What do probiotics do, exactly? And what are they? Probiotics are microscopic organisms that live on, and inside your body. It is estimated that there are over 100 trillion living bacteria on your skin, in your mouth, inside your digestive system and just about everywhere else. These include an estimated several hundred different species in the mouth alone! That’s a LOT of tiny buggers living (and dying) in your body. In fact, it is so many that researchers estimate there is one living microorganism for every cell in your body.1
With so many of these organisms calling your body “home,” you may want to know what, exactly, they are doing in there. Here are five of the most wonderful ways probiotic bacteria benefits your body for good health.
What do Probiotics do for you?
1. Digestive Support
Most of the microbes in the human body can be found inside the digestive tract, and they are most highly concentrated in the colon. Probiotic bacteria (“good” bacteria) is able to restore an imbalance in gut bacterial strains, helping to keep the population of “bad” bacteria from taking over.
An overgrowth of “bad” bacteria strains has been linked to digestive upset, including diarrhea, gastroenteritis, irritable bowel, inadequate lactase digestion, constipation, intestinal gas, bad breath, and more.2,3
A review of 35 studies showed that specific strains of probiotics were able to reduce the duration of infectious diarrhea cases by an average of 25 hours.4
Lactobacillus rhamnosus, and Lactobacillus casei strains, along with a yeast known as Saccharomyces boulardii, are the probiotics most commonly associated with a reduced risk of diarrhea.5,6
2. Better Immunity
It is estimated that 60 to 80 percent of the entire human immune system can be found inside of the digestive tract. If you were to put the amount of bacteria living in your digestive system on a scale, it would weigh about three pounds! Within all of that, the types of bacteria can be broken down into two (very large) categories – “good” and “bad” bacteria. Examples of “good” bacteria strains include L. acidophilus and B. bifidum. Examples of “bad” bacteria strains include E. coli and Salmonella.
While they are referred to as “good” and “bad,” none of the bacterial strains that live in the digestive tract are actually “bad,” as all types are needed to keep the body in good health. However, some strains can be considered “bad” when there is too much growth of that particular strain (ex: E. coli).
Probiotics (“good” bacteria) are known to help reduce the spread of “bad” bacterial strains by keeping their populations low. This enhances the intestinal barrier against pathogenic species that can cause illness.7
Additionally, some probiotic strains have been shown to provide therapeutic benefits to the immune system by boosting the production of immune cells like T lymphocytes (T cells) and natural killer cells.8,9
3. Mental Health
The community of living bacteria on and inside your body is so vast that it has been called the “second brain” by researchers because the gut microbiome actually has a mind of it’s own. It may sound like science fiction, but scientists have confirmed there are so many bacteria inside the gut microbiome that they actually influence the way our brains work. The gut microbiome, or “second brain,” can impact mood, stress, energy levels, sleep patterns, food choices, and more.10,11
One review of 15 human studies confirmed that subjects who took a probiotic supplement with a combination of Bifidobacterium and Lactobacillus strains for 1–2 months reported improvements in anxiety, depression, autism, obsessive-compulsive disorder (OCD), and memory.12
4. Clear Skin
There are many different ways probiotics help to support a healthy body. Skin care is just one way probiotics show how helpful they really are – on the outside.
One study found that participants who suffered from acne noticed skin health benefits, including a reduction of acne, improvements in skin repair, and shrinking of existing acne lesion size.13
Other clinical studies show that probiotics support clearer skin in acne and rosacea patients. This may be due in part to the antibacterial protective shields living probiotic microorganisms provide.14,15
One recent review of probiotics’ effects on the skin revealed that probiotic bacteriotherapy has great potential in skincare for eczema, atopic dermatitis, acne, allergic inflammation, skin hypersensitivity, UV-induced skin damage, and wound protection.16
5. Weight Loss
Probiotics support weight loss in many different ways. Studies have shown that people with a healthy weight have a more diverse gut microbiome than overweight or obese subjects.17,18
Two specific families of “good” bacteria (probiotics) have been associated with successful weight regulation: bacteroidetes and firmicutes. Studies have confirmed that a proper balance of these two microbiota families is needed.19,20
Probiotics have also been shown to help people feel fuller, longer.
Increased probiotic levels have been clinically shown to increase the level of GLP-1 – a hormone known to increase calorie burn and fat burning, and even reduce appetite.21,22
One study showed that probiotics may also increase the production of a protein called ANGPTL4. This protein is a central player in fat storage regulation. Studies show it may help reduce fat storage.23
Probiotics are a one-stop shop for overall health. These are simply the five best health benefits the friendly little bugs offer our bodies. But there are many more. Make sure to getting more probiotics—be it in the foods you eat or a supplement—in your daily diet, today!
1 Campbell K, Prados A, Prados A, Prados A. 1:1 is new estimated ratio of bacterial to human cells – Gut Microbiota for Health. Gut Microbiota for Health. 2016. Accessed November 29, 2016.
2 Brown AC, Valiere A. Probiotics and medical nutrition therapy. Nutr Clin Care. 2004 Apr-Jun;7(2):56-68.
3 Clemente JC, Ursell LK. The impact of the gut microbiota on human health: an integrative view. Cell. 2012 Mar 16;148(6):1258-70.
4 Allen SJ, Martinez EG. Probiotics for treating acute infectious diarrhoea. Cochrane Database Syst Rev. 2010 Nov 10.
5 Johnston BC, Goldenberg JZ. Probiotics for the prevention of pediatric antibiotic-associated diarrhea. Cochrane Database Syst Rev. 2011 Nov 9;(11).
6 Sazawal S, Hiremath G. Efficacy of probiotics in prevention of acute diarrhoea: a meta-analysis of masked, randomised, placebo-controlled trials. Lancet Infect Dis. 2006 Jun;6(6):374-82.
7 Resta-Lenert S, Barrett KE. Live probiotics protect intestinal epithelial cells from the effects of infection with enteroinvasive Escherichia coli (EIEC). Gut. 2003 Jul;52(7):988-97.
8 Reid G, Jass J. Potential uses of probiotics in clinical practice. Clin Microbiol Rev. 2003 Oct;16(4):658-72.
9 Ouwehand AC, Salminen S. Probiotics: an overview of beneficial effects. Antonie Van Leeuwenhoek. 2002 Aug;82(1-4):279-89.
10 Emeran A. Mayer, Rob Knight. Gut Microbes and the Brain: Paradigm Shift in Neuroscience. J Neurosci. 2014 Nov 12; 34(46): 15490–15496.
11 Andrey Smith, Peter. The tantalizing links between gut microbes and the brain. Nature. 14 October 2015.
12 Wang H, Lee IS. Effect of Probiotics on Central Nervous System Functions in Animals and Humans: A Systematic Review. J Neurogastroenterol Motil. 2016 Oct 30;22.
13 Muizzuddin N, Maher W, Sullivan M, Schnittger S, Mammone T. Physiological effect of a probiotic on skin. J Cosmet Sci. 2012;63(6):385-95.
14 Acne vulgaris, probiotics and the gut-brain-skin axis – back to the future? Gut Pathog. 2011; 3: 1. Published online 2011 Jan 31.
15 Whitney P Bowe, Alan C Logan. Could probiotics be the next big thing in acne and rosacea treatments. 30 January 2014. American Academy of Dermatology (Academy).
16 Roudsari MR, Karimi R. Health effects of probiotics on the skin. Crit Rev Food Sci Nutr. 2015;55(9):1219-40.
17 Ley RE, Turnbaugh PJ. Microbial ecology: human gut microbes associated with obesity. Nature. 2006 Dec 21;444(7122):1022-3.
18 Turnbaugh PJ, Hamady M. A core gut microbiome in obese and lean twins. Nature. 2009 Jan 22;457(7228):480-4.
19 Eckburg PB, Bik EM. Diversity of the human intestinal microbial flora. Science. 2005 Jun 10;308(5728):1635-8. Epub 2005 Apr 14.
20 Ley RE, Bäckhed F. Obesity alters gut microbial ecology. Proc Natl Acad Sci U S A. 2005 Aug 2;102(31):11070-5. Epub 2005 Jul 20.
21 Yadav H, Lee JH. Beneficial metabolic effects of a probiotic via butyrate-induced GLP-1 hormone secretion. J Biol Chem. 2013 Aug 30;288(35):25088-97.
22 Pannacciulli N, Bunt JC. 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.
23 Aronsson L, Huang Y. Decreased fat storage by Lactobacillus paracasei is associated with increased levels of angiopoietin-like 4 protein (ANGPTL4). PLoS One. 2010 Sep 30;5(9).