval. January 28, 2014
  9. Hamad EM1, Sato M, Uzu K, Yoshida T, Higashi S, Kawakami H, Kadooka Y, Matsuyama H, Abd El-Gawad IA, Imaizumi K. Milk fermented by Lactobacillus gasseri SBT2055 influences adipocyte size via inhibition of dietary fat absorption in Zucker rats. Br J Nutr. 2009 Mar;101(5):716-24. doi:10.1017/S0007114508043808. Epub 2008 Aug 7.
  10. Kadooka Y1, Sato M, Imaizumi K, Ogawa A, Ikuyama K, Akai Y, Okano M, Kagoshima M, Tsuchida T. Regulation of abdominal adiposity by probiotics (Lactobacillus gasseri SBT2055) in adults with obese tendencies in a randomized controlled trial. Eur J Clin Nutr. 2010 Jun;64(6):636-43. doi: 10.1038/ejcn.2010.19. Epub 2010 Mar 10
  11. Kadooka Y1, Sato M, Ogawa A, Miyoshi M, Uenishi H, Ogawa H, Ikuyama K, Kagoshima M, Tsuchida T. Effect of Lactobacillus gasseri SBT2055 in fermented milk on abdominal adiposity in adults in a randomised controlled trial. Br J Nutr. 2013 Nov 14;110(9):1696-703. doi: 10.1017/S0007114513001037. Epub 2013 Apr 25.
  12. Pellegrini N, Di Cagno R, Turroni S, Brigidi P et al. High-level adherence to a Mediterranean diet beneficially impacts the gut microbiota and associated metabolome. Gut. September 2015.